A quarterly publication of the Autism Research Institute
Spring 2025 | Number 2, Volume 39
A study by researchers at the University of California at Davis adds to evidence that environmental pollutants may play a role in autism spectrum disorders (ASD).
The study, by Amanda Goodrich and colleagues, examined data on 1,526 children between two and five years of age who were enrolled in the CHARGE (Childhood Autism Risk from Genetics and the Environment) study. Of the children, 810 had ASD, 186 had a developmental disability (DD), and 530 were neurotypical controls. The researchers examined the relationship between household insecticide use and ASD or DD, focusing on the timeframes between three months pre-conception and the childdren’s second birthdays. They examined household pesticide use, timing, and frequency, as well as the types of applications used (including professional or non-professional applications, indoor or outdoor use, and flea applications).
The researchers report, “Professionally applied indoor insecticides were associated with greater than twofold increased odds of ASD for all time periods.” In addition, they say, “Higher exposure frequency was associated with greater odds of ASD for nearly all application types and time periods.” They also detected an association between increased odds of DD and non-professional indoor insecticide use during the third trimester and the pregnancy period overall.
The researchers say stratification of their data showed that the association of indoor insecticide exposure with ASD was stronger for male children than female children, noting that this “parallels the higher baseline risk of ASD in males and may reflect underlying sex-specific neurobiological vulnerabilities.”
They conclude, “These findings add to [a] growing body of evidence that exposure to household insecticides during pregnancy and early life may be associated with ASD, underscoring the need for heightened awareness and precautionary measures regarding household insecticide use, particularly in environments inhabited by pregnant women and young children. Secondly, these results highlight the potential need for regulatory oversight in the approval and marketing of these chemicals, advocating for stricter safety standards and the promotion of nonchemical pest control alternatives.”
“Professionally and non-professionally applied household insecticides during pregnancy and early life and their associations with autism spectrum disorder and developmental delay in the CHARGE case-control study,” Amanda J. Goodrich, Daniel J. Tancredi, Yunin J. Ludeña, Deborah H. Bennett, Irva Hertz-Picciotto, and Rebecca J. Schmidt, Environmental Research, February 2025 (free online). Address: Amanda J. Goodrich, Dept. of Public Health Sciences, School of Medicine, University of California Davis, Sacramento, CA 95616, [email protected].
