Measuring chemicals in Californians
California is the first state to pass a human biomonitoring bill that sets rules for measuring people’s exposures to pollution.
Keeping up with its reputation as a leader in environmental protection, California plans to launch a biomonitoring program to measure the chemical load in residents across the state. The California Environmental Contaminant Biomonitoring Program, signed into law by Gov. Arnold Schwarzenegger (R) on September 29, will be the first state-sponsored effort in the U.S.
Periodically measuring certain biomarkers in humans can indicate long-term exposure to chemicals, and the results can be useful when setting priorities for which chemicals to control. The data help to identify trends—for example, in at-risk populations—and to determine whether prevention methods or regulations have had their intended effects, according to the Centers for Disease Control and Prevention (CDC).
Public-health specialists and epidemiologists say that biomonitoring is gaining in importance, especially as small-scale, locally focused initiatives. A program tracking several thousand people in New York City, for example, uncovered a hidden threat from mercury contained in illegal skin-lightening products [272KB PDF], and this led to a public-health campaign and a crackdown on importation, says Dan Kass, director of Environmental Surveillance and Policy for the New York City Department of Health and Mental Hygiene. The nonprofit Washington Toxics Coalition in Seattle has attempted an even more limited study—monitoring nine people—in an attempt to introduce the concept there.
The federal biomonitoring program, part of the larger program of environmental health monitoring known as NHANES (National Health and Nutrition Examination Survey), tracks 5000 people in 15 locations around the U.S. Participants give blood samples and have a full medical exam every 2 years.
NHANES, which is run by a division within CDC, “does not give regional data. One can’t say what the levels are in California, [even though] the California population may be sampled quite a bit,” says Larry Needham, an epidemiologist with CDC’s National Center for Environmental Health. The countrywide study can only give national views because of the sampling pattern and the statistically based analysis used. Local information remains necessary for epidemiological and health policy decisions, argue supporters of the California bill and other epidemiologists.
The California program will be the first state-funded survey independent of the CDC program. CDC will, however, provide guidance on how to run it, including laboratory protocols to enable later comparison with NHANES data. So far, CDC has given grants to New Hampshire, New York City, and a consortium of six Western states.
California’s legislation doesn’t lay out any details for its program, such as which chemicals will be tracked and who will be tested. A scientific review panel will help make these decisions. The program’s first report to the state is due January 1, 2010.
The state legislature is expected to provide funding for the program next year, says Gretchen Lee with the Breast Cancer Fund, a nonprofit activist organization that assisted in drafting the bill. The list of compounds to be monitored could also go beyond the 400-plus currently in the NHANES database, Lee says, to “look at chemicals of concern [that are] unique to California.”
In the West, most states expect to find evidence of a long list of human-health-threatening compounds, including phthalates, PCBs, and other products due to heavy agricultural chemical use, as well as exposures in industrial and home settings, says David Mills, the head of the New Mexico state health laboratory. Mills and others suggest that California’s program, if it goes forward, will increase the laboratory capabilities of other states in the Western Tracking and Biomonitoring Collaborative, which includes the 12 westernmost states and Hawaii. It could also provide baseline data for the region.
California’s legislation also requires that the data collected be made available to individuals tested, so they can see their own “body burden”. This “right to know” is not incorporated into NHANES and was important to the parties writing the California legislation, says Amy Kyle, a University of California, Berkeley, public-health professor, who testified about the public-health implications of the bill during legislative hearings.
Despite the availability of individual data, the California program is directed more toward producing results for the state population as a whole than neighborhood-level snapshots, Kyle says. She adds that she and others hope the program will be implemented in such a way as to tease out focused information on smaller, highly impacted groups.
The American Chemistry Council (ACC), a trade group, opposed the biomonitoring bill when it was introduced 3 years ago. But ACC removed its opposition after the approval of several amendments, including the requirement for a scientific review board.
