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Your Environment. Your Health.

Chemicals Released in New Cars Increase Cancer Risk

David Volz, Ph.D.
University of California, Riverside

People who spend a significant amount of time in their vehicles may have higher cancer risks from inhaling benzene and formaldehyde, which are used in car interiors, according to a recent NIEHS-funded study.

Researchers estimated exposure to benzene, formaldehyde, phthalates, and other chemicals in vehicle interiors using a meta-analysis of chemical concentrations measured in other studies and commute times. They compared these estimated exposure levels to those established by the California Office of Environmental Health Hazard Assessment to determine the probability of increased cancer risk. The team used a benchmark of 10% probability of exceeding cancer risk as a level of concern.

Benzene and formaldehyde were the only two chemicals with higher cancer risk estimates across any of the commute times, with a large proportion of commuters in the state of California estimated to have at least a 10% probability of having higher cancer risk. Specifically, the researchers estimated that 78% of Californians had higher risk of cancer due to formaldehyde exposure, and 63% were at higher risk due to benzene exposure. They also estimated that 11% of commuters had higher risk of poor reproductive or developmental health resulting from benzene exposure while commuting. According to the authors, people experiencing long commutes over years or decades likely represent a vulnerable subpopulation for exposure to these chemicals.

Citation: Reddam A, Volz DC. 2021. Inhalation of two Prop 65-listed chemicals within vehicles may be associated with increased cancer risk. Environ Int 149:106402.

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