New research suggests fetal exposure to a chemical used to make plastic containers and other consumer goods called BPA is associated with a slight but nonsignificant increase in behavioral and emotional problems in young girls.
Scientists note that BPA is still found in some consumer products, including canned food linings, polycarbonate plastics, dental sealants, and some receipts made from thermal paper.
As a result, most people living in industrialized nations are exposed to BPA. Prior studies have shown that BPA may interfere with normal development in animals and may be associated with cardiovascular disease and diabetes in people. In a 2009 study, for instance, researchers showed that drinking from polycarbonate bottles increased the level of urinary BPA.
In this study, lead author and epidemiologist Dr. Joe Braun, research fellow in environmental health at Harvard School of Public Health, and his colleagues found that gestational BPA exposure was associated with more behavioral problems at age 3, especially in girls.
The researchers collected data from 244 mothers and their 3-year-old children in the Health Outcomes and Measures of the Environment Study, conducted in the Cincinnati area.
Mothers provided three urine samples during pregnancy and at birth that were tested for BPA; their children were tested each year from ages 1 to 3. When the children were 3 years old, the mothers completed surveys about their children’s behavior.
“None of the children had clinically abnormal behavior, but some children had more behavior problems than others. Thus, we examined the relationship between the mom’s and children’s BPA concentrations and the different behaviors,” Braun said.
BPA was detected in over 85 percent of the urine samples from the mothers and over 96 percent of the children’s urine samples. The researchers found that maternal BPA concentrations were similar between the first sample and birth. The children’s BPA levels decreased from ages 1 to 3, but were higher and more variable than that of their mothers.
Researchers discovered higher levels of gestational BPA concentrations were associated with more hyperactive, aggressive, anxious, and depressed behavior and poorer emotional control and inhibition in the girls. This relationship was not seen in the boys.
The behavior found in girls with higher levels of BPA, however, were still within the normal range of behavior for 3-year-old children. The children would not meet the diagnostic criteria for the problems observed.
Furthermore, the researchers did not control for issues where BPA may simply be a marker, such as lower socio-economic status.
Researchers believe the study confirms two prior studies showing that exposure to BPA in the womb impacts child behavior, but is the first to show that in utero exposures are more important than exposures during childhood, the researchers claimed. It is not clear that the researchers’ claims are warranted, given the small sample size, single geographic location of the subjects, and before the study has been replicated.
“Gestational, but not childhood BPA exposures, may impact neurobehavioral function, and girls appear to be more sensitive to BPA than boys,” he said.
Experts say that while additional research is necessary to clearly understand the health effects of BPA exposure, clinicians can advise those concerned to reduce their BPA exposure by avoiding canned and packaged foods, thermal paper sales receipts, and polycarbonate bottles with the number 7 recycling symbol, the authors wrote.
The entire study is published in an advance online edition of Pediatrics.
Source: Harvard School of Public Health