Aerial spraying to combat mosquitoes linked to increased risk of autism in children

Researchers who will present the abstract, "Aerial Pesticide Exposure Increases the Risk of Developmental Delay and Autism Spectrum Disorder," identified a swampy region in central New York where health officials use airplanes to spray pyrethroid pesticides each summer. The pesticides target mosquitoes that carry the eastern equine encephalitis virus, which can cause swelling of the brain and spinal cord. They found that children living in ZIP codes in which aerial pesticide spraying has taken place each summer since 2003 were approximately 25 percent more likely to have an autism diagnosis or documented developmental delay compared to those in ZIP codes with other methods of pesticide distribution, such as manually spreading granules or using hoses or controlled droplet applicators.

"Other studies have already shown that pesticide exposure might increase a child's risk for autism spectrum disorder or developmental delay," said lead investigator Steven Hicks, MD PhD. "Our findings show that the way pesticides are distributed may change that risk. Preventing mosquito-borne encephalitis is an important task for public health departments," he said. "Communities that have pesticide programs to help control the mosquito population might consider ways to reduce child pesticide exposure, including alternative application methods."