The New York Times
January 1, 2009
Error Seen in E.P.A. Report on Contaminant
By FELICITY BARRINGER
The Environmental Protection Agency failed to follow its own guidelines and made a basic error in evaluating how a toxic contaminant in rocket fuel harms human health, according to a report by the agency’s inspector general.
The contaminant, perchlorate, has been found in significant levels in drinking water in at least 400 locations; scientific studies indicate that perchlorate blocks the necessary accumulation of iodide in human thyroid glands. Iodide insufficiencies in pregnant women are “associated with permanent mental deficits in the children,” the E.P.A. said.
Perchlorate can occur naturally, but high concentrations have been found near military installations where it was used in testing rockets and missiles.
The new report, issued late Tuesday, said the E.P.A. should not have looked at perchlorate individually, but should have followed its own guidance and examined the cumulative impact of perchlorate, other substances in the environment that inhibit the uptake of iodide by the thyroid and potentially inadequate supplies of iodide in American diets.
While the report criticized the agency’s analytical approach, it did not quarrel with two controversial regulatory actions involving perchlorate: one decision to set a safe dosage level four times greater than California’s, and a second not to require cleanup of perchlorate contamination.
In October, the E.P.A. announced that after “extensive review of scientific data related to the health effects of exposure to perchlorate from drinking water and other sources,” a rule setting nationwide maximum limits for the chemical in drinking water was unnecessary as it would do little to reduce risks to human health.
The inspector general’s report said “the single chemical approach and remedy underestimates the complexity of the public health issue.”
“The actual occurrence of an adverse outcome,” it continued, “is determined” by at least three other factors.
The E.P.A. has not completed its proposal on whether to set drinking water standards for perchlorate. Lisa P. Jackson, President-elect Barack Obama’s choice to be the agency’s administrator, will most likely decide what course to take on the issue.