Tuesday, February 27, 2007

Could you reheat that please, but hold the plasticizers

Yesterday my mother asked about using plastic wrap in the microwave. She uses it when reheating or warming food, and her reheated food is moist and her oven clean. I don’t, and my oven is encrusted with splatter and my food dry. I don’t know how important covering food is for reheating (other than the splatter) but I just don’t like to use more plastic in my daily life than is needed. I muttered something about probably not a problem, since reheated plastic wrapped microwave food items are not part of her main diet, but then thought maybe I ought to give it a bit more thought.

I know this is one of those questions that has been around for years, and there were lots of websites with titles like “Truth or Fiction” and “Big hoaxes”, and “Plastic Myths” that popped up when I asked Google about it. But the most informative site was one form the Louisiana State University Agricultural Center (see excerpt below.) Basically, the FDA acknowledges that substances like diethylhexyl adipate (DEHA), a chemical used to make plastics more flexible, can and do transfer from plastic to foods during reheating. The controversy (if there is one) is over how much and how toxic.

But most seem to agree that it if one wants to avoid or minimize their ingestion of contaminants from plastic, they heed the following advice:

According to the LSU article on “What’s Safe for Microwaving”:

"• Use only cookware that is specially manufactured for use in the microwave oven. Glass, ceramic containers and all plastics should be labeled for microwave oven use.

• Don’t use margarine tubs, take-out containers, whipped topping bowls and other one-time use containers in microwave ovens. These containers can warp or melt, possibly causing harmful chemicals to migrate into the food.

• Use safe items like plastic wraps, wax paper, cooking bags, parchment paper and white microwave-safe paper towels. Do not, however, let plastic wrap touch foods during microwaving.

• Never use thin plastic storage bags, brown paper or plastic grocery bags, newspapers or aluminum foil in the microwave oven.

In addition, the American Plastics Council recommends that carryout containers from restaurants should not be used in the microwave. These containers may melt or warp, which can increase the likelihood of spills and burns."

Friday, February 16, 2007

Yesterday NPR had an interesting story on mercury in those compact fluorescent lightbulbs (you know those odd shaped spiral bulbs that promise to reduce energy use.)

Who knew, unless they read the not-so-fine-print that says : LAMP CONTAINS MERCURY; Manage in Accord with Disposal Laws; See www.lamprecycle.org. But really, who has time to read when they're struggling just to open the plastic packaging without breaking the bulb?!

Anyway, there's lots of good information on the NPR site on amounts of mercury (small - according to the Energy Star site, which says that if a bulb breaks getting cut by a shard of glass poses a greater risk than the potential for exposure to mercury), and what to do to dispose of the bulbs (check out earth911.org), which shouldn't be an immediate problem since they're supposed to last for five years or 8,000 hours. That's right - five years, and if they don't, all you have to do is send in your receipt and UPC (UP-what? And, where are those receipts?!)

But the bottom line, as noted by the EPA is that in the end, using these bulbs (in addition to other measures reducing electricity use) could help reduce overall emissions of mercury, since coal, one of the most common fuels for electricity production, is one of the major sources of mercury released into the environment.

Wednesday, February 14, 2007

So What’s in Your Hometown: The Toxic Release Inventory and Citizen’s Right-to-know

A news article published today in Environmental Science and Technology reports on the recent changes to EPA's Toxic Release Inventory. Below is an article I wrote a while back (and just updated), when the EPA was considering changes to the TRI.

What's In Your Hometown?

“So why doesn’t everybody know about these web sites?” demanded Belle, my student. She had just completed the “hometown” assignment for class. The assignment required that they use several websites including the Environmental Protection Agency’s Toxic Release Inventory and Envirofacts websites and the Environmental Defense Fund’s Scorecard website to research their home town. The results, as always are eye-opening, and sometimes distressing.

Together, the three sites listed above, provide location specific information on toxic waste releasers and handlers, Superfund sites, currently operating landfills, the potential health impacts of chemicals in one’s neighborhood. Best of all, their primary purpose is to serve the public, so they are fairly user friendly. In fact, the Toxics Release Inventory is an outcome of the Emergency Planning and Community Right to Know Act, passed in 1986 after the Bhopal, India catastrophe. The Right to Know act requires that the EPA collect information on the handling and release of toxic chemicals from companies around the country, and that they make it open and accessible to all.

While the site is informative, it can be difficult at times to make sense of some of the chemical release information. Fortunately the Environmental Defense Fund’s Scorecard does this for us. Scorecard draws from over 400 databases including the Toxic Release Inventory, and combines these data with other useful information such as health effects data for individual chemicals, and geography, presenting a huge amount of information into “what this means for you.”

And finally, the EPA’s Envirofacts website provides a wealth of information on chemical releases to air, water, and land, and will overlay these data on a map of your town (the other sites map facilities also, but this site includes other information like the location of schools, roads and rivers.)

Using these sites, Belle, who grew up in suburban Pennsylvania, found that in 2002 the SPS Corporation, a supplier of fasteners and metal products to the aerospace and automotive industries, released 1,400 pounds of trichloroethylene into the air, along with smaller amounts of various other pollutants. The plant is just down the street from her home.

Belle also found that her county, Montgomery, PA, ranked number one in the state for superfund sites (there were 16). Fortunately, she also discovered that over the past decade, SPS has reduced their toxic releases by approximately 98%.

But Belle’s revelation paled in comparison to Jaime’s, who reported who reported on the 50 million pounds of toxic chemicals released into the air and waters of her home community of Harris County, TX, which is home to 22 superfund sites. Granted it’s not a fair comparison, one large industrial area verses suburban, PA, but when it’s your own hometown you might want to know about that nearby factory or superfund site, or that well groomed industrial campus down the block. As my students have found, these sites provide a powerful tool for investigating chemical releases in your own community, or in a community you might be considering relocating to.

So why doesn’t the public know about them, my students wanted know. Someone should write about this,” they said. Hmmmm, had I only been quick enough to turn around and give them an impromptu writing assignment. The next day as I skimmed through New York Time headlines online, an article in the business section caught my eye, “Location, Location, Location, Research, Research, Research,” aha, I thought, here it is, now I won’t have to write about it.

Wishful thinking, though the article listed several sites that might help a future property owner research their location, none of the sites discussed above were included in their list. After some more searching, I managed to find one article on Scorecard, but that was in Realtor Magazine Online, not one that’d I would have just found skimming through the news, and I’m not sure many others would either.

So, I decided, I should write about them. But before I could, I had to fully explore the sites myself (yes, yes, I admit it, after giving this “Hometown” assignment to students for the past five years, I had yet to investigate my own hometown.) Although I didn’t expect our community to turn out anything like Belle’s or Jaime’s, you never know.

Researching my own hometown and surrounding towns, I found dramatic reductions in chemical wastes released, which they attributed to either changing processes or through increased recycling. These reductions or changes in chemical processes are reflected graphically using the “Release Trends Graphs,” a useful feature of the Toxics Release Inventory, and are in part the result of Massachusetts’ Toxic Use Reduction Act, which encouraged facilities to reduce the amount of toxic chemicals they use by increasing efficiency and/or using less toxic alternatives.

There is one small limitation of the Release Inventory that I need to mention. Reporting limits. A facility must report only those chemicals that require reporting (currently EPA a total of 666 chemical and chemical categories) and must only report quantities of those chemicals that are treated, recycled or released, which up ‘til now, were quantities in excess of 500 pounds, or the “annual reportable amount.” So if a facility releaseed 500 pounds or less of a particular chemical release inventory chemical they are not required to report specific amounts. (Although chemicals categorized as “persistent and/or bioaccumulative” have lower reportable amounts.)

Depending on the chemical, 500 pounds may not be much if we’re talking just one or two industries in a community, but here’s the problem, recently, the EPA increased the “annual reportable amounts,” from 500 pounds to over 2,000 pounds. Effectively reducing what we have a right to know about. While a 4-fold change in the amount of chemical reported might not make a huge difference in Jaime's hometown, it would in ours or other small communities who depend upon the Release Inventory to keep tabs on local businesses, or in those communities which may have several smaller releasers.

Thursday, February 08, 2007

Toxicology Down in Whoville: Who's testing nanoparticle toxicity?

My daughter is rehearsing to be a Who down in Whoville, a creature invisible and nonexistent to all but Dr. Suess’s Horton who first hear the Whos. This would make her and her fellow Whos, inhabitants of a world the size of a dust mote, nanoparticles I suppose, which according to at least one definition are particles smaller than 100 nanometers (or one billionth of a meter). Around the time Dr. Suess was envisioning the importance and potential of the nanosized Whos, Dr. Richard Feynman, the Nobel Prize winning physicist was also envisioning the technological potential of the very small, well before the term nano-anything even existed. Towards the end of a 1959 lecture, Feynman offered a $1000 reward to anyone who could figure out how produce a nearly Who-sized version of the Encyclopedia Britannica, shrinking the entire series so could fit on the head of a pin.

Though Feynman expected rapid progress, the technological breakthrough (and a legitimate claim for the reward) didn’t come for another thirty years. But since then, the production of nanoparticles, and the field of nanotechnology has blossomed. One institute, Foresite Nanotechnology offers a Feynman Grand Prize of $250,000 for “the first persons to design and build ...a nano-scale robotic arm and a computing device….” By some estimates, nanotechnology is now a billion dollar field, involving both government and industry dollars and it’s growing. The promise of nanotechnology includes both environmental and health applications including more effective drug delivery, potential applications for solar derived power, reduced use of industrial chemicals, and improved environmental cleanup methods.

Until researching this article I had thought the emerging field of nanotechnology would be a great opportunity to witness the fruits of over thirty years of experience with environmental standards, guidelines, laws and regulations. I had thought that development of nanoparticles and nanomaterials (made of nanoparticles) would go hand in hand with human health and environmental toxicity testing. That we would avoid yesterday’s and today’s problems like PCBs, lead paint, and climate change, so that today’s little Cindy-loo Whos won’t need to ask, “How did you let this happen, and how do we fix it?”

Unfortunately, it seems that the Whoville cats have already left the bag. According to Dr. John Balbus of Environmental Defense, the production of nanomaterials has already outpaced knowledge of human health and environmental impacts.

“The Wilson Center [Woodrow Wilson International Center for Scholars] notes 356 nanoparticle products on the shelves around the world,” says Balbus, “and most of them have virtually no in-depth toxicity testing done on the basic material in them…..There are huge knowledge gaps about how these materials will move about and persist, whether they will bioaccumulate, let alone their toxicity to humans or other animals.”

Whoops. What about those thirty years of regulations and guidelines and experience? What about all those toxicity testing techniques designed to protect human health and the environment? After decades of data on thousands of chemicals, one cannot argue that we’re not better off today than we were thirty years ago, but there are also plenty of chemicals that we still just don’t know enough about. And nanoparticles are like the new kid on the block who doesn’t play by the rules, and that’s what makes them so intriguing for industry. In many cases nanomaterials are just different from their counterparts (including both their basic atomic building blocks, and their larger composites – both of which may or may not have already been through all the toxicity testing hoops).

“Ordinary new chemicals go through a series of [initial] screens using computer-based structure-activity-relationships,” explains Balbus, meaning that to some extent researchers and regulators can predict the activity of a chemical based on its structure, comparing the similarity of that structure to chemicals of known toxicity, allowing regulators to determine the need for further more detailed toxicity testing.

“With nanomaterials, we don’t have the experience to be able to predict, so they can’t go through the same screening tests…the tools to use for regular chemicals don’t apply to nanomaterials.”

Titanium dioxide is an example of a chemical with a long history -- dating back to the early 1900’s -- of mass production (now millions of tons per year) in non-nano form, and a more recent history of mass production as a nanomaterial. Traditionally one of the most important white pigments in commerce, one new use for nano-sized titanium dioxide is as a next generation sunscreen, ironically labeled “non-chemical.” Ever wonder how those new sunscreens with titanium and zinc oxide protect you from the sun’s ultraviolet rays without making you look like a clown? Turns out that the typical white smear associated with titanium or zinc oxides result from the excellent light scattering properties of these chemicals. But nanosized particles of titanium dioxide allow visible light to pass through them and so appear clear, while still scattering the sun’s shorter and harmful ultraviolet rays. And, while many in the field agree that a sufficient number of studies on dermal or skin toxicity of nanosized titanium dioxide have been conducted, the same cannot be said of ecotoxicity studies evaluating the potential impacts on the environment.

Although the pending large scale production and potential release of nanoparticles like nanosized titanium dioxide is a recent development, nanoparticles or ultrafine particles have existed in our atmosphere ever since there were fires, volcanos and sea spray to produce them. More recently, manmade sources including traffic and industry have added to the suite of nano-sized particles in the atmosphere, and higher amounts of particulates in the air are consistently linked with adverse health impacts such as increased death rates and respiratory distress. The most recent studies suggest that ultrafine particles cause the greatest harm to the lungs.

In the lungs, says Dr. Vicki Stone, of Napier University, Edinburgh, Scotland, “Smaller particles almost always induce greater cellular response than larger particles of the same chemical composition. Such responses include cell death, and responses that cause activation of inflammation (immune response) and pathways that drive disease.”

In general as particle size gets smaller the toxicity increases, in part because of increased surface or reactive area, and in part because the behavior of the chemical in the environment or in living systems might change.

For example, nano-sized forms of chemicals that normally would not be able to cross into the brain (blocked by what is know as the blood-brain-barrier,) might be able to penetrate and gain access more easily. Similarly nano-sized particles may act differently in the environment. Perhaps becoming more easily dispersed than their counterparts, or perhaps just the opposite, sinking into sediments or settling on soils, making them more likely to be ingested by critters that make a living by stripping chemicals from sediment and soil particles.

However, cautions Stone, “Only a relatively small number of particles of different chemical composition have been tested…so many experiments are needed to verify whether this is a general phenomenon.”

In many cases, whether a product is tested for toxicity and how it is tested depends on the product, the potential for exposure, the amount in production, the proposed end use. For example, a product may be classified as a pharmaceutical, a food additive, a pesticide or a “device” such as a washing machine that sanitizes clothes as it washes, by releasing silver ions and perhaps some nanoparticles as well, (yes there is such a thing, and EPA is currently struggling with how to classify it.) The regulations, standards and guidelines that govern the use and release of a particular chemical may consider all of the above, and this is where a chemical, or an altered form of an existing chemical, may slip through the regulatory cracks.

Fortunately, the US EPA along with several other government agencies, acknowledging the different nature of nanoparticles and nanomaterials, have over the past five years, committed millions of dollars towards health and environmental effects research on nanomaterials; and they’re not the only ones.

“Large companies are certainly concerned about releasing toxic products and having liability risks,” observes Balbus, “so they have done some of the toxicity studies on nanoparticles…..but much of the development and commercialization is being done by small startups that don’t have the resources to do much toxicity testing or exposure testing.”

Stone agrees, “There appears to be huge variation in the way in which different companies are approaching the questions about testing nanoparticle hazard and risk – some have funded extensive research, others are waiting to see whether legislation will require testing, while others are avoiding using nanomaterials until they have a clear understanding of how they will be regulated.”

So, the question is, will the threat of regulation prompt responsible and meaningful health and environmental testing of nanomaterials by industry, heading off further involuntary regulation, or increased creativity in classification of nanoparticles? Let’s hope for all those Whos down in Whoville that it’s the former.

Wednesday, February 07, 2007

Popcorn, hold the PFOA

Cruising through the latest news in the journal Environmental Science and Technology, I came across an article on PFOA (you know, those fluoropolymers that just a couple of years ago resulted in people tossing out their old non-stick pans, and returning to the heavy iron frying pans that could really knock someone out,) in both non-stick pans and, even more interestingly in the coating of microwave popcorn bags. The chemicals are known to accumulate in the environment (I've got a longer article on this in Green Living if you want to read more.)

The work, led by Kurnthachalam Kannan, published just this month in ES&T, reveals that yes, PFOA and related chemicals (for example chemicals called fluorotelomer alcohols or FTOHs) are released into the air from pans heated to normal cooking temperatures, and even into water boiled in these pans. The good news, was that the amounts released, in most cases, was reduced with repeated use.

But here's what's interesting, Kannan's group also reported that PFOA and FTOHs were released into the air from the packaging used for certain (unnamed brands) of microwave popcorn, and in some cases the amount of FTOHs released from popcorn bags was greater than amounts released from cookware.

SO, the next time you cook popcorn, you might want to do it the old fashioned way, in your new iron pot!