Despite being banned in the 1970s, chemicals used in certain pesticides and in consumer goods may still be affecting babies, acccording to a new study from the A.J. Drexel Autism Institute.

Children born after exposure to the highest levels of certain PCBs during pregnancy were roughly 80 percent more likely to be diagnosed with autism than those with the lowest levels of exposure, researchers found.

80%

Increased likelihood of children born with autism after being exposed to the highest levels of certain PCBs during their mother’s pregnancy.

Although PCBs are no longer produced in the United States, they can remain in the environment and become absorbed in the fat of animals that humans eat.

Along with a team of researchers from the California Department of Public Health, the Kaiser Permanente Division of Research and the National Center for Environmental Health, Lyall looked at a sample of children born in Southern California between 2000 and 2003.

Blood tests taken during the second trimester of the mothers’ pregnancies showed that two compounds in particular — PCB 138/158 and PCB 153 — stood out as being significantly linked with autism risk. Children with the highest in utero levels of the compounds were between 79 and 82 percent more likely to have an autism diagnosis than those with the lowest levels. High levels of two other compounds, PCB 170 and PCB 180, were also associated with approximately 50 percent greater likelihood of an autism diagnosis.

“The results suggest that prenatal exposure to these chemicals above a certain level may influence neurodevelopment in adverse ways,” Lyall says.