Parents’ workplace exposure to chemicals may affect ASD severity in their children

Parental exposure to certain substances in the workplace is associated with greater symptom severity in children with autism spectrum disorders (ASD), according to a study by U.S. researchers.

Erin McCanlies and colleagues say, “Although studies have linked parental occupational exposure (e.g. paints, xylene, solvents, exhaust and combustion products, pesticides) to ASD, to our knowledge there are no studies that have evaluated if parental occupational exposures are associated with common co-occurring behaviors or cognitive and adaptive skills in their children with autism.” To address this issue, the researchers analyzed data on 532 families in the CHARGE study, focusing specifically on children already diagnosed with autism.

In the study, industrial hygienists explored both parents’ job histories from three months before pregnancy to birth, estimating their exposure to 16 chemicals or agents—for example, plastics, car fluids, disinfectants, and medications. The researchers then assessed the severity of the children’s symptoms using the Calibrated Severity Score derived from the Autism Diagnostic Observation Schedule. In addition, they analyzed the children’s scores on the Mullen Scales for Early Learning, the Vineland Adaptive Behavior Scales, and the Aberrant Behavior Checklist.

Study coauthor Irva Hertz-Picciotto says the study shows that “workplace safety isn’t just about protecting the worker—it’s also about protecting their future children. We must consider how workplace chemicals might affect the next generation.”

They report, “Parental occupational exposures to phenols, ethylene oxide, and plastics/polymers were associated with more severe autism spectrum disorder symptoms. Several parental occupational exposures were associated with autism spectrum disorder behaviors, including anesthetic gases, disinfectants, and pharmaceuticals. However, plastics/polymers stood out, being associated with multiple developmental and behavioral outcomes including irritability, hyperactivity, respective and visual language, and daily living.” The researchers say their results showed the importance of including fathers in similar studies in the future, as many associations they detected were linked to paternal exposures.

McCanlies says, “Our findings suggest that parental exposure to certain workplace chemicals during key fetal development periods may influence not just autism likelihood, but also severity and functioning outcomes for children with autism.” Study coauthor Irva Hertz-Picciotto adds, “This research shows that workplace safety isn’t just about protecting the worker—it’s also about protecting their future children. We must consider how workplace chemicals might affect the next generation.”

Citations

“The effects of parental occupational exposures on autism spectrum disorder severity and skills in cognitive and adaptive domains in children with autism spectrum disorder,” Erin C. McCanlies, Ja Kook Gu, Claudia C. Ma, Wayne T. Sanderson, Yunin J. Ludeña-Rodriguez, and Irva Hertz-Picciotto, International Journal of Hygiene and Environmental Health, July 2025 (free online). Address: Erin McCanlies, [email protected].

—and—

“Parental workplace chemical exposure linked to autism severity and behavior in children,” news release, University of California at Davis, August 9, 2025.