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Dioxins More delays for EPA assessment of the chemical’s most hazardous form

by Cheryl Hogue
September 5, 2011 | A version of this story appeared in Volume 89, Issue 36

The Environmental Protection Agency’s assessment of the hazards from the most potent form of dioxin—a report that has been in the works for two decades—is facing still more delays. Now, EPA says it will split its analysis of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) into two parts—one to be released at the beginning of next year, and the other “as quickly as possible.”

Information from the assessment will guide federal and state regulators in setting cleanup requirements for areas polluted with TCDD, polychlorinated biphenyls (PCBs), or related chlorinated and brominated dioxins and furans.

The agency says it will first finalize the section of the report that addresses adverse health effects other than cancer, including reproductive problems, from TCDD exposure. A second, more controversial, part of the TCDD document will deal with human cancer risk from exposure to the chemical. The agency says the cancer section will be released after the first part of the report is finished.

“How much longer will we have to wait?” asks Lois M. Gibbs, executive director of the Center for Health, Environment & Justice, an activist group. “For over 20 years, EPA’s study on dioxin has been delayed time after time. American families have been exposed to this poisonous chemical for far too long.”

EPA’s announcement followed the release of recommendations about the TCDD assessment from the agency’s Science Advisory Board. The board said EPA should provide greater justification on why agency scientists relied on some studies—and not others—to determine the hazards posed by TCDD. The agency should also explain why it excluded studies on dioxin-like compounds, such as PCBs, the board said.

Meanwhile, EPA continues to rely on its 1984 TCDD assessment.



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