U.S. to Study Whether Water Containing Chromium 6 Is Safe
Seeking to resolve scientific debate, officials with the National Toxicology Program plan to conduct a comprehensive study to determine whether chromium 6 is a carcinogen when people drink it in water.
The study, estimated to cost $2 million to $4 million, was requested by Rep. Adam Schiff (D-Burbank). Water wells in Schiff’s district have been closed because of chromium 6 contamination by Lockheed Corp. and other industrial polluters.
A byproduct of metal plating and painting, chromium 6 has been found in drinking water throughout Los Angeles County. Although it is a known carcinogen when inhaled as a vapor, experts are divided over what threat it poses when ingested in water.
The National Toxicology Program decided to conduct the study, in part because of the large number of people, especially in California, who may have been exposed to the chemical in drinking water, said Dr. Christopher Portier, the agency’s acting director.
“The fact that there is no scientific clarity here is one of the things we weigh when we study a chemical,” Portier said. “A second, is how much exposure there is out there and clearly there are people being exposed to it.”
Established in 1978, the National Toxicology Program is charged with coordinating toxicological testing programs within the U.S. Department of Health and Human Services.
The study, to be formally announced at a press conference at the Glendale Water Treatment plant today, was announced the same week that Sen. Barbara Boxer (D-Calif.) introduced a bill calling on the U.S Environmental Protection Agency to establish a separate federal standard for chromium 6 based on a National Academy of Sciences review.
Two California agencies have also announced they will create a separate standard for the chemical and asked the University of California to convene a panel of experts nationwide to recommend a safe level for the chemical.
But Schiff and others said those studies are reviews of scientific literature on chromium 6, not the comprehensive laboratory analysis that will be undertaken by the National Toxicology Program over the next two years.
Allan Hirsch, spokesman for the state Office of Environmental Health Hazard Assessment, said that in contrast to the UC panel review, the National Toxicology Program effort will be a new study with new information on chromium 6.
“When we first looked at the scientific literature about chromium 6, one of the most relevant studies on chromium 6 dated back to 1968,” Hirsch said. “That tells us it’s time for some new [scientific] work.”
“There hasn’t been a commitment until today to actually do the hard scientific work to get a precise answer to how toxic chromium 6 is and whether it causes cancer,” Schiff added. “It’s a huge thing for California and for local communities that have said we want clear answers on the health affects from chromium 6. Now, they’ll get them.”
*
In addition to California, federal officials say the agency has also received reports of chromium 6 contamination in New York, Massachusetts and Ohio.
The National Toxicology Program, based in Research Triangle Park, N.C., is part of the National Institute of Environmental Health Sciences. Schiff said the agency only conducts eight to 10 toxicity studies out of more than 20 requests every year.
Portier said the agency was planning to make its decision in June but expedited it after receiving letters from the California Environmental Protection Agency, the Department of Health Services and 14 members of the California congressional delegation.
Currently, neither the state nor 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, but California has set a tougher limit of 50 ppb.
The California Office of Environmental Health Hazard Assessment in 1998 recommended an even stricter limit of 2.5 ppb to ensure optimum safety. Reports in The Times detailing delays by the state Department of Health Services in implementing that stricter standard triggered state legislation to accelerate a review of safe levels of chromium 6.
During a state legislative hearing in October, scientists, including USC toxicology professor Joseph R. Landolph, urged lawmakers to nominate chromium 6 for the program.
