The Chemicals Within

As an Alaskan fisherman, Timothy June, 54, used to think that he was safe from industrial pollutants at his home in Haines—a town with a population of 2,400 people and 4,000 eagles, with 20 million acres of protected wilderness nearby. But in early 2007, June agreed to take part in a survey of 35 Americans from seven states. It was a biomonitoring project, in which people's blood and urine were tested for traces of chemicals—in this case, three potentially hazardous classes of compounds found in common household products like shampoo, tin cans, shower curtains and upholstery. The results—released in November in a report called "Is It in Us?" by a coalition of environmental groups—were not reassuring. Every one of the participants, ranging from an Illinois state legislator to a Massachusetts minister, tested positive for all three classes of contaminants. And while the simple presence of these chemicals doesn't necessarily indicate a health risk, the fact that typical Americans carry these chemicals at all shocked June and his fellow participants. As Stephanie Felten, 28, of Aurora, Ill., put it, "Why should chemical companies be allowed to roll the dice on my health?"

Clearly, there are chemicals in our bodies that don't belong there. The Centers for Disease Control and Prevention conducts a large, ongoing survey that has found 148 chemicals in Americans of all ages, including lead, mercury, dioxins and PCBs. Other scientists have detected antibacterial agents from liquid soaps in breast milk, infants' cord blood and the urine of young girls. And in 2005, the Environmental Working Group found an average of 200 chemicals in the cord blood of 10 newborns, including known carcinogens and neurotoxins. "Our babies are being born pre-polluted," says Sharyle Patton of Commonweal, which cosponsored "Is It in Us?" "This is going to be the next big environmental issue after climate change."

The shocking thing to most Americans is that we really don't know the health effects of many chemicals on the market today. Under the Toxic Substances Control Act of 1976, chemicals already in use were grandfathered in without scrutiny. These include the three classes of compounds targeted in "Is It in Us?"—a plastic strengthener called bisphenol A (BPA), brominated flame retardants known as PBDEs and plastic softeners called phthalates. The chemical industry says these compounds have been used safely for decades, and certainly they do not have the overtly toxic properties of mercury or lead. But in animal studies and human cell cultures, they mimic hormones, with effects even at minute levels, down to parts per billion. Scientists say we're now awash in a chemical brew of hormone-mimicking compounds that didn't exist 100 years ago. "We've changed the nature of nature," says Devra Lee Davis, director of the Center for Environmental Oncology at the University of Pittsburgh.

Take bisphenol A. It's a basic constituent of the polycarbonate plastics found in many baby bottles, sippy cups and juice bottles. A highly versatile compound, it is also found in dental sealants, CDs, DVDs and the resin linings of food and beverage containers, including many cans and takeout cartons. But most scientists say small amounts can leach out—and ultimately find their way into our bodies—when the plastics start to break down under high heat or wear and tear. The CDC has found BPA in 92 percent of Americans age 6 and older who were tested. But the chemical industry says it's safe—and the Food and Drug Administration agrees. "It's not possible to contact harmful levels of it," says Steven Hentges of the American Chemistry Council, which represents the major chemical companies.

Reproductive biologists aren't so sure. Patricia Hunt of Washington State University was alerted to possible dangers of BPA in 1999 when her mouse study on an unrelated topic suddenly went haywire, with dozens of female mice unexpectedly developing chromosomal abnormalities in the eggs they carried in their ovaries. As it turned out, a lab worker had used the wrong detergent to clean the animals' cages—one that caused BPA to leach out of the plastic cages and feeding bottles. Hunt tried washing brand-new cages with the same detergent to confirm the source of the problem. She then began studying BPA exposures in unborn rodents, which she followed into adulthood. The results were striking. Almost half the eggs of female mice exposed to low doses of BPA during gestation carried extra copies of chromosomes or were missing chromosomes. No one has replicated the findings.

There are other potential effects. Hundreds of animal and test-tube studies suggest that low-dose exposures, particularly during gestation, may later lead to breast and prostate cancer, abnormalities in the reproductive tract and behavioral problems, among other things. But there is disagreement about the implications for human health. Two groups convened by the National Institutes of Health have reached opposite conclusions. In 2007, advisers to the government's National Toxicology Program found "minimal" cause for concern. Meanwhile, another scientific panel produced a consensus statement saying that, based on animal data, common levels of exposure could pose a problem and that further study was needed. "We can't say there are conclusive data in humans," says Frederick vom Saal of the University of Missouri, who headed the second panel. "But given the fact that we're seeing irreparable damage in animals, for heaven's sake, let's get this out of products our babies are coming in contact with."