Boys exposed to higher bisphenol A concentrations in the womb or during childhood were more likely to develop anxiety, depression and hyperactivity, according to a study of children from the Salinas Valley. The study adds to previous research that has linked the hormone-altering chemical — which is found in polycarbonate plastics, canned food liners, and some cash register receipts — to behavioral problems in children.

Researchers from the UC Berkeley measured BPA concentrations in 292 pregnant mothers and then measured the levels in their children’s blood at age five. Mothers and teachers evaluated the children’s behavior at age seven, and then they were assessed for Attention Deficit Hyperactivity Disorder (ADHD) at age nine.

At age seven, boys who had been exposed to higher BPA concentrations as a fetus were more likely to suffer from anxiety, aggression, and depression, although there was no association for girls. For exposures during childhood, BPA was linked to conduct problems in girls, and inattention and hyperactivity in boys.

No link was found between BPA and ADHD in boys or girls exposed either in the womb or during childhood.

It is unknown why there were differences between the genders, according to the authors. Among previous studies that linked BPA exposure to child behavior problems, “there is little consistency about whether these effects are in boys or girls,” the authors wrote.

In previous studies, prenatal BPA concentrations were associated with increased behavior problems in girls, but not boys. Also, in a low-income black population, prenatal BPA concentrations were associated with fewer behavior problems in girls, but more for boys.

The mothers and children in the new study had lower BPA concentrations than the US average. Nearly all were Hispanic, and 70 percent lived below the poverty level.

In the new study, the researchers took into account factors that could affect children’s behavior such as poverty, family income, and pesticides that have been associated with attention problems. However, the BPA measurements (taken five years apart) may not accurately represent the children’s ongoing BPA exposure.

About 95 percent of Americans have BPA in their urine, according to a 2008 study. People are exposed via plastic containers, canned food, dental sealants, and receipts. Animal studies have linked BPA exposure to altered brain function, disrupted hormones, increased anxiety and hyperactivity, with little gender consistency among the studies. It is biologically plausible that BPA may impact child behavior by altering sex hormones or dopamine and other neurotransmitters, the authors said.

This report was originally published by EnvironmentalHealthNews.org