In one of the largest studies looking at the potential effects of pesticide exposure on still-developing fetuses and newborns, scientists found that exposure to the most commonly used pesticides was linked to higher risk of autism spectrum disorder.

Led by Ondine von Ehrenstein, associate professor in the Fielding School of Public Health at the University of California, Los Angeles, the researchers analyzed autism registry data in California along with data on pesticide spraying in the state. They published their findings in the BMJ.

Overall, the study included nearly 38,000 people, with 2,961 cases of autism. The scientists found that women who were pregnant and who lived within a 2,000 meter radius of a highly sprayed area were anywhere from 10% to 16% more likely to have children diagnosed with autism than women who lived in places farther away from sprayed areas. The researchers reviewed spraying of 11 popular pesticides, including chlorpyrifos, diazinon and permethrin (often used to control ticks).