A research has proved that pregnant women who have been exposed to DDT have an increased risk in bearing children with autism.
Notably, dichlorodiphenyltrichloroethane or DDT was condemned in the 1960s due to its environmental impacts. Since then, the pesticide has been banned in many places around the world.
However, some countries still use it. The dangerous chemical was already banned in America in 1972.
The study titled "Association of Maternal Insecticide Levels With Autism in Offspring From a National Birth Cohort" was published in the American Journal of Psychiatry. Its goal was to find out a link between maternal levels of assiduous organic pollutants such as PCBs and DDTs and autism cases.
The paper identified cases from the Finnish Prenatal Study of Autism that contained over a million cases of Finnish women who gave birth between 1987 and 2005. Researchers studied the DDE levels in the maternal blood samples of more than 750 children with autism.
The samples were compared with control subjects and were tested for DDT and p,p'-dichlorodiphenyl dichloroethylene or p,p'-DDE, the metabolite that is formed as DDT breaks down in the body. Furthermore, researchers also studied the levels of polychlorinated biphenyls or PCBs that could potentially be toxic pollutants as well.
Although the study found no significant relationship between PCBs and autism, they concluded that a child is at risk of developing autism if the mother had high concentrations of the DDT byproduct, DDE.
According to the study, the top 25 percent of mothers who have high concentrations of DDE in their blood have a 32 percent chance of giving birth to children with autism than those who scored lower.
"In addition, the odds of children having autism with intellectual disability were increased more than twofold with maternal DDE levels above this threshold," noted a statement from the American Psychiatric Association.
"While these results indicate an association, they do not prove causation, although the findings persisted after controlling for confounding factors."
Dr. Alan Brown, the lead researcher and also a professor of psychiatry and epidemiology at NYC's Columbia University Medical Center, encourages pregnant women or those who are planning to bear children to eat organic produce. They must wash the vegetables and fruits thoroughly before consumption to get rid of toxic residues. However, he does not consider it as a cause for alarm.
"We showed that overall in autism, there was a modest increase in risk, but the vast majority of offspring who are exposed to the high levels still won't get autism," he said.