California’s nation-leading restrictions on toxic chemicals in consumer products reduced the population’s body levels for many dangerous compounds linked to cancer, birth defects, reproductive harm and other serious health issues.
New peer-reviewed research showed levels in residents’ blood for 37 chemicals the authors analyzed had declined after the substances were designated under Proposition 65, which regulates toxic chemicals in consumer goods.
Among levels that fell were highly toxic PFAS “forever chemicals”, flame retardants, diesel chemicals, phthalates and bisphenol.
The findings come as the federal government faces mounting criticism for not doing enough to rein in toxic chemicals in consumer goods, and the paper’s authors say their findings suggest regulations work.
“It suggests a tangible public health payoff from the state’s more stringent environmental regulations,” said Claudia Polsky, director of the Environmental Law Clinic at UC Berkeley School of Law, and a study co-author.
Researchers largely looked at chemicals covered by Proposition 65, which was implemented in 1986. It requires companies that sell products in California to warn consumers if the goods contain harmful chemicals that cause cancer, birth defects or reproductive harm.
About 850 chemicals have been designated under the law. The paper compared data for 37 Prop 65 chemicals, or other compounds closely related to those that are designated, for which federal regulators also track levels in the US population’s bodies.
Median levels decreased for several PFAS, which are among the most common and dangerous manmade substances. PFOS and N-MeFOSAA, two PFAS compounds, dropped by 77%, and PFOA levels fell by 62% – the levels are lower than national medians. Meanwhile, median bisphenol-A (BPA) concentrations decreased 15% after the designation.
Though people in California showed lower levels than the rest of the US in many instances, the law’s benefits may not be limited to California: levels of toxic chemicals in people’s bodies often went down in the state and across the US in the years following the chemicals’ Prop 65 designation, suggesting companies reformulated products to avoid the compounds.
However, the authors cautioned that drops in body levels may not only be attributable to Prop 65. Though levels for phthalates, a common plasticizer, dropped in California, it coincided with a push by other states and the federal government to reduce the usage of some of the compounds.
The study also found evidence of companies swapping out one toxic chemical for another problematic chemical with similar chemical structure and health effects. BPA levels dropped after it was designated, but levels of a related compound, bisphenol S (BPS), increased 20% over the same period.
Similarly, levels of the phthalate DEHP, used in vinyl and other plastic products, went down after it was listed in 2003. At the same time, exposures to a closely related unlisted phthalate called DiNP went up. Levels of DiNP then dropped after it was also listed in 2013.
The substitution “undermines the net health benefits of some chemical-specific restrictions and illustrates the need for chemical policies that address groups of closely related chemicals as classes”, the study’s authors wrote.
