Chemicals We Have Loved—and May Need to Break Up With
THE BODY TOXIC: How the Hazardous Chemistry of Everyday Things Threatens Our Health and Well-Being. Nena Baker. viii + 277 pp. North Point Press, 2008. $24.
My course on toxicology was never easier to teach than this past year. For subject matter, I no longer had to rely solely on stories about the well-known legacy toxins—PCBs (polychlorinated biphenyls), PBBs (polybrominated biphenyls), DDT (dichlorodiphenyltrichloroethane) and dioxins. Every week, for their “current events” assignment, students eagerly brought in an abundance of news articles revealing the widespread contamination of people and wildlife with such chemicals as PFOA and PFOS (perfluorooctanoic acid and perfluorooctane sulfonate, used in the manufacture of items with nonstick surfaces or protective finishes), PBDEs (polybrominated diphenyl ethers, which are flame retardants), phthalates (used to plasticize polyvinyl chloride), bisphenol A (used in the production of polycarbonate) and atrazine (an herbicide).
Although most of these so-called emerging contaminants have been around for decades, they have only recently “emerged” into our collective consciousness. There are several reasons that we are now hearing more about them: Thanks to much-improved detection methods and technologies, chemists can now find these substances in human tissue and urine in concentrations as minute as a few parts per billion or even trillion. In addition, over the past couple of decades, as better methods of testing have allowed the evaluation of smaller (and often more environmentally relevant) concentrations, toxicologists have expanded the definition of “adverse effect” to include the subtle effects that tiny amounts of foreign chemicals may have on reproductive and developmental processes in people and animals. Another important factor is that in 2001 the U.S. Centers for Disease Control and Prevention issued their first National Report on Human Exposure to Environmental Chemicals and announced plans to continue to report the results of their biomonitoring. The second report was published in 2003 and the third in 2005; the fourth will be released sometime this year.
The publication of the 2003 report struck journalist Nena Baker as a big event, because it expanded the realm of pollution to include the body. She eventually dropped her day job to write a book on the subject, The Body Toxic. Her aim was to chase down the answers to three basic questions:
Should we be worried about the effects of these pollutants on our health? Can everyday items be responsible for the chemicals inside us? Don’t regulators already make sure we’re safe from daily doses of hazardous substances?
We’ll save the first question for later. The answer to the second is a resounding yes: We are all contaminated by chemicals found in everyday items from our kitchens, living rooms, bedrooms and offices, and even our hospitals. We’ve known for some time, for example, that organochlorines such as PCBs and dioxins collect in human tissue.
As for Baker’s third question, no one can deny that in the United States, thanks to expanded federal regulation, releases of chemicals into the environment and our food and water have been greatly reduced over the past 30 years. But Baker shows that there is still cause for concern. Often the Environmental Protection Agency (EPA) lacks adequate information. Chemicals that the agency once deemed safe have turned out not to be. Some are more bioavailable or absorbable than was initially believed, and others break down less rapidly than scientists first thought.
The problem, Baker points out, is this:
When questions arise about chemicals, manufacturers can—and often do—use the absence of information to argue that a substance is harmless. Under our regulatory structure, ignorance is rewarded: manufacturers have no obligation to test for the safety of the substances they sell.
The “regulatory structure” referred to is presumably the Toxic Substances Control Act of 1976, or TSCA. At the time of its passage, EPA 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, TSCA has proved itself “notoriously weak and ineffectual,” Baker says. The U.S. Government Accountability Office, she reports, has concluded that “the EPA has given up trying to regulate chemicals and instead relies on the chemical industry to act voluntarily when concerns arise.”
One notorious incident illustrating the naiveté of making compliance voluntary is that DuPont failed to report that PFOA is persistent and is possibly toxic to humans and wildlife. As a result, in 2005 DuPont settled with the EPA for $16.5 million—pocket change for such a large corporation—and the EPA initiated a voluntary phase-out of the chemical by 2015 (a program in which DuPont, along with several other manufacturers, is a participant).
A point of concern that Baker doesn’t address (perhaps because there isn’t enough to discuss just yet) is the fate of nanomaterials under TSCA. An advantage of certain nanomaterials is that they act differently than their larger chemical counterparts. But this very quality concerns some toxicologists, who fear that chemicals that have been “nanoized” may behave differently in toxicology tests. Yet under TSCA, new registration will not be required for nanoformulations of some existing chemicals. Furthermore, submission to the EPA of health and toxicity data on nanomaterials that may slip by TSCA is currently—you guessed it—voluntary.
The bulk of the book explains why and in what ways regulation has been inadequate and shows what the consequences of regulatory failure have been. Drawing on the primary literature, anecdotes, interviews and popular news articles, Baker presents thorough case studies of atrazine, phthalates, PBBs, bisphenol A, PFOA and PFOS. I was pleasantly surprised to find that she is not an alarmist—after the somewhat hyperbolic introduction, she sticks for the most part to science and policy.
Let’s return now to the first of Baker’s three questions: What does it mean to be exposed to all these toxicants at low concentrations? She makes it clear that we’re a long way from knowing the answer. Biomonitoring studies provide an increasingly accurate picture of the chemical burden our bodies bear, she says, but
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.
More research is needed, obviously.
The final chapter, “Reaching Ahead,” is devoted to the European Union’s new approach to regulation of chemicals. In 2006 the European Parliament passed landmark legislation referred to as REACH (for Registration, Evaluation, Authorisation and Restriction of Chemical Substances). Far more stringent than TSCA, REACH requires that manufacturers test chemicals to ensure that they do not pose an unacceptable risk. It’s an approach that the United States would do well to emulate.
The Body Toxic is informative without being overly technical, although I would have liked some synthesis (for example, some discussion of contaminants that share a common target). Nevertheless, by providing insight into the complexities of regulation and the work of scientists, Baker’s book serves as a good introduction to toxicology and a useful springboard for conversations about policy.
Emily Monosson is the editor of Motherhood, the Elephant in the Laboratory: Women Scientists Speak Out (Cornell University Press, 2008). Her focus as a toxicologist is the impact of emerging contaminants on human health and the environment. She is on the stewardship committee of the electronic reference Encyclopedia of Earth and has a blog about toxicology, The Neighborhood Toxicologist (http://theneighborhoodtoxicologist.blogspot.com/).