EPA limits perchlorate in drinking water: What are they drinking?

Yesterday we reported on a bizarre letter from EPA administrator Lisa Jackson that ran in USA Today. Coincident with the missive’s appearance, the agency announced that it was setting new limits on the amount of “toxic substances” permitted in U.S. drinking water. Among the chemicals specified by the EPA as a target is perchlorate. The EPA’s announcement came even though a recent National Academy of Science report, as well as several prior EPA assessments, had concluded that the trace levels of perchlorate found in American drinking water did not pose a threat to public health.

That information, however, was omitted from a New York Times account of the decision written by reporter John Broder, who suggested in his article that perchlorate is a carcinogen and that “measurable amounts” of it have been found in drinking water in 26 states. But ACSH’s Dr. Gilbert Ross points out something the article conveniently neglects to mention: these “measurable amounts” are typically parts per billion or even parts per trillion — trace levels. Moreover, Dr. Ross observes, “While perchlorate, as it was used years ago in medical treatment at levels hundreds of thousands of times the levels in water, did affect the thyroid, no one has ever said that perchlorate is a carcinogen. And ‘measurable amounts’ of anything can be found in water with modern technology.”

ACSH’s Dr. Elizabeth Whelan asks a further question: how and when did the EPA become an agency charged not with protecting the environment, but with public health? Dr. Whelan says that when she spoke at the EPA headquarters some years ago that EPA administrators themselves asked her this. Dr. Whelan says that this is especially pertinent as the agency’s chief administrators are ill-prepared to judge these matters. “They don’t get the big picture,” she says. “They don’t understand the difference between trace exposure to a chemical and toxic exposure.”