"Feds Set to Eliminate Water Regulations for Toxin"

From wiredscience

Among the Bush administration's final environmental legacies will be a decision to exempt perchlorate, a known toxin found at unsafe levels in the drinking water of millions of Americans, from federal regulation.

The ruling, proposed by the Environmental Protection Agency in October, was supposed to be formalized on Monday. That deadline passed, but the agency expects to announce its decision by the year's end, before president-elect Barack Obama takes office. It could take years to reverse.

Critics accuse the EPA of ignoring expert advice and basing their decision on an abstract model of perchlorate exposure, rather than existing human data.

"We know that breast milk is widely contaminated with perchlorate, and we know that young children are especially vulnerable. We have really good human data. So why are they putting a model front-and-center?" said Anila Jacobs at the nonprofit Environmental Working Group. "And they used a model that hasn't yet gone through the peer-review process."

The ruling is one of dozens planned for the final days of the Bush administration. Others include a relaxing of air pollution standards for aging power plants, and a reduction of the U.S. Fish and Wildlife Service's traditional role in evaluating the impact of federal projects on endangered species.

These have received more attention than the status of perchlorate, a chemical found mostly in jet rocket fuel and detected in 35 states and 153 water public water systems. It is known to lower thyroid hormone levels in women; it poses a particular threat to pregnant women and breast-feeding children, whose long-term neurological development can be stunted by youthful hormone imbalances.

As many as 40 million Americans may now be exposed to unsafe levels of perchlorate, and the EPA's own analysis puts the number at 16 million. The most comprehensive human exposure study, which measured unexpectedly high perchlorate levels and correlated them with thyroid hormone drops, was concluded by the federal Centers for Disease Control and Prevention in 2007.

Environmental health advocates saw the study as supporting tightened restrictions on perchlorate levels in drinking water — something the EPA had been loath to do under the Bush administration. The study was not considered in the anticipated ruling, which could effectively end federal monitoring of perchlorate in drinking water.

"If you used the human studies from the CDC, then you would be forced to regulate it, because we know there are health effects at current levels of exposure," said Jacobs.

Benjamin Blount, co-author of the CDC's study, would not comment on the EPA's decision, but said that infants — who consume, proportional to their body weight, about six times more water than adults — "are thought to have a higher dose than at any other life stage."