EPA study confirms dioxin links to cancer, sterility, miscarriages.

The Environmental Protection Agency (EPA) recently asked industry and the public to comment on a draft report reevaluating dioxin toxicity. "This study is the most important thing the EPA has ever done," said Gerson Smoger of Oakland, California, who heads ATLA's Dioxin Litigation Group.

The massive study was originally expected to modify the agency's tentative 1985 conclusion on dioxin's toxicity, but would up reinforcing it. The draft report estimates that dioxin and related chemicals cause between 1 in 1,000 and 1 in 10,000 human cancers, including lung cancer and soft-tissue sarcoma. (Gary Lee, EPA Study Links Dioxin to Cancer, Wash. Post, Sept. 12, 1994, at Al.) Exposure to the chemical has also been linked to reduced sperm production, abnormal fetal development, and immune system suppression.

Dioxin first caught public attention as a component of Agent Orange, an herbicide used in the Vietnam War. Exposure to Agent Orange sometimes caused lasting health problems for soldiers and their families.

The EPA believes that the primary pathway for human exposure now is via airborne dioxin that settles on plants and is eaten by animals in the food chain like beef and dairy cattle. The chemical, which is very stable and is destructive in tiny amounts, is passed along in food in association with fats.

Most dioxin in the environment is believed to come from emissions from municipal and medical waste incineration. Some comes from chlorine bleach in paper and pulp processing.

"Dioxin sets the standard of toxicity for other chemicals, and it's nearly all manmade," said Smoger. "It hardly occurs in nature, and we don't seem to have any natural defenses against it. The scary part of the study is that it finds damage likely at levels of exposure we know are commonplace in this country today." The chemical is structured somewhat like estrogen, he said, and apparently causes havoc by binding to a special receptor on cell walls and stimulating random growth.

The draft reassessment stops short of labeling dioxin a known human carcinogen. The agency is asking industry to provide further data on human exposure levels, sources, and health effects.

For a copy of the 2,000-page draft reassessment, contact CERI-ORD Publications Center, U.S. E.P.A., 26 West Martin Luther King Dr., Cincinnati, OH 45268, tel. [phone], or fac the request to [phone].