Dioxin Reassessment Finds Low-Dose Exposures Persist Without Significant Health Risk
The U.S. Environmental Protection Agency (EPA) has issued its non-cancer
dioxin reassessment 27 years after the ubiquitous chemical was last assessed
and has established a consumption limit of 0.7 picogram of dioxin per
kilogram of body weight per day. The agency has found that, while low-dose
exposures persist, primarily from the consumption of meat, fish and other
animal products, and ultra-low levels of exposure can pose health risks,
“current exposure to dioxins does not pose a significant health risk” over a
lifetime, given significant reductions in industrial dioxin emissions.
According to EPA, air emissions of the chemical from industrial processes
have been reduced 90 percent since the 1980s, but it breaks down slowly and
remains in the water and soil to be consumed by fish and livestock feeding
on contaminated plants. Most ambient dioxin today is apparently a result of
backyard trash burning. The non-cancer health effects examined in this part
of the dioxin reassessment, purportedly the result of large exposures from
accidents or significant contamination events, are chloracne, “developmental
and reproductive effects, damage to the immune system, interference with
hormones, skin rashes, skin discoloration, excessive body hair, and possibly
mild liver damage.” EPA intends to release a cancer reassessment at a later
date.
Environmental activists reportedly lauded the reassessment, but questioned EPA’s minimal risk conclusion because some people have higher exposures or are more vulnerable to potential health effects than others. According to one scientist, fetuses, nursing babies and those with suppressed immune systems, such as AIDS patients and transplant recipients, are more sensitive to dioxin exposure. Industry interests called the draft reassessment on which the document is based “scientifically flawed” and claimed that EPA overstated the risks because exposures are now exceptionally low. See EPA News Release and Environmental Health News, February 17, 2012.
