Gestational exposure to
chemical BPA before birth associated with behavioral and emotional
difficulties in young girls
Exposure in the womb to bisphenol A (BPA)
- a chemical used to make plastic containers and other consumer
goods - is associated with behavior and emotional problems in young
girls, according to a study led by researchers at Harvard School
of Public Health (HSPH), Cincinnati Children's Hospital and Medical
Center, and Simon Fraser University in Vancouver, British Columbia.
BPA is found in many consumer products, including canned food linings,
polycarbonate plastics, dental sealants, and some receipts made
from thermal paper. Most people living in industrialized nations
are exposed to BPA. BPA has been shown to interfere with normal
development in animals and has been linked with cardiovascular disease
and diabetes in people. In a 2009 study, HSPH researchers showed
that drinking from polycarbonate bottles increased the level of
urinary BPA.
In this study, published October 24, 2011, in an advance online
edition of Pediatrics, lead author Joe Braun, research fellow in
environmental health at HSPH, 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% of the urine samples from the mothers
and over 96% 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.
After adjusting for possible contributing factors, increasing 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 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,
Braun said. "Gestational, but not childhood BPA exposures,
may impact neurobehavioral function, and girls appear to be more
sensitive to BPA than boys," he said.
Although more research is needed to fully 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.
Bruce Lanphear of Simon Fraser University was senior author of
the study.
The study was funded in part by the National Institute of Environmental
Health Sciences and the U.S. Environmental Protection Agency.
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