Early life exposure to bisphenol A (BPA) may be linked to an increased risk for the development of several types of behavior problems, new research suggests.
A study of almost 292 participants showed that prenatal exposure to BPA, as measured in maternal urine tests, was associated with internalizing behaviors, such as anxiety and depression, in the boys at the age of 7 years — but not in the girls.
However, early childhood BPA concentrations were associated with increased externalizing behaviors, such as conduct problems, in the girls. Childhood urine measurements of BPA were also linked to the internalizing behaviors of inattention and hyperactivity in both sexes.
"I’d say the take-away is that exposure to BPA, such as in hard plastic containers or canned foods, should be avoided if possible," coinvestigator Robert B. Gunier, data analyst and PhD candidate at the Center for Environmental Research and Children’s Health in the School of Public Health at the University of California, Berkeley, told Medscape Medical News.
"There have been a few studies now that have shown very similar results, as far as the internalizing behaviors in children. Although a single study can’t prove any relationship like this between environmental exposures, there have now been a few that are fairly consistent," said Gunier.
The study was published online July 17 in Environmental Research.
Prenatal Exposure
BPA is “an endocrine disrupting chemical used in some food and beverage containers, receipts, and dental sealants, [and] has been associated with anxiety and hyperactivity in animal studies,” write the researchers.
They add that although some human studies have shown that early life exposure to BPA may be linked to behavior problems in children, specific results have been mixed — including what role the different sexes may play.
The ongoing Center for the Health and Assessment of Mothers and Children of Salinas (CHAMACOS) study was started in 1999 to assess environmental exposures in 601 pregnant women who were living in an agricultural area of California.
Robert Gunier
"This study started off primarily to examine pesticide exposures in this farm-working community. Since then, the study has branched out to look at other chemicals, such as flame retardants and BPA," said Gunier.
For this analysis, the investigators evaluated data on the CHAMACOS study participants (98.6% Latina, 4% other), as well as on 292 of their children.
During pregnancy, maternal urine samples were collected and measured for BPA concentrations. Urine samples were also collected from the offspring at 5 years of age.
When the children were 7 years of age, their mothers and teachers filled out the Behavior Assessment System for Children 2 (BASC-2) and the Conners’ ADHD/DSM-IV Scales (CADS).
Aggressive Behavior
When assessing prenatal exposure to BPA, the researchers found that the boys who had been exposed to higher concentrations had increased internalizing problems, according to scores on the BASC-2.
In fact, each doubling of concentration was linked to an increase in internalizing scores by 1.8 points (95% confidence interval [CI], 0.3 - 3.3; P Abstract 