The Environmental Protection Agency’s (EPA) own science advisory board has joined a host of critics questioning the agency’s decision not to set a drinking water standard for perchlorate, a rocket fuel ingredient that can hinder brain development. Perchlorate has shown up in more than 150 drinking water systems in 35 states, and the EPA has wrestled with what to do about it for years. Critics charge that the agency has been reluctant to act because the pollutant is released by the politically influential aerospace industry and Department of Defense.
In 2002, EPA scientists found that perchlorate posed a danger to human health at concentrations greater than one part per billion (ppb), but the agency told staff members not to talk about the issue, pending further study by the National Academy of Sciences (NAS). An NAS panel reported in 2005 that it could not find a conclusive link between perchlorate and health hazards, but the panel acknowledged that there had been no research examining the relationship between perchlorate exposure and highly vulnerable populations such as pregnant women and their babies.
In 2006, the Centers for Disease Control (CDC) published a study finding that perchlorate exposure endangers fetal brain development in one-third of pregnant American women at levels of 7 ppb. But the EPA announced in October 2008 that it would set no safety standard for perchlorate, arguing that a new regulation would not present a “meaningful opportunity” for reducing health risks.
The agency’s own advisory board disagreed: “Given perchlorate’s wide occurrence and well-documented toxicity to humans, the [Science Advisory Board] strongly believes that there must be a compelling scientific basis to support a scientific determination not to regulate perchlorate as a national drinking water contaminant,” the board chair wrote. In response to the criticisms, an EPA official stated that the agency “is committed to sound science and transparency in decision making.”
The EPA’s Children’s Health Protection Advisory Committee criticized the agency’s decision and the Scientific Advisory Board urged a three-month extension of the public comment period on the decision. But the EPA said the comment period would end on November 28, with a determination finalized in December after two independent scientific peer reviews are completed. Senate Environment and Public Works Committee Chair Barbara Boxer, Democrat of California, vowed she “will do everything in [her] power” to reverse any decision to not regulate perchlorate.