Prenatal exposure to a widely used plasticizer is associated with more early signs of autism and attention deficit disorder in some children.
The substance studied is DEHP, a chemical added to some plastics to make them more flexible. It can be found in vinyl objects and certain medical devices, among other products. Because it can leave the material containing it, people may be exposed through their environment and diet.
Pregnant woman.
Pixabay illustration
The researchers followed 847 children from the Barwon Infant Study, a study conducted in Australia. They estimated the children's exposure to DEHP before birth, then examined behavioral traits associated with autism and attention deficit hyperactivity disorder, or ADHD. These assessments were carried out at ages 2 and 4.
Children with the highest levels of prenatal exposure had more of these early signs.
The team also examined blood taken from the umbilical cord at birth. They studied DNA methylation, a phenomenon involving small chemical marks attached to DNA that can alter how certain genes are used without changing their sequence.
The researchers identified a set of marks associated with DEHP exposure. They also detected a network of 531 genes with interconnected changes. This network includes genes already associated with nervous system development, as well as targets of hormone receptors on which DEHP can act.
A statistical analysis indicates that these methylation differences may contribute to the observed link between exposure and behavior.
Exposure to DEHP largely depends on the products, packaging, and processes present in everyday surroundings. The authors therefore mainly emphasize the importance of regulations governing these substances. Future studies will need to verify these results in other populations and follow the children for longer than the first few years of life.