Mothers with high levels of the pesticide DDT in their blood during pregnancy are more likely to bear children who develop autism, according to a study of blood samples from more than one million pregnant women in Finland.
Although the authors stress that the findings do not prove that autism is caused by DDT—whose use has been banned in many countries for decades over concerns about its effects on wildlife—it is the first such association using a direct measure of exposure to the pesticide.
…[Researchers] found that mothers with high concentrations of this chemical—those in the top quartile—were 32% more likely than women with lower DDT levels to give birth to children who developed autism. The likelihood that a child with autism accompanied by intellectual disability was twice as high in mothers with elevated DDT levels compared to those with lower levels.
It’s unclear how exactly DDT could raise the risk of autism, but [researcher Alan] Brown proposes two hypotheses. DDT has been shown to cause low birth weight and premature birth, which are known risk factors for autism. DDT is also known to bind to proteins in the body called androgen receptors, which allow cells to respond to testosterone and other hormones.
Read full, original post: Autism and DDT: What 1 Million Pregnancies Can—and Can’t—Reveal