Monday, April 27, 2009

Chemicals we love to hate, Body Toxic book review

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]