California’s Proposition 65 law is achieving its goal of reducing exposure to toxic chemicals, according to a new study. The findings show a nationwide decline in harmful chemical levels in people’s bodies, highlighting the broader impact of state regulations.
As the concern over toxic chemicals in everyday products continues to grow, a recent study highlights the effectiveness of California’s Proposition 65 in reducing harmful exposures. Published in the journal Environmental Health Perspectives, the study reveals significant reductions in toxic chemical levels in people’s bodies, both in California and nationwide, following the listing of these chemicals under the state law.
“Not only have people’s exposures to specific toxic chemicals gone down in California, but we also see exposures going down across the country driven in part by Proposition 65,” lead author Kristin Knox, a research scientist at Silent Spring Institute, said in a news release.
Proposition 65, also known as the Safe Drinking Water and Toxic Enforcement Act, requires companies to warn Californians about significant exposures to chemicals that cause cancer, birth defects or reproductive harm. With a list that has grown to over 850 chemicals, the law is one of the most comprehensive of its kind.
The new study, conducted in collaboration with researchers at the University of California, Berkeley, analyzed data from the U.S. National Health and Nutrition Examination Survey (NHANES). This federal program collects health data, including blood and urine samples, to test for various synthetic chemicals and pollutants.
The researchers focused on 37 chemicals, including 26 listed under Prop 65. The results showed a decline in the levels of these chemicals in people’s bodies after they were listed. This trend was observed not only in California but across the United States.
“This aligns with what we’ve learned by interviewing companies,” added Knox. “When companies reformulate their products to avoid Prop 65 chemicals, they end up doing that for all their products, not just those sold in California.”
The study also found that Californians generally exhibit lower levels of certain toxic chemicals compared to the rest of the country, which is attributed to the state’s stringent regulations and heightened public awareness.
“Our finding that Californians are generally less exposed to toxic chemicals than are other Americans has potentially far-reaching implications. It suggests a tangible public health payoff from the state’s more stringent environmental regulations,” co-author Claudia Polsky, the director of the Environmental Law Clinic at UC Berkeley School of Law, said in the news release. “We hope other researchers will probe this issue further so we can better understand which regulations work and why.”
Notably, while the law has led to decreased exposure to listed chemicals, the study discovered that some companies have substituted these with similarly harmful chemicals not yet listed under Prop 65. For instance, levels of BPA decreased after its listing, but its replacement, BPS, saw an increase.
The researchers emphasize the need for enhanced biomonitoring programs and more comprehensive policies.
“We have relatively good national-level biomonitoring data, but NHANES isn’t designed to detect changes in chemical exposures driven by local or state-level policy,” said co-author Meg Schwarzman, a physician and environmental health scientist at the UC Berkeley School of Public Health.
“Policymakers could change this picture by better supporting both NHANES and state-level biomonitoring programs, as well as creating chemicals policies that require before-and-after testing to measure the policy’s effectiveness. This could really help identify interventions that actually reduce toxic exposures,” Schwarzman added.
The study provides a hopeful outlook on the effectiveness of environmental regulation in protecting public health.