State Advised to Wait on Chromium 6 Standards

A scientific panel examining the health risks of chromium 6 in water said Friday that state officials should not toughen standards for the chemical until after a national study is completed several years from now.

The Chromate Toxicity Review Committee disputed a 1999 recommendation by the state Office of Environmental Health Hazard Assessment that the drinking water goal for total chromium--to limit chromium 6--be lowered to 2.5 parts per billion from 50 ppb.

The five-member committee said it found flaws in a German study that the state relied on in setting the stricter public health goal. The scientists said the state should keep its current standard until more is learned about the risks of ingesting chromium 6, a suspected carcinogen, in water.

They also said they expected more data from a comprehensive study by the National Toxicology Program, the agency charged with coordinating toxicological testing programs within the U.S. Department of Health and Human Services.

Environmental hazard office spokesman Allan Hirsch said his agency will use the committee’s finding to set a new goal for chromium 6. A final determination will be made by the Department of Health Services.

“We are going to be starting from square one with a complete review of the scientific literature,” Hirsch said.

Chromium 6, a chemical used in paint, chrome plating and other manufacturing processes, has been detected in water systems across the state, including industrial areas of Los Angeles and the San Fernando and San Gabriel valleys.

Scientists say the chemical can cause cancer when inhaled as a vapor, but disagree over safe limits when it is ingested in water.

In March, the hazard assessment office and the Department of Health Services announced they would convene a panel of expert scientists to review the health hazard posed by chromium 6.

The agencies also agreed to develop a specific standard for chromium 6 after well-water surveys showed chromium was appearing in much higher concentrations than officials had anticipated.

Neither the state nor the federal government specifically limits chromium 6 in water. Instead, both limit amounts of total chromium as an indirect means of regulating chromium 6.

The federal government limits total chromium to 100 parts per billion, twice the state limit of 50 ppb.

One of the review committee’s key criticisms of the state panel was its use of a 1968 German study to come up with the 2.5 ppb goal.

The committee said mice used in the study had contracted a virus during laboratory tests, making it difficult to determine whether the rodent’s health problems were due to the chemical contamination.