October 24, 2011 — New research suggests an association between gestational exposure to the widely used industrial chemical bisphenol A (BPA) and increased anxious, depressive, and hyperactive behaviors at age 3 years, particularly in girls.
The research was published online October 24 in Pediatrics.
"At this point, we don't know what these findings mean in terms of clinical disorders of behavior," Joe M. Braun, MSPH, PhD, from the Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, told Medscape Medical News. "Future studies will need to determine if BPA exposures are associated with clinical behavior disorders," he said.
BPA is used in a variety of consumer products, including dental sealants, food/beverage containers and linings, medical equipment, and thermal receipts, such as those from ATM machines. Virtually all people in industrialized nations are exposed to the plasticizer.
"People who are concerned about BPA exposure could decrease or eliminate their consumption of canned or packaged foods; they could also avoid contact with thermal receipts," Dr. Braun said.
Increased Hyperactivity, Aggression
In an earlier study, Dr. Braun and colleagues found that gestational BPA exposure was associated with increased hyperactivity and aggression in 2-year-old girls in a prospective birth cohort from Cincinnati, Ohio.
They have now followed the children out to age 3 years, with similar results. The cohort includes 244 mothers and their 3-year-old girls. Mean urinary BPA concentrations were determined at 16 and 26 weeks' gestation and at age 1, 2, and 3 years in the children. Behavior and executive function were measured using the Behavior Assessment System for Children 2 and the Behavior Rating Inventory of Executive Function–Preschool.
As expected, BPA was detected in more than 97% of the gestational and childhood urine samples. Median concentrations were 2.0 μg/L and 4.1 μg/L, respectively.
There was no association between childhood urinary BPA concentrations and behavioral issues.
However, after adjusting for various confounding factors, each 10-fold increase in gestational BPA concentration was associated with more anxious and depressed behavior on the Behavior Assessment System for Children 2 scale and poorer emotional control and inhibition on the Behavior Rating Inventory of Executive Function–Preschool, the researchers report.
Sex Difference Intriguing
Girls were more sensitive to gestational BPA exposures than boys, but the authors urge caution in interpreting this finding, "given the imprecision of the observed associations among girls and the low statistical power for interactions between gender and BPA exposures."
Nonetheless, they say, the apparent sex difference is "intriguing, given the endocrine-disrupting nature of BPA."
The authors acknowledge that there is considerable debate regarding the toxicity of low-level BPA exposure, and say current findings warrant further research.
"My colleagues at the Mt. Sinai School of Medicine have reported that gestational BPA exposure is associated with atypical social behaviors (behaviors observed in children with [attention-deficit/hyperactivity disorder] and autism)," Dr. Braun told Medscape Medical News.
"Going forward," he said, "we will continue to examine other behaviors including autistic-like behaviors and spatial abilities" in relation to BPA exposures. "We will also try to determine if BPA impacts fetal sex steroid production or action during gestation."
The study was supported by the National Institutes of Health. The authors have disclosed no relevant financial relationships.
Pediatrics. 2011;128:873-882. Abstract
Medscape Medical News © 2011 WebMD, LLC
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Cite this: Megan Brooks. Prenatal BPA Exposure May Negatively Affect Kids' Behavior - Medscape - Oct 24, 2011.