On Wednesday the European Union's Council of Ministers finally agreed on a new regulatory framework for registering and testing potentially hazardous chemicals. Known as REACH
<http://www.envirovaluation.org/htsrv/trackback.php?tb_id=2592>, the system will affect some 30,000 chemicals, an estimated 90% of which are merrily sprinkled all over the place without any evidence that they are safe. Originally, REACH would have required chemicals found to be dangerous to be phased out within five years unless their continued use had some strong social or economic justification, but the ministers seem to have watered down this provision.

Predictably, neither chemical manufacturers nor environmentalists are happy. But Europe is at least trying to come to grips with the very difficult problem of balancing modern society's need for chemicals with the risks that many of them pose. That debate is all but nonexistent in Washington these days.

So it was good timing for a visit to the Scientific American offices yesterday by Peter Myers, a biologist, environmental activist, and co-author of the 1996 book /Our Stolen Future/ on the effects of endocrine disruptor chemicals. Endocrine disruptors, which mimic natural hormones and can throw various body functions out of whack, spilled into public attention in the mid-1990s when they were linked to deformed frogs, drops in men's sperm count, and ever-earlier puberty in girls. In an October 1995 article in our pages, biologists Devra Lee Davis and Leon Bradlow suggested that these chemicals could partly account for a rise in the number of breast cancer cases.

Like so many issues, the hazards of endocrine disruptors quickly became politicized. Many environmentalists jumped to conclusions based on incomplete science, while conservatives wrote off legitimate concerns as political correctness run amok. In chapter 8 of /The Republican War on Science/ and opinion columns
<http://www.chriscmooney.com/blog.asp?Id=2091> this past summer, Chris Mooney described how Republicans managed to stop the Environmental Protection Agency from taking scientific papers on the herbicide atrazine into account, thereby hobbling a review of the chemical's safety. This was a particularly egregious case of political meddling in science. Shortly thereafter, the Bush Administration tried to zero out<http://www.nrdc.org/onearth/06win/chem6.asp> the EPA's funding for research on endocrine disruptors. The EPA's own testing program has been desultory to begin with. The chemical industry and its advocates can make a case that the benefits of atrazine and its ilk outweigh their costs, but they should do so openly, rather than seek to suppress data.
(Some environmentalists have said problematic things, too, but I focus on the Republicans because they're the ones in charge right now.)

Myers runs a website <http://environmentalhealthnews.org/> that is an excellent resource for keeping up with the science of these chemicals. He told us that epidemiologists have been developing new approaches to vet them. Simply measuring chemical concentrations and correlating them with disease may fail to pick up effects, which can take decades to show up, long after a person has been exposed. One way around this is to follow people over time, as is now being done by the National Children's Study <http://www.nationalchildrensstudy.gov/> run by the EPA, National Institute of Environmental Health Sciences, Centers for Disease Control, and National Institute of Child Health and Human Development.

Another possibility is to analyze the blood not just of people who get sick but also of their mothers, whose blood might continue to harbor the chemicals they were exposed to during pregnancy. And yet another is to look deeper than the proximate cause of disease. A person who dies of a bacterial infection may actually have suffered from a chemically compromised immune system.

Myers also explained that chemicals may do nothing when considered individually, but could cause serious damage when they act in concert. You could practically drink some chemicals by the glassful, but when other substances are present, one part per billion might give you cancer. Stress can also amplify a chemical's effect. Unfortunately, the official exposure limits are set by studying chemicals one by one.

Animal tests suggest that endocrine disruptors are particularly prone to synergies, because they don't poison the body outright. Rather, they switch genes on and off and cause natural evolutionary adaptations to go awry. For instance, a developing fetus might interpret the presence of a certain combination of hormones as a sign that mom is going hungry, in which case the fetus prepares itself for a world of food scarcity. That, in turn, could lead to obesity and metabolic disorders such as type II diabetes. To be sure, animal studies may not extrapolate to human beings.

Europe's systematic testing program will help pin down the risks, and rather than continuing to resist it, the U.S. should lend a hand. Different countries may make different cost-benefit tradeoffs, but we need to face those tradeoffs squarely. The faster we can get through those 30,000 chemicals and lift the cloud of ignorance that surrounds their use, the better off everyone -- the public and the chemical industry alike -- will be.

by George Musser, published in Scientific American.