(AP) -- The federal government is taking another look at the long-debated question of how chemicals called dioxins affect human health and the environment.
Environmental Protection Agency head Lisa Jackson announced the move Tuesday in a telephone interview with The Associated Press.
The EPA's 2003 assessment of dioxins' health effects drew criticism from the National Academies of Science, which said the agency didn't sufficiently justify assumptions it used to evaluate risks.
Jackson also says the agency plans a new strategy for cleaning a dioxin-contaminated Lake Huron watershed, which extends 50 miles from a Dow Chemical Co. plant in Midland to Lake Huron's Saginaw Bay.
Dow has acknowledged responsibility for the pollution.
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