For the first time, a study has found a potential connection between a pesticide and the risk of a woman having a child with autism, researchers say.
A study published in The American Journal of Psychiatry found that exposure to DDE, which forms after the now-banned pesticide DDT breaks down, can as much as double the chance that a woman gives birth to an autistic child.
Dr. Priyanka Chaurasia — a researcher not involved with the study who teaches data analytics at Ulster University — told Newsweek that this new research is “significant because it establishes evidence that environmental factors play a larger role in causing autism than previously thought.”
“Mothers’ exposures during pregnancy may play a role in the development of autism spectrum disorders,” she said in an interview with Newsweek. “This study does suggest that exposure to farming chemicals during pregnancy is probably not a good thing.”
For the study, researchers gathered data from the Finnish Prenatal Study of Autism, conducted between 1987 to 2005, to examine what relationship, if any, there was between the disorder and DDE and PCB, a chemical once used for coolant fluids.
More specifically, scientists examined data for the 750 pairs of children and parents that the study collected to examine if there was any connection between the chemicals and autism.
While scientists found “no association” between autism and PCBs, they did find that women who had DDE in their system were “significantly” more at risk for having a child with autism. The quarter of women who had the highest DDE levels were twice as likely to see their child develop autism, the study says.
DDT, a colorless and tasteless insecticide, was banned in the United States in 1972 amid concerns that it would harm the environment and cause cancer., according to the Environmental Protection Agency. DDE forms from DDT as it begins to break down, and it can be found in food, soil and groundwater, HealthDay wrote.
Dr. Alan Brown, a co-author of the study, said that the chemical is still present decades after it was banned because it breaks down “slowly over time,” according to HealthDay.
“Even though they’re not produced any more in the Western world,” he said, “almost everyone is exposed to some of them.”
A press release from The American Psychiatric Association offered another explanation for why the chemical sticks around.
“Although DDT and other persistent organic pollutants were widely banned in many countries decades ago, they persist in the food chain, resulting in continuous exposure among populations,” it reads. “These chemicals transfer across the placenta, resulting in potential prenatal exposure among nearly all children because of existing maternal body burdens.”
Still, Uta Frither — a professor from the UCL Institute of Cognitive Neuroscience, U.K. — casts doubt on the study’s findings in her interview with Newsweek.
She instead argued that the evidence for autism being genetic, and not caused by external factors, is “overwhelming.”
“It may well be that man-made hazards harbour dangers that we don’t yet know about, and insecticides in particular are worrying for many reasons,” she told Newsweek. “Unfortunately, it is not possible to draw practical implications from the present study.”
The uncertainty is one more reason why research is needed to determine just how powerful the relationship between the pesticide and autism can be, the study’s authors wrote.