Dioxin Labeled Cancer-Causing Epa Assessment Raises Stakes At Facilities Such As Spokane’S Garbage Incinerator
There are few compounds as controversial as dioxin, a chemical Frankenstein and unintended byproduct of modern industry.
It was in Agent Orange, the defoliant that sickened thousands of Vietnam vets. It’s a suspect in declining sperm counts worldwide. It’s passed on to babies in breast milk. It’s a worrisome toxin at Spokane’s trash plant and other industrial incinerators.
It’s also a political football.
For the first time in the United States, dioxin has been formally identified as causing cancer, according to a long-overdue U.S. Environmental Protection Agency study released as a draft in June.
The EPA study undergoes peer review Tuesday and Wednesday in Washington, D.C., and will be critiqued anew this fall by EPA’s science advisory board.
“The evidence is all there” that dioxin is a carcinogen with long-lived reproductive effects, said Peter DeFur, of Virginia Commonwealth University’s Center for Environmental Studies, cochair of the dioxin peer review panel.
“The EPA has all the ammunition it needs now to treat dioxin as a reproductive toxin,” DeFur said. The EPA risk assessment has major implications for any facility that generates dioxin - including Spokane’s $94 million trash incinerator. It could lead to further efforts to reduce plastics, the major source of dioxin in trash.
In response to public concerns, a $500,000 carbon injection system to further control mercury and dioxin will be installed in the Spokane plant by the end of the year, said Lloyd Brewer, the city’s environmental programs manager.
“We are trying to be environmentally responsible,” Brewer said.
Spokane’s garbage plant is the state’s largest known source of dioxin, most of it captured in the ash the plant generates, according to a 1998 study by the Washington Department of Ecology.
More than 80 percent of dioxin is from municipal and medical waste incinerators, the EPA says.
Trash incinerators expect to further reduce dioxin emissions by December, when the Clean Air Act requires additional pollution control equipment on older plants, the Integrated Waste Services Association told EPA Administrator Carol Browner in a June 26 letter.
The good news in the EPA report: a downward trend in dioxin emissions.
Dioxin levels were very low before 1930, rose steadily with industrialization until about 1970, and then began a decline, due mostly to better pollution controls on industry.
The EPA study says the most toxic compound of dioxin, called 2,3,7,8-TCDD, is 10 times more dangerous than previously believed.
The average American has a 1 percent chance of getting cancer from dioxin exposure - mostly from food, which contains dioxin in minute amounts from industrial emissions and fertilizers, according to EPA estimates.
In 1998, the Washington Department of Ecology called for a phaseout of dioxin and other persistent, bioaccumulative chemicals over the next 25 years. The agency will propose how to do that in a report next month.
“We knew dioxin was bad - but we’ve been waiting for several years for the EPA report to know how bad,” said Ecology spokeswoman Sheryl Hutchison.
The U.S. lags in tightening regulations on dioxin. Three years ago, the World Health Organization classified dioxin as a carcinogen and lowered the acceptable daily intake by 30 percent.
But in the United States, industry hostility to a stricter standard triggered a regulatory battle. That opposition continues, said an EPA toxicologist who spoke on condition of anonymity.
The new draft study is “supercontroversial,” the toxicologist said. “This will be sharply criticized and heavily debated. But the science points to (dioxin) being a lot more toxic than previously thought.”
Dioxin is created by the burning of plastics in garbage and medical waste and by the manufacture of chlorine and other consumer products, including bleached pulp and paper.
It collects in the fatty tissues of people, fish and animals. It can block the work of cells, damaging the immune system and interfering with the delicate endocrine system, which regulates bodily functions including reproduction, scientists say.
In animal tests, it promotes cancers at minuscule doses - a few parts per trillion, equivalent to a drop of water in 300 Olympic-sized swimming pools.
Large dioxin exposures have poisoned people in industrial accidents. It’s the health impacts of low levels that have been hotly debated for a decade.
The EPA report reflects that uncertainty.
It says dioxin may be resulting in adverse health impacts, but says no “clear indication” of increased disease linked to small amounts has been detected in the general population. That may simply mean the effects aren’t easily detectable, the report says.
Critics say evidence of dioxin’s unusual potency has been available for years, and EPA has been far too slow to warn the public.
“The dioxin risks are truly shocking, especially for young children and nursing infants, who have a higherthan-average risk,” said Carol Dansereau of the Washington Toxics Coalition.
“It’s ironic that EPA undertook this reassessment after pressure from chlorine-producing industries. That strategy has backfired with EPA’s conclusion that dioxin is far more dangerous than previously thought,” Dansereau said.
In response to the new EPA study, the Chlorine Chemistry Council said it supports efforts to reduce dioxin but “does not believe that the extremely low levels of dioxins in today’s environment pose a risk to public health.”
Nationwide, an estimated 2,800 grams of dioxin was released from industrial sources to air, water and land in 1995, vs. 13,500 grams in 1987, the EPA report says.
But the regulators admit they don’t know how much is released from non-industrial sources, such as farmland and urban runoff.
Today, the body of the average American contains an estimated 5 nanograms (a nanogram is a billionth of a gram) of dioxin per kilogram (2.2 pounds) of body weight, the EPA study says.
That dioxin body burden was higher in the late 1980s, at 9 to 13 nanograms per kilogram. Infants and toddlers have larger body burdens - and more risk - because of their size, the report notes.
A new government survey begun last year is measuring dioxin blood levels in about 1,700 people per year at 15 locations chosen as statistically representative of the U.S. population.
Industry groups have fought EPA over dioxin since 1991, when the agency first signaled its concern over the chemical as a “likely” human carcinogen.
The chlorine industry pushed for further scientific review, saying animal studies on dioxin’s effects at extremely low levels weren’t conclusive enough.
In 1994, an EPA review panel of government and industry scientists released a 2,000-page report that raised significant new concerns. Industry again urged further review.
That report said health problems from dioxin were induced in laboratory animals at levels “at or near” what people are already being exposed to in the environment.
The EPA also said exposure to infants through breast milk is an especially important pathway.
Last year, as the new EPA reassessment neared completion, dioxin’s dueling interest groups turned to the courts.
The Chemical Weapons Working Group and the National Institute for Environmental Health Sciences sued EPA to get the completed report released. In May, the release was temporarily blocked by a court injunction sought by a New York restaurant association.
That group said EPA hadn’t proved that the health risks of dioxin outweigh the economic harm to their industry of new public advisories warning people to reduce fat, where dioxin accumulates, in their diets.
Dioxin isn’t monitored continuously at Spokane’s garbage plant on the West Plains. An annual stack test projects measurements for the entire year to estimate how much of the chemical the plant produces.
Critics say the annual test may not represent plant conditions the rest of the year because garbage is so diverse and the tests are conducted under ideal conditions. Defenders say the tests are representative of what the plant burns most of the time.
A new team of scientists hired by the city to study the long-term health risks of Spokane’s plant is looking at nine years of emissions data to determine whether the annual stack test reflects reality.
In a September 1999 stack test at Spokane’s garbage plant, total dioxin compounds were emitted at an estimated rate of .03 milligrams per day.
Projecting that rate over a year, the city’s Regional Solid Waste System estimates the plant emits about 10.9 milligrams (.011 grams) of dioxin and related compounds to the air.
Far more dioxin - about 16 grams per year - is contained in the ash that’s a major incineration byproduct, according to recent city estimates. Because it’s not ejected into the environment, it’s not included in the EPA’s 2,800-gram estimate of dioxin “releases” nationwide.
Spokane’s plant burns about 300,000 tons of trash a year, producing 98,000 tons of ash. The ash is hauled to a regional landfill in Klickitat County for burial in a lined, ashonly landfill.
The city has made efforts to get plastics out of the waste stream, including curbside recycling and overtures to local businesses, Brewer said.
Some area residents say no dioxin risk is acceptable. They want the plant shut down.
“It’s too big a risk to accept,” said BrightSpirit, a biologist, organic farmer and founder of the Spokane group, People for Environmental Action and Children’s Health.
Her group demonstrated outside the plant in May to protest its dioxin emissions. The critics prefer recycling of plastics and landfills to trash incineration.
The Spokane plant’s dioxin limit is nine times more stringent than when it went on line in 1991 due to pressure from citizen activists.
Environmental groups appealed the initial limit to the state Pollution Control Hearings Board, which agreed the standard was too lax. The new limit took effect in 1995.
Spokane’s trash burner controls dioxin well, said Mike Burt, Wheelabrator Spokane Inc.’s plant manager. Wheelabrator, a wholly owned division of Waste Management Inc., runs the plant for the city.
“The important thing is the industry is making dramatic improvements,” Burt said during a plant tour last week. “The dioxin numbers are down.”
Graphic: Dioxins: A modern threat to health