After decades at the top of the list of “deadly chemicals” decried by liberal environmentalists, dioxin’s risk has been found to be too small to merit new government regulations.
Common-sense dietary balance, rather than restrictive government regulation, should guide people in reducing their intake of dioxin, reported the Institute of Medicine of the National Academy of Sciences (NAS) on July 1.
The NAS report culminated a decade-long dioxin assessment begun by the Environmental Protection Agency, but then transferred to the NAS after other federal agencies questioned EPA’s impartiality and commitment to sound scientific principles.
Dioxins are long-lasting compounds that accumulate in the body fat of animals and people. Dioxins are never deliberately manufactured, but appear as an unwanted byproduct of some manufacturing processes, forest fires, and waste incineration.
Dioxins build up in the body fat of livestock that eat feed or grass that has been exposed to dioxins, and are in turn passed on to people who eat animal fat. Although no evidence has ever linked common dioxin exposure levels to human health problems, some tests have indicated extremely high doses of dioxin, like extremely high doses of many other natural and synthetic chemicals, can cause health problems in some laboratory animals.
Dioxin was a preferred target for radical environmentalists in the 1980s and 1990s, after potentially toxic chemicals, including dioxin, were discovered in the Love Canal neighborhood of Niagra Falls, New York and in Times Beach, Missouri. Ralph Nader, the Sierra Club, and other liberal environmentalists called for a “zero tolerance” approach to dioxin–although no scientific research had established the emissions posed any danger to human health.
No New Regs Needed
The NAS study notes environmental dioxin levels have declined by as much as 76 percent since the 1970s, when environmental concerns caused a steep decline in dioxin emissions. Most experts expect environmental dioxin levels to continue to decline, as the compounds gradually slip out of the food chain.
Stated the NAS report, “the health risks posed by the levels of dioxins in foods have yet to be ascertained, so the report does not recommend regulatory limits on dioxins or dioxin-like compounds in food or feed.”
“Because the risks posed by the amount of dioxins found in foods have yet to be determined, we are recommending simple, prudent steps to further reduce dioxin exposure while data are gathered that will clarify the risks,” said Robert Lawrence, a Johns Hopkins University associate dean and chair of the committee that wrote the NAS report.
The most effective means of limiting dioxin exposure, according to the NAS, is to eat a balanced diet consistent with current dietary recommendations. Excessive consumption of dietary fats is detrimental to human health for a variety of reasons, notes the report, and heightened dioxin levels may fit the same pattern.
Some specific strategies were proposed. “To reduce dioxin exposure in all children–especially girls–government-sponsored food programs, such as the National School Lunch Program, should increase the availability of foods low in animal fat. For example, low-fat milk should be made more widely available in the school lunch program. Also, the U.S. Department of Agriculture should analyze the impact of setting limits on the amount of saturated fat that can be present in meals served in the school breakfast and lunch programs. Except for children under Age 2, participants in the Special Supplemental Food Program for Women, Infants, and Children should be encouraged to choose low-fat milk and foods.”
Additionally, the NAS urged government to reduce dioxin levels in animal feed. “Federal agencies should work with food producers to develop voluntary guidelines for animal feeding and food-production practices that would minimize animals’ exposure to dioxins.”
Frustration with EPA
The NAS report originated with a long-delayed EPA assessment that pro-regulation groups had hoped would empower the agency to tighten existing regulations and implement a host of new environmental cleanup mandates. Even though dioxin levels are only a quarter of what they were three decades ago, a comprehensive cleanup program would be costly.
In April 2003, as the EPA assessment began nearing completion, the U.S. Department of Agriculture (USDA), the Food and Drug Administration, and the Department of Health and Human Services raised concerns about how EPA extrapolates data to make children seem more susceptible to environmental chemicals than is actually the case. Moreover, according to Monica Rohde Buckhorn of the Center for Health, Environment and Justice, “USDA officials [were] also uneasy about EPA’s characterization of dioxin as a ‘known’ human carcinogen” despite a lack of supporting scientific data.
After those sound science concerns were raised, the EPA assessment was handed off to the NAS to ensure a more objective final report.
James M. Taylor is managing editor of Environment & Climate News. His email address is [email protected].