A study published online in a scientific journal suggests a possible link between aggressive behavior in 2-year-old girls and prenatal levels of bisphenol A in their mothers.
But the authors were quick to add that their study has a number of limitations.
“Prenatal BPA exposure may be associated with [aggressive] behaviors in 2-year-old children, especially among female children, but this study has several limitations,” concluded the report, which was published online Oct. 6 in Environmental Health Perspectives. “The results of these analyses should be interpreted cautiously.”
Specifically, the researchers said, a number of “unmeasured [factors] may be responsible for some or all of our observed associations [and that] it is possible we did not adequately assess parental psychology” and how that influenced the behavior of the children in the study.
In addition, they noted that it is “difficult to accurate characterize exposure [to BPA] from a single measurement” and added that they did not examine whether postnatal BPA exposure was associated with childhood behavior.
The study, which looked at the possible effect on early childhood behavior and prenatal BPA exposure, assessed the results of standard behavioral assessment tests given to the children of 249 Cincinnati-area women whose BPA levels were measured through urine samples 16 and 26 weeks into their pregnancy and at birth.
The study was conducted by researchers at the University of North Carolina, Simon Fraser University in British Columbia and Cincinnati Children's Hospital Medical Center.
In an Oct. 7 interview, Steve Hentges, executive director of the polycarbonate/BPA global group of the plastics division of the American Chemistry Council in Arlington, Va., warned that people should be cautious about drawing definite conclusions from the study.
“There is significant potential for this study to be misconstrued, so you need to be very careful about how you look at its conclusions,” Hentges said. “The study cannot be considered meaningful for human health unless the findings are replicated in a more robust study.”
He said the study only evaluates parameters measured in the study for “statistical associations which may be neither real, nor meaningful. It is a very limited study which does not establish cause-effect relationships,” said Hentges. “There are many other things that were not measured” that could cause the results suggested in the study.
Hentges said the study did not evaluate the impact of diet, nutrition or parental guidance on the children's behavior.
But Joe Braun, a doctoral student at the Gillings School of Public Health at the University of North Carolina, and the study's lead author, defended the research paper.
Braun said researchers wanted to know if there was a risk in humans for neurodevelopment problems based on prenatal BPA levels after five studies of rodents indicated that prenatal BPA exposure is associated with increased aggression. “The study results indicate that exposure to BPA early in the pregnancy seems to be the critical issue,” he said.
The researchers did not suggest why the higher BPA levels only affected girls.
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