This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
WASHINGTON—The catchphrase "chemical body burden," or the presence of hazardous chemicals and their residues in humans, has started to be teased apart by researchers and environmental health advocates in recent years.
Good thing, because awareness of this issue is rising in the public sphere, and more Americans are obtaining laboratory results for the extent of certain chemicals lingering in their bodies, compounds that include pthalates (plasticizers), PCBs (polychlorinated biphenyls), VOCs (volatile organic compounds such as those found in some paints), bisphenol A, lead, arsenic, mercury, asbestos and chlorpyrifos (an insecticide). Tested individuals remain uncertain about how to respond to this information, even as they see potentially linked poor negative health outcomes in their families. Some of these results are made available to subjects participating in household exposures studies who typically are eager to receive their personal results, compare them with national trends and learn how to mitigate impacts.
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Correlations among various pesticides, fertility and other health outcomes have been demonstrated in research on animals and sometimes humans too, although mechanisms are not always detailed or known. Are these relationships causal? And even if they aren't, is there a legal requirement to disclose exposure risks to workers and residents? And are researchers liable when they discover potential risks encountered at home, and must they inform study subjects of them?
There's a lot of hedging in the replies to these questions, especially when it comes to regulations relating to the presence of such chemicals in the home, not just the workplace.
For instance, there are "some duties to report some sorts of pollution under some circumstances" to people to whom you are selling or renting a home, according to research presented here Sunday by Shaun Goho of Harvard Law School, at the annual meeting of the American Association for the Advancement of Science.
Part of the confusion stems from the fact that it is unclear how hazardous chemicals get into homes or the bodies of residents. Were these hazards endemic to the home or imported from an external source?
Hazardous waste laws, which go by acronyms such as RCRA, CERCLA and EPCRA, are designed to regulate the disposal and clean-up of hazardous synthetic chemicals, but they are written in ways that often make homes largely exempt from regulation.
The Toxic Substances Control Act (TOSCA), aimed at regulating products using PCBs and other chemicals, Goho said, "has not really lived up to what it was intended to do" and is a fairly ineffective law. PCBs are often found in floor polishes and paint, and some studies have found surprisingly high levels in homes. But illegal residential levels of PCBs are not an enforcement priority, he said, among regional and federal agencies.
In terms of disclosure in sales and renting, 37 U.S. states have statutory real estate transfer disclosure forms that require some disclosure of environmental hazards in the home, such as lead, asbestos, urea formaldehyde, pesticides, PCBs and VOCs.
But in other states, there is no clear duty to disclose on any hazardous substances other than lead. "You must answer questions truthfully if asked by the buyer, but how likely is it that buyer is going to ask seller, 'Have you found pthalates in the home?'" Goho said.
Overall, these are "novel issues to consider," he said.
Sharyle Patton of Commonweal, a non-profit health and environmental research group in California, told stories of people responding to their own biomonitoring results. A total of 103 hazardous chemicals showed up in lab results conducted on her body.
"I won the PCB and dioxin contests," she said, talking about similar tests done on a group of colleagues, including the journalist Bill Moyers. "I grew up in little village high in Rockies in Colorado, away from industrial facilities, away from freeways. We raised our own cattle and vegetables. These chemicals in my body are calling cards, but they have no return address. I was outraged."
"You get a sense that web of life is also a web of contamination," she said, adding that you can't just "shop your way out of the problem" by using only green cleaning and beauty products. Industrial practices must also change. It's the additive impact of hazardous chemicals that leads to eventual illness, not any one exposure, Patton says.
Commonweal went on to oversee testing of some residents in California's Central Valley who were concerned about pesticide drift. Subjects were advised of the risks surrounding making their results public and the uncertainties about how to respond to them. Still, some subjects went ahead and obtained results and linked them to experiences with infertility and miscarriages persuasively enough to force some changes in regional regulations surrounding pesticides spraying in schools, health centers and homes.
Image: Ohio Environmental Protection Agency
