Studies show airborne dioxin vapors travels great distances from their source
BY C.D. STELZER
(first published in the Riverfront Times, June 19, 1996)
Dioxin found in the Great Lakes region originated at incinerators located as far as 1,500 miles away from the affected area, according to recent scientific studies conducted by the Center for the Biology of Natural Systems (CBNS) at Queens College in New York City.
The findings draw into question the reliability of long-established risk assessment guidelines used by the Environmental Protection Agency (EPA) for rating incinerator safety, including the current Times Beach Superfund project. The research also contradicts assurances issued here last week by Linda Birnbaum, head of the EPA’s reassessment on the dangers of dioxin. Birnbaum was in St. Louis to address a conference of the Society of Toxicologic Pathologists. In an interview following her speech, she cited the dangers of allowing dioxin-contaminated soil from 27 sites in Eastern Missouri to be further distributed by the wind.
Blaming potential dust storms, however, is not an accurate representation of how dioxin enters the environment, says former Washington University professor Barry Commoner, the biologist who heads the CBNS.
“What Birnbaum was forgetting is that we now know exactly how dioxin gets into crops, which is the key thing for human exposure. It penetrates the leaves of the crops as vapor — not as dust,” says Commoner. “Any time you burn dioxin or any other chlorinated material, you are going to get some airborne dioxin that contributes to the health hazard.”
Commoner’s warnings are partially based on the EPA’s own research showing the average person is already exposed to dioxin levels that can result in health problems, including cancer and reproductive and immunological disorders. Birnbaum was out of the country last Friday and unavailable for comment.
“Our study, … released a year ago — (which) she must know about — shows that the stuff travels all over the country,” Commoner says. The CBNS Great Lakes data tracks dioxin from incinerators as far away as Florida. Typically, dioxin enters the food chain through crops and is passed to humans through dairy products and meat.
Standard EPA site risk assessments, such as the one at Times Beach, are flawed because they misrepresent dioxin dangers by limiting their focus to a very small geographic area, Commoner says. “The risk doesn’t come from any one incinerator, it comes from all the incinerators.”
Burning the dioxin-contaminated soil at Times Beach is actually contributing to the problem not solving it, according to Commoner. “The way you get dioxin vapor is out of an incinerator,” he says. “If you keep dioxin attached to the soil particles and not able to get into the air it’s safe.” The biologist recommends paving over the contaminated soil or confining it in concrete bunkers.
Meanwhile, the St. Louis County Executive Buzz Westfall has refused to meet with opponents of the Times Beach incinerator, citing a revised EPA risk assessment that again claims the project is safe. In a June 10 letter to incinerator opponents, Westfall called their concerns “alarmist attacks.”
Opponents had requested the meeting to explain factors that have been omitted from the latest EPA report, including data on incomplete combustion, fugitive emissions and food chain exposure. The renewed assurances from the EPA come after repeated electrical outages at the incinerator, which allowed unknown quantities of dioxin to escape into the atmosphere.
The burn continues.