Girls exposed to the industrial chemical bisphenol A (BPA) while still in their mother's womb may face an elevated risk of developing behavioural and emotional problems, a new study suggests.
The research team collected urine samples from 244 pregnant women to measure their levels of BPA, which is used for making hard, clear plastics and food packaging – including the liners of most tin cans. The mothers evaluated the behaviour of the children at the age of three.
The data revealed that girls whose mothers had the highest BPA levels during pregnancy showed more signs of being hyperactive, aggressive, anxious, depressed and emotionally out of control displayed less emotional control. This association was much less apparent in boys, according to the study results published in the journal Pediatrics.
Some scientists have warned that BPA could interfere with numerous biological processes, including normal physical and psychological development, because its chemical structure resembles the female hormone estrogen.
As a precautionary measure, the federal government has banned BPA in baby bottles and other infant products. But the new study "raises the question of whether the BPA ban in children's products is sufficient," said the senior researcher, Bruce Lanphear of Simon Fraser University in Burnaby, B.C.
"Did it [the government] miss the mark by neglecting exposures that happen during pregnancy?" he asks. Dr. Lanphear acknowledged his study involved a relatively small number of subjects. But he said it serves "as a red flag" that warrants further investigation.
Even though prenatal BPA exposure did not seem to alter male behaviour, "there could be other effects in boys that become evident as more study is done," Dr. Lanphear said. In the meantime, he said, pregnant women should try to minimize their exposure to BPA.