EPA to screen products for invasive chemicals

By Scott Allen, Globe Staff Copyright 1998 Boston Globe August 27, 1998

Disturbed by reports linking genital deformities and cancers to common manmade chemicals, the US Environmental Protection Agency is preparing a massive project to screen everything from pesticides to plastics to cosmetics for substances that may invade the body by posing as hormones.

Gary Timm, senior technical adviser to the EPA's chemical control division, said yesterday his agency would screen 15,000 chemicals by the end of 1999 to develop a "suspect list" of chemicals that behave like estrogen and other hormones that govern development of female and male sexual traits.

"This is a very controversial issue at the cutting edge of science," said Timm, speaking at the American Chemical Society's national meeting in the Hynes Convention Center, but "it is at least a compelling hypothesis that deserves additional study."

The EPA study, which ultimately could cost businesses tens of millions of dollars, follows reports of shrunken alligator penises, declining sperm counts and other sex organ problems that biologist Theo Colborn attributed to the proliferation of synthetic chemicals in her 1996 book, "Our Stolen Future."

Colborn theorized that the rise of pesticides such as DDT, along with the increased use of plastics and other chemicals since World War II, has exposed almost everyone to substances that the body mistakes for the female hormone estrogen, its male counterpart, androgen, or other hormones. She called these pervasive chemicals "endocrine disruptors."

"When you get into your new car and you smell that synthetic leather, maybe you are breathing" an endocrine disruptor, said Dr. Ana M. Soto of Tufts University Medical School, one of the original scientific supporters of Colborn's view.

The hypothesis holds that during fetal development and in puberty, these endocrine disruptors may block the functioning of key genes, disrupting animal and human sexual development and causing other problems such as poor hearing or, later in life, certain cancers.

But proving the endocrine disruptor theory is extremely difficult, in part because so little scientific attention has been paid to the health effects of seemingly inert materials such as plastic. In addition, some of the reported effects, such as the notion that sperm counts are declining, turned out to be contentious and peppered with contradictory studies.

Finally, if estrogen mimics are bad, skeptics asked, why don't natural estrogen-like chemicals in vegetables cause problems?

However, even skeptics agree that manmade chemicals have disrupted development among some animals, producing small penises in the male alligators of Lake Apopka in Florida, for example. Recently, some studies have suggested that such chemicals may play a role in human disease and deformity. The Centers for Disease Control reported last December that the US incidence of hypospadias, where the urethra is improperly located in the penis, almost doubled from 1968 to 1993.

And Dr. John Brock of the CDC found a five-fold increase in non-Hodgkins lymphoma among women who were exposed to the highest levels of PCBs, or polychlorinated biphenyls, a now-banned insulator fluid that mimics estrogen.

Timm of the EPA said his agency is developing a comprehensive set of tests to see which chemicals, if any, actually disrupt human hormonal function. The first test, he said, will determine which of 15,000 chemicals can bind to estrogen, androgen or thyroid receptors, the molecular doorways that allow the hormones inside cells. Once the EPA has a "suspect list," the chemicals will undergo more tests, costing about $ 200,000 each, to be paid for by the manufacturers. A third round of tests on the chemicals' effects on rodents, fish, and other lab animals will cost $ 2 million each.

In the meantime, the pace of endocrine disruptor research is picking up. A major National Academy of Sciences review of endocrine disruptors is due in September, and federal agencies are underwriting 396 endocrine disruptor projects.

But Tufts' Soto, who worked on the Academy of Sciences review, said politicians shouldn't wait for all the research before protecting people from exposure to endocrine disruptors.

"It is going to be a policy decision, and I hope it is going to be made soon because the science won't come for many years," she said.

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