Up in Arms over Arsenic 949

Patricia-Anne Tom

It’s almost as if arsenic is screaming for attention. The metal certainly has caused concern as it leaches from CCA-treated wood. And in March 2001, President George W. Bush’s administration suffered scrutiny when EPA Administrator Christie Whitman announced the EPA would withdraw Clinton administration-approved rules to lower the limit for arsenic in drinking water until more research could be done.

The lower standard, which was proposed by the EPA in June 2000 and finalized by former EPA Administrator Carol Browner in the last days of President Bill Clinton’s final term, would reduce the acceptable level of arsenic in drinking water (the maximum contaminant level, or MCL) from 50 parts per billion (ppb) to 10 parts per billion.

The EPA proposed MCL of 5 ppb for arsenic on June 22, 2000 (65 FR 38888) and the final MCL of 10 ppb was published on Jan. 22, 2001 (66 FR 6976). Discussion arose when Whitman delayed the effective date of the MCL until Feb. 22, 2002 (see 66 FR 28342. May 22, 2001) to seek additional public input on science and cost issues.

“While scientists agree that the previous standard of 50 parts per billion should be lowered, there is no consensus on a particular safe level,” Whitman said at the time. “I want to be sure that the conclusions about arsenic in the rule are supported by the best possible science. [Some cities and states] have raised serious questions about whether the costs of the rule were fully understood when the rule was signed,” she said.

Environmental groups blasted the administration for turning a deaf ear to a potential health concern. But the EPA insists that there is no safe magic number — no one really knows how low arsenic levels should be to be considered safe.

Arsenic is a toxic substance found naturally in the earth, but it also is produced during industrial processes such as semiconductor manufacturing and petroleum refining. However, a 1999 National Academy of Sciences, Washington, D.C., study linked arsenic in drinking water to bladder, lung and skin cancer.