WASHINGTON - The latest draft of a federal study of cancer-causing chemicals concludes there is insufficient scientific evidence to determine whether levels of dioxins in meat are a health risk for humans.
The study, known as the Dioxin Reassessment Review, has been going on for 10 years. Previous drafts have reached different conclusions. The most recent one, criticized by environmentalists as too pro-industry, concludes that laboratory studies have found that some of the 30 manmade chemicals - known as dioxins - may promote cancer growth but do not cause it.
In a 74-page draft report compiled for the Environmental Protection Agency, released for final discussion this week, the panel also says there is insufficient scientific evidence to show for certain whether this means dioxin levels in animal meat causes cancer in humans.
The latest draft reverses some conclusions reached in earlier versions, compiled by the Clinton administration last fall, which concluded that even very low levels of dioxins pose a significant cancer threat to people who ingest the chemical in a normal diet.
Dioxin comes from both natural and industrial sources, and is released into the atmosphere through waste incineration and paper mills. The chemical concentrates in the fat of mammals and fish, and is transferred to humans in meat. About 95 percent of dioxins in humans comes from eating food, while 5 percent comes from breathing in chemicals.
Based on the available evidence, a majority of the experts concluded they couldn't support classifying dioxins as a human carcinogen. Nor would they endorse EPA guidelines contending that 1 in 1,000 Americans is at risk of getting cancer from dioxins. The draft report says some experts disagreed, and believed that dioxins should be listed as cancer-causing agents.
The committee says it is expecting to finish work on the final report by May 15. The scientific panel, composed of 21 experts from federal agencies and universities, was convened in 1991 to reassess the science behind EPA efforts to regulate dioxins.
Environmentalists noted the report was only a draft and that the panel has been reorganized to reflect industry views. "It's premature to say this is the last word on any of this," said Rick Hind of Greenpeace International's toxics program. Hind said there is ample scientific evidence to show dioxins are linked to cancers in humans, and "if they finalize this, it would be astonishing."
Meat industry representatives were pleased with the draft findings.
"We think this is a positive step," said Sonia Voldseth, associate director for food policy at the National Cattlemen's Beef Association.
She said the draft report should focus attention away from dioxins in food, and towards polluting industries, which are responsible for dumping the chemical in the environment. "We agree with that 100 percent," she said.
The EPA began examining dioxin after the chemical agent was blamed for causing cancers in GIs who handled the defoliant Agent Orange during the Vietnam War.
The agency took tough regulatory action to cut down on the emissions of dioxins in the 1980s, and claims that levels of the chemicals released into the environment were reduced 80 percent between 1985 and 1995. In 1991, the agency ordered in-depth studies of the scientific evidence in preparation for further regulatory steps and convened a panel of experts to comb through the scientific evidence.