The Neighborhood Toxicologist

Peanut allergies in a nutshell

2010-08-16T15:15:00.000-07:00

This summer I met a family from Australia who’d mentioned their daughter was highly allergic to peanuts. Wondering if all the concern about peanut allergies was yet another case of Americans overreacting to anything health-related I asked if they’d ever heard of schools in Australia banning peanuts.

“Our daughter’s school has been peanut-free for years,” they replied, as if it were an odd question. They added, “Lots of schools are.”

Like many people, I’ve also wondered if the seeming rise in prevalence of peanut allergies was real. After all, how many times have I heard someone say, “Well, we all grew up with peanut butter, and I didn’t know anyone who was allergic. What’s all the fuss about now?”

Turns out -- according to several studies published in medical and allergy journals over the past decade -- that peanut and tree nut related allergies, or hypersensitivity of the immune system to specific proteins in these nut families, truly is on the rise in Australia, the US and other Westernized countries. It is now estimated that over 1% of the US population has peanut or tree nut allergies, and one study reported a doubling of peanut allergies in children over a five year period.

So what’s going on? Has something changed in the way we are exposed to peanuts, tree nuts and other increasingly allergenic foods (sesame, and soy for example)? Or is it simply that our immune systems are going haywire?

The immune response is complex. While we’re all familiar with the role of antibodies, which confer immunity to anything from the common cold to polio, they are only one of five different types of immune proteins, or immunoglobulins. Other immune proteins protect vulnerable regions of the digestive and respiratory tract from pathogens, elicit our bodies to produce antimicrobials, and help us get a “jump” on our response once pathogens have breached other protections and entered our bloodstream.

Then there is immunoglobulin E (IgE). Although recent studies suggest that IgE may protect against certain parasitic worms (less of a problem these days in western countries compared with other regions of the globe), IgEs are most notorious for their role in causing allergic reactions, or an inappropriate immune response to a relatively harmless substance. Basically, once a body is sensitized by a potential allergen, a bit of basement mold perhaps, or a whiff of pollen from the old oak tree, IgEs are then distributed thoughout the body in association with immune cells like mast cells and basophils, which lay in wait for the next exposure.

When subsequent exposure occurs, these sensitized immune cells release a slew of potent chemicals including histamine, cytokines, and prostaglandins. These are all useful chemicals when released at the appropriate time and place, as during a normal immune response when the body is combating a pathogen or healing a wound (and even then they may cause some damage to healthy cells and tissues.) But as far as anyone knows, there is no appropriate time or place for an allergic response. Yet no matter the reason, when these chemicals are released the body responds.

The allergic responses many of us experience are caused by the increases in vascular permeability, constriction of smooth muscles (including those around the smallest passages of our lungs), and increased mucus production caused by histamine and other chemicals. The impacts on a body can range from mild to severe.

So, while I might suffer through a month or two of asthma, sneezing and itchy eyes (along with the more than 20% of the U.S. population affected by allergies), thankfully my IgEs seem to respond relatively mildly. But for some, an IgE response can cause anaphylaxis, a far more severe and systemic condition which may include vomiting, constricted breathing, and plunging blood pressure. The onset of these life-threatening responses can lead to anaphylactic shock and can occur within minutes of exposure.

A 2008 study published in the journal Current Opinion in Allergy and Clinical Immunology estimated that allergic anaphylaxis may occur in up to 2% of the U.S. population at some point in their life, with varying degrees of severity. And the risk of occurrence, particularly in children, is on the rise.

Which brings us to some of the top triggers for anaphylaxis - a list that includes many common substances like latex, insect venom (e.g. bee stings), medications (e.g. penicillin) and certain foods including shellfish, milk, tree nuts, and peanuts. Of these, food allergies are among the most common triggers of anaphylaxis requiring emergency room treatment. By some estimates, in the US food allergies account for roughly 30,000 visits to the emergency room and at least 100 fatalities a year, and several reviews of the medical literature including a 2009 review published in Clinical Pediatrics conclude that peanuts and tree nuts cause the majority of reported allergy-induced fatalities.

When a food is allergenic, the allergic reaction is usually caused by a specific type of protein contained in the food. In peanuts, eight different allergens have been identified. What differentiates allergenic proteins from other food proteins is that they resist acid, heat, and enzymatic breakdown in the gut. So they tend to be identified by the body’s immune system as an intruder rather than a nutrient, with potentially devastating consequences.

Efforts to understand why the US and other Westernized populations has a higher prevalence of peanut allergies than, say, China, where peanut consumption is also high, have identified the U.S. food industry’s practice of dry roasting peanuts rather than boiling or frying peanuts as one potentially relevant factor. The higher temperatures reached by the dry roasting process increases the allergenicity of peanut proteins. Other factors contributing to higher prevalence likely include differences in diet, routes (oral or dermal) and timing of nut exposures. Additionally, scientists have hypothesized that improved hygiene and reduced disease incidence in young children may also contribute to increased prevalence of allergies in general. Scientists and allergists have also speculated that increased use of peanuts in common consumer products, from soaps to shampoos and skin creams, may contribute to creating a more sensitized population.

Whatever the underlying cause, some people, once they are sensitized, need only ingest a very small amount (50 millgrams, approximately 100^th of a teaspoon, down to as low as 2 mg) of peanut product to cause what could become a life-threatening reaction.

It is a mind-boggling response. Consider the tiniest oral exposure setting off a systemic response within minutes. How does this happen?

“What you think of as low dose might contain plenty of stable antigen [or allergenic protein],” explains Southeastern Louisiana University Immunologist Dr. Penny Shockett. “Also,” Shockett added, “once the system is sensitized it doesn't necessarily take a high dose for tripping the mast cell response. If you are highly sensitized (i.e. allergic) you have more sensitized mast cells in tissues (or basophils in the blood) sitting and waiting for the allergen, which can potentially detect it quickly and strongly.”

Studies indicate that not only has the prevalence of peanut allergies risen over the past few decades, but also the risk of anaphylaxis in general, at least in the United States and other Western countries. As we alter our diets based on the ever-changing suggestions of health and nutrition experts, cultures adopt one another’s diets, and diseases are reduced through changes in hygiene and vaccines, scientists are in a quandary as to the causes of increased peanut and tree-nut sensitivity. Hopefully both the underlying causes and solutions for those who are allergic will be identified sooner than later.

For those currently affected by severe allergies, the focus is on management. In addition to education of individuals with allergies, particularly children, this means a range of options for schools. First and foremost involves appropriate medical and treatment plans in schools, followed by education of the school community, and strategies to avoid exposures for allergic individuals. In the case of peanut allergies avoidance in schools ranges from peanut free buildings to peanut free classrooms or separate lunch tables. As to the most effective management practice, the jury is still out.

Emily Monosson, Ph.D. writes and blogs as the Neighborhood Toxicologist, is a member of the GMRSD school committee, and is a member of the district’s Wellness Committee. The information presented here is the product of her own research into the issue and does not represent the opinion or work of the GMRSD school district, or the Wellness Committee.

McElligott's Plastic

2010-05-05T12:31:00.000-07:00

“Ask for a cone, save the environment!” proclaimed the sign at the local Creamee. The girls asked for cups anyway, to catch the drippings of the oversized soft-serve half-and-half cones they'd ordered. “Guess we’re not saving the environment today,” said one, dipping her plastic spoon into the Styrofoam cup.

Styrofoam is one incarnation of polystyrene plastic – more affectionately known as “#6” or, the plastic we can’t recycle. Polystyrene is also the black polystyrene casing of my computer, my bicycle helmet, the foamed polystyrene clamshell we were offered to carry home the remainders from a local restaurant and, the countless little white Styrofoam pellets degraded from sheets of weathered insulation I spent the weekend picking from the weeds at the local junk-yard turned conservation land along with a handful of diligent volunteers.

While collecting the little white bits from the earth, I imagine how each year some portion of those beads along with larger rafts of insulation are blown or washed into the bordering Sawmill River, some journeying only as far as the local swimming hole, while others carried by the Sawmill make their way to the Connecticut and beyond. I imagine their journey a perverse version of Dr.Seuss’s McElligot’s Pool, where you never know what exotic species might make their way from the deep ocean to a backyard pond, only these make their way to the deep ocean. This isn’t fanciful fiction. Just this year scientists confirmed the presence of a plastic “patch” of our own in the North Atlantic, the evil twin of the infamous North Pacific trash gyre – a region known for its accumulation of plastic from soccer balls to microscopic bits of Styrofoam and other assorted plastics. Looking around at all the Styrofoam I’ve missed, the scientist in me wants to radio-tag those naughty bits and send them on their way. Maybe in a few years we’d know for sure if pieces of Montague were swirling about the wide Sargasso Sea.

Captain Charles Moore, an adventurer, environmentalist and researcher, credited with discovering the North Pacific patch once commented on the return of plastic to the oceans and its consumption by marine life in an article for Natural History Magazine, “Ironically,” wrote Moore “the debris is re-entering the oceans whence it came; the ancient plankton that once floated on Earth's primordial sea gave rise to the petroleum now being transformed into plastic polymers. That exhumed life, our ‘civilized plankton,’ is, in effect, competing with its natural counterparts, as well as with those life-forms that directly or indirectly feed on them.” Research by Moore and others, now shows that plastics in the ocean can accumulate toxicants long banned like PCBs and DDTs, and there is some concern that once ingested, contaminated plastics might release these chemicals, along with others used for plastics production including colorants, fire retardants and plasticizers into their host. Someday there may be no need to shrink-wrap seafood.

Like other plastics, polystyrene – the base material for Styrofoam or foamed polystyrene clamshell food containers, microwavable cups (think cup-o-noodles), plastic plates and coffee cups – is a polymer, a chemical chain of repeating units, like beads on a string. In this case the beads or monomers are styrene. Produced naturally by plants and animals, styrene – like many chemicals - is relatively non-toxic in these small amounts. And, like many chemicals, natural production is dwarfed by human production (at least in localized concentrations,) which in the case of styrene tops 13 billion pounds a year in the US alone. The majority is used to produce polystyrene. While polystyrene might not appear on the top ten list for toxic chemicals, it is made from benzene. Over 50% of all benzene that is produced from oil is eventually turned into styrene. And sweet smelling benzene is nasty stuff. Just a whiff brings me back to organic chemistry lab in college. We used it without a care until the day it was officially deemed a carcinogen – and then we didn’t. At the risk of showing my age, that was in 1979. And in a strange case of collective heads- in-sand, benzene was known to cause cancer since the 1920s. (We can thank industry along with federal regulators to for that small lapse.) Benzene is now one of the few industrial chemicals officially listed as a known human carcinogen – causing leukemia in this case – and it is industry workers who are most at risk.

So what happens to all that polystyrene? The EPA estimated that in 2007, nearly 3 billion pounds of it was used in the production of disposable goods, including foamed polystyrene plastic plates, cups, egg cartons, and packaging peanuts. Aside from the packaging peanuts we might bring to a UPS store for reuse, with a recycling rate for all polystyrene estimated as a mere 0.8%, most will end up in a landfill. At worst it’ll end up our local streams, rivers and oceans.

And, when it does according to new research by Katsuhiko Saido and colleagues from the Nihon University, in Chiba, Japan, it will not only degrade more rapidly than it would on land (under certain marine conditions) but it will also release toxicants including a small amount of bisphenol A, notoriously linked with polycarbonate plastics, and styrene which brings us back to – d’oh!

The good news is that like most other plastics, technically, polystyrene foam is recyclable. In fact, it can be recycled back into many of the products from which it came – plates, clamshells, egg cartons and insulation, or into less desirable “dead end” products like light-weight concrete. The bad news is that the process isn’t cost effective, at least in the US – and so isn’t all that popular.

Then there are the more creative uses for this problem plastic. Some, like Cass Phillips, writer and co-owner of Kamuela Greenhouse/Specialty Orchids in Waimea, Hawaii have considered turning the environmental blight into beauty. With USDA grant funding, Phillips is currently testing the utility of various locally collected and processed recycled plastics as a growth medium additive with an eye to providing a durable low cost product for the Hawaii orchid industry. When asked about foamed polystyrene, she responded:

“I found that a certain type of orchid, miltoniopsis (aka the pansy orchid), grew fastest and largest in straight granulated polystyrene foam, in a trial that included three controls (cinder, coconut fiber and orchid bark)…... What truly stunned me is that the pansy orchids went into their bloom cycle 2-3 months before any other sample." There could be several reasons for the accelerated growth. One might suppose improved water retention could be a factor, but the ground polystyrene foam dried out almost instantly. That leaves us pondering other possibilities, including one that could be considered insidious: the release of growth-inducing chemicals. Sorting out the differences will require further analysis, but in the meantime Phillips has found herself wondering about the wisdom of schools using Styrofoam plates in their lunch programs, and the consequences of slurping down cups-o-soup from Styrofoam tubs.

Of course the best way to keep this ubiquitous plastic from polluting the oceans and clogging the landfills is to reduce use (according to the American Chemistry Council, the PS industry has been in decline for the past four years, though they give no reason), and close the recycling loop. More immediately, I’m sure there’ll be many more opportunities to pick Styrofoam from newly acquired conservation land, and for those rare occasions when I can’t clean my plate while dining at one of the local eateries, I’ve begun asking for foil or cardboard for the leftovers.

Yankee Swap: tritium contaminated water anyone?

2010-01-25T09:16:00.000-08:00

First published in the Montague Reporter

First we hear about tens of thousands of picocuries* in the groundwater beneath Vermont Yankee Nuclear Power plant, next it’s over one hundred gallons of water contaminated with over 2 million picocuries in some sort of concrete trench. Oops. Besides sloppy practices, lax monitoring, shoddy construction, and obfuscation (what underground pipes?) what do these numbers mean? Should we worry about all that tritium? And what the heck is a picocurie anyway?

Tritium is a radioactive isotope of the element hydrogen. What sets apart the radioactive elements from the non-radioactive is their lack of stability. They can disintegrate spontaneously, sometimes changing into other elements over time. Uranium, for example, decays into lead (although it may take billions of years,) while it takes roughly a decade for tritium to decay into helium.

The difference between a radioactive element and a plain old element depends upon what’s in the nucleus. The nucleus of any atom consists of protons (positive elements), neutrons (neutral elements) and electrons (negative elements). While the chemical properties of an element mostly depend on the number of protons in the nucleus, the radioactive properties are determined by the number of neutrons and the balance amongst the protons, neutrons and electrons. An element like hydrogen and its radioactive twin, tritium, have the same number of protons (and so, the same chemical properties), but instead of a single neutron, tritium has three neutrons. Tritium occurs naturally in small amounts, in addition to being produced by man either purposefully for research and consumer products (ever wonder about that glowing watch dial or that luminous EXIT sign?), or as a by-product of the nuclear industry.

Because tritium is chemically similar to hydrogen it can and does take the place of hydrogen – when this happens in water tritiated water or radioactive water is formed.

The radiation released by tritium is referred to as a beta particle. Beta particles, or electrons, are a form of ionizing radiation capable stripping electrons from other atoms, causing a sort of chain reaction of destabilization, and breaking chemical bonds. Although the beta particles released by tritium are low energy, incapable of penetrating through barriers such as skin (unlike some other forms of radiation), should tritium enter the body through inhalation or umm…water, those emitted particles would then have full access to vulnerable tissues and molecules.

Tritiated water is particularly insidious. The tritiated water lurking below Vermont Yankee for example, could be absorbed by the root systems of nearby plants, or imbibed by unsuspecting animals. Once consumed, distributes rapidly throughout the body of plant or animal. Additionally, ingestion of tritiated water, can lead to incorporation of tritium into organic materials like DNA, proteins and amino acids. Only, unlike hydrogen, tritium will eventually decay, leaving behind an atom of helium and releasing a beta particle with enough energy to break nearby chemical bonds.

In the body, the making and breaking of the chemical bonds between atoms is a highly coordinated process, normal and essential to life. The “unscheduled” breaking of chemical bonds can cause permanent cell damage, damage to the cell’s DNA or cell death.

The human genome is contained within the DNA of our 46 chromosomes located in a cell’s nucleus. Replication of these chromosomes during cell division is a critical process, requiring a number of complex biochemical interactions including copying and construction of identical chromosomal pairs that are then split off into the newly divided cell. Because integrity of the genetic material is essential to life, not only are there biochemical systems involved in maintaining chromosomes during division, but there are also a number of mechanisms by which errors may be repaired.

Say a few molecules of tritium enter the cell and cozy up to nuclear DNA. At some point in their unstable life-time they will disintegrate, releasing their energized electrons. Should the cells’ chromosomes be in their pathway, the transfer of energy from electron to chromosome may be enough to break off a bit of chromosome. Sometimes, depending on conditions within the cell and location of the break, the broken pieces may rejoin the chromosome, leaving little or no evidence of damage; other times a broken piece remains separate, becoming a chromosomal deletion; or both the deleted piece and the damaged chromosome will be copied as if nothing happened, only it will be altered. Or, instead of direct interference with DNA, emitted electrons may interact with other molecules such as oxygen, causing “indirect” damage by creating highly reactive oxygen radicals.

Since DNA tends to be a target of ionizing radiation, tissues made up of cells that are rapidly dividing – such as blood forming organs constantly churning out cells – tend to be far more sensitive to radiation damage than say, brain cells. Similarly, embryos and fetal tissues are more susceptible to radiation damage than adult tissues.

There is some good news amidst all this havoc and destruction. That is, most if not all cells have some capacity for DNA repair. These include an array of enzymes and proteins that find and correct damaged DNA in addition to a number of antioxidants capable of disarming those reactive oxygen radicals. The presence of such repair mechanisms have led some to speculate that exposures to very low amounts of radiation may be a good thing, “priming” these repair systems and leading to greater protection with low levels of exposure – a phenomenon referred to as hormesis. However, a National Academy of Science report on The Health Effects of Low Level Ionizing Radiation, published in 2007, found no available evidence of radiation induced hormesis in mammals, and concluded that any single track of ionizing radiation (for example by a single ejected electron in the case of tritium) has the potential to cause cellular damage.

And, despite the capacity for repair, sometimes the system is overwhelmed, or sometimes the repair itself introduces a new error (think sloppy auto mechanic.) At this point the genetic damage has the potential to become permanent, or “fixed.” Permanent damage to DNA can result in the eventual development of cancerous cells, or a defect in an exposed fetus or as a mutation passed on to the next generation. While the evidence for carcinogenicity in human populations is strong for some radioactive isotopes like strontium-90, plutonium and radium, the health effects of tritium, a weak beta emitter are less clear.

Which brings us to concentration. How much is too much? What does it mean that the groundwater has over 200,000 picocuries of tritium per liter of water, or that there are “troughs” with over 2 million picocuries per liter? A curie (named in honor of radiation pioneers Pierre and Marie Curie) is a quantity of radionuclide in which there are 37 billion disintegrations a second. That’s a lot of disintegration and in the case of tritium would be a lot of beta particles whizzing about. But the amounts drawn from the ground water were measured in picocuries per liter – or one millionth of a millionth of a curie. So, every second, until all the tritium has disintegrated to helium (the half-life for tritium is 12.5 years) there would be roughly 7,400 electrons winging about in a liter of Vermont Yankee groundwater.

As a result of the current hypothesis that exposure to any amount of ionizing radiation carries with it some risk of cancer, the U.S. EPA’s Maximum Contaminant Level Goal for all radionuclides in drinking water, a goal which aims for “zero-risk” to public health, is zero picocuries per liter. Unfortunately, achieving “zero risk” is not only wishful thinking but currently unenforceable and, because there is some naturally occurring tritium impracticable. Instead, EPA has developed Maximum Contaminant Levels (MCL) for drinking water. While the MCLs are enforceable, they are calculated considering best available technology and economic feasibility. For tritium, the derived** MCL is 20,000 picocuries per liter, while the derived MCL for strontium 90, a more powerful beta emitter associated with bone cancer and leukemia, is 8 picocuries.

Here’s the thing. Right now we’re talking two wells and a trench (where, incidentally, a small amount of radioactive cobalt has turned up as well.) While current concentrations in the ground water (the trench is another story) may not present an immediate health risk, who knows what a more comprehensive analysis - currently underway - might reveal?

*As of Feb 10, 2010 over 2 million pCi was measured in test wells around the plant.

For more see: http://www.rutlandherald.com/article/20100205/NEWS04/2050349/1003/NEWS02

**The MCL for beta emitters is based on a dose of 4mrem/year to the total body and assumes ingestion of 2L a day – the picocurie concentrations are derived for each specific beta emitting isotope depending on their strength. Over the years, there has been discussing of using different calculations for tritium that would dramatically reduce the MCL.

Evolution of the Toxic Response: In the beginning there were chemicals....

2010-01-07T10:17:00.000-08:00

The following is what I intend to be the first in a series of essays on the Evolution of the Toxic Response – a topic which piqued my interest after what could either be called a disastrous flirtation with the publishing world, or an invaluable lesson in pursuing your passion. The disaster was allowing myself to be duped into thinking the content and style of this blog would actually make an engaging book (wrong,) the passion was in realizing that writing primarily about toxicants of interest to the consumer (and in the style that would be most appealing to mass market publishers) has caused me to lose my way as a toxicologist and a scientist.

There is no doubt that some toxicants are, well, toxic. But there is always the question of exposure, dose, and potency. Topics often lost in breezy articles meant to engage a reader – rather than inform about the complexities not only of toxicology but science in general. Unfortunately the publishing world seems to have no confidence in its mass readership. Readers are attracted by alarmism, so hype it up. They’ll doze if there is too much science, so keep it simple. They just want to be told what’s best for them, so just tell them. But after whipping off one light and fluffy page after another about dangerous toxicants hidden away our homes and gardens (along with a few good toxins in our ‘fridges) all in preparation for my failed Book Proposal, a request by the local news paper to write about bisphenol A or BPA resulted in a nearly visceral reaction at the thought of writing yet one more article for consumer consumption about chemicals consumed by consumers.

But after the storm, and the lull where I could barely bring myself to write another word about chemicals, came the passion. I was attracted to toxicology because I was fascinated by chemicals that screwed up the normal processes of life. But that was back in a time long long ago when toxicology meant PCBs, lead, mercury, dioxin, and assorted pesticides. These were obvious chemicals in concentrations that couldn’t hide within the peaks and valleys of the chemists’ printout. But science has come a long way since then. Now, we know far more about the minute amounts of a myriad of chemicals contaminating our water, air and food than we do about the way they might interact with our lung cells, or livers, or brains. We know that our bodies sequester the smallest amounts of these chemicals in our bones, brains, and fat cells.

Many of these chemicals will stick around on earth at least for our lifetimes, and those of our children. What will be the consequences of these chemical exposures – if any? What do we really mean when we say that these chemicals are toxic? At what point does a contaminant become a toxicant? Given all the synthetic and naturally occurring chemicals entering and exiting our bodies with virtually every breath – some of which by now are unavoidable, others we might choose to inhale and ingest, and still others have been with us for eons, how can I, as toxicologist better understand the collective impact?

This was when I remembered I’ve inherited more than my big ears, hazel eyes and dry skin from my ancestors. I’ve inherited a whole system of toxic defense mechanisms, because really, well before the first animal ventured onto land, well before the first single-celled organism respired oxygen, life on earth relied upon chemical defense mechanisms of one sort or another.

And to some extent, we owe our lives -- as do all life forms -- from bacteria, to plants and all animals -- to these toxic detoxification processes.

Yet are they enough to protect life from the steady rain of natural and synthetic chemicals experienced by life on earth today?

That is the question I intend to explore in this upcoming series of essays, so stay tuned if you dare.

Also if you are a toxicologist, chemist, geologist etc. and would like to discuss the topic further please don't hesitate to contact me at emonosson@verizon.net I'd love to begin a virtual journal group on this topic.

Is there bias in bi(a)sphenol A?

2009-11-25T07:37:00.000-08:00

Over the past two years the debate about bisphenol A (BPA) has become a quagmire where highly regarded scientists who once worked side by side, now sit across the fence virtually flinging insults at one another. You wouldn’t know this reading the Sunday paper or countless mainstream press articles, blogs and even academic journals which have successfully vilified this ubiquitous chemical. Like many Americans, you’re probably tossing away your polycarbonate bottles and looking askance at the stash of cans in your pantry.

Yet two summary panel reports on BPA prepared by the National Toxicology Program (NTP) and by the Food and Drug Association (FDA)* downplayed the risks of BPA, while at the same time, NTP highlighted the need for more research - and as of January 2010 the FDA indicated they too have concluded there is some cause for concern, particularly in infants and children. As a writer I find this disconnect fascinating. As a mother who replaced the polycarbonate bottles shortly after the first round of BPA press, I wonder if the chemical is deserving of its reputation as the evil twin of estrogen. As a toxicologist, I am dismayed by the apparent bias found on both sides of the fence.

Years ago, while interviewing for a job, I was asked if science was objective. I quickly answered in the affirmative. My future employer’s brow wrinkled, but she remained silent – giving me time to think. While science is objective, it is carried out by mere humans. And we all have our biases. I wouldn’t have been interviewing with a group whose mission was to support communities affected by industrial contaminants and who could only offer a pittance in salary if I didn’t lean towards the affected. Yet, I pondered, when reviewing the literature in support of their mission would I be biased? Here’s the truth – when reading studies funded by either the military or industry my sci-dar is on full alert. Likewise, I’m just as wary when reading studies conducted by environmental activist organizations, yet I am more trusting of studies produced by academics, particularly those funded by sources that tend not to have a stake in the outcome. Really, my sci-dar should be on full alert at all times, and in the end, I am careful not to cherry-pick studies from any one source, just to support a position.

Are there concerns about bias in the bisphenol A analysis? As a recent memoirist who shall not be named, likes to say, “You Betcha.” Just Google “BPA bias” and you’ll find over one million pages.

One need only read Environmental Health Perspectives, published by the National Institute of Environmental Health Sciences (NIEHS), where the most recent BPA battle is playing out. But the stakes are higher than simply resolving BPA’s toxicity. Bisphenol A has brought to the fore the very nature of toxicity testing and regulation, questioning the role or (or lack of) basic research in chemical testing and regulation.

That toxicity testing, particularly of endocrine disrupting chemicals like BPA is in dire need of overhaul is not in question. Says Dr. L. Earl Gray**, Research Biologist and Team Leader of the Reproductive Toxicology Division at the US EPA, about updating routine chemical testing:

“There is a lot more awareness of the issues with endocrine disrupting chemicals and thoughts about screening….they are also trying to shorten the multigenerational protocol [one of the standard toxicity tests required of industry]…hopefully and likely the new assays will be able to replace the old ones fairly quickly.”

Problem is, it took a decade to develop and validate those new assays. A snail’s pace, and a significant chunk of time for those at greatest risk, the very young. Even so, when it comes to BPA, there are those who suggest reviewers and regulators stick with studies based on regulatory testing protocols, because those methods have been rigorously validated, even if they don’t incorporate the latest science.

Of the hundreds of scientific articles on BPA many could be classified as basic science, while only a fraction use regulatory testing protocols. Studies in rodents report that BPA causes diabetes, weight gain, mammary gland cancer, early onset puberty, infertility and behavioral changes. Some of these findings cannot be repeated (reproducibility is a central tenet of science). Meanwhile studies in human populations report associations (which are not cause and effect linkages) between BPA and heart disease, diabetes, infertility in industry workers, and behavioral changes in toddlers born to mothers whose urine concentrations during pregnancy mirror those in the general population.

Despite the uncertainties, aren’t all of these studies enough to require that industry remove the chemical from our food and drink? While I am skeptical of studies produced by industries whose bottom line depends upon a particular chemical and in sticking with decades old testing procedures, I also know that a chemical posing an imminent danger is good for academic business, generating more grant money, more publications, and more consulting. It’s not an ideal system, but given time the scientific method prevails – and in the interim we have guidance from the expert panels. In the case of BPA both panels had the freedom to consider any and all relevant and valid studies.

While the NTP panel concluded there was cause of “some concern,” noting the need for more research, the FDA concluded that current exposures to BPA do not present a health risk. So began the fireworks. Critics charged the panels were biased omitting too many basic studies from their final analysis. In his congressional testimony, Gray who was a member of the NTP panel disagrees. Testifying before congress about BPA, Gray noted, that “the criteria [for inclusion in the review] provided minimum standards for experimental design and statistical analysis. Many studies failed to meet these minimal criteria – these studies came from industry, government and academic laboratories.

“The controversy,” says Gray “resides over the fact that standard and enhanced multigenerational studies are negative for low dose effects and many academic studies were positive…. several of the multigenerational studies have added low dose groups, estrogen sensitive endpoints and tried to replicate the low dose effects to no avail... These differences are due in part to differences in how a chemical is administered in a study.” Differences which also include the use of live animals versus test tube studies (which preclude metabolism and excretion of a chemical), the timing of exposure and the range of doses tested.

Yet based on accounts by the popular press, enviro-blogs and magazines – if you still drink from a polycarbonate bottles or serve your kids canned foods then you must be an irresponsible parent. When I replaced our reusable bottles with BPA free – but didn’t toss the canned goods, my inner toxicologist reasoned that we are exposed to a myriad of natural estrogenic chemicals in foods like soy, plants, and milk – was BPA any worse? Meanwhile the environmentalist in my brain reminds me that we don’t choose to consume industrial chemicals like BPA. Shouldn’t we have that choice? But since BPA does not accumulate in humans (a quality that may trigger a chemical ban), “that choice” depends primarily upon the amount and frequency of BPA exposure, how it’s metabolized and its potency.

So is it or isn’t it? Maybe the nearly 30 million dollars recently committed by NIEHS for BPA research will solve the question, and maybe BPA will be one more example for the scientific flip-flopper pile along with fiber, mammograms, and therapeutic estrogens. For now, there’s FDA’s final report due at the end of the month, and Consumer Report’s recent investigation of BPA in canned goods – both of which will surely add a few feet to the fence separating some very good scientists.

*This report is the 2008 draft, a final report was just published you can find FDA's current position on BPA here.

Here is a recent article on the relationship between BPA in urine and heart disease

CHECK OUT the US DEPT Health and Human Services site for the latest on BPA (added Jan 16 2010)

AND a Jan 28 2010 interview with Dr. Linda Birnbaum of NIEHS

**In the spirit of disclosure, I worked for Earl back in the early nineties, he was not only a great guy to work for, but I also respect his science and opinions.

Recombinant DNA, Synthetic Biology,and Nanotechnology, oh my!

2009-10-07T08:07:00.000-07:00

There is an interesting article on Synthetic Biology in last week's New Yorker. Though I just gave it a skim, and didn't read the ending – the topic is intriguing and describes a field of science devoted to developing the capacity to build and manipulate biological systems as if they were Legos. According to SyntheticBiology.Org their goals begin with identification of the parts that “have well-defined performance characteristics and can be used (and re-used) to build biological systems” and end with “reverse engineer and re-design a ‘simple’ natural bacterium."

Wow. Should they succeed, they’d bear a hefty biological, ethical, environmental responsibility. Were these people nut jobs? Nascent Frankensteins? Or were they just being realistic about the future of their science? As I thought about what this all meant it dawned on me that Synthetic Biology, being an extension of Genetic Engineering, in some ways wasn’t so different or separate from nanotechnology.

I don’t mean that they’re similar in how the products of these technologies interact with living systems, all threats of “grey goo” (a worst-case scenario hypothesized by Eric Drexler, popularizer of nanotechnology, whereby nanobots run a muck, literally mucking up the world) aside - one science proposes to build biological systems while the other builds chemicals. Although, I suspect, as time goes on these two technologies will mingle if not marry (if they haven't run off to Las Vegas and done so already.) Biological systems after all are nothing more than chemical building blocks – so once those building blocks are better understood, and once we have the capability to not only engineer one cell at a time, but also to build chemicals one atom at a time, why not?

As a toxicologist observing the emergence of nanotechnology it has been easy to ask what nanotechnology can learn from past practices of chemical production, regulation, use and disposal. But beyond toxicology, biotechnology, has also laid some groundwork as to how to proceed with – or not-- development of a new technology that will impact all of our lives for better or worse, in ways we cannot fully understand.

Genetic engineering, the cornerstone of biotechnology, has been around since 1972 when scientists including Paul Berg of Stanford University first recombined pieces of DNA – the molecule which holds the secrets of all live on earth. Two years later, Berg and others raised serious concerns about unfettered recombinant DNA research, eventually calling for a temporary moratorium on certain types of research. Berg’s committee proposed that, “…until the potential hazards of such recombinant DNA molecules have been better evaluated or until adequate methods are developed for preventing their spread, scientists throughout the world join with the members of this committee in voluntarily deferring the following types of experiments....” the authors then listed specific research that they considered most risky, acknowledging that…”our concern is based on judgments of potential rather than demonstrated risk since there are few available experimental data…and that adherence to our major recommendations will entail postponement or possibly abandonment of certain types of scientifically worthwhile experiments.” A year later, the first conference on “Recombinant DNA molecules” widely referred to as Asilomar for the idyllic conference center by the sea, took place, and is still referred to, and reflected upon as a model of “self-regulation” by the scientific community (the meeting included scientists from around the world, lawyers, government officials and journalists as well.)

Of course the concept of self-regulation may be an oversimplification since the conference purposefully focused on health and environmental safety only. The ethics and legalities of recombinant DNA were not on the agenda, “This choice of agenda,” wrote Berg years later, “was deliberate, partly because of lack of time at Asilomar and partly because it was premature to consider applications that were so speculative and certainly not imminent.” Perhaps. I imagine, like my district’s school committee meetings which I’ve sometimes referred as “adults behaving badly” – if we stuck with the nuts and bolts rather than the deeper questions – we too might be more successful.

Berg revealed one other key to success on at a symposium celebrating the 25^th anniversary of Asilomar: molecular biologists weren’t yet heavily invested in the science and the public knew very little – so that there was still room for fluidity in the conversation. Positions on the recombinant DNA were not yet “hardened,” and scientists were primarily academic. This was a time when government funding was flush, when there was separation of academia and industry and the biotechnology industry with all its promises of the next million dollar drug was more “Jetsons” than reality.

Which brings me back to nanotechnology - a field developing under incredible public, government, and scientific scrutiny. Even industry, as I’ve read and heard, wishing to avoid the genetically modified foods fiasco (which is either ironic or inevitable considering Asilomar), seems willing to tread carefully when it comes to development of nanomaterials. A recent report by the DEEPEN (Deepening Ethical Engagement and Participation in Emerging Nanotechnologies) project – emphasizes a role for increased public participation in governance decisions related to nanotechnology development. In part because nanotechnology is poised to affect everyday life – so why not include all participants -- those who deliberately participant and those who are incidental nano-tourists in the conversation?

There's one caveat to suggestions by DEEPEN and others. There have been so many meetings, and project reports on how best to move forward conscientiously with nanotechnology, that there is some concern there’s too much talk and too little action. Meanwhile, nanomaterials find their way into more and more consumer products (1000 and counting,) and the body of research papers continue grow like a bacterial culture in log growth phase. But that's no reason not to broaden the conversation.

Perhaps comparisons between nanotechnology and Asilomar are unfair for nanotech.

As Berg noted, in 1975, neither Joe Public nor Joe the Plumber were invited members of the 'Recombinant DNA steering committee,' the focus of the meeting was strictly focused, and recombinant DNA was, and still is fairly easily defined. Isolating and rejoining segments of DNA – that was recombinant DNA. Today we have the world wide web of information where the public, if they wish can be informed, NGOs following and reporting on nanotechnology, a technology that is already in use, and scientists who can’t even agree on what constitutes a nanoparticle. Are they particles with one dimension measuring 100 nm or less? Or, should they be much smaller, encompassing particles in the 30 nm or smaller range, particles most likely to exhibit new and different physical-chemistry?

Then there are nanodots, nano-metals oxides, nanotubes and other nanos – all very different chemically although they may share some basic properties in terms of size, or increased reactivity as a result of decreased size, but how much do we know of their differences in terms of how nanoparticles will move and react inside a living being, or outside in the big wide world?

Our best hope right now, is that nanotechnology as a field is still young and flexible. Hopefully the talk with turn to action before nanotech’s arteries begin to harden before, as Berg observed twenty-five years after Asilomar – the issues become “chronic.”

(For the results of a recent poll on public understanding of nanotechnology and synthetic biology click here. )

Lining Asbestos-Concrete Drinking Water Pipes with Vinyl: Its enough to make you wonder

2009-10-05T18:19:00.000-07:00

I’ve been a “lurker” on the TCE List serve – a gathering site for those impacted by this old industrial solvent and one of this country’s most important groundwater contaminants. Unfortunately it is an incredibly active list because so many people are affected by this legacy pollutant. Often, I let the emails pile up - shifting them into my TCE folder - in case, one day, I might have something useful to offer the list. But today one email caught my attention.

It began with a posting by Lenny Siegel, Executive Director, Center for Public Environmental Oversight – and list host. The subject line was “PCE in pipes - this is new to me.” If something about these chlorinated solvents is new to Lenny it’s new to a lot of folks, activists and scientists alike, because Lenny really knows his stuff. So I took a look.

According to the Cape Cod Times article posted by Lenny, a study by Boston University epidemiologist Ann Aschengrau, found an association between exposure to PCE (perchlorethylene, or tetrachlorethylene – a solvent most commonly associated with dry cleaning) contaminated drinking water, and an increased risk for birth defects in offspring of Cape Cod women exposed to the water back in the 70's and early 80's.

That PCE was in drinking water wasn’t surprising – it’s a common contaminant in groundwater near old dry cleaning sites . What was surprising was that an old leak, landfill or dry cleaner wasn’t responsible for contamination this time around. The culprit was the municipal drinking water pipes.

Apparently back in the good old days (in this case the 1960’s and '70's) according to the Aschengrau, who was interviewed for the article,

“…water pipes in several towns on the Cape and elsewhere in Massachusetts were purposely sprayed with vinyl plastic and PCE to improve the taste of drinking water.....

Manufacturers wrongly assumed the PCE would disappear during the drying process, but large amounts remained and slowly leached into drinking water in Barnstable, Bourne, Falmouth, Mashpee, Sandwich, Provincetown, Brewster and Chatham, ……Once the PCE contamination was detected, authorities cleared the pipes through a flushing process, saying replacing hundreds of miles of vinyl-coated pipe would be too expensive..”

Reading the chatter on Lenny’s list, I learned that back in the early 1980s Avery Demond, an MIT master’s student studied leaching of PCE from those vinyl lined pipes. Back then Demond wrote that while his focus was on the hydrodynamic factors controlling release of the toxicant, it was “difficult if not impossible” to ignore the social context of the problem. Meaning, people were drinking the contaminated water. As Demond noted, PCE was a common contaminant in drinking water a levels of 1 part-per-billion (ppb) or below. But then a 1976 survey of organic chemicals in water (with a focus on water treatment byproducts) turned up PCE concentrations ranging from 6 ppb to upwards of 1000 ppb in water from a Newport RI state park, warranting a closer look. After seeking potential industrial sources, municipal pipes eventually came under suspicion.

Wrote Demond, early on,

“...the PSWB [water board] tested the liner in May 1968 and contemporary analytical tests and techniques could not find anything undesirable in the water that might have arisen from the water’s contact with the liner. (The sophisticated powerful gas chromatography equipment in general use today was either unavailable or not thought to be needed.) The development of the liner predates the current widespread concern about organics.”

That last statement about sums it up, if you were wondering what they were thinking using pipes recently treated with a solvent combined with a plastic matrix allowing it to leach out over time. They weren't, because they didn't have to. Smell no evil, taste no evil, measure no evil.

Although by the time Demond wrote his thesis, organic solvents were losing their innocence, as residents of Woburn, Massachusetts were realizing the possible linkages between high incidences of childhood leukemia and water contaminated with PCE's chemical cousin, TCE.

Unfortunately for New Englanders, according to Demond, the vinyl-lined asbestos-cement pipes produce by Johns Mansfield Company (of asbestos fame) were used primarily in New England to control alkalinity-related corrosion of the pipes. Over 600 miles of vinyl lined asbestos-cement pipes were laid in Massachusetts, with the majority on Cape Cod. A few years after the leaching problem was identified the company stopped production.

While some pipes were replaced, remediation more often consisted primarily of flushing, until concentrations fell below levels of concern at the time.

Twenty year's later, Aschengrau’s paper in the journal Environmental Health reports finding “large increases in the risk of gastrointestinal defects (particularly oral clefts), neural tube defects (particularly anencephaly) and, modest increases in the risk of genitourinary defects (particularly hypospadias),” and concludes

“The results of this study suggest that the risk of certain congenital anomalies is increased among the offspring of women who were exposed to PCE-contaminated drinking water around the time of conception. Because these results are limited by the small number of children with congenital anomalies that were based on maternal reports, a follow-up investigation should be conducted with a larger number of affected children who identified by independent records.”

For more, check out Aschengrau's paper.

The salty dumping grounds: plasticized Part II

2009-09-30T10:30:00.000-07:00

[Here is the second part of The Dumping Grounds, a history of ocean plastics.]

An Earlier Voyage

In 1971 over twenty years before the Alguita’s first voyage, nearly forty years before the recent Scripps voyage into the Gyre and roughly twenty years after his own voyage across the Pacific in Kon-Tiki, anthropologist and adventurer Thor Heyerdahl with a small international crew made his way across the Atlantic aboard the Ra I, a papyrus raft-vessel constructed as a modern day experiment using ancient technology. On that first voyage, as Ra made its way from across the Atlantic from Morocco to just east of Barbados, Heyerdahl, commenting on the preponderance of oil-clots and other flotsam wrote “pollution observations were forced upon all expedition members by its grave nature…” [1]

Encouraged by interest in their findings by members of United Nations, Heyerdahl set off in the Ra II a year later prepared to record observations, and to collect samples. With oil lumps washing aboard at one point, the Ra II’s log reported that “the pollution is terrible.” A couple of days later, after encountering a plastic bottle, some rope, a can and other items, a log entry expressed shock at the degree to which remote regions of the Atlantic had become polluted by man. From the day of departure, wrote Heyerdahl, to the day they landed in Barbados, the Ra II was accompanied not only by lumps of oil, but also by plastic containers, metal cans and glass bottles. In closing wrote Heyerdahl,

“The present report has no other object than to call attention to the alarming fact that the Atlantic Ocean is becoming seriously polluted and that a continued indiscriminate use of the world’s oceans as an international dumping ground for imperishable human refuse may have irreparable effects on the productivity and very survival of plant and animal species.”

Plastics Overboard!

Years before Heyerdahl’s journey, Stephen Rothstein, then a University of California biologist, had discovered small plastic particles in the stomachs of Leach’s Petrels and nestlings captured on Gull Island, Newfoundland in 1964. Wondering why the petrels might ingest plastics, Rothstein wrote, “Before the occurrence of plastic particles, it is probable that nearly all such objects were edible. Thus, natural selection would not have favored petrels which avoided nonedible floating objects…[2]” It seems this was the case with other marine creatures as well, as researchers throughout the early 1970’s and ‘80s cataloged the impacts of plastics on marine mammals, birds, turtles and fish. While plastic fishing nets, ropes and packing bands ensnared Neptune’s creatures, small bits substituted for food. Seabirds mistook plastic bits for prey, inadvertently feeding them to their young, as green sea turtles gobbled down plastic banana bags tossed off the side of a dock. Wrote David Laist, then senior policy and program analyst at the Marine Mammal Commission, in his testimony at the 1986 hearing on Plastic Pollution in the Marine Environment, “Animals which become entangled may exhaust themselves and drown, be slowed to the point of becoming easy prey for other predators, or unable to catch fast moving prey, or develop wounds and infections from abrasion of attached debris. Animals which ingest plastics may be poisoned or have digestive tracts blocked or damaged by plastics that are difficult or impossible to excrete, regurgitate, break down, or otherwise eliminate once ingested.[3]” As a 1970’s teenager, the “Keep America Beautiful” decade, it’s hard to forget the heart rending photos of fur seals girdled by discarded plastic strapping, or young turtles and seabirds caught up in six-pack rings. By some accounts, a 1988 cleanup along a 1.8 mile stretch of the Texas coast turned up almost 16,000 six-pack rings[4]. I have a vague recollection of pulling six-pack rings from my parent’s trash after chastising them for carelessly throwing them away without first slashing them apart. There was growing concern that endangered marine mammals and sea turtles alike were adversely impacted by their encounters with plastic waste, the likes of which the Alguita had stumbled upon in the North Pacific gyre. Only the hearing to prevent plastic pollution took place ten years earlier.

One of the first suggestions proposed by Laist to improve the situation was ratification and implementation of the International Convention for the Prevention of Pollution from Ships or MARPOL Annex V, introduced through the International Maritime Organization by the United States and other countries. MARPOL is the main international convention dealing with release of pollutants by ships. Before MARPOL, there was OILPOL, an international convention adopted to prevent ships from releasing waste oil, back in the 1950’s, strengthened over the years to include releases of oily bilge water and toxic chemicals. Not until 30 years later, as plastic lines and nets became integral to the fishing industry, and plastic strapping and packaging of food items and other consumables became common aboard all sea-going vessels from the merchant marines to the world’s Navy’s did the international community recognize the need to control the release of plastics from ships as well. Ratification of MARPOL Annex V would ban the dumping of plastics into the ocean from all vessels, in all locations. There is some unintended logic to the progression from the early OILPOL to MARPOL’s Annex V, for oil is the precursor to our modern day plastics.

The Marine Mammal Commission wasn’t alone in calling for the ratification of annex V. MARPOL’s annex V was supported by a rare combination of organizations and federal agencies, including those normally in opposition such as the Environmental Defense Fund, and the Society of Plastics Industry. In his testimony in favor of ratification at the Plastic Pollution hearing, C.E. O’Connell, sounded much like today’s National Rifle Association’s dictum that “guns don’t kill people, people kill people,” when he essentially stated that the plastics industry did not pollute the world’s oceans, plastics users, including beachgoers, municipalities and the marine, naval and fishing industry did[5]. And they did - legally. Back in 1982, when the merchant marine fleet registered around 71,000 ships, and plastics had worked their way on board in every conceivable role, from the packaging galley food to plastic strapping, it was estimated that some 639,000 plastic containers were tossed daily[6]. And that estimate didn’t even include all the plastics tossed overboard by navy ships, luxury cruise ships, like the QE2, which serve as a luxury playground for nearly 10 million Americans each year, or the tons of plastic fishing nets and gear lost to the sea.

I inadvertently contributed my share back in 1989. After collecting winter flounder from the Narrow River, a seemingly clean river that cut through Narragansett, RI on its way to the bay, and finding them distressingly contaminated with polychlorinated biphenyls I was eager to collect winter flounder untainted by coastal contaminants. As it turned out, EPA’s ocean survey vessel the Anderson, a converted Vietnam era Naval Patrol gunner, had a few unscheduled days that fall. We booked four days at sea, hired Mike the Rebel fisherman (he kept a confederate flag in the rear window of his truck, had long blond hair and a good sized tattoo on his bicep) and headed 130 miles offshore to Georges Bank to trawl for flounder. When the Anderson nearly jerked to a halt mid-tow, and the winches spun a little too easily, the loss of our net, along with the heavy metal doors that dragged along the oceans bottom became all too clear. We had just made our contribution to the hundreds of miles of ghost fishing nets drifting about or laying upon the ocean floor. Though I never would have tossed my Styrofoam coffee cup overboard, the episode didn’t register as an environmental catastrophe. The ocean was big and the net was gone. “It happens,” was all Mike had to say, that was why we brought a spare.

The thousands of lost fishing nets and lines are only part of the ocean’s plastic problem. Like early twentieth century coastal cities, merchant marines, cruise ships, navy vessels and fishing boats have looked to the sea for disposal. And why not? Aircraft carriers with crews of 6,000 sailors generate over 3 million pounds of trash during their six months at sea[7]. By some estimates, plastics, before any major efforts by the navy to reduce plastic waste, accounted for over 12 % of all waste generated on board[8]. That means over 300,000 pounds of plastics dumped in a six month period by a single vessel, in just one of the world’s navies. Up until 1988, the Navy estimated it contributed more than 4.5 million pounds of plastic to the world’s oceans[9] [insert volume analogy, e.g. # of coke bottles]. For far too many years it was common practice to dump trash directly overboard.

In total, just the amount of plastics dumped at sea from say, the 1960’s when plastics entered our lives in a big way through the mid-1980s (when at least those adhering to MARPOL Annex V quit dumping) is mind boggling. Particularly because all of that plastic is still with us – somewhere – today. We’ve contaminated the largest of earth’s commons, the oceans, with our plastics.

Considering this enormous tonnage of plastic in addition to that which has floated down rivers and out with the tides or with the sewage, left on beaches, blown from the decks of hulking garbage scows on their way to mega landfills in New York and New Jersey like Fresh Kills, Meadowlands and Pelham Bay, the recent encounters with a gyre full of plastic is sadly not surprising. What is surprising is that until now, no one really knew the extent to which we’d contaminated our oceans, and how that contamination would eventually come back to haunt us.

[1] Heyerdahl, Biological Conservation Vol 3 April 1971, 164-168

[2] Plastic Particle Pollution of the Surface of the Atlantic Ocean: Evidence from a Seabird, The Condor 75:344-366, 1973.

[3] Statement of Mr. David Laist Senior Policy and Program Analyst Marine Mammal Commission, Plastic Pollution in the Marine Environment, 1986 Hearing before the Subcommittee on Coast Guard and Navigation, Washington, DC Serial No. 99-47. P. 21

[4] http://www.seaweb.org/resources/writings/writings/seatroubles.php

[5] Statement of C.E. O’Connell, President of the Society of the Plastics Industry, Plastic Pollution in the Marine Environment, 1986 Hearing before the Subcommittee on Coast Guard and Navigation, Washington, DC Serial No. 99-47 p. 108.

[6] Horsman, 1982, The Amount of Garbage Pollution from Merchant Ships, Marine Pollution Bulletin, 13:167-169. Wastes in the Marine Environment, Office of Technology Assessment, Washington, DC, 1987.

[7] Navy’s Shipboard Solid Waste Management Program, Ye-Ling Wang, 1997.

[8] A Float Solid Waste Characterization Study, http://www.agraco.com/pdflinks/NimitzReportAbbrev.pdf 2008

[9] Clean Ships, Clean Ports, Clean Oceans p. 23

Lice patrol

2009-09-25T08:52:00.000-07:00

Though I’ve got lice stories to tell of my own, I’ve been embargoed by the victims. So instead I’ll begin with my friend, Kate’s* daughter, who discovered the unwelcome visitors two days before her first day of high school – a school in a new town where she didn’t know a soul. As if walking into a new social situation wasn’t hard enough!

Although Kate makes a point to tread lightly on this earth, choosing natural to synthetic, and organic when possible, for her, this called for an exception.

“We went for the toxic stuff,” she said.

Why lice, so common these days, can still cause one to be ostracized I don’t know. There isn’t a school around that hasn’t reported a recent outbreak.

Growing up in the suburbs circa 1960s, lice was more of a joke than a problem. “You don’t have lice do you?” was a common refrain when offered a comb or brush for our preteen locks. No one ever thought their best friend would seriously be harboring the little critters.

So back in the mid-ninties when lice hit my daughter’s day care, I was appalled.

A few years later those lice had apparently moved on to my kids’ elementary school, where the motto “Caring is Sharing” apparently went a little too far (and yes embarrassingly enough, that was their motto - at least for a time.) Each year, as the dreaded “letter” indicating a new crop of lice arrived in the mail, we’d tentatively comb through our kids’ hair, thankful every time we found suspect nits to be nothing more than lint. Our school wasn’t alone. It is estimated that upwards of six to twelve million kids ages 3-12 are infested each year in the United States alone.

Humans have been battling lice since the earliest days of our existence. Archeological digs reveal lice or nits (the rice-like egg cases adult female lice affix to human hair shafts) on human hairs, old combs, mummies you name it. And, just to dispel any fears, the body lice associated with Typhus and other diseases are not the lice that infect our silken locks. In fact there are three types of lice, head lice, body lice and pubic lice. Curiously and thankfully they not only seem to know their place on our bodies, but can apparently distinguish us, their favored and only host, from our pet pooches and lap cats. And, head lice, unlike body lice, are seldom associated with disease other than excessive itching and an occasional infection as a result of said itching.

Given all these years living together, humans of course have developed a diverse arsenal from the lethal to the eccentric fight these beasties. A swig of shed snake skin tea anyone? Or perhaps a liniment of mercury and stavesacre - also known as lice-bane, or Delphinium staphisagria – a beautiful but highly toxic plant. In the 1920’s its topical use was apparently associated with the death of at least one child. And then there was, and according to some reports still is, kerosene. A treatment which brings me back to my tree-climbing days when my father used gasoline to remove sticky pine-sap from my hands. Clean of sap, but coated with a flammable solvent I’d walk to the shower afraid I might explode. Not a recommended practice – and something I’d thought was left behind with the generation for whom chemicals were life saving and life simplifying miracles – not for our generation who was left to clean up their mess. So I was surprised when, besides exhortations to avoid using kerosene, I came across a recent report from Harvard School of Public Health warning those seeking lice-treatments away from “…motor or machine oils, as these materials can be harmful.” Really? But then, we’ve used plenty of harmful treatments to remove the itchy pests over the years.

For decades the most effective treatment was DDT – credited with keeping lice out of our hair from the 1940s when it was first hailed as a wonder-pesticide through the 70s (the chemist Paul Muller snagged a Nobel Prize eight years after patenting this now notorious organochlorine chemical.) DDT’s widespread use has been credited with keeping me and my 1960s compatriots lice-free throughout our youth. But then DDT became the poster-chemical for all that was wrong with wonton use of industrial, persistent, bioaccumulative and toxic chemicals. Not only did it contribute to the demise of raptors and fish eating birds, but after only a little over twenty years of use, the wily little beasts began to develop resistance (as did other pests treated with DDT.) Not surprising for an insect that can eat and mate at the same time. Clearly lice are efficient when it comes to survival and reproduction.

More recently, lice have developed resistance to other standbys like Lindane, now banned in California and some European countries for a combination of reasons - including its toxicity. One wonders why it’s still available for use in the U.S. when according to the FDA “….serious side effects including seizures and deaths have been reported to the FDA in patients who use too much Lindane or after a second treatment with Lindane….Seizures can happen in some patients even if they use Lindane as directed; Certain people are at higher risk to develop seizures and death from Lindane. This includes: babies and children; elderly; people weighing less than 110 pounds (50 kg).”

If for some reason you are prescribed Lindane, I would suggest you check out FDA’s site and read carefully.

And then there are the commonly used and readily available over-the-counter formulations including RID, Pronto and licetrol, which rely upon an ancient remedy derived from chrysanthemums – pyrethrin. Unfortunately, today’s lice have developed resistance to both pyrethrins and their synthetic chemical cousin permethrin (found in NIX, another popular treatment.) According to one report, if lice are still hanging around after two courses of correctly applied treatments – your little guests are very likely resistant to eviction – at least by those chemicals.

And finally (for toxic stuff) there’s malathion – an FDA approved lice treatment for children greater than six years of age. Malathion not only is an irreversible neurotoxicant but also, in its commercial formulation, has the added risk of going up in flame. Because the treatment is so flammable, users are warned away from using hair dryers and curling irons (for the 8-12 hours required for treatment,) and while resistance has yet to be documented in the U.S. that’s not the case worldwide.

So, what’s a modern parent like Kate to do when faced with a head full of lice, and an impending social disaster for her child?

Enter the Medical Letter On Drugs and Therapeutics, an independent nonprofit organization dedicated to appraisals of new drugs, which just published a review of lice medications including FDA’s most recently approved treatment, a 5% benzyl alcohol lotion. According to Medical Letters, because it actively suffocates lice by opening and obstructing their airways – rather than working at a biochemical level (inhibiting certain enzymes, a mode of action to which insects may develop resistance) there’s some hope this treatment won’t contribute to development of “superlice.” Additionally studies suggest the required ten-minute treatment is not only effective but “well tolerated,” even by the very young. Though they note that “preterm neonates injected intravenously with products containing benzyl alcohol have developed a ‘gasping syndrome’ with CNS depression,….sometimes progressing to neurological deterioration and cardiovascular collapse,” lice treatments are topical and this one has been approved for infants six months of age and older.

There are also “smothering” treatments – like mayonnaise and olive oil – to which I can personally attest (though I won’t say how.) These treatments slow active lice down enough to easily remove, but be warned, at least one recipient of the treatment (which involves spending the night with hair dressed in mayonnaise) has sworn off the stuff for life.

Here again, one can find words of wisdom offered up by Harvard’s School of Public Health which cautions that “Olive oil (or any similar food-grade product) would seem intrinsically safe, but may have associated hazards nonetheless. Oil may cause accidents (slips), and would be difficult to remove from the hair and scalp.” Hmmmm, here's a thought - avoid swabbing your floors with the stuff, and you may be OK. Seriously though, their site is worth checking out for a review of lice treatments in general.

Another smothering agent is dimethicone, the “primary” and apparently active ingredient in another newish product, LiceMD (I say apparently because it is frustratingly difficult to find any information on how the product works other than it contains dimethicone.) Dimethicone is type of silicone oil. I can confirm the ease of combing one’s hair (my own) after use – silicone after all is an excellent lubricant for rusty chains and creaky doors too. So maybe we’re not too far from motor oil and other lubricants after all.

A more pleasant treatment might be a combination of essential oils including lavender, peppermint and eucalyptus dissolved in ethanol and isopropanol (another alcohol) – reported to work as well on active lice as some of the more traditional pesticides to which lice are resistant.

Lice shouldn’t be cause for social trauma, but they are. So when the bugs find their way to your home, be patient – and at least give the non-toxics a try - they might just do the trick. And, you never know, there may even be some unexpected benefits - there’s nothing like gently combing through and nitpicking your kids hair to (at least temporarily) strengthen family ties - not that I'd know.

*Not her real name.

The salty dumping grounds: a brief history of ocean dumping

2009-09-16T12:06:00.000-07:00

In light of all the recent activity surrounding ocean plastics including voyages by both Captain Charlie Moore and Scripps, I thought it might be relevant to consider our practice (past and present) of using the oceans as receptacles for our waste. This is a little different than the typical posts (it's from an earlier project on plastics) and will be posted in sections. Here's the first.

In with the tides, Nantasket Beach, 1988

As far as plastics in the ocean, I needed no introduction. All along the sandy beaches of Hull, a thin barrier beach reaching out into Massachusetts Bay, where my family resided each summer, plastics washed up by the incoming tide were a common sight. We knew when Boston’s sewers had overloaded by the condoms, tampon applicators and other assorted bits of plastic that washed ashore after a storm. When lobstermen switched from the picturesque wooden traps to plastic coated metal, we knew by the fragments of trap that poked up from the wet sand below the high-tide mark. So when the Coastweeks cleanup came to Hull in 1988 my father, garbage bag in hand, wearing his Sears dungarees, faded blue denim shirt, and size 12 Jack Purcells, combed the beach separating plastic, metal and cardboard from the sand. My father, along with hundreds of other volunteers that year, collected a total of 25 tons of debris from Massachusetts’s beaches.

That fall, as I attended the annual Society of Toxicology and Chemistry Halloween Dance dressed as “Beach waste,” I was naïve about the dangers of plastics. As far as I knew plastic was a nuisance and an eyesore but was essentially inert unless burned; not all that interesting to a toxicologist. But it made a good costume. A necklace of pink and white tampon applicators and milk bottle caps collected by my father was the perfect accessory to the orange fishnet cape adorned with fading coke bottles, pieces of old lobster trap and other assorted beach waste items. Problem was, only other east coast attendees got that I was beach waste.

Back then, Alice Outwater, fresh out of MIT’s graduate school worked with the floatable scum of Boston - wastewater scum - for the Massachusetts Water Resources Authority. She writes about the 1980s, “roughly fifty thousand tampon applicators a day were arriving at the wastewater treatment plants in Boston.”[1] Recently, I asked her about the fate of those applicators, “Most of the plastics in the wastewater,” she replied, “ended up in the scum, which, originally, was released on the outgoing tide. ” As recently as 1989, Boston’s sewage treatment plants released upwards of 10,000 gallons per day of that scum, which included grease, oil, and rosy pink tampon applicators,[2] and it was all legal.

Who would have thought that the applicators my sisters and I flushed from our Newton home might one day wash up on our beloved Nantasket beach in Hull? Did Playtex consider this when they manufactured the first silky plastic applicators back in 1962[3]? Or, did both Playtex and consumers assume, as generations before them, that flowing water combined with technology was the solution for much of our waste?

The solution to pollution

Our relationship with the world’s oceans includes worship, fear and contemplation, yet throughout history we have dumped our waste into the nearest water body. If the ocean was large enough to hide fearsome sea monsters, make ships disappear, and swallow Atlantis, surely it was large enough to absorb our waste. By one estimate, for every million molecules of the world’s waters, the ocean contains over 970,000 molecules, while glaciers and ice caps contain 21,000, rivers contain a single molecule[4], and all of life including us watery beings contains a mere half a molecule. So what could beings who represent less than one part-per-million of all the oceans water possibly do to harm the oceans? Turns out, quite a lot.

Four thousand years ago, the Sumerians not only figured out how to move water to where they wanted it, but they also managed to develop a sewer system to carry away their waste. Two thousand years ago Romans built public latrines that discharged via their central sewage system, aptly named the Cloaca Maxima, directly into the river Tiber. Despite all this historical precedent (although one might think we’d have figured this out sooner) western world city dwellers were still dumping chamber pots into the streets and ditches until well into the late nineteenth century. Fortunately for us, city engineers and health departments finally figured out what the ancients had known - that flowing water could carry away a city’s human waste. By early twentieth century, when my father’s father was setting down roots in his new country after a trip across the Atlantic, and in his new city Boston, Boston was being celebrated for having one of the best sewage treatment systems in the country thanks to a collection of pipes that sent the city’s wastewater out into Boston Harbor.

As east coast cities like Boston and New York exploded with immigrants like my grandfather and his family, so too did the amount of household waste, including ashes, garbage, night soil and cesspool cleanings (for those not hooked up to the cities sewers) which along with street sweepings and dead animals, ended up in watery graves along the eastern seaboard, out of sight. While our coastal ancestors paved the way for dumping at sea, inlanders were no different. For them, flowing water, was also the solution to growing waste problems. By the end of the nineteenth century, some Midwestern cities were dumping upwards of 270,000 tons of garbage, manure, night-soil and dead animals into the mighty Mississippi River, while others dumped into the Missouri, the Ohio[5] and the Great Lakes

Occasionally, all this dumping was problematic. Once in a while, dumping interfered with the boats and barges that worked the rivers, or the tides and winds conspired, pushing putrid waste back towards the shore. Navigation became difficult, and coastal areas became hazardous to one’s health. After this happened in Boston during the summer of 1898, ninety years before tampon applicators washed up in Hull, and almost 100 years before Alguita’s maiden voyage, the wisdom of dumping at sea was reconsidered[6]. By 1899 the country’s first law protecting our waterways was enacted.[7] Although key phrases like floatable waste and navigable waters separated the lawful from the unlawful, centuries-old habits die hard. Seven years after the new law, Bostonians were still sending literally tons of market waste, ashes and house dirt, street sweepings and cesspool and catch basin cleanings out to the coastal ocean. Dumping at sea was cheap. In 1912 for just 40 cents, Boston could unload a ton of garbage[8]. As long as the stuff didn’t reappear and as long as ships could still sail, there was no reason not to dump it.

Thankfully for us all, coastal garbage dumping eventually ceased, but our mindset, that the solution to pollution is the ocean, persists. Throughout the past century and into the next, coastal cities and towns have continued to rely upon local rivers and harbors to swallow up their citizen’s sewage. Yet the sewage and wastewater that traveled from my grandfather’s apartment out to the harbor was far different than the sewage that flowed from the subsequent generation of Bostonians who came of age living better through chemistry. Before the current age of plastics, much of what was dumped eventually degraded – even the oil. But plastics don’t break down – at least not within our lifetime. And as recently as 1987, over 1,000 major industrial facilities and nearly 600 municipal sewage treatment plants discharged directly into estuaries or coastal waters around the country[9] dispersing not only fugitive tampon applicators and other bits of plastics but industrial contaminants as well.

To find out more about plastics in our oceans today, check out websites of both the ORV Alguita (Captain Moore's vessel) and the New Horizon, (Scripps' vessel.)

The second part to this article can be found here.

[1] Water, by Alice Outwater pg 169, and personal communication.

[2] http://www.mwra.state.ma.us/03sewer/html/sewhist.htm

[3] http://www.fundinguniverse.com/company-histories/Playtex-Products-Inc-Company-History.html; "The new Gentle Glide tampon is a major breakthrough in design. Since 1962 when Playtex created the first plastic applicator tampon, we've continually improved the design of our feminine care products by listening to consumers and anticipating their feminine care needs. This exciting new product is designed to meet women's needs for ultimate comfort and protection", commented Julie Elkinton, Vice President of Feminine Care at Playtex.” From http://goliath.ecnext.com/coms2/gi_0199-6908790/Playtex-Introduces-a-New-Gentle.html

[4] Gaia’s Body, Tyler Volk, p 112

[5] The Collection and Disposal of Municipal Waste, 1908, Wm F. Morse, The Municipal Waste Journal and Engineer, Ny, NY

[6] The Collection and Disposal of Municipal Waste, 1908, Wm F. Morse, The Municipal Waste Journal and Engineer, Ny, NY.

[7] http://www.eoearth.org/article/Rivers_and_Harbors_Act_of_1899,_United_States

[8] R. Hering and S. Greeley: Collection and Disposal of Municipal Refuse, 1921

[9] Wastes in Marine Environments, OTA, 1987 p.13.

PCBs: back with a vengence?

2009-09-09T10:19:00.000-07:00

Teaching college-aged students can keep you young or, make you feel really old. In this case I was feeling particularly old. My college advisor, with whom I’d kept in touch over the years, had invited me to talk about chemical contaminants with her class of soon-to-be graduating seniors. Wanting to distinguish between the “trendy” chemical contaminants, and the “legacy” contaminants, I brought up PCBs.

“You all know what PCBs are don’t you?” I’d asked, after observing what seemed like puzzled expressions on more than a few young faces. Shrugs all around, with the exception of one eager and confidently raised hand.

"Polychlorinated biphenyls,” responded the proud owner of that hand.

The rest were still clearly puzzled. As was I. How could these bright young students be ignorant of one of this century’s most important legacy chemicals? Not only that, but how could these students who attended college in Schenectady, home of General Electric – the company that not only brought “Good Things to Life,” but also introduced PCBs to much of the Hudson River - be ignorant of one of the most important contaminants in their backyards? (Well, aside from depleted uranium, but that’s another story.)

PCBs, I realized, define the chemical generation gap. These kids didn’t have a clue. Except for all the flap over the Hudson River cleanup nearly a decade ago unless you're unfortunate enough to be directly impacted by Monsanto (one of the primary producers of PCBS), GE or other PCBs users, you rarely hear about the chemical these days.

Until this past weekend, that is. I should have known something was up when a friend and colleague working at Berkshire Community College sent a Facebook message indicating she had some questions about PCBs. She never followed up, and to be honest, I thought, “What could anyone want to know about those these days?” Never mind that the college is located in Pittsfield, MA – the other home of GE – where the company not only contaminated the nearby Housatonic River, but also neighborhoods all over the city (again – a story for another time.)

But PCBs reentered my life, and many others, on a sunny Sunday morning, with a front page article about PCBs in caulking published by the Boston Globe. Over the past couple of years, PCBs have been discovered in samples of window and masonry caulking of school buildings and others built circa 1960-70 and possibly earlier. Most of it found following incidental or voluntary testing including voluntary testing by Berkshire Community College. At some sites, testing revealed incredibly high concentrations - meaning hundreds of thousands of parts per million. Which means hundreds of parts per thousand. That’s high, when disposal of waste containing just fifty part-per-million PCBs often requires special consideration. I immediately wondered about my kid's school - though recently renovated, the original building had that 60's look. As a new member of the school committee and more than well aware of our dire finances did I even want to know about this? As a parent with two kids in the school, and a toxicologist - I am obligated to ask.

PCBs are really a complex mixture of similarly structured chemicals – carbon rings with assorted number and placement of chlorines. Which means when considering PCB toxicity, one must consider toxicity of many different chemicals which may act independently or as a complex mixture. That is, exposure to one PCB may influence the toxicity of another PCB, or one kind of PCB might affect the brain, while another may affect reproduction. Understanding health and environmental impacts of single chemicals is difficult enough. Understanding complex mixtures can take a lifetime -- and plenty of good scientists have devoted their careers to PCBs (they just don't make Science News or the front page these days.)

To date, PCBs are considered all-around toxicants at least in laboratory studies (and by association, in epidemiological studies on highly exposed human populations) affecting reproduction, neurological development, immune response and reproduction and are considered a probable human carcinogen by the USEPA. In the environment in addition to impacting other species, they are credited with wiping out mink populations that once lived along contaminated rivers. Mink for example, are exquisitely sensitive to the reproductive impacts of certain kinds of PCBs.

But before there is widespread panic, there are questions that must be answered, including 1) concentrations of PCBs in caulking 2) amounts of PCBs released from contaminated caulking 3) how might one be exposed to PCBs from caulking, 4) and potential exposures of teachers and students exposed PCBs released from caulking? (According to the Globe this is the topic of an ongoing study.)

Now that PCBs are back on the front page, maybe the next time I ask students about these important legacies, they won’t be so puzzled.

UPDATE: EPA recently issued a press release (on Sept 25 2009) along with the following website for those concerned about PCBs in caulk: http://www.epa.gov/pcbsincaulk/

Back to school with less plastic

2009-08-24T05:35:00.000-07:00

For those interested in the LA Times op-ed Back to School with Less Plastic -- a teaching moment, I've posted a slightly longer version of the editorial below, along with a few links to reports associated with the editorial. For those of you seeking to reduce plastics from school and office, there is also a sampling of sites offering alternative school and office supplies.

My thirteen year-old daughter and I have just returned from the annual back-to-school pilgrimage to the local Big Box Office Store and I am appalled. While for me the leathery smell of new shoes stirs sweet pangs marking those precious last days of summer -- for my children it will most likely be the smell of vinyl and assorted plastics that will remind them of those bitter-sweet end-of-summer days.

As a child of the ‘60s, back when plastics had yet to touch every aspect of our lives, my pencils and rulers were wooden, my binder cardboard and fabric, my book bag canvas, and back-to-school shopping wasn’t a major industry – let alone a “season.”
As a toxicologist who's spent much of the past year studying the world’s overabundance of plastics and their associated toxicities and a consumer who carries cloth bags, avoids over packaged lunch items, much to my kid’s dismay, and diligently recycles -- though admittedly I am not a purist when it comes to plastic-- this year’s shopping trip has left me feeling particularly hypocritical. We entered Big Box armed with “the List.” Parents of school-age kids, know to expect this list sometime in July, the kickoff for the “season.” We left Big Box with an armful of poly vinyl chloride (PVC), polystyrene, polypropylene, polyethylene – all neatly packaged in yet more polystyrene and PVC. We passed on the plastic bag at the checkout counter. At least we could do that much. Never mind that the store's bags were among the few easily recyclable or reusable plastic products available.
The hundreds of brightly colored disposable plastic pens sold by Big Box certainly are not recyclable. Not only are the plastics often mixed (polystyrene, thermoplastic elastomer and polycarbonate, for example) but without a sufficient market for the materials recycling is not feasible. By some estimates hundreds of millions if not billions of disposable pens are bought in the U.S. each year. Once disposed or lost, bits of those pens will eventually add to the earth’s expanding “plastic layer,” a marker of our twentieth century penchant for the disposable rather than reusable.
Then there is the scourge of the 3-ring binder. I’ve got a stack in the corner of my office. Some are reusable. Others not. Their covers and inside pockets are torn, the rings sprung partly open, their cardboard innards peek through the corners and the colors are all wrong. Last year’s binders were orange and yellow. This year according to “the List” binders must be purple, blue, green and red, a different color for each subject. No kidding. While binders in good condition can be reused, eventually, they will join their plastic companions in the waste-pile.
If Big Box Office Store can collect e-waste and printer cartridges, you’d think they could collect and encourage reuse and recycling of school and office supplies. Apparently once all that plastic leaves the door – it’s our problem not theirs. So much for "extended producer responsibility." And with nearly 56 million k-12 students returning to school, all of those new plastic binders, lunch boxes, pens, rulers and pencil sharpeners (which break more easily than an egg shell,) are a big problem.
A problem which, with a little creativity, could be turned into a sobering educational opportunity --just as students now study the water cycle, what if they studied the life-cycle of their pen or better yet, their PVC notebook? What if they learned that the production of PVC may contaminate the air of local neighborhoods with vinyl chloride, a known carcinogen, and may be associated with increased dioxin concentrations in local residents? Or that some portion of the plastics in their school supplies could end up circulating for decades in remote ocean regions? What if they learned that in some locations marine birds have been found with guts full of colorful plastic bits? Or that plastic could even be a good thing if we reused or recycled over and over?
Of course, school supplies are only a drop in the plastic bucket. A small fraction of the over100 billion pounds of plastic resin reportedly produced by US industries. This is 100 billion pounds of substances resistant to degradation. Substances that will, over the years break into smaller and smaller pieces, some of which will release their chemical building blocks and additives like heavy metals and phthalates– several of which are now known to interfere with endocrine function – into the environment. But plastic school supplies for many kids are, in addition to all those lunch baggies and packaging, part of a yearly ritual which teaches kids that our disposable plastic culture is normal and acceptable
Each new mechanical pencil, binder, report cover and lunch box adds to the planet's steadily accumulating plastic burden. According to the EPA, we discarded thirty million tons of plasticin 2007, 12% of our municipal waste. Back in the 1960s less than 1% or our waste was plastic. Of those thirty million, we recycle a paltry 2.1 millon tons. The rest is landfilled, burned in incinerators, washed up onto remote beaches, or is swirling around in the great Trash Gyre of the North Pacific, where scientists from the Scripps Institute of Oceanography are busy sampling little bits of our discarded plastics.
By sending our kids back to school with a backpack that is, if not plastic, filled with plastic, what are we teaching them? Buying new shoes each year made sense – kids grow out of shoes. Buying a whole new set of school supplies which last barely a year under the best of circumstances, does not.
But there’s hope. Just as plastic is a man-made modern miracle of chemical-engineering, cleaning up after the plastic mess could be this century’s modern miracle. For some products, closed loop processing – fully recyclable carpets for example - reduces resource use and waste. For school supplies that can’t be easily recycled, what if kids were challenged (or bribed) to keep their plastic binders, rulers and pencil sharpeners safe and in good shape so they can be reused the next year? For items that fail to last– perhaps a collection box piled high – sent to key politicians or even back to Big Box, who might in turn, send a message to industry. And better yet, what if teachers - creators of “the List” - urged students to seek out recycled, recyclable or plastic-free school supplies?
At the very least, let’s teach them that it’s time to slow the growth of the plastic layer, a worthy goal for the 21^st century.

There are plenty of sites out there to help reduce plastics in school and office too - below is just a sampleing :
The Green Office
Care2 make a difference
Center for Health and Environmental Justice
For binders, try recycling industries near you, some may take back and redistribute binders that are in good condition.
For pens, try the Pen Guy - not exactly recycling but reuse as art!

A lot of information on a little topic: EPA's Nanotitanium Case Study

2009-08-06T11:18:00.000-07:00

Still stuck in the sunscreen limbo? Wondering which to choose - "chemical" filters or "natural" filters like nanotitanium? While we know chemical filters tend to be absorbed into the skin, should we be concerned about absorption of nanotitanium as well? Or perhaps you're wondering when anyone is going to get around to really thinking about how best to evalute risks of nanomaterials? Well here's your chance to read all about it - at least all about the life and times of nanotitanium in one relatively complete report.

EPA has just releasee their Nanomaterials Case Studies: Nanoscale Titanium Dioxide in Water Treatment and in Topical Sunscreen DRAFT. I haven't read the section on water treatment, but this past winter I was involved in the review of the section on sunscreen - sure to be a hot topic even as summer is sadly winding down. While the report won't help you choose which sunscreen to use, it provides a fairly comprehensive review of nanotitanium.

The document, according to EPA is, "...a starting point to to identify what is known and, more importantly, what needs to be known about selected nanomaterial applications."

And, as they tackle the moving target (in the sense that research and publications just keep rolling in) that is nano from production to product, birth to afterlife they invite readers to:

....consider the questions listed throughout the document and offer specific comments on how individual questions, or research needs, might be more precisely or accurately articulated. If additional questions should be included or if information is already available to address some of the questions posed here, readers are encouraged to provide such comments as well. These or other comments on any aspect of the document should be submitted in writing in accordance with instructions, including the specified time period, stated in a Federal Register notice appearing on or about July 31, 2009 referring to Docket ID No. EPA-HQ-ORD 2009-0495.

So have at it. It'll be interesting to follow the further development of this report.

Woodsmoke: a dose of our own, in my backyard

2009-07-28T12:02:00.000-07:00

Updated: February 2010

"Do you have a woodstove," the doctor asks as I sit, barelegged in my too-small hospital gown, and give the respirometer a feeble puff. It’s my second try and I beg for one more, surely I can do better.

“Woodstove? Yes - but it’s one of those new ones,” I answer defensively, “you know, with a catalytic converter.”

Not one of those smoke belching dinosaurs, I’d like to add, the kind that blackens the cobwebs and sends clouds of smoke throughout the neighborhood as did the one in our old rental.

But I’m in denial. I ought to know better. Burning wood is dirty, pure and simple. No matter how hot the stove, no matter the catalytic converter devoted to reducing our share of wood smoke.

Chemically wood is about fifty percent carbon and forty-five percent oxygen, some hydrogen (around 6%) with a dash of nitrogen and assorted elements such as calcium, potassium and magnesium. That means that a cord of maple wood, roughly the amount we burn each winter, which weighs around 4,000 pounds, depending on how dry it is, contains roughly 4,000 pounds of carbon, oxygen and hydrogen. But, once we stuff the old pizza boxes, the Sunday Times, a little kindling from my husband’s workshop and add a few matches all that is neatly bound up in those logs up will be transformed into heat, light, gas and particles large and small. Some of those particles will end up in the ash pile at the bottom of our stove, and some, along with a mixture of hot gases will flow up the chimney and into the air. Technically, our little stove should release no more than 4 grams of particulates into the air per hour – a tenth of what stoves used to emit before the EPA stepped in. But is that good enough?

Even though we’re talking as little as four grams an hour (and upwards of 30 grams over a day), it is primarily those small particles which concern my doctor. As our wood burns, no matter how efficient or tight our stove, particulates and gases will leak out – if not into our home then up and out our chimney into the neighborhood, mingling with all of our neighbor’s wood gases and aromatic (in more ways than one) wood smoke.

The lovely smoky aroma that comes with wood burning not only indicates the return of crisp fall weather – but the slew of airborne chemicals from carcinogenic polyaromatics to volatile organic carbons (VOCs) to gases like carbon dioxide (the major gas), carbon monoxide and methane – and minerals like potassium, wafting around our "fresh country air." (I say this with some irony as our semi-rural valley sees its share of air pollutants hailing from NYC. And, depending on the weather, can have some of the worst air in the state, particularly in the summer.)

There are also very small bits of carbon in our wood smoke, known as particulate organic carbon, which make up in large part the particulate material or PM, released when wood is burned.

As with any science, the science of air pollutants like wood smoke evolves over time. What’s known to be released into the air when wood burns, and how much, is refined as technology allows scientists to measure increasingly smaller amounts and sizes of pollutants, as are the dangers of exposure to such pollutants.

The old adage you can’t condemn what you can’t measure (or something like that) often accounts for the all too common phenomenon of the dropping baseline in toxicology. The baseline being what was once considered “safe” or acceptable concentrations of exposure. Think lead, mercury, and radioactive chemicals like strontium and plutonium. All chemicals once treated more cavalierly, back in the day, than they are now. And all chemicals for which “allowable” concentrations have continued to decline over the decades.

When EPA first regulated particulates in 1987, they focused on PM₁₀, or particulates 10 microns and smaller. Subsequent studies suggested that the much smaller particles were likely more dangerous, leading EPA to regulate PM_2.5, (particulates that are 2.5 microns) nearly 10 years later in 1997. Flash forward nearly another ten years, and further concerns about these small particulates, caused EPA to reduce the acceptable amount of PM_2.5 exposures in a 24 hour period by almost half. And, as technology provides scientists with the tools to study smaller and smaller particles, the studies that led to reductions in PM_2.5 are being supplanted by studies revealing the toxicological importance of smaller and smaller particles. Some studies suggest that the majority or peak size of particulates released by wood smoke range from 0.15 to 0.4 microns – a few hundred nanometers in size.

Not only are researchers figuring out that bigger is sometimes better (much like FOX television which offered up a new Plus-sized reality show “More to Love,”) they’re also realizing that mass or weight isn’t everything.

The current U.S. EPA standard for PM_2.5 considers only the combined mass, essentially the combined weight, of these little particles. Not the chemical composition nor the number of particles, nor the relative size of the particles. As scientists well know by now (or ought to) when it comes to very little things – like chemicals in the nanometer range (which include some of these particulates) – size does matter.

Typically the smaller things get the more surface area they have. Think about peeling a pound of granny smith apples, and a pound of crab apples. Which would you rather peel? More apple skin, more surface area on those little crab apples. Same with particulates. As these little particulates get smaller, they reveal more surface area. Same amount of mass but more area to react with a body’s cellular surfaces. Typically, the more reactive a particle, the more toxic it tends to be.

In fact, scientists are now linking the smallest of the small particulates, the ultrafine particles (particles smaller 100 nanometers in size) which comprise the smaller end of PM_2.5 with a range of adverse health effects including asthma, chromosomal damage and cardiovascular effects linked to inhalation of particulate matter.

Using the woodstove is one of those lifestyle choices we make every day. As I swear up and down that my asthma tends to worsen with the leaf-mold season rather than wood smoke (although admittedly the two coincide - so who's to say) we rationalize that for each cord of the old maple that fell into our yard years ago, we avoid burning the imported fuel oil sitting below in our basement tank. Besides, we’re only burning a cord or two a year – and although could same can be said for our neighbors on either side, down the street and around the block, at least we’re not burning five hundred thousand tons of wood as proposed by Pioneer “Renewable” Energy....right? But that’s a story for another day.

For a good review of several recent studies on ultrafine particles check out Janet Raloff’s “Bad Breath.”

If you’d prefer primary literature, you can read all about it in Environmental Health Perspectives:

Gent et al., Symptoms and Medication Use in Children wtih Asthma and Traffic-related Sources of Fine Particle Pollution

Delfino et al., Air Pollution Exposures and Circulating Biomarkers of Effect in a Susceptible Population: Clues to Potential Causal Component Mixtures and Mechanisms

Get your BPA FREE with each new bottle!

2009-05-26T08:05:00.000-07:00

Roughly a year ago one of the first studies showing that BPA, the known estrognic plastic used to make polycarbonate bottles, leached into liquids under extreme conditions of heating and rigorous washing was published to much fanfare. The study raised a serious issue, although it seemed that unless you were routinely heating your liquids in a well washed bottle (huh? wash my water bottle? In the dishwater?) – a problem clearly relevant to new parents, but not so to folks like me who were done reproducing – ridding the household of all polycarbonate wasn’t a high priority. While I did replace the kid's bottles with the now suspect PET bottles (more on that one later) the old polycarbs still went to the tennis courts and up Mount Toby with me. I just couldn’t justify adding more plastic so the recycle or waste cycle so as long as I had it, I used it. Same with the gem-colored polycarb juice glasses we’ve used for years.

Well, as usual with chemicals we’re just getting to know more intimately than we’d like, there's always one more study that makes us wonder if "we've" really done our best when it comes to using chemicals wisely. This time it's a new study published in Environmental Health Perspectives by researchers at the Harvard School of Public Health which reports that BPA molecules really don’t need all that much coaxing to be released from bottle to water. In fact, just regular use, filling them up with cold liquids and drinking was enough to raise concentrations of BPA in the urine of polycarb bottle using Harvard students.

After one week of drinking all their cold beverages from Nalgene Lexan bottles (could you fill this bottle rather than that beer stein please?), and peeing into a cup during the designated hours of 5-8PM, students increased their pre-polycarb urine concentrations by 69%. In other words – you get a little BPA with your water even if you don’t heat it up and abuse the bottle.

Given that the very young (newborns and infants) tend to retain their BPA a bit longer (because their metabolic system which clears chemicals like BPA is less active than adults) this study, one of the first to show that normal use of polycarb means exposure to BPA, should give pause to any parent still using the old polycarb baby bottles. It’s certainly enough to push me to take those pretty gem-colored juice glasses and relegate them to the craft cabinet.

A Very Disney Earth Day 2009

2009-05-14T12:43:00.000-07:00

It took some digging, but the “Disney World Envirodisaster” article is now being replaced by a more circumspect, “They May be Behind the Times, but Maybe They’ve got Good Intentions,” article.The one week Disney Extravaganza organized by my daughter’s dance school (about 70 young dancers with parents in tow) which is what landed me in Disney, was, and was not, exactly what I’d expected.

The dancing plastic fairies, plastic pirates, plastic Mickey, plastic plastic at every turn, artificial ponds, and fried food mixed in with messages of conservation and recycling was expected – that I actually enjoyed myself as Disney was a pleasant surprise. The messages of conservation (in the “Circle of Life” Simba stops Timon and Pumba from laying waste to the land to build their vacation resort) by the organization whose originator “secretly bought up thousands of acres in Florida” to build a vacation resort (a boast you can hear on your Hollywood Studios back-lot tour) not only gave me more whiplash then the Test Track ride, but also left me wondering if this wasn’t the very definition of hypocrisy. Yes I know, they’ve devoted much land to conservation, and they did that back in the day, and they do convey the message through their movies. But there’s also plenty of land buried beneath layers of asphalt thanks to Disney and a whole lot of energy and resources devoted to marketing products that are broken or tossed within a few short years (but of course being plastic, will last for many, many more.) Not that hypocrisy is anything new – our political system thrives on it – but these hypocrites are directly addressing our kids. The Kids of America.

How do you explain to your kids, after Pumba and Timon’s parting message: recycle, recycle, recycle , that apparently there is no recycling (or no obvious recycling) in Disney’s Sunshine Season Food Fair located just outside the theater? Thankfully at least we weren’t eating surrounded by a sea of plastic dishes, plates and boxes, but rather paper plates – chalk one up for Disney. I guess they didn’t want to add to the billions of pounds of plastics released into the oceans each year – although I’m not sure what they plan to do with all the plastic utensils.

OK so I’m a skeptic. Hailing from Massachusetts’ Happy Valley, where small organic farm stands dot the road-side, solar panels gleam from yards and rooftops and where you can mix up your “leaf green” Prius with the five others in the parking lot – Disney is, indeed, another world. “You just have to let your brain float,” says one mom, as we sip acid coffee from styrofoam cups in a fish and chips joint in the even more befuddling and depressing Downtown Disney awaiting our children’s “Disney Performance of a Lifetime.” Maybe it’s a small price to pay to watch them smile, sing and hoof their way through a twenty minute routine they’d been rehearsing since September.

After a week of scribbling notes, while admittedly enjoying the parks (Animal Kingdom was my favorite – and yes I do reluctantly consider myself a hypocrite) I vow to look up Disney’s enviro record upon returning home. Something I look forward to after a week of Disney food, which my daughter observed, no matter what we got always seem to come out to be $16 per person. Pricey, but on a per calorie basis it’s quite a deal - the “single serving” chocolate cake is 200 calories “per serving,” and each little single foil serving dish provides 3 servings. Gobbling down my cake, I wouldn’t have noticed that little caveat had my friend Kata not pointed it out. So, upon returning home and doing a little digging, I was surprised to read about Disney’s commitment to “providing healthier options for families that seek them.” Either I wasn’t seeking hard enough or that must refer to the small packets of carrot sticks you can get with your chicken fingers and chocolate cake. Hooray.

Reviewing their Corporate Responsibility Report with a hefty dose of skepticism (rather than simply dismissing Disney based on experience) took some effort, not because there’s much content or detail but, because after going to the parks it’d be easy to write them off. They have grand plans and apparently they’re just getting started according to their 2007 “Enviroport”:

Last year, Disney President and Chief Executive Officer Robert A. Iger appointed an Environmental Council of senior executives from across the Company. The Council is putting into place a comprehensive plan to analyze and implement sustainable long-term strategies for minimizing Disney's impact on the environment within an ambitious corporate growth strategy. The Council includes members from a wide variety of academic and professional backgrounds, including biologists, chemists, engineers, and government affairs specialists. Together, they are taking a measured approach to the complex and important set of tasks at hand, frequently seeking expert external advice as part of the policy-making process.

Like I said, you wouldn’t know it to visit the parks except maybe the part about corporate growth. If they’re conserving water in the parks why don’t they tell that to visitors? If they’re conserving electricity with LEDs, why don’t they let folks know? It’s almost as if they want to make sure they’re not seen as environmental educators, because after all, girls, like Jasmine, Cinderella and Snow White just want to have fun.

Although we did finally find recycling bins dotting the streets of Disney World, we wondered if maybe some Disney robotic squirrels were out back separating Sunshine Season’s trash. Maybe they were. Seeking information on Disney’s recycling programs I couldn’t’ find much, except a comment on another blog who also wondered about recycling at Disney:

Comment by Joe Shelby

2007-07-27 12:12:47

On the backstage tour, while showing us the VACKS (sp?) vacuum based trash system (also discussed in the Modern Marvels documentary - the main outlet site is backstage @ frontierland behind Splash Mountain, where it’s intentionally downwind, and downhill, of the park), our tour guide discussed how the trash is sorted, by hand (well, with tools to avoid touching it) for recycling and biodegradable materials as it’s brought into the landfill a mile away. They don’t bother with separate recycling bins because they’re often ignored, create an eyesore (and a violation of theme) in certain parts of the park, especially Main Street, and get filled with trash anyways by foreign tourists and ignorant bafoons who don’t know or don’t care what the recycling symbol means.

But they do recycle. Otherwise, he said, their landfill a mile away would have been filled up years ago.”

Interesting, but pathetic. Even more pathetic was Disney’s tribute to Earth Day when we happened to be stationed at the Magic Kingdom. A few hours set aside for Jimminy Cricket photo-ops, and a kiosk that could have been more effective had it been designed by a bunch of school kids rather than Disney’s Imagineers. Notably, and obviously there was a plug for their movie Earth and I suppose their offer to plant a tree for each ticket purchased during the first week is part of their green growth strategy. I just wish they were a bit more “out” about their enviro-plans at the parks where over twenty million people – that’s a heck of a lot of impressionable kids - visit a year. If anyone can teach the “kids of America” to respect their environment, reduce, recycle and reuse, Mickey, Jasmine and Prince Charming ought to be up to the task. Maybe then some Disney disciple might go home and say hmmm, how about we ditch the plastic, turn off the lights and reused the water, just like Mickey does?

Chemicals we love to hate, Body Toxic book review

2009-04-27T08:43:00.000-07:00

A while back I was invited by American Scientist to write my first ever book review. After having just edited a book that was reviewed (mostly favorably), I was nervous. What if I didn't like it? When reading books about toxics, especially books written by non-toxicologists, my sci-dar is on full blast. Most authors seem to have an agenda whether it's chemicals=bad, or the opposite (although those tend to be written by scientists.) Over the years, I've encountered a few written by toxicologists who seem to have forgotten the "oath" of objectivity, or rather, taken the "better living through chemicals" oath. Although those books are great for teaching (so... who checked out the author's affiliation, the funding source or the publisher?), and readers tend to be self-selecting.

Controversy sells. Wishy washy, we don't fully understand doesn't. It's a problem.

So with some trepidation that my first (and possibly only) book review might be negative, I cracked open Body Toxic, written by journalist Nena Baker. What follows is the uncut version of the review recently published in AmSci:

Teaching toxicology to college seniors and juniors was never easier than this past year. Each week students easily and eagerly fulfilled their “current events” assignment with links and clippings of articles revealing widespread contamination of wildlife or humans, with PFOA and PFOS, PBDEs, PBBs, phthalates, BPA, and atrazine. No longer did I have to rely on stories from the “old days” of legacy contaminants like PCBs, DDT and dioxins - not when there all these great so-called “emerging contaminants.”

Although these chemicals have been around for decades they’ve “emerged” into our collective consciousness thanks to much improved chemical detection methodologies and technologies. As chemists extracted and detected smaller concentrations of chemicals from smaller and smaller tissue and urine samples, chemicals like PCBs, and dioxins were detected not only in parts-per-million or parts-per-billion, and but also parts-per-trillion. Many of those emerging chemicals were there, we just didn’t know it. But it wasn’t simply the improved chemistry that helped raised awareness. As analytic methodology improved, many, including toxicologists were stumped by the “so what?” question. So what does it mean when a fish is contaminated with parts-per-trillion concentrations of dioxin?

Now with improvements and some maturation of toxicological testing, toxicologists are now able to evaluate the subtle effects of smaller and often more environmentally relevant concentrations of potentially toxic chemicals.More importantly over the past couple of decades, toxicologists have expanded the definition of “adverse effect” to include impacts on subtle reproductive and developmental processes which may respond to very small concentrations of foreign chemicals.

The outcome of all this new and improved sensitivity? A greater awareness of all the new and improved products that are in all of us, thanks in part to the Center for Disease Control’s (CDC) 2003 National Report on Human Exposure to Environmental Chemicals. And this is where Nena Baker begins The Body Toxic.

Back then, CDC reported concentrations of 250 chemicals including stain repellents, flame retardants and phthalates along with the old standbys, including mercury lead, and DDT in human blood and urine (data from their subsequent analysis will be released this year.)The report piqued Baker’s interest to the extent that she eventually dropped her day job as a journalist to chase down the answers to three basic questions that we all ought to be asking: 1) Should we be worried about the effects of these pollutants on our health? 2) Can everyday items be responsible for the chemicals inside of us? 3) Don’t regulators already make sure we’re safe from daily doses of hazardous chemicals?

We’ll save the first question for last. The answer to the second question, as everyone knows by now, is a resounding yes, of course. We are all contaminated by bits of everyday items from our kitchens, living rooms, bedrooms, offices, even our hospitals.Is this a surprise? Well, yes and no.We know from the history of fat-loving chemicals like the organochlorines (many now banned nationally and internationally) that we can indeed be “incidentally” exposed to environmental contaminants. No one ever purposefully ingested PCBs (at least not that I know of,) yet we’ve all got them in us. And, more importantly, no was ever asked if they minded being exposed to PCBs, DDT, dioxin or any other of these chemicals. It simply wasn’t and unfortunately still isn’t, a choice.But hey, that was back in the day, before Silent Spring and before the birth of the Environmental Protection Agency, when those chemicals were freely released as pesticides or into the environment both legally and illegally.

To address Baker’s third question, no one can deny that over the past 30 years chemical releases into the environment, food, and water have been greatly reduced thanks to expanded federal regulation. But, as Baker reveals in both the Introduction and in her first chapter, A Chemical Stew, what we are dealing with now is more insidious.These chemicals have flown “under the radar” and into our bodies.Some like bisphenol A were never expected to be released from their chemical matrix or become “available”, others including PFOA and PFOS were thought to break down more rapidly than they did, and still others like certain phthalates managed to be absorbed, apparently unexpectedly, into the body. These are chemicals that many of us never thought would end up circulating our bodies, or worse, those of our children. The second chapter, Chemicals We’ve Loved, explores how we got here from there beginning with the post World War II chemical frenzy, and ending with the myriad of chemicals currently registered by the EPA. In the best of all worlds the book would end here. If they’re registered, then surely EPA must have adequate information to protect the public from exposure to toxic concentrations?

Au contraire. As Baker writes, “under our regulatory structure, ignorance is rewarded: manufacturers have no obligation to test for the safety of substances they sell. [p51]. And we, the public, are ill-informed as to whatever chemicals we may ingest, absorb or inhale. The regulatory structure to which Baker refers is EPA’s Toxic Substances Control Act of 1976. When first enacted, TSCA was a big deal. Writes Mark Schapiro in his book Exposed: the toxic chemistry of Everyday Products and What’s at Stake for American Power, “TSCA was the first effort by any government to assert some level of oversight over the vast amount of chemicals that had been introduced into the marketplace since the end of World War II. With TSCA, the EPA was a world leader in chemical regulation.” [p 132.]

It was a hopeful time. It was a hopeful time. According to an October 1976 EPA press release, EPA’s Administrator Russell E. Train, declared TSCA to be "one of the most important pieces of 'preventive medicine' legislation…..its basic aim is to give public health far more of the weight that it deserves in the decisions by which chemicals are commercially made and marketed, by which they enter and spread throughout the human environment."

Sadly, 30 years later as Baker writes, TSCA is “notoriously weak and ineffectual” [p.7]. A conclusion shared by many others including the General Accountability Office, which concluded according to Baker, that “the EPA has given up trying to regulate chemicals and instead relies upon the chemical industry to act voluntarily when problems arise.” [p.16]

One notorious example of the naivety of such a voluntary program was when DuPont apparently forgot to report that not only was PFOA persistent, but also possibly toxic to humans and wildlife. Subsequently in 2005, DuPont paid over $10 million in fines and EPA initiated a voluntary phase-out of the chemical by 2015 (a program in which DuPont along with several other manufacturers, is a participant.)

And, although not discussed by Baker (perhaps because there isn’t enough to discuss just yet,) is the fate of nanomaterials under TSCA. Nanomaterials encompass a broad category of chemicals with one thing in common they’re small. Really small. One of the advantages of certain nanomaterials is that they act differently than their larger chemical counterparts. But this very quality concerns some toxicologists who fear that nanoized chemicals may be different enough that they may behave differently in traditional toxicology tests. Yet under TSCA, nano-formulations of existing chemicals will not require new registration (or registration as a new chemical). Further, EPA is asking for voluntary submission of health and toxicity data, by manufacturers and users of nanomatierals. At this point, feel free to ask, “when will we learn?”

What went wrong with TSCA and other federal regulations and the consequences of regulatory “misses,” make up the bulk of The Body Toxic’s chapters beginning with the pesticide Atrazine, followed by chapters on phthalates, polybrominated biphenyls, bisphenol A, PFOA and PFOS. And Baker presents a thorough case study of each through a combination of primary literature, anecdotes, interviews, and popular news articles, all cited in the Notes section. As I am often leery of books on toxics, having perused a few too many alarmist articles and books I was pleasantly surprised to find that, beyond Baker’s Introduction where at times words like “ghastly” and images of bathroom shelves “brimming with chemical-laden personal care products” (of course they’re chemical laden – what isn’t?!), the bulk of her writing kept to the science and the policy.

Returning to Baker’s first question, what does it mean to be exposed to all these toxicants at low concentrations, she doesn’t take the easy route and proclaim they’re the route of all evil. “While biomonitoring studies provide a much more accurate picture of our chemical body burden,” she writes, “limitations remain. The studies don’t tell researchers the source of an exposure, how long a substance has been in the body or, most important, what effects, if any a substance is having on human health.” [p.23] She continues with quote from Linda Birmbaum, then director of experimental toxicology at EPA, who acknowledged that “We really need more research to understand whether the levels we’re finding could be associated with adverse health effects.” [p.23] Fortunately Birnbaum, now director of the National Institute of Environmental Health Sciences, should be in a good position to do just that.

The final chapter Reaching Ahead is devoted to the European Union’s new approach to toxics, REACH. The approach is essentially a mirror image of TSCA. Where TSCA requires the EPA to demonstrate that a chemical is a risk to human or environmental health, REACH requires that the manufacturers test and ensure that chemicals do not pose a risk. Where the US was once a leader in chemical control, we can only hope it will become at the very least a follower.

Overall, The Body Toxic makes for informative reading that is not too technical- a plus in this case. Although I would have liked to some synthesis, (for example a discussion of all contaminants discussed which share a common target,) by providing some insight into the complexities of regulation and the workings of scientists Baker’s book opens many avenues for discussion. It’s a good book for a “non-majors” introduction to toxicology.

[1] [EPA press release - October 21, 1976] http://www.epa.gov/history/topics/tsca/03.htm

We do have a choice: VOC in paint

2009-03-11T12:00:00.000-07:00

Our white wall to wall bookcases, blackened from over a decade of “dog” rubbing against the corners, kids whose little shoes marred the window seat, and woodstove particles that had settled into the cracks and crevices, were looking dingy. They’d become a shade of off-white no paint store would dare market, and were in need of some attention.

A good scrubbing helped. But there’s nothing like a new coat of paint to brighten things up, especially after a long winter. With my hired hand in tow (whose little shoes are now size 11) we trudged into Dakor Center and plunked down a can of old paint.

Filler up with the same, I requested. But no such luck. Apparently Deerfield Academy just cleaned Dakor out of the Benjamin Moore Regal I’d used before. But, suggested Richard from behind the counter, I might try the Benjamin Moore Eco-spec™, the virtually no (or very low) VOC paint they use over at the Franklin Medical Center.

VOC means volatile organic compounds, a family of chemicals that paint companies have been trying to phase out or reduce for years – with a little push from state and federal environmental regulations.

The term VOC encompasses a broad category of chemicals with at least two things in common: they are easily volatilized and many are not soluble in water. VOCs are everywhere, from the chlorinated cleaning fluids of olden days which now contaminate drinking water around the country to the ingredients of the Purell Hand Sanitizer that kills 99.99% germs. They are also released from home furnishings, household cleaning products, air fresheners and cigarette smoke. VOCs are produced when coal and oil are burned, when chlorine combines with organic material in water resulting in chloroform, and when cows fart. Recall the flap about cow farts and global warming? That was methane, a VOC. You know that “fresh-cut” grass smell? That’s the VOCs released when the blades are damaged, though they pale in comparison to all the VOCs released by the very act of mowing the lawn (unless of course, you’re using a push mower, then it’s just your own gas that counts.)

Outdoors, VOCs contribute to the formation ground-level ozone or smog, when they combine with other air pollutants like the nitrogen oxides released by burning fossil fuel. The EPA estimates that the nearly 600 million gallons of latex paint (which contains far less VOC than some other paints) sold each year in the US, accounts for nearly 120 million pounds of VOCs released to the atmosphere. Indoors, VOCs can occur at concentrations as much as five-times higher than outdoors, and as much as 1000-times higher after stripping paint.

Some of the worst VOCs are really nasty, causing a range of effects from liver and neurological damage to cancer - though some of the worst offenders are no longer used in consumer products or are present only in very small concentrations. But that doesn’t mean that indoor or home exposure to VOC is harmless. Particularly for those who are sensitive to certain chemicals, who have asthma, or are very old or very young.

Knowing all of this, and as low toxic as I try to be, I wasn’t sure I wanted to pony up more cash for the low VOC paint, the Benjamin Moore Regal was pricy enough. Sensing my hesitation, I was quickly informed that the two paints cost the same.
I could have kicked myself right then and there. How long had this stuff been around, I asked? Since 1999.

Ah, but was it really any better in terms of indoor air pollution than regular latex? Hadn’t latex gotten much safer over the years anyway? The answer to that question took some digging.

“Ingredients that are in conventional latex paints that are not in our Zero VOC paints would be, ammonia and coalescing agents, biocides that are formaldehyde releasers such as Nuosept 95, propylene or ethylene glycol, mineral spirits such as Isopar L, and pigments that contain any free crystalline silica,” emailed Mark Lamborn from Benjamin Moore, when I’d asked about the difference between semi-gloss latex and Eco-Spec.

What did all that mean? Aside from the biocides, which are highly toxic and release formaldehyde, but tend to be used in relatively small amounts – and no-VOC paint still has biocides - the other major difference is the VOC Isopar L, (other paint companies may use something called Texanol.) As listed, the VOC for Regal latex paints ranges from 50-149 grams per liter of paint. Roughly, that’s a bit less than a cup for the lower end, to two cups of VOC for the higher end, per gallon. When painted on gypsum board or drywall, according to an EPA study, those VOCs will volatilize slowly over a period of 3 years.

Mark also explained that the “recently reformulated Waterborne version of Eco Spec (WB) are formulated with raw materials that do not volatize during the drying/curing process. Any trace amounts of VOC [Eco-Spec still has 0.96 gram per liter of VOC] stay within the paint film.” Which, I suppose is why it can be sold as no VOC.
So, no-VOC paint, verses a few cups volatilizing over a few years? Although we’ve got plenty of other indoor pollutants circulating around our home (particularly after a good burrito dinner) why add more in a home where the asthma inhaler often makes the rounds. I went with the low-VOC paint and so far, have been pleased with the results.

A few considerations if you’re in the market for paint:
•There are now many different brands of low or no VOC paint – some rated better in terms of coverage and durability than others, so shop around.

•Watch out for tints. Tints tend to have high VOC so if you’re looking for little or no VOC ask about the type of tints. Some companies now produce Zero VOC tints.

•I focused on latex paint, which uses very little VOC containing solvent, it’s noteworthy that paints for tougher situations (the alkyd paints) can contain upwards of 400grams/L of VOC, now we’re talking VOC. That’s over four cups and, it’s worth noting much of that is released from a painted wall within the first ten hours after application.

Get Your Peanuts Here....or not

2009-02-04T05:47:00.000-08:00

First published in the Montague Reporter, Montague, MA

Lately, I’ve been craving peanut butter. Maybe it’s because my husband finished off the jar a week or so ago, and didn’t put it on the list (grrrr,) or maybe it’s because I can’t pick up a newspaper without reading about the great peanut butter recall. Although you’d think that hearing it linked with Salmonella as it so often is these days would be enough to scare me away, who’s to reason with a craving?

Plunking a jar of Teddy All Natural peanut butter onto the check-out belt at Stop & Shop, I felt a little sheepish. Was anyone wondering if I’d been in a news blackout for the past few weeks? Who in their right mind would be buying peanut butter when peanut products are the stars of the Federal Food and Drug Administration’s (FDA) largest food recall ever? Certainly not Robert Humphrey, the retired insurance executive from Georgia, who according to the Atlanta-Journal Constitution has given up all peanut products (normally a mainstay of his diet.) And Humphrey isn’t alone. In Houston schools pulled all peanutty products from vending machines and menus, as did school districts in Michigan, Connecticut and California among others. While I couldn’t find any evidence of Baystate districts jumping on the ban-wagon, according to Jim Loynd, Food Service Director for Gill-Montague district, “All of our elementary schools are peanut free. At the middle school and high school building we’ve checked to make sure we don’t have products affected by recall. The only peanut butter products we have are from the USDA commodities program,” which, according to their web site did not purchase any recalled peanut butter. Amidst all the furor, the FDA asserts that “major national brands of jarred peanut butter found in grocery stores are not affected by the [Peanut Corporation of America] recall,” though they caution that some “boutique brands” of peanut butter may be subject to recall.

Salmonella typhimurium isn’t a bug to be trifled with. The Centers for Disease Control and Prevention have reported over five hundred cases of illness from 43 states since September, with a 22% hospitalization rate. Eight deaths have tentatively been linked to the outbreak. Like most bacteria that live or infect our guts, Salmonella typhimurium, are facultative anaerobic bacteria. That means that they grow and thrive with or without oxygen. They’re versatile, unlike one of my favorites, Clostridium botulinum, a strict anaerobe for which oxygen is toxic. When present in an airtight can, for example, Clostridium may produce botulinum toxin, one of the most potent toxins known. Fortunately for us, it not only produces toxin but also gaseous metabolic byproducts – enough to cause bulging lids in canned goods, cluing us in to its deadly presence. Last year at Stop&Shop I picked up a nice toxic can of tuna.

Salmonella infections, caused by ingesting contaminated foods like undercooked chicken, eggs, and more recently tomatoes are the most frequently reported food-related infections in the U.S. While some studies indicate upwards of 1 million little buggers are required for one to experience acute onset of fever and chills, nausea and vomiting, abdominal cramping, and diarrhea, some outbreaks may be caused by just a few hundred bugs. This “infectious dose” varies based on a number of factors including age and immunity of the host, and the food matrix. According to the USDA, foods high in fat, (like peanut butter,) may protect the bacteria from harsh conditions in our guts. In this ongoing FDA case, contaminated peanut products have been linked to a single peanut processing plant owned by the Peanut Corporation of America’s (PCA) Blakely, Georgia plant, now the focus of a criminal investigation.

In the largest food recall to date, over 400 items and 31 million pounds of peanut product have been removed from store and institution shelves. The recall ranges from Cliff Bars and Luna bars that contain peanut butter to Trader Ming's (AKA Trader Joe’s) Spicy Kung Pao Chicken, Big Y Sundae Cones and Famous Amos Soft Batch Peanut Butter cookies. But so far, the only tubs of actual peanut butter recalled is King Nut, a brand distributed only through food services.

Wondering about my Teddy peanut butter, I found the American Peanut Council’s web page which lists links to dozens of company sites whose products have not (yet) been recalled, including the Leavitt Corporation of Everett, MA, who produces Teddy brand. Teddy, they say, is clean. According to Leavitt’s site, they’ve never used PCA products, and don’t use peanut products from outside the company. While Teddy was clean, cruising the FDA recall site I found reason to pitch the Keebler Toast & Peanut Butter Sandwich Crackers that had been sitting in the pantry since last spring.

If you’ve got peanut products in your house, I’d suggest taking a gander at the FDA site. Of course if you’re in doubt you’d do best to throw it out, especially when President Obama has just promised a complete review of FDA itself.

Oh, and just in case you’re wondering, it’s been a week since we got the Teddy, and so far so good.

Musings of an obsolete toxicologist: nanotoxicology is a whole new world

2009-01-16T09:47:00.001-08:00

This morning while walking across town to the Lady Killigrew , a small hipster café located just around the corner from home, I was thinking about a report I’d just begun to draft. The focus was how to evaluate the toxicity of nanoparticles. I was wondering if I’d been too strong in my dismal assessment of toxicology and had hoped that a good slap of cold air (the thermometer outside our kitchen window read -25C) would weed out the dramatic, and clarify the reality.

I’ve pasted some key points below, and while the topic and eventual report are confidential – there’s nothing confidential about the sentiment – I, and many others have been writing about it for a while:

1) The field of nanotoxicology is in its infancy, yet is ever expanding as newly created nanomaterials require assessment of potential health and environmental impacts. I’ve never before had the experience where I’ve considered research from 2006 as “old,” and where, the majority of literature cited is 2008 and 2009. Yet development of a new field within toxicology provides opportunity, and at the same time demands that toxicologists use both hindsight and foresight as they develop the methodology appropriate for these new materials.

2) Hindsight provides us with a glimpse of toxicology as a field, in large part, focused on application as a science catering to the need for rapid assessment and cost-effective regulation. Standardized toxicity testing methodology was developed and implemented as a result, quickly becoming a rigid set of test procedures, a good deal of which, over the years have become obsolete.

3) In part, because of the difficulties with changing test methodologies associated with a regulatory framework (check out the timeline for reproductive and developmental testing – “in development” for what, at least 10 years?) - standardized toxicity testing, useful for screening out the obvious is insufficient for detecting more subtle adverse effects or revealing the impacts of the complex mixtures of contaminants, drugs and naturally occurring chemicals to which we are all exposed.

4) We have an opportunity to consider the history of toxicology as we move forward. Many have expressed concern that “business as usual” may result in failure to adequately evaluate toxicity of nanomaterials. Oberdorster et al., (2005) representing the International Life Sciences Institute Research Foundation/Risk Science Institute (ILSI/RSI) writes “There is a strong likelihood that biological activity of nanoparticles will depend on physicochemical parameters not routinely considered in toxicity screening studies.” Additionally different physicochemical parameters may also affect behavior of particles in media typically used in preparing for traditional toxicity testing, the ability of researchers to adequately evaluate exposure concentrations, and particle behavior in the body. Problems only occasionally encountered in the past.

5) When it comes to some nanomaterials, such as quantum dots and functionalized particles we’re potentially dealing with multiple organic and inorganic materials that may, or may not, be released over a period of time. How do we assess that?

Well, as I wondered if I was getting a bit too dramatic, after grabbing a cup of decaf and ordering a breadboard with mustard I settled in and checked my emails. Bingo. There in the inbox was a link to Peter Montague’s recent article entitled "Can Chemicals be Regulated?" published in Rachel’s Democracy and Health News. Read it and weep.

Or, read it and be hopeful. I really do think that we’re at the proverbial crossroads. We’ve seen the consequences of becoming too rigid, of constrained linear thinking. But this is a new multitasking interconnected networked “wisdom of the masses” kind of world, not just for me and my Lady K compatriots (the majority of whom – to the dismay of the management - are more attentive to their electronics than to their stomachs) but also for those laboring away in research laboratories around the globe.

Maybe I need another slap of cold air, but if we can embrace this new fluidity in information, knowledge, and thinking, perhaps we can embrace a new way of not only evaluating health and environmental impacts of new chemical products, but a new way of using that information wisely.

This isn't your mother's melamine - or is it?

2008-12-10T11:59:00.000-08:00

Melamine is yet another cool ‘50s invention that failed to enter my mother’s kitchen. While friends and neighbors stocked up on the nifty new light, durable and colorful plastic dishware, my mother filled her kitchen with white, pure white, simple, elegant, breakable ceramic. Her cupboards are still filled with the stuff – white, white, white. Not so at my in-laws, where the everyday dinner ware is red, blue and yellow melamine, pleasingly smooth, tough and virtually unbreakable.

Just a couple of years ago, Crate and Barrel in an effort to appeal to boomers who recall dining off the colorful plastic, offered melamine in colors that harkened back to the fifties and sixties – bright orange, acid green and red (far better on plates than on the cabinets and counters) and, being deprived of the plastic as a child, I pounced, buying a cute set of eight orange, green and red oval-shaped melamine dishes.

This is all to say that until a year or so ago any thoughts I had about melamine were pleasant and nostalgic. Now when I think melamine, I hear the rattle-snake sound of the old westerns, the sound that happens just before something bad is about to happen. Just before the good guy is about to drink the tainted water, or the heroine is about to drink the poisoned wine.

Chemically, melamine is a pleasingly round molecule made up of hydrogen, carbon and nitrogen, and is used in the preparation and production of a range of items including house wares, flame retardants, and fabrics. When combined with formaldehyde and heated up – melamine is transformed into the dinnerware. Which by the way, when heated together with your favorite acidic food, (reheated tomato sauce anyone?) can release upwards of 2.5 milligrams of melamine per 100 cm2 according to the National Toxicology Program, that’s roughly 2.5 mg per one big round plate – but that’s a separate issue.

By itself, melamine’s acute toxicity is comparable with that of table salt (i.e. not very toxic) although recall that toxicity is often a moving target depending on the sensitivity of the endpoint, exposure duration, age of test subject and other considerations. That melamine causes kidney toxicity following longer exposures to high concentrations in test animals (say 2 – 4 parts per thousand in feed,) is well known and until now, not considered highly relevant, because those concentrations were considered unrealistically high. Here I’d emphasize were, but we’ll get back to that later.

What first brought melamine to our attention here in the states, is the toxic transformation that occurs when it combines with cyanuric acid, an FDA approved feed additive, also used to produce dyes, herbicides, antimicrobials and pool water disinfectant. That's when the "watch out" snake start rattling. Cyanuric acid, a derivative of melamine is also a ringed nitrogen containing structure, and like melamine it is considered not acutely toxic. But when these two chemicals get together, like the Witches of Eastwick, the mayhem begins. Following ingestion, the chemicals make their way to the kidney destined for simple excretion. Unfortunately should they meet up, melamine and cyanuric acid join together to forming melamine cyanurate crystals, a toxic combination capable of lodging in kidney tubules and causing acute renal failure and death.

A year ago contaminated pet food from China was implicated in the deaths of dozens of cats and sickened thousands of dogs and cats. The culprit was subsequently traced to melamine tainted gluten. Gluten, derived from wheat or rice, is a common source of protein. Protein is sometimes estimated by measuring gluten nitrogen content. Given the high amount of nitrogen groups in both melamine and cyanuric acid (available as “scrap residue” from the melamine industry) it isn’t hard to imagine unscrupulous processers adding the stuff to their products to dupe purchasers or regulators into thinking they were selling a higher protein product.
After the massive recall of over 150 brands of pet food one would think that the incident alone would deter anyone from trying the same thing again, at least anyone with a conscience. But sadly, like the string of corrupt Illinois politicians, there’s always someone next in line no matter the consequences.

This past fall over 50,000 infants became ill, and at least four died of kidney failure after drinking melamine laced formula in China. The scandal soon spread beyond formula to candy, milk, and other diary containing products produced by dozens of companies. To date, only melamine has been implicated – leaving scientists to wonder about the mechanism of toxicity – recall with the pet foods melamine was mixed with its evil twin, cyanuric acid.

According to the World Health Organization upwards of 6196.61 mg/kg have been measured in dairy products including infant formula. That’s 6 grams in one kilogram of product, or, 6 parts-per-thousand. While that may be the high end, recall the sub-acute toxicity tests mentioned above and those screamingly high concentrations now seem more relevant. Additionally, chemicals are most often tested in weaned animals – not nursing animals – so concentrations that might be OK for adults may not be OK for the very young.

The Sanlu Group one of China’s major diary and infant formula producers whose products were fist shown to contain the chemical quickly blamed the dairy farmers – suggesting that they were the ones who added melamine to fool protein tests.
More recently, according a news article in the journal Science, investigators concluded that the adulterated infant formula was “nothing short of a whole-sale re-engineering of milk,” a skill likely out of reach for dairy farmers, but perhaps not for milk-collecting companies or corporations higher up the milk-chain.

China’s response to the tragedy, according to Science, is to pledge greater transparency and vigilance. In addition, China plans to open Food and Drug Administration offices here in the U.S. and the US FDA recently opened three offices in China. But old habits die hard and according to Chen Junshi a risk assessment specialist at China’s Center for Disease Control and Prevention, and quoted in Science, it’s likely that food adulterers will only become cleverer. Those willing to make money at the expense of their fellow citizens, will seek alternative methods challenging both Chinese agencies and the newly opened US Food and Drug Administration offices in China.

Now, about those colorful plates...

Wrapped in Plastic

2008-11-04T07:50:00.000-08:00

First Printed in the Montague Reporter Nov 2008

I pull a gallon sized Ziploc bag from its sunny yellow box, one of several boxes my mother, who shops at Costco, sent home with me last weekend, and swallow the guilt as I add yet another virginal plastic bag to the relatively permanent archive of plastic things in the world.

Just to be clear, I don’t buy plastic bags. Well, not unless it’s for a good cause like packing away the twenty pounds of wild low-spray blueberries we raked last summer. I tell myself I’ll reuse them, and I do, from storing bagels, to blueberry muffins, to banana bread before tossing them in for a spin in the wash whenever a greasy film builds up. But then the inevitable happens. The plastic zipper tab breaks off, or the blue and yellow tracks warped by warm water and dryer heat no longer join. For a while the bag limps through still storing food, closed up with a rubber band, or rolled up tight and tucked away. But that only puts off its fate for so long – eventually the plastic shows its age, as small cracks and holes begin to let in air or let out drips of last night’s soup.

That’s when it’s pitched into the trash. I’d add them to the Stop&Shop recycling (or down cycling) pile – which allows shopping bags, dry cleaning bags and newspaper bags - but wary of “contaminating” plastic batches with Ziplocs I refrain, and make a note to ask Stop&Shop about this.

As frugal as I am about Ziplocs and Saran wrap, my mother is not. But it wasn’t always that way. I can still recall my envy over the little plastic sandwich baggies Amy Ellis, my best friend in grade school, pulled from her lunch box each day. Her mother, a decade younger than my 42 year old mom, was far more “with-it,” or so I thought. If there was a new product, Amy had it. While her sandwiches were moist and soft, good material for a lunch-time trade, mine, in its wax-paper sandwich bag, couldn’t compare. Now the shoes are on my slightly older feet and I refuse to pack my kids’ lunch in plastic baggies. Just check out the garbage pail in any school room around the country and you’ll find plenty. Their total useful life-time? About three hours.

According to the history of plastic bags, those little baggies, thin sheets of blown polyethylene film sealed along three sides first came into being around 1957, roughly twenty-four years after the discovery of the stuff, and ten years before the ubiquitous and larger, produce bag.

Plastic produce bags, primarily LDPE or low density polyethylene, now fill the cotton shopping bags of the most plastic-wary consumer whether they’re shopping the farmer’s market, the local co-op, Whole Foods or Big Y. So I was heartened last week when I loaded my bagels into a recycled plastic produce bag at Whole Foods. If only the darn thing didn’t break open and spill six bagels onto the floor! I’m sure in time they’ll get it right.

Like sandwich baggies, by some estimates the useful lifetime of produce bags is measured in minutes, or however long it takes to stuff some string beans into the bag, hit the check-out counter and dump them into the colander for dinner. Though the most fastidious of us might reuse them or cart them back to Stop&Shop for recycling, plenty still end up in the trash.

Like all plastics, plastic baggies flow from the crude oil tap which is refined and distilled before cradling our organic broccoli. Crude oil is a complex mixture of hydrocarbons – carbon and hydrogen containing molecules. Some are long, some are short. They are straight, or branched – but all have a carbon “back-bone,” or a chain of carbons C-C-C-C. For years I had a small vial of crude oil in my office, rescued from the Valdez Oil spill, the label thanked me for helping to remove some ridiculously small percentage of the original spill (it now sits somewhere on my son’s science teacher’s desk – beseeching impressionable minds to think more deeply about the consequences of using oil.) This particular crude is the darkest of browns, a thick balled up tar-like substance floating atop the Prince William Sound water captured along with it. It is hard to imagine the link between the transparent filmy Ziplocs in my pantry and a vat of crude oil.

During distillation successively lighter fractions are boiled off and collected, the shorter carbon chain the lighter the fraction. Gasoline for example is “light,” and one of the first fractions collected, while the heating oil that warms our house is thicker, heavier and consists of longer carbon chains. Carbon chains can also be “cracked” into shorter chains, like ethylene, a simple two-carbon molecule. Ethylene is a highly versatile molecule used in hospitals and medical offices for sterilization, fruit ripening (it is also a naturally produced fruit hormone which initiates fruit ripening – try storing some apples next to an overripe banana and see what happens), antifreeze, a one-time gasoline additive, and plastics.

It is one of the highest volume organic (carbon containing) chemicals in production. According to a recent report by SRI consulting in 2006 “…global ethylene production amounted to about 110 million metric tons, with an estimated value of $122 billion.” 110 million metric tons, and guess what? Over half of that goes right into the production of polyethylene plastics including bags and plastic wrap.

“Everyone’s asking about plastic wrap in the microwave,” says my mother one afternoon. Apparently some of her friends had read or heard about the email promising death and destruction by dioxins and other “toxins dripping into your food.” For years she’s been using plastic wrap when reheating. Her reheated food is moist and her oven clean. I don’t cover, and my oven is encrusted with splatter and my food dry. Turns out the email was a hoax, but – according to both the American Chemistry’s Plastic’s Info site (Better Living with Plastics), and the FDA (for what it’s worth these days), consumers should be wary of combining their wrap with their food when microwaving. According to the Plastic’s Info, site, “..most manufacturers recommend leaving at least an inch between the food and the wrap covering the dish. This is to prevent the plastic wrap from melting, which could result from contact with extremely hot foods.” Not to mention allowing chemical additives present in some of the clear cling wraps to leach other chemicals into your food.

Plastic wraps are made from LDPE or polyvinyl chloride (PVC). Concern about toxics leaching from PVC wrap started the rumors flying. Although plastics are incredibly versatile materials, sometimes they are tweaked with chemical additives to get just the right clinginess, or color or flexibility. That meant diethylhexyl adipate (DEHA) in the case of chlorine containing cling wraps. Problem was under the right circumstances, like heating in a microwave, particularly heating things with high fat content, like cheese or meat, DEHA, a reproductive and developmental toxicant (although so far as we know just at relatively high doses) migrated from the plastic wrap resting on top of last night’s Buffalo Chicken Wings into the wings.
While the FDA acknowledges that substances like DEHA can and do transfer from plastic to foods during reheating, the controversy is over how much leaches and how toxic. While FDA maintains whatever leaches out is safe, some countries have banned the additive, while S.C. Johnson, producer of the granddaddy of all cling-wrap, Saran, switched from PVC to LDPE, winning an EPA “Designing Greener Chemistry Award” in the process.

Now, if we just can figure out how to consistently recycle all that wrap and all those LDPE baggies – we’ll all be a little bit greener.

Just another brick in the wall: more on bisphenol A

2008-09-26T11:06:00.000-07:00

My neighbor, the “real” doctor, called the other day, asking for “The Neighborhood Toxicologist.”

“So, what are you doing about your bicycle bottles,” she asked.

She’d just read the latest study and related commentary on the potential dangers of bisphenol A in the Journal of the American Medical Association. It’s rare that I get to advise Katta, most often it’s me calling her – how does Sophie’s staph infection look? What do you think of this little black spot on my arm? I just called an ambulance for Ben, do you think you could come take a look at him while we wait?

I leaned into my expertise. “Well,” I said, “you know those aren’t polycarbonate. It’s just the polycarb that has bisphenol A. Those bicycle bottles are polyethylene,” I said with some authority – impressing myself with my own recall. “As far as I know no-one’s found anything bad about those,” I pause, “not yet anyway.” Not unless you consider the filmy black crude (I’m guessing something biological rather than chemical) that inevitably coats the insides of those bicycle bottles – even if all you’ve ever had in them is water.

What’s confusing about the polycarbonate issue is that it provides s a perfect (or maybe imperfect) opportunity for the public to crab about the wishy-washyness of scientists. Most folks just want an answer – yea or nay, good or bad. But with bisphenol A you get two conflicting answers from two federal organizations, the FDA and the National Toxicology Program.

While the National Toxicology Program (under the National Institute of Environmental Health Sciences) concludes, as far as anyone can conclude, that bisphenol A “is of “some concern” for effects on development of the prostate gland and brain and for behavioral effects in fetuses, infants and children” (for details check out their final report, NTP-CERHR Monograph on the Potential Human Reproductive and Developmental Effects of Bisphenol A ,) the FDA gives the A-okay all-clear for the chemical. According to their recently issued draft report, “…FDA concludes that an adequate margin of safety exists for BPA at current levels of exposure from food contact uses for infants and adults .”

So what gives? The FDA’s overall findings suggest that the available studies are “inadequate” (problems with dosing, species, timing – you name it.) It’s true that all of these can impact the outcome and that even the very best study on a particular contaminant can be rendered relatively irrelevant because the concentrations say, were screamingly high (for example beyond those anyone would ever be exposed to unless they ate their pretty blue bottles); or that the method of exposure is irrelevant (say, injecting a chemical – essentially mainlining it – rather than feeding it to experimental animals); or the so-called mechanism of action – how a chemical causes toxicity – is unique to a particular test species (though this one goes both ways – the sedative thalidomide offers a tragic example of why chemicals need to be tested in several different species.)

Unfortunatley, sometimes we just have to do the best with what we’ve got when it comes to data. Sometimes knowing what’s lacking informs experimental design, so studies that are “most appropriate” can be done. While I won’t review the review that reviewed the review (FDA’s most recent draft) I would like to point out that there are no conflicts about BPA’s femininity. The chemical is indeed estrogenic – scientists knew that long before it ever became a part of those polycarbonate bottles. Estrogen, as we all know is a pretty powerful hormone.
And estrogenic chemicals can bind with, and activate estrogen receptors (referred to below as ERα and ERβ) which means that, like estrogen, they can also elicit all or some of the biological outcomes triggered by estrogen.

But contaminants like BPA must compete with both estrogen in the body and other ingested estrogens, here’s FDA again, “In fact, BPA has an approximately 1000 - 10,000 fold lower affinity for ERα and ERβ as compared to E2, whereas genistein, a phytoestrogen, has a much higher affinity than BPA for ERα and ERβ. Accordingly, if equal concentrations were available, the assumed order of binding to the ERs would be E2, genistein, and then BPA.”

Here’s where even I’m a little confuzuled as my daughter used to say. Though I hesitate to reveal my ignorance – and I do pledge to take this on and fully understand the implications one day – are they saying that it doesn’t matter that BPA binds a powerful receptor because there are several other more “natural” chemicals that will beat it out? When we know that too much estrogen, or estrogen exposure at the “wrong time” could be bad (what I mean by “wrong time” is that there are times during say, development – particularly development in the male when natural concentrations of estrogen may be very low)? Why not take the cautious approach that adding another estrogen to the mix could also be bad – particularly one that is apparently easy to avoid – stop using BPA containing bottles (although that still leaves can linings.)

What follows is an excerpt from a review by Alex Vidaeff and Lowell Server explaining why just knowing the relative potency of estrogens isn’t necessarily enough:
“It has been said that xenoestrogens and phytoestrogens, being weak estrogens with a low level of environmental contamination, are not sufficient to produce adverse effects. The opinions were mainly based on the observations derived from DES-exposed cohorts where only “sufficient” doses of DES generated adverse effects [71] . Such considerations, based on an estrogen potency threshold, or dose-response effects, may underestimate environmental estrogens activity. Hazard identification and assessment in this area cannot rely solely on linear measurements of estrogen activity. Undoubtedly, the xenoestrogens are weaker estrogens than estradiol or even estriol, but studies focusing on binding activity may overlook the complexity of ER action as described above, and the fact that factors other than the binding affinity of the ligand for the receptor may affect gene expression…... When vom Saal et al. [70] observed an increase in prostate size after prenatal exposure to estrogens in mice, the dose-response curve was an U-shaped curve, whereby lower doses also resulted in larger effects. This supports the possibility that even low doses of estrogen in fetal life may affect the expression of genes involved in the morphogenesis of the prostate gland and possibly other genital tissues.”

And then there’s that JAMA article. What alarmed Dr. Katta wasn’t the squabbling over laboratory studies or the reproductive and developmental impacts in rats – but the more recent finding that very real concentrations of bisphenol A in human urine samples (yes we drink the stuff in and pee it out in small but measurable amounts) was positively associated with heart-disease and type 2 diabetes in adult humans in addition to the prostate and brain effects which are of concern to the National Toxicology Program.

But remember, an association is just that – the two things tend to travel together. In this case those with more BPA in their urine tended to have a higher incidence of disease but that doesn’t mean disease was caused by BPA – maybe those with more disease just eat more canned food compared with fresh potentially healthier food (can lining is another source of BPA.) It will take further laboratory studies to confirm any cause and effect linkages. But what’s notable about the study was that there are already rat data linking the chemical to insulin resistance – which in turn is key in the development of type 2 diabetes.

If you’ve read to this point – you must, by now get the idea of how complicated it can be to figure these things out. Oh only if we could just sit a bunch of infants down and have them chug warm milk from polycarb bottles – and then wait and see what happens.

Oops we’ve already done that.

Silencing Spring: WWRD

2008-08-14T13:49:00.000-07:00

First Pulished September 2008 in the Montague Reporter

In her 1962 publication, Silent Spring, Rachel Carson wrote about a spring in the near future potentially silenced by “indiscriminate use of pesticides,” with names like DDT, lindane, aldrin and mirex. What she didn’t write about back then, are the now infamous perfluorinated chemicals used in nonstick and waterproof surfaces, the polybrominated flame retardants that are infused into textiles and plastics, or the triclosan and triclocarban antibacterials in soaps, toothpastes and a range of consumer goods. Back then, no one knew that these chemicals used primarily in consumer products, would eventually find their way into not only you, but also your neighbor, and your neighbor’s neighbor, and, depending on the chemical possibly their uncle in Alaska and definitely the polar bear that just roamed through your neighbor’s neighbor’s uncle’s town.

Instead, Carson chronicled what in retrospect seems obvious now, but clearly wasn't back then. That spraying long-lasting (and by long - I mean decades) chlorinated chemicals like DDT, which accumulate in the fat and are designed to be toxic, on farms, suburbs, even cities just wasn’t smart. But if her expose seems obvious now, then why almost fifty years later are scientists finding, in addition to the remnants of chlorinated pesticides banned years ago, industrial fluorinated and brominated chemicals in water, sediments, wildlife and in humans? And why is one of the “next generation,” shorter lived, barely-bioaccumulative pesticides, atrazine, turning up in surface and groundwater supplies across the nation?

There is no doubt that the publication of Silent Spring wakened the American public to the very real consequences of “better living through chemistry.”

“I was in 8^th or 9^th grade,” recalls my neighbor Jeff, “and learned about it from the mainstream media. It had a pretty big impact – it started to frame the way you looked at things. I remember kayaking down the Connecticut. It was disgusting. But,” he conceded, “none of us were really sure what to do about these things.”

Barely a year old at the time of publication, and not cognizant of books except maybe as suitable teething material, I don’t recall its publication or the impact it had on my suburban life, although I do recall tanker trucks trundling along our road, spraying for mosquitoes and gypsy moths; the shelf in the garage full of bottles and spray cans that my father used to combat whatever ailed his beloved trees and shrubs; and, befitting my current occupation, I recall mixing up my own toxic potions – from cleaning materials stashed under the sink or in the laundry room, and testing them out on the earwigs and carpenter ants that raced along our swing set. Unlike Jeff, I was clueless.

Thankfully, there were plenty of folks who were neither clueless, nor baffled about what could be done to avert the impending environmental disaster described so elegantly by Ms. Carson. Eight years after Silent Spring, the US Environmental Protection Agency, the primary body responsible for registration, release and management of chemicals was born.

Of the December 2, 1970 launch of the agency Jack Lewis, writing for EPA Journal noted, “…Surely no factor was more pivotal in the birth of EPA than decades of rampant and highly visible pollution. But pollution alone does not an agency make. Ideas are needed--better yet a whole world view--and many environmental ideas first crystallized in 1962. That year saw the publication of Rachel Carson's Silent Spring….In fact, EPA today may be said without exaggeration to be the extended shadow of Rachel Carson. The influence of her book has brought together over 14,000 scientists, lawyers, managers, and other employees across the country to fight the good fight for "environmental protection."”

That’s an impressive legacy. But sometimes, I wonder what Ms. Carson would think of her legacy today?

Reading Silent Spring for the first time (I am ashamed to admit), it’s unsettling that nearly fifty years later, albeit on a different scale, Carson’s writing is still relevant. I don’t mean the the details – I think for anyone who didn’t live through those times – or who doesn’t live near farms where aerial spaying is still used – the events Carson described are hard to imagine. It’s been over thirty years since DDT fell from the sky like snow, and “housewives” swept pellets from their front steps or washed the stuff out of their kids’ hair, and the death of so many songbirds suggested a bleak future.

No doubt, we are all better off thanks to the EPA’s slew of chemical regulations and policies, but on a different scale, pesticides and industrial chemicals continue to contaminate water, consumer products, wildlife and us. And scientists, rather than focusing on lethality and reproductive success are now measuring more subtle changes in wildlife like altered reproductive function and development. The perfluorinated and polybrominated chemicals provide examples of history repeating itself – even with regulations in place. Sometimes chemicals slip by because scientists haven’t figured out how to measure them in the environment. Sometimes they slip by because no one expected them to be there, and sometimes they slip by because the industry that produced and released them didn’t provide all the relevant data. But thanks to greater collective environmental awareness ( by consumers, activists, scientists, policy makers and even industry), unlike DDT, it won’t take over a decade to phase-out fluorinated and brominated chemicals – phase-outs for these chemicals are already in progress.

But then there’s Atrazine. The top selling herbicide in the United States, banned by the European Union in 2003, atrazine is an example of a “new and improved” pesticide gone awry. Applied primarily to corn, with minor uses including lawns and golf courses, the EPA estimates that roughly 73 million of pounds of atrazine are applied to crops each year. Compared with the longevity of the chlorinated pesticides like DDT atrazine lasts for merely a blink in time with a half-life 146 days or so (although in these more enlightened days even that’s considered long-lived.) Unfortunately once Atrazine works its way into ground water it may last for years. The result? In the midwest, Atrazine is one of the most commonly detected contaminants in surface and groundwater, additionally it’s been detected although to a lesser extent in groundwater in the Northeast, including Massachusetts. Though detected concentrations often fall well below EPA’s 3 part-per-billion drinking water standards, there are a growing number of studies suggesting that other species, particularly amphibians may be susceptible to much lower concentrations.

University of California, Berkely researcher Tyrone Hayes reported back in 2003 that exquisitely low concentrations of atrazine, as low as 0.1 ppb, altered the steroid hormone balance in frogs, feminizing male frogs and resulting in hermaphrodism and demasculization of the vocal cords. And just recently, Krista McCoy and others, publishing in Environmental Health Perspectives, reported a link between hectares of farmland and feminization in local frogs. Although the authors didn’t measure specific pesticides, among the suspects is atrazine. All this got me wondering – where’s our EPA? Atrazine was recently up for reregistration, an opportunity for EPA to review data accrued over the years since a pesticide is first registered. For atrazine that was 1958. This was well before scientists were clued in to subtle reproductive and developmental impacts caused by small concentrations of chemicals. Nor was consideration given back then, and only rarely now, to the reality that seldom are individuals or wildlife exposed to single chemicals. We are all exposed to complex mixtures of contaminants released by industry, agriculture and from consumer products like soaps, sunscreens and pharmaceuticals.

Surely, I thought, given the pervasive groundwater contamination and the recent data on frogs, atrazine’s registration if not revoked would at least be restricted. At the very least maybe the allowable environmental concentrations (the “chronic criterion”) would be reduced below those found to impact amphibians? Unable to find the appropriate numbers on EPA’s website, I emailed EPA. “We anticipate this chronic criterion, when finalized later next year, will fall within the range of 10 to 20 ug/l [ppb]” wrote Frank Gostomski of EPA’s Health and Ecological Criteria Division. I asked if Hayes’ studies had been included. Yes, was the answer. But if Hayes’ studies hold up to scientific scrutiny –and there seems to be a growing body of literature that suggests that they do - then EPA’s concentrations are way higher than those found to feminize male frogs.

Though hard to imagine in our own backyard where spring peepers and cluckers keep us awake, is it possible that some day thanks once again to “indiscriminate use of pesticides” spring could still be silenced?

Anti antimicrobials - time to get serious about triclosan and triclocarban

2008-07-24T13:00:00.000-07:00

I thought I was “antibacterial” savvy. For years I’ve read labels on antiperspirants and soaps before tossing them into the shopping cart. It wasn’t until I joined a consumer products working group, whose current focus is the dynamic duo of antibacterials, triclosan and triclocarbon, that I found I should also be checking my toothpaste. That’s right, listed right there on the ingredients for Colgate toothpaste was triclosan.

So why the outrage, what’s so bad about these products? Most experts including physicians groups and an FDA panel agree that these antibacterials, originally used in hospitals, aren’t really necessary for the average consumer. Unless there’s a reason to be ultra-clean, there’s nothing like a good hand washing with plain old soap.

Then there are the environmental implications of washing this stuff down the drain. As discussed a while back on this site, these chemicals tend to make their way through sewage treatment plants, persisting in soil and water. But that’s not all folks. Back when I wrote about antimicrobials I focused on the release and impact of these things into the environment. But now I read that triclosan is detectable in breast milk. And although the author concludes that concentrations are below those that might be cause for concern, here we have a chemical that 1) doesn’t seem to do much good 2) gets into the environment and stays there and 3) gets into breast milk. Hmmm.

The breast milk study, by A.D. Dayan, found “No triclosan was detected in 2 samples, it was barely detectable in 9 and the concentration ranged from about 100 to about 2100 μg/kg lipid in the other 51 milk samples.” With the majority of samples testing positive it’s curious that Dayan ponders the results, adding the following “caveats” for how and why these samples might contain the antibacterial:

"Possible contamination at the time of collection.• For example, might the mother have used a triclosan-containing soap to wash her breasts shortly before donating the milk? When did she last use a medicated deodorant, dentifrice or dusting powder?• Was the milk sample collected early or late in lactation after parturition because the body’s fat stores change with time, possibly affecting systemic exposure to any lipophilic material stored in fat?• When was the sample collected in each episode of lactation, i.e. was it ‘fore-milk’, which is more watery, or a later, hind-milk sample with a higher fat content?• Was the sample collected after a period during which the mother had not breast fed or expressed milk? Even a necessarily brief period without milk expression may make the first sample of milk then obtained more concentrated than usual.”

Skepticism is fine – what would science be without some healthy skepticism. But in this case I can’t help but be skeptical in the opposite direction – if there’s no clear benefit of the stuff – why risk exposing the most vulnerable population? Besides none of these caveats lessen the implication that breast fed infants of these women would likely be exposed at some point.

Now, a study by Bruce Hammock (from the University of California, Davis) and others, published in Environmental Health Perspectives suggest that use of these products may in fact, do more harm than good. Reporting that while triclocarban enhanced activation of steroid hormone dependent genes, triclosan was found to be antagonistic in assays designed to evaluate interaction with steroid hormone dependent activity, the authors suggest caution when it comes to triclosan and triclocarbon concluding:

“These observations have potentially significant implications with regard to human and animal health since exposure may be directly through dermal contact or indirectly through the food chain. These screening studies revealed that further investigations into the biological and toxicological effects of TCC [triclocarban], its cabanilide analogs, and TCS [triclosan] are urgently needed."

Perhaps one route, rather than relying on the consumer to read, read, read is to encourage producers to remove the stuff - or to encourage the EPA to cancel all non-medical uses - which is exactly what several environmental and public health organizations are suggesting according to an article in Water and Wastewater News.

But for now, until their campaigns are successful, it’s time to take cleanliness into our own hands and keep reading those labels.

Who's screening sunscreens?

2008-07-23T12:06:00.000-07:00

A while back I wrote about sunscreens here and here. But that was already over a year ago - and as anyone who is confused by he says and she says in science knows - the reports just keep on rolling. Just yesterday the New York Times Science Section published an article by Tara Parker-Pope c alling sunscreen safety into question, and based in large part on an Environmental Working Group (EWG) report on the stuff. In short, it seems that the EWG is concerned about chemicals like oxybenzone (or BP-3 )which are absorbed by the blood and can be detected in urine - the problem is - health impacts are unknown (although a recent news article in Environmental Health Perspectives reports that in animal studies BP-3 " effects in liver, kidney, and reproductive organs, and studies by other groups have shown endocrine-disrupting effects,") and some claim EWG's rating system for sunscreens lacks scientific rigor. Either way, there just aren't enough studies - though one would wonder maybe why consumers are allowed to slather products on themselves and their young ones when "there aren't enough data."

According to Parker-Pope, "Of nearly 1,000 sunscreens reviewed, the group recommends only 143 brands. Most are lesser-known brands with titanium and zinc, which are effective blockers of ultraviolet radiation. But they are less popular with consumers because they can leave a white residue." But many of the titanium and zinc sunscreens don't leave a residue, and the reason they don't is that titanium and or zinc in "micronized." In other words - really small - sometimes nanosized.

Those who remember smearing the white stuff on their noses in the summer - most likely were using zinc that scattered not only the undesirable UV light but also visible light (hence the clown effect.) Today's micro or nano zinc allow visible light to pass through them and so appear clear, while still scattering the sun’s shorter and harmful ultraviolet rays. Cool right?

Maybe. My friend Cal Baier-Anderson, blogging over at Environmental Defense just posted about a study initiated following an "...observation that installers of metal roofs who used these sunscreens inadvertently transferred the product onto the roofs. In places where the workers’ skin had touched the painted metal surfaces, the paint showed accelerated weathering. Why? Because the particular type of nanoscale TiO2 in the sunscreen (the anatase crystal form) is photoactive – when it absorbs UV light, it releases free radicals that speed up the oxidation of the underlying paint."

Cal wondered if the same might happen to our skin - inadvertently accelerating the weathering of our skin just as we are trying to stop any further damage. For more on the topic check out Cal's entry Nano on a Hot Tin Roof (rusted!) and her other entry on nanoproducts and sunscreen Burning Questions.

Will Nanoregulators avoid the Woulda, Coulda, Shoulda syndrome?

2008-06-20T10:21:00.000-07:00

Before heading into nanotoxicology over the next few weeks (the bit that there is), I wanted to add the following tidbits both of which I think reiterate the need for sincere action – in the spirit of avoiding the inevitable shoulda, coulda, woulda, or maybe worse inertia:

1) The U.K. Council for Science and Technology, cautions that unlike in the past government “must cease to rely primarily on responsive mode of funding to fill the knowledge gaps.”

2) In their history of nanotoxicology, Oberdorster, Stone and Donaldson (2007) referring to abundance of national and international meetings producing and associated reports, “…these reports are not followed by appropriate action, thus creating the impression that there may be just too many of these meetings without serious follow-up.”

So as development and production of NP steams ahead of health effects research, for what it’s worth, national and international governments and regulators are wary and eager to track progress related to analysis and evaluation of the health impacts of nanoparticles (NP).

The result is an international consensus on some key issues that should guide future research and regulatory efforts:

1) There are potential differences of NP behavior in both the environment and in biological systems compared with their larger (or smaller) counterparts, and the potential inadequacy of traditional toxicity exposure and testing currently employed to evaluate NP toxicity. (And if you really read this – you note the overuse of potential. Of course there are plenty of synonyms, possible, probable, likely, impending – but the point is, we just don’t know enough to know right now – and so it’s all possible, probable and maybe even likely.)

2) These potential differences include differences in dose metrics, absorption and distribution as a result of size and/or external modifications, mechanisms of toxicity as a result of increased access to cell matrices or generation of reactive oxygen species because of new characteristics such as increased surface area (in addition to many as yet characterized differences.)

3) Many traditional testing and detection methodology may be inappropriately applied to NP. Further, beyond the current understanding of the impacts of natural and combustion-related NP on the lung, and the toxicity of fibers related to occupational exposures (both areas of research which currently lay the foundation for NP toxicology – appropriately or not), there is consensus that data on the impacts of NP (either naturally derived or engineered) in humans and on environmental receptors is insufficient or worse, altogether lacking.

And, on that note, have a nice weekend.

Nanothoughts

2008-06-12T05:53:00.000-07:00

A while back I posted a few items about nanotoxicology. Back then, I must confess I didn’t know much beyond those few articles. Now that I’ve had some time to really review the nanotoxicology literature here are a few thoughts about the rapidly developing field.

The potential toxicity of nanomaterials or nanoparticles in either human or ecosystems is of concern to researchers, government, non-governmental organizations (NGOs), industry and consumers around the globe. However, even with all of the past experiences with developing and regulating chemicals – even with the knowledge that before new chemicals (or new formulations of old chemicals) blanket the earth we ought to understand their potential impacts – the health and environmental impacts of specific nanoparticles lags far behind nanoparticle technology.

I’ve also learned that although government agencies, research collaboratives and others are working to remedy this situation, the funding available for research on health and environmental effects of nanoparticles, or nanotoxicology, compared with money spent on R&D, is in the millions verses billions spent on development.

But before we despair that once again, the nanokitties have left the residents of Whoville holding the bag, nanotoxicology does have several advantages over other “ancestral” fields of toxicology including:

Hindsight revealing flawed strategies of the past which led to inadequate prevention and protection (though this one is quickly slipping away.)

The more global economy, where regulations in one country for example may impact development of a product in another (the newer EU requirements under REACH for example) in addition to greater potential for international collaboration may stretch resources beyond those that any one government might be able to contribute alone.

Industries wishing to convince us that in addition to the “bottom line,” they really do care about health and the environment have shown some interest, and in some cases taken leadership in the field of nanotoxicology research – or entering partnerships with environmental NGOs (for example Dupont and Environmental Defense).

These days, the internet provides a powerful mechanism for rapid distribution of government, NGO and academic reports, providing all stakeholders – even us peons who sit at home, our computers our only source of information - access to emerging data, technology, and publications. It will be interesting to monitor the impact of public oversight of the field as it develops.

Yet despite all of this potential, the “state of the science” on environmental and health effects research today is something of a hodgepodge. But more on that later!

Flush with drugs: a new database for common pharmaceuticals provides insight into surface water contaminantion

2008-06-02T11:15:00.000-07:00

A while back I wrote about the “drugs down the drain” program, targeted primarily at those with unused drugs who might decide to tip those bottles of old aspirin, or unused antibiotics. Yes, yes, I know – there should be no such thing since we’re all told to complete the course. But – there have been times when amoxicillin just didn’t cut it. Those times when the kids’ ears still screamed with pain and a visit to the docs office leads to a mid-course correction - a stronger antibiotic– leaving a half-full bottle of the pink stuff in our fridge.

In these cases it’s important to dispose of the stuff properly – so they don’t end up medicating everything downstream. But what about the pain-killers, heart drugs, antidepressants, antibiotics, gastrointestinal aids that we (and here I’m using the royal WE) take daily? What happens to them when we, pardon the expression, pee?

According to a recent review (introducing a new database) by Emily Cooper and others, just published in Science of the Total Environment, “…between 30 and 90% of an administered dose of many pharmaceuticals ingested by humans is excreted in the urine as the active substance…” and “…up to 90% of drug residues may remain in effluent after [sewage] treatment…”

Although the fact that flushed drugs end up in local streams, rivers and estuaries isn’t new to me – these numbers are astounding. Just imagine if we could reclaim all those drugs. Why - in our school district that might just pull us out of the fiscal hell we've been experiencing for the past decade! And aside from all that waste (though it makes you wonder if pharmaceutical companies design them that way,) once they're in the water - they're no longer beneficial, but rather, environmental contaminants.

But wait – the astute reader (perhaps one of my astute students) might say. What about dose? Certainly the stuff gets diluted, certainly the local trout are not exposed to therapeutic doses of valium or Tylenol? Certainly not. But as the authors point out, several studies now show that chronic exposures to low concentrations can adversely impact aquatic organisms. And, don’t forget – that the Tylenol that I might send over to the local treatment plant will mix with my neighbor’s kid’s antibiotics, and the psychotherapeutics of another neighbor and …you get the picture. There’s a little bit of a whole lot of stuff going down all of our drains collectively.

So what to do with a problem so pervasive? Prioritize, prioritize, prioritize. Fortunately Cooper and co-authors introduce a new, fairly user-friendly database called “Pharmaceuticals in the Environment, Information for Assessing Risk” or PEIAR that will allow researchers and others to do just this.

After a quick tour, I found the site easy to navigate, and easy to track back to original sources, and full of useful information. However, since I’ve made a career of avoiding risk assessment I can’t comment on its utility to risk assessors. I’ll leave that to the pros.

Check it out at http://www.chbr.noaa.gov/peiar.

Great Future in Plastics

2008-05-20T13:36:00.000-07:00

First published in the Montague Reporter, May 2008

It was a simple enough design. Pink and white tampon applicators separated by blue milk bottle caps and strung into a necklace. Those treasures washed by the sea onto our beach, and collected by my father over the course of a few hours one Sunday morning, provided the perfect accessory to the orange fishnet cape adorned with fading coke bottles, pieces of old lobster trap and other assorted beach waste items. Twenty years later, the image of my father, in his faded blue oxford shirt, dungarees and size 12 Jack Purcells sterilizing a pot of tampon applicators in my mother’s kitchen and in my mother’s soup pot, reminds me of a rare moment of father-daughter complicity.

That year as I attended the annual Society of Toxicology and Chemistry Halloween Dance dressed as “Beach waste,” I was naïve about the dangers of plastics. At the time those tampon applicators and milk bottle caps simply signaled failures of waste handling and sewage treatment – an issue George Bush the first used disingenuously to his advantage while campaigning against Massachusetts’ Michael Dukakis.

What I didn’t know back then was that the plastic army of tampon applicators, bottle tops, fishing nets, coffee cups and Barbie dolls (an occasional head, arm or leg had been know to wash ashore) wasn’t just gathering on the shores of my beloved Nantasket beach. These insidious soldiers of the chemical revolution were infiltrating oceans world-wide – and worse, over the years bits of plastic have literally become a part of life. In their relatively short time on earth (in 2007, synthetic plastics celebrated centennial birthday) plastic now contaminants marine mammals, seabirds and most of us – kids and pets included.

I’m sure John Wesley Hyatt hadn’t intended to promote such a legacy when in an effort replace the ivory used for billiard balls he invented one of the first known plastic back in 1863. Although, it’s not clear that his intention was to save the thousands of elephants slaughtered for their tusks, but rather to collect a $10,000 award offered for suitable ivory replacements. Nor should he have been concerned, since his process used natural substances including cellulose, a compound more prone to biological degradation than its synthetic followers, (and 140 years later, a compound that is back in style.)

Probably Leo Baekeland, hadn’t envisioned the reach of his invention either, when, in 1909 he developed Bakelite the world’s first synthetic plastic and wonder material. As a thermoset plastic, a magical resin that could assume any shape as a liquid resin, and then once hardened remain resistant to heat and solvents – Bakelite quickly found its way into the American dream – from telephones to electrical devices, automobiles and jewelry.

But it’s not Bakelite that scientists are finding in North Pacific albatrosses, or in us. It’s the next generation of polymer plastics which have invaded our lives for better or worse. In 2007, the American Chemistry Council reported upwards of 13 billions pounds of plastic resin produced by U.S. industries a year. This is 13 billion pounds of substances resistant to degradation and substances which we are now just beginning to understand can impact the development and function of reproductive systems in subtle yet potentially very important ways.

By now, unless you live radio-free and newsprint free you’ve likely heard about bisphenol-A which leaches from those colorful polycarbonate Nalgene bottles we all bought to avoid buying bottled water, and hard plastic baby bottles and some food-can linings. If not, you must have heard about phthalates – the plastic additive used to soften poly-vinyl chloride (or PVC) and which leaches from items like IV bags, those cute yellow rubber duckies my kids used to mouth during bath-time, teethers and soft plastic books. (Phthalates are also ubiquitous in personal care products including shampoos and lotions –another route of exposure for infants.)

Bisphenol A, and some forms of phthalates act like the potent sex hormone estrogen. For decades scientists have known that exposure to unnatural levels of sex hormones (either too much or too little), particularly during key periods of sexual development can result in tragic outcomes for both sexes. Estrogen is a naturally occurring hormone, which acts by binding with an estrogen receptor. Any other chemical that binds with this receptor and turns it on is an estrogen mimic. Some chemicals may bind with the estrogen receptor but instead of acting like estrogen, block the receptor from any further action – these substances are referred to as antiestrogens. The same is true of other hormones like the male sex hormone testosterone – there are mimics and inhibitors. Collectively these substances are called endocrine disruptors.

The impacts of synthetic estrogen exposure are best illustrated by diethylstilbesterol or DES. For those who don’t recall, DES was a synthetic estrogen prescribed to women from the 1950s through the 1970s to stem complications during pregnancy. Although eventually found ineffective, it continued to be prescribed until the consequence of extraneous estrogen exposure reared its ugly head in the form of clear cell adenocarcinoma in daughters exposed in utero. Later, structural differences in the reproductive tract and infertility were identified in both DES sons and daughters.

That bisphenol A acts as an estrogen is no surprise. Back in the 1930’s the chemical was almost developed as a synthetic estrogen, until DES stole the show. So seventy years later how does this stuff – a known estrogen - end up in plastic drinking bottles and plastic can liners?

Plastics are polymers – that is, they’re made up of many repeating units, strung together like a paper chain. The broad range of plastics we’re familiar with today results from the diversity of repeating units and chain formations discovered and developed at a feverish pace over the past century: vinyl, polyurethane, polystyrene, Teflon, Nylon, neoprene, polyethylene, polypropylene, and in 1953, researchers resurrected bisphenol A in the form of polycarbonate. That’s right. A key link in the polycarbonate chain is bisphenol A. Only back then, we can only hope, no one figured their grandchildren would be sucking down mom’s milk, lovingly pumped so that she could continue to work, from polycarbonate plastic bottles, or that food cans would be lined with the stuff. Or maybe no one figured that individual units of plastic could actually break loose.

But the fact is they do. And the more scientists look, the more they seem to find – whether it’s bisphenol A leaching from polycarbonate bottles, or phthalates leaching from IV bags. And as with many toxicants like mercury and lead, it’s our precious next generation that bears the brunt of our collective ignorance.

“So what would you do?” asked my neighbor, mother of two young boys. “Do you still drink out of plastic?”

Her mother had just given her the “You’re intelligent, how can you feed your children that stuff,” lecture – but she hadn’t yet tossed the sippy cups, rubber duckies and baby bottles.

I nodded sheepishly. I do love those colorful polycarbonate drinking glasses I purchased at Stop&Shop several years ago. And yes, last hiking trip we all sipped from the bright red Chaco Canyon polycarbonate liter bottle.

“I figure the water’s not sitting there all day,” I said, explaining that the greatest leaching of bisphenol A was reported after liquids were heated, or in very “well-used” or distressed polycarbonate. We didn’t even get into the phthalate issue, which extends beyond the use and leaching of phthalates from plastics, to personal care products

“But,” I conceded, “I did just buy some new water bottles, made from polyethylene, for the kids.” Unlike polycarbonate, polyethylene doesn’t leach any thing toxic, at least not that we know.

As I said this, I am sure that the little enviro-region of my brain, the one that lights up every time I do something hypocritical, began flashing away. Did I say I replaced one plastic with another? And did I say that while wearing my favorite purple polyester fleece and polyvinylchloride-bottomed Dansko clogs? Did I say that after dumping a box of broken plastic toys – nonrecyclables – into our 40 gallon plastic barrel?

Even more concerning than the plastic and related compounds in our food and beverage containers – substances which can eventually be manufactured out of these products, or avoided by the careful consumer, are the reports that millions of tons of plastic, from fishing nets to bits of what might once have been tampon applicators and polyester clothing, now circulating in the regions of the Central North Pacific Ocean (gyres). By some estimates, these trash or plastic gyres cover an area equivalent to the size of Texas. And although plastics may not degrade they can break into bits – some as small as 20 microns, creating a plastic soup served up to unsuspecting wildlife.

Writes Charles Moore founder of Algalita, a marine research foundation focused on the protection of marine environments, “I now believe plastic debris to be the most common surface feature of the world's oceans. Because 40 percent of the oceans are classified as subtropical gyres, a fourth of the planet's surface area has become an accumulator of floating plastic debris.”

Further, scientists suspect that some of that plastic may be circulating around for hundreds of years to come. For better or worse – plastics are part of our lives. But they don’t have to be part of us and they don’t have to be part of all creatures on earth. Improved production practices, and products that are easily recycled back into the same products, rather than dead ends like lawn furniture and plastic lumber, and improved public awareness might not rid the North Pacific of its trash right now – but maybe generations from now.

In the ‘60’s movie The Graduate, when Mr. McGuire, a family friend of young Benjamin Braddock advised “Plastics…..There’s a great future in plastics,” he had no idea.

Motherhood the Elephant in the Laboratory: time to speak up

2008-05-14T05:57:00.000-07:00

This is, and isn't, a little off topic but as editor of Motherhood the Elephant in the Laboratory: women scientists speak out, I'm happy to announce that this book of 34 personal essays is now in print thanks to Cornell University Press, and many bold women who wrote about how motherhood influenced their science careers and vice-verse.

Writing and teaching about toxicology (to undergrads and sometimes to highschoolers) is one of the indirect impacts becoming a mother has had on my own career. Because I made the choice to work part-time, which is not an easy thing to do in the sciences, I've kept my own scientist alive through all sorts of interesting people and projects over the years. All of this fueled my desire to reach a broader audience through writing, beginning with articles in our local paper, the esteemed but very small Montague Reporter (hence the Neighborhood Toxicologist) and now through this blog.

As I write on the blog created for the book, Sciencemoms, those who take alternative routes through science ought not be considered failures, or second-class scientists - but apprecaited for their role as communicators, educators, and synthesizers. For more on this see the sciencemoms blog about the two recent editorials in the journal Science. The editorials, written by Bruce Alberts, highlight and support development of programs encouraging scientists to seek alternatives to academia.

Any thoughts on this topic are welcome either here, or at sciencemoms (and you don't have to be a mom - or a women to speak up!)

Tetrodotoxin 101

2008-05-13T08:12:00.000-07:00

A good way to hook students into the wonderful world of toxicology is tetrodotoxin. Sound familiar? It’s what makes fugu, or puffer fish, what it is - a potentially deadly Japanese delicacy. Or does it? Would the delicacy be so appealing if the consumer didn't risk death or paralysis?

For those unfamiliar with fugu or tetrodotoxin, note that a mere “taste” of the stuff can and does kill. Although not the most potent toxin in the toolbox (recall that we’re talking toxin - or naturally produced poison) that honor most likely goes to either C. botulinum toxin (the toxin whose presence may be indicated by those puffed up cans – like the tuna can I once pulled from a grocery shelf,) or ricin – most recently of Las Vegas fame – and produced by the lowly castor bean.

Although non-toxic preparation of fugu has been raised to an art by highly skilled Japanese chefs, and although not all wild puffer fish contain enough toxin to kill, one article estimates that upwards of 50 mortalities may occur each year in Japan following puffer fish ingestion.

But now there’s good news for those who just must nibble – yet who’d prefer to avoid death or illness (tetrodotoxin inhibits muscle contraction causing paralysis). A recent article in the New York Times by Norimitsu Onishi reveals not only some interesting fugu history, but also describes the current trend towards raising tetrodotoxin free fugu.

For years, scientists seeking out the source of fugu (and many other marine species) tetrodotoxin had been baffled – where did it come from? Was it produced by the fish themselves or was it in the food they ate? And why didn’t it kill puffer fish and other tetrodotoxin laden marine animals?

Recent studies now suggest that, like many other potent toxins, tetrodotoxin is produced by the smallest of small, bacteria. By providing a home for bacteria, the boxy puffer is offered protection (and fortunately for the puffer fish, they’re at an advantage thanks to a genetic mutation, which makes them immune to its toxicity.)

As you might guess, here’s where the non-toxic fugu come in. By knowing the source, fish farmers can now feed fugu tetrodotoxin-free food (say that ten times fast) producing a risk free meal.

Although, for some the thrill of fugu may be in the risk – for others writes Onishi,, fugu liver is just plain tasty – like foie gras but without the guilt.

Polycarbonate redux

2008-04-16T19:29:00.000-07:00

I am listening to NPR’s All Things Considered – it’s a story about bisphenol A, a common chemical that many of us have heard about by now. You know the estrogenic chemical that’s in those colorful polycarbonate clear plastic bottles that we all bought when we didn’t want to use bottled water, as well as in the linings of food tins and clear plastic baby bottles – that yes, I’m sure I used with my kids. And I’m thinking maybe we all ought to drink a little bisphenol A if it’s true that a little estrogen is good for improving memory.

Here’s why.

There is no question that exposure to estrogenic contaminants is problematic – particularly when exposure occurs during fetal development and in young children. There are reams of data that demonstrate adverse impacts on the development of reproductive organs, timing of puberty, and other effects on both male and female offspring of test animals exposed in utero and during lactation. Then there is the unfortunate example of diethylstilbesterol or DES, the synthetic estrogen prescribed to women back in the twentieth century to stem complications during pregnancy. It was found to be ineffective in the 1950’s but prescribed until the ‘70s (go figure) when the consequences of exposure to extraneous estrogenic chemicals during development first reared its ugly head in the form of clear cell adenocarcinoma in the daughters exposed in utero.

But did you know that at one time, back in the 1930’s scientists seeking synthetic estrogens like DES found that bisphenol A also behaved as a weak estrogen? That’s right. Back in the 30s this was known. Then some genius discovered that it could be linked together to make plastic. And voila – perimenopausal women like me just have to drink from our polycarbonate bottles to replenish our estrogen. Apparently back then no one figured anyone would be drinking from the plastic, or storing food in it, or sealing children’s teeth – and then when they did discover these uses of the plastic they must have forgotten that it was a known estrogen.

Seriously, we could all use a memory boost. Here’s a Science News article from back in 1999 by Janet Raloff which, besides being so last century, is so similar to recent reports about leaching of bisphenol A from polycarbonate that I did a double take when I came across it on the web (actually I probably read it back then, being a fan of Ms. Raloff, but have since forgotten.) It’s uncanny. Right down to reports that bisphenol A is more likely to leach from well-used polycarbonate and when liquids are heated in polycarbonate.

If that was then, why has it taken us ten years to toss our bottles? Maybe it’s because as Raloff pointed out, the jury was out. Well, almost ten years later it has returned in the form of a report by the National Toxicology Program’s Expert Panel evaluation of bisphenol A, here’s what they conclude (their emphasis):

“The NTP concurs with the conclusion of the CERHR Expert Panel on Bisphenol A that there is some concern for neural and behavioral effects in fetuses, infants and children, at current human exposures. The NTP also has some concern for bisphenol A exposure in these populations based on effects in the prostate gland, mammary gland and an earlier age for puberty in females.”

“The NTP has negligible concern that exposure of pregnant women to bisphenol A will result in fetal or neonatal mortality, birth defects, or reduced birth weight and growth in their offspring.”

Although I’ve confiscated my kids bottles I might keep them around for a few years in case I’m needing a little extra estrogen – if I can remember where I’ve stashed them!

It’s TOXICANTS stupid

2008-04-12T07:52:00.000-07:00

Whenever I have the opportunity to teach, I quickly learn how little I know. Maybe that’s what draws me towards the classroom. Besides the opportunity for human contact – especially contact with students who are so eager to learn about how we’ve managed to muck things up and what we can do about it.

A few months ago, I took on two challenges 1) introducing students at Mount Holyoke College to the fascinating world of toxicants, which, as they all now know– it’s toxi-c-a-n-t-s – unless of course it's a biologically produced toxin (and each time I reminded them of this, I was reminded of my graduate school advisor, the one we called “the pedant,” and shudder,) and 2) asking them to write about toxicants (and in one case, a toxin) for publication in the very public Encyclopedia of Earth or EOE (www.eoearth.org). (And write they did - articles ranging from PBDEs to Atrazine to Synthetic musks - something I hadn't know even existed!)

For some it was a slog. As one student wrote, and I’m sure more than a few students thought, “I never realized writing for the EOE would be so tedious.” For others it seemed a breeze. For me it was nerve-wracking. Particularly after I had the brilliant idea that each student should send her article out for review to whatever expert on her topic she felt most appropriate.

When they sent their work out for expert review, writing letters of introduction, attaching their articles and sending a small part of themselves out into the unknown – I warned them,

“Don’t be surprised if you don’t hear back.”

But then something amazing happened. Scientists wrote back. Scientists - many who are respected in their field, who are pressed for time, who let reviews for prestigious journals sit on their desk until pinged for the tenth time by the journal editor - these scientists took the time to review articles written by undergraduates struggling to comprehend and communicate their research.

It was frightening.

“I didn’t open the response for a day,” said one student about her “expert review.” Another found a sea of red marks – comments, corrections, and No! Wrong! Wrong again – followed by helpful suggestions and further reading.

I wondered if I’d thrown my students to the wolves. Though I’d commented, edited and corrected as best I could before review, the fact is – I could never claim expertise on the breadth of topics covered by this group of young women. This was the lesson I'd learned. I hadn't planned for that level of expert review - but when the drafts came rolling in, I knew I was over my head. Without reading each and every reference - there was no way I could truly comment on the accuracy of what they'd written.

So was it worth the ego-bruising effort? (And I'm not referring just to the students here.)

I had asked my students to write not only for the highest level of review, but also in the end, to put themselves out there in a way that many scientists haven’t dared, communicating a highly technical topic - one which they'd just learned about virtually on their own, to the public and in plain language.

It’s something that I never felt comfortable with until I was out of the lab. Until I felt I had nothing to loose. But these days it is often necessary for scientists to communicate not just with each other but with the public, and it is my hope that that’s the lesson that sticks.

Maybe the difference between “toxicant” and “toxin” is pedantic. But sometimes you’ve just got to get it right. I think they did.

Check out their articles on the Encyclopedia of Earth:

PBDE
Pfeisteria
CFC-11
Pthalates
Atrazine
Perchlorate
Synthetic musks

Toxicant Inspired Poetry: Happy April Fools!

2008-04-01T11:42:00.000-07:00

I’d like to share a poem written by a student who is no April’s Fool.

Last week I'd asked my students to respond to an Earth Forum posting by Sidney Draggan about the detection of a range of chemicals from personal care products to pharmaceuticals to detergents (all considered indicators of municipal waste) measured in earth worms by scientists from U.S. Geological Survey’s Toxic Substances Hydrology Program and reported in Environmental Science and Technology.

Sidney asked if anyone was surprised.

This was one student's response:

When you have a disgruntling ache,
Ibuprofen’s the thing to take.
If you’re feeling a little blue,
Pop an antidepressant or two.
Your kid’s attention span is shorter than that of a fly?
Stimulant medication is the thing to try.
You see, we’ll cook up a cure for whatever ails you,
And maybe a smattering of things you never knew
We're problems with chemical solutions;
We assure you all your kinks have easy resolutions.
Pharmaceuticals are the way to go
When you get an infection in your big toe
If plaque has clogged your blood’s flow
If your hair refuses to grow
If your insulin has fallen a little low.
And a bazillion other things, you know.

With this present in your mind,
It may not be such a surprising find
That even our worms are taking drugs!
Yes these naughty little bugs
Load up all day long!
But before you begin to think them wrong,
And go about accusing,
You might consider it is not their choosing
To ingest this vile mix of stuff.
You see, oddly enough
We are the ones to blame.

We may nobly aim
With pills to eliminate our daily pain
But it all ends up going down the drain.
Everything we get down with a drink,
Everything we throw down the sink-
Be it detergent or anti-bacterial soap
(It would take ages to enumerate the scope)-
Goes right on to a waste treatment facility.
I hope it does not affect your mind’s tranquility
To hear this is not where they stay,
Some into our drinking water stray!
Others catch a ride on our own waste-
Or “biosolids” if you want to show some taste-
And are applied freely to agricultural fields
So they will have record-breaking yields.
Their life sentence may sound tragic,
But worms are the ones that work the magic-
Turning dung into beautiful soil,
And what do they get for all their toil?
A mouthful of our chemical excess.
I think this is something we should address.
There is simply no good to gain,
When these things enter the food chain.
Against our wishes,
Some find their way into our dishes.
You can imagine this creates
Some concern over the toxicity of what’s in our plates
Maybe the effects of these chemicals are not so bad,

Or maybe we’ll be driven raving mad.
But the truth is it’ll take years to unveil
The effects these multiple low-level exposures entail.
If we one day find
That deeply entwined
Are the causes of our health woes
And our daily chemical dose

I can assure you of this:
There is guaranteed eternal bliss
For the one who finds an antidote
Clarity Guerra

If you'd like to pass this around, please remember to credit Clarity!

Making Lists: Dr. Cal's thoughts on priortizing chemicals

2008-03-24T08:07:00.000-07:00

Guest blogger, Dr. Cal Baier-Anderson, a toxicologist at the University of Maryland, Baltimore; and Environmental Defense, adds her own thoughts about prioritizing chemicals (also check out the list created by J. Lowe from Impact Analysis in the comments section of Fav Five.)

A few years ago at a professional meeting I participated in a panel on the chemical perchlorate, which was receiving a lot of attention as an emerging drinking water contaminant. Perchlorate, an oxidizing agent that is used in rocket fuel, can block the uptake of iodide in the thyroid. One member of the audience suggested that focusing attention on perchlorate was a waste of time and money, that there are other chemicals that are more important. Make a list, I challenged the group; professional organizations and industry should step up to the plate and identify the top 10 chemicals of concern, from an industry perspective. It is certainly not an easy task, as Emily pointed out, many different lists can be made, depending on what features are most important.

With tens of thousands of chemicals in commerce, chemical prioritization is a hot topic. The traditional risk assessment process focusing on one chemical at a time requires a lot of data collection: the identification of the most important hazard endpoints (a prioritization process in and of itself); determination of dose-response for the priority endpoint, the characterization of exposure; and the assessment of risks. Chemical prioritization can be based on hazard, it can be based on likelihood of exposure, or it could be based on risk, incorporating both hazard and exposure. Many environmental groups argue that there is so much uncertainty in the risk assessment process that it is better to focus on hazard, emphasizing carcinogens, mutagens, reproductive toxicants, and endocrine disruptors. This has lead to the creation of lists, such as California’s Proposition 65 list of carcinogens, mutagens and reproductive toxicants (CMR), which requires that products containing a chemical on this label their products with a special notice.

Chemicals that can be classified as persistent, bioaccumulative and toxic (PBT) are also considered to be high priority chemicals. EPA initially devised a list of PBT chemicals, but then developed a computer program that evaluates individual chemicals to score them as to PBT properties. Persistence and bioaccumulation are determined by basic chemical properties, whereas toxicity is based on aquatic toxicity data.

With public attention focused on chemicals in consumer products, many companies are critically evaluating their products’ ingredients to determine if they are made with chemicals of concern. But how can we define chemicals of concern? Based on hazard, or based on risk? Some companies have developed their own restricted substances list that contains chemicals that the companies believe to pose some unacceptable risk to their workers and/or consumers. REI has a list, but a simple Google search of “restricted substance list” will uncover many more.

At the recent SOT meeting in Seattle, there was a session on hazard vs. risk-based approaches. Many state governments and large companies are defaulting to hazard-based approaches as a simpler approach to removing chemicals of concern from consumer products. Several prominent toxicologists opined that focusing on hazard without considering exposure will result in time and money wasted on chemicals posing very little risk. But as my colleague noted during the discussion, there are many folks in the environmental community that are wary of our capacity to predict exposure, citing numerous examples where it was initially predicted that there would be no exposure, and the experts were wrong: PCBs, Bisphenol A, phthalates, PFOA, PBDEs…If we can’t correctly predict exposure, then confidence in the risk assessment plummets, shifting focus to hazard.

A new approach is being promoted by some very smart people: alternatives assessment. Rather than making simple restricted substances lists, focus on what are the alternatives and compare using a suite of criteria. These assessments can be used to drive continual improvement in materials safety – protecting workers, the environment and consumers. Makes sense to me!

What’s in Your Fav Five? Five top contaminants

2008-03-12T10:07:00.000-07:00

I’d been blabbing away for the past hour or so about chemical contaminants, imparting my imperfect knowledge upon my seven brilliant college students.

“So, what do you think are the five most important contaminants?” asked Beth, my student who has been investigating atrazine, one of the most ubiquitous pesticides in this country.

I was speechless. “Um..” I wavered, “well….” I pondered, before finally copping-out with “that’s a really good question.”

“I guess that’ll be my assignment,” I grimaced, “but I’m not sure I’d be able to come up with just one list.” Although it seemed a fair if not daunting assignment, since I’d been asking them to stretch their brains all semester, I’m guessing if you asked ten toxicologists for their “Fav-Five” they’d come up with at least twenty different lists.

As with anything in toxicology, there are some basic questions about exposure, toxicity, how the stuff behaves in the environment, and who’s most at greatest risk? For example, we might use some pretty nasty stuff to clean our ovens, paint our toenails or kill rats but we might not expose ourselves to concentrations that are of concern (though that might be debatable), unless we drink them.

Then there’s toxicity. Does it cause cancer? Impair reproduction? Contribute to the development of asthma? Which is worse? Or maybe it’s more insidious, as one of my students, Liz, revealed about a group of fragrances, used in more consumer products that I can name, called synthetic musks. Some of these compounds impair the ability of our cells to spit out foreign chemicals. Finally, there’s the question of how the chemical behaves in the environment, and in us. Does it accumulate? Do we metabolize it? Does it seep into water? Is it spewed into the air? And this is just considering human toxicity. Finally there’s the ‘at risk’ question. Are we talking most problematic for humans? The Environment? Wildlife?

My brain was off in all directions. There are just too many variables. Even David Letterman hasn’t attempted at top-ten list for chemical contaminants I checked.

But I already copped-out once. I couldn’t do it again. So I did some academic soul-searching (A.K.A: A Google Search).

Maybe there are some existing lists that hordes of experts, policy makers and regulators have already developed? But no such luck (although please correct me if I’m wrong. I’d love to see one.) Then I dared write to representatives from USGS and EPA’s Office of Water, but got no response other than a boiler plate answer from the EPA's press office assuring me that in addition to protecting us from acute problems like pathogens, "EPA is concerned that water systems protect their sources of drinking water, address replacement of aging infrastructure, have properly trained operators, and charge sufficient rates to ensure that they have the revenue needed to provide access to safe drinking water."

So for better or worse it seems I’m on my own (with help from the universe of information available on the web – and these are in no particular order – they are about as random as my selection process,) though I’d love to see a poll of those in various fields to see what they’d come up with, here goes – not in any particular order:

1) Arsenic is linked to many different types of cancer, and occurs naturally in soil and water (and may occur in drinking water). It's a chemical once used widely as a pesticide. As a result it may be found in the neighborhood playground (arsenic is one of a triumvirate of metals in CCA or chromated copper arsenate,) or contaminate the soil of old fruit orchards (and elsewhere) thanks to its effectiveness as a pesticide. In terms of large scale environmental release, mining industries – like the Newmont Mining Corporation, in Nevada which describes itself as one of the leading gold companies in the world - may be most important. According to Scorecard a site originally created by Environmental Defense (and now "owned" by Green Media) that digests and synthesizes EPA’s Toxic Resource Inventory into a more readable format, arsenic is the number one cancer concern, and Newmont releases almost 300 millions pounds of arsenic a year into the surrounding environment.

Arsenic also tops the Agency for Toxic Substances Disease Registry Top 20 List which is based on contaminants most commonly found at National Priority List or Superfund sites and which are considered most important in terms of potential for exposure and potential for causing adverse health effects.

Finally, in 2002, the EPA dropped the drinking water standard from 50 part-per-billion (ppb) down to 10 ppb, after considering even lower standards of 3 and 5 ppb.

2) Lead. This is not only important as a neurotoxic contaminant now because it exists in old house paint and other paint (e.g. on old peeling highway bridges), courtesy of the lead industry who once encouraged Americans to paint their houses with white lead, and advertised, yes actually advertised that “Lead Takes Part in Many Games,” (see Deceit and Denial for some fascinating reading,) but it’s also in our water having been used for pipes and solder. The EPA estimates that twenty percent of human lead exposure is the result of contaminated drinking water. Lead also tops NRDC’s Scorecard for number one, non-carcinogenic contaminant, this time thanks in part to Red Dog Ops in Alaska, another mining company.

Several years back, as a pregnant mother of a toddler, I dutifully tested the window sills of our new 1860’s home for lead paint – when the hardware store lead-test stick turned a shade of hot-pink I hadn’t seen since the psychedelic ‘70s. I immediately (and maybe not so wisely) purchased some gel non-toxic stripper and scraped away. Sometimes we do dumb things. And sometimes we just don’t learn. Maybe we will this time around.

Here’s a little ditty I found on EPA’s site:

Hence gout and stone afflict the human race;
Hence lazy jaundice with her saffron face;
Palsy, with shaking head and tott'ring knees.
And bloated dropsy, the staunch sot's disease;
Consumption, pale, with keen but hollow eye,
And sharpened feature, shew'd that death was nigh.
The feeble offspring curse their crazy sires,
And, tainted from his birth, the youth expires.
(Description of lead poisoning by an anonymous Roman hermit,
Translated by Humelbergius Secundus, 1829)

3) Priority Air Pollutants. Air is not my field, but no top-five list can be complete without at least a few air pollutants. These include particulate matter - released by power plants, motor vehicles, (especially older diesel vehicles), and some factories; ground-level ozone (primarily from motor vehicles and industry), carbon monoxide (from burning fossil fuel), sulfur oxides (fuel again, particularly coal burning plants), nitrogen oxides (yup, burning fuel again) and finally lead (again – so now you see it’s a double assault.)

We’ve all heard how asthma rates are going up. At least a few of those pollutants listed above aggravate asthma, and are known to cause or aggravate other respiratory conditions (for a historical perspective on the killing smog of Donora Pennsylvania, When Smoke Ran Like Water is a sobering read)

Although thanks to the Clean Air Act, smoke no longer runs like water, it’s still a pervasive pollutant, as anyone with a respiratory condition will tell you. As a parent who watched her asthmatic toddler’s every breath, and then watched as he bounced off the walls following massive doses of Ventolin (he’s thankfully grown out of it), I cannot imagine living in fear of the air. But people do, every day, and it’s criminal. Unfortunately, unlike water, until the sources clean up their act, there is no choice when faced with contaminated air (except perhaps, to visit one of those oxygen bars.)

4) Trichloroethylene, the “miracle” solvent of the twentieth century. I don’t know of too many contaminants that have their own blog, except for TCE (there’s also a very active TCE list serve run by Lenny Siegel, director for Center for Public Environmental Oversight). Though it may or may not reflect the importance of this developmental immuno - , neuro – (basically you name it) toxic and potentially carcinogenic contaminant, it does reveal the importance of this chemical. According to the EPA, TCE is present in 60% of their National Priority (NPL) or Superfund sites around the country, not to mention all the tens of thousands non-NPL sites contaminated with TCE as a result of past industrial, military, small business, or legal and illegal dumping. TCE not only contaminates water – including drinking water, but, depending on the depth of the water table and soil conditions, TCE vapors from contaminated ground water can and have intruded into homes, businesses and schools. Several years back, a class of mine worked with residents in North Adams, MA – a town where seventeen houses were bought-out and razed because of concerns about TCE vapor intrusion.

5) Bisphenol-A. Actually, I don’t know that anyone might consider this one a top-five, though it’s certainly among the top-five in “Buzz.” Bisphenol A is one of those seemingly all too-common estrogenic plasticizers. As we’ve all heard by now, this is the stuff that leaches from polycarbonate bottles – including those colorful Nalgene bottles that college students carry around (to make a statement about their environmental mindfulness) baby bottles, metal can linings, and even tooth sealants. Way back when, in the dark ages of 1993, when the realization that very small amounts of chemicals could really tweak developing reproductive systems was just dawning, the EPA’s Integrated Risk Information System (IRIS) stated, “The developmental toxicity of bisphenol A has been adequately investigated. Confidence in the RfD, therefore, is high.” Consequently the EPA set the “Reference Dose,” an amount considered as safe, at 50 parts per billion per day. Recent studies now suggest concentrations nearing this reference dose may cause reproductive and developmental toxicity. Bisphenol A now contaminates rivers, streams, with unknown impacts on wildlife, and because of its use in consumer products, its in us as well, at concentrations nearing the EPA reference dose.

Phew. That about does it for me, I now submit to class for grading. Comments, corrections, additions and subtractions are welcome.

EU to the Rescue? Regulating Toxic Chemicals

2008-03-05T13:28:00.000-08:00

Throughout my professional life, I have, for the most part buried my head in research. That’s what it’s all about - the science - right? Wrong. Not when it comes to toxic chemicals. Back when I was in graduate school, there were some hints that other things, like regulation and risk assessment were important – but I couldn’t be bothered. Even as Sheila Jasanoff, who boggled me with her intelligence and eloquence, led us graduate students through the morass of legalese in her Toxic Torts class, I just didn’t get it. Why laws were written so unintelligibly I could never understand, except maybe to help employ more lawyers.

So twenty years later – maybe even to the semester that I earned the only “C” in my post-secondary career (well – I also pulled off a C in History of the World a well known “gut,” freshman year of college), I am struggling to understand why our country’s Toxic Substances Control Act, the legislation designed to protect us from harmful effects of toxics does not; and why Europe’s new chemical control policy promises so much more.

Thankfully I’m not the only one trying to figure this out. This summer the General Accountability Office or GAO released a report comparing TSCA with Europe’s new Registration, Evaluation, and Authorization of Chemicals (REACH) legislation. Noting one primary difference between the two, the GAO states:

“TSCA places the burden of proof on EPA to demonstrate that a chemical poses a risk to human health or the environment before EPA can regulate its production or use, while REACH generally places a burden on chemical companies to ensure that chemicals do not pose such risks …….” (emphasis added)

You don’t have to be a toxicologist to know how difficult it is to determine that any one particular chemical poses a risk, you just have to read the papers. He says this, she says that, and meanwhile, polybrominated fire-retardants contaminate the dust in our homes, bisphenol-A leaches from baby bottles, and we’re wondering how the gasoline additive MTBE, which now contaminates groundwater across the country could ever have been allowed. But now the EU is requesting that industry take the lead ensuring (as best they can) that a chemical poses little risk to human health and the environment before setting it loose.

Then there are the tens of thousands of chemicals that were on the market prior to the 1980 enactment of TSCA. Unless there was reason for suspicion, those were grandfathered into chemical complacency. And into our food, clothing, air and water.

Unlike TSCA, REACH does not distinguish between new chemicals or old chemicals, according to a recent article in Environmental Health Perspectives REACH will require safety and exposure data on something like 30,000 chemicals currently sold in Europe. Those chemicals that are “carcinogenic, mutagenic, persistent or bioaccumulative or toxic to reproduction” will receive special attention. I just hope the EU has armies of toxicologists lined up to review this stuff!

Many times I’ve harped on how we seem to make the same mistakes over and over again. But it seems the EU has finally looked back before moving forward. When in class, I try to make it clear that being toxic isn’t enough to raise the reputation of a chemical to celebrity status. Exposure matters. How and how much we are exposed to certain chemicals is key. Sometimes exposure takes us by surprise. Who knew that polybrominated fire-retardents would shake free from their products (although one would think that their similarity to PCBs and dioxins might have raised some concern early on about their tendency to bioaccumulate), or that bisphenol-A would leach into water and food to the extent that it does, or that MBTE would wend its way around soil particles into our water, leaving other fuel components behind to be degraded? To address exposure – the EU proposes to consider all uses of a chemical – and to inform all “downstream uses,” clothing, cosmetic, packaging manufacturers for example, of not only the chemical’s properties but also how it behaves in humans and in the environment.

This kind of information, according to Joel Tickner, from the Lowell Center for Sustainable Development, (as reported by EHP), may drive innovation towards less toxic, safer products. According to EHP, “[Tickner] says there is a clear interest of downstream users of chemicals who want the functionality of the chemical but not their toxicity. Companies in sectors such as health care, footwear, electronics, and cleaning chemicals have already started to demand these products from suppliers.”

Amen. And with some trickle down – U.S. companies wishing to supply E.U. with chemicals will have to comply with REACH – there’s hope that we can clean up our act here at home.

Well, we're better off than in the '70s right?

2008-02-26T09:26:00.000-08:00

Toxicology fascinates me, and I love passing that fascination on to students eager to learn about how chemical contaminants impact their environment, and what they can do about it. But it’s a difficult science to teach to undergraduates. It’s hard not to talk about environmental contaminants without the doom and gloom. Particularly this semester, when I’ve decided to run a new course, introducing students to emerging contaminants, by having them investigate and write - for this site and others - about what they’ve discovered.

Because really, there’s nothing “new” or “emerging” about these chemicals, except that we’re now aware of their existence in the environment, and in us. As most of my students now know, many of these contaminants have been around for decades. Some were never regulated; some were regulated, but ended up contaminating land and water across the country anyway; some, have taken environmental scientists and regulators by complete surprise.

“How do you not get depressed?” asked one student, head in hands, slouching into the desktop.

“Well,” I reply, “we’re a lot better off than we were back in the ‘70s.”

Whoa, did I really say that?! The ‘70s? Do I have to harken back to the 1970’s to make us look OK now? A time when many environmental regulations were new, and couldn’t help but improve the condition of air, water and land?

I can relate to my students' sense of loss. It’s like having the rug pulled out from under. We all want to believe that all the regulations and regulatory agencies that serve to protect us from harmful chemicals really are effective. And, for the most part they are, and we are better off for it. But these emerging chemicals are more insidious. For decades many of these chemicals have contaminated food, water, us – in part because they were beyond the reaches of the analytical chemist. No one knew they were there - although some might have been predicted to be a problem, others were thought to degrade, break apart into harmless products.

But now, with improved techniques we know that we are not only stardust, but we’re synthetic chemicals as well.

So I point out that there’s hope. I say that even though PFOA and PFOS, which belong to a class of perfluorinated contaminants, were a big regulatory “whoops,” they now are undergoing the appropriate scrutiny, and within a fairly short timeframe, scientists have begun to measure their decline in the environment.

Shortly after that discussion, I sent the students off to investigate their favorite “emerging contaminant.”

Now I’m depressed.

Of the seven different “emerging contaminants” they chose to investigate, four of them, Pthalates, Atrazine, PBDEs, and Nitro-musks are banned by the European Union. But here in the United States? All four are still legal. (OK, California recently banned pthalates and many states have issued bans on specific PBDEs .)

As Mark Schapiro, editorial director of the Center for Investigative Reporting, reveals in his book Exposed , the differences in chemical regulation between the U.S., once an environmental leader, and the EU the rapidly emerging new leader are vast, and like the universe, rapidly expanding.

“All this makes me want to move to Europe,” commented one student, or maybe California.