The researchers found anxiety, depression and hyperactivity were seen more often in toddler girls whose mothers had high levels of the chemical in their urine while pregnant.
“This pattern was more pronounced for girls, which suggests that they might be more vulnerable to gestational BPA exposure than boys,” write the researchers in their study which appears in the journal Paediatrics.
BPA is used in the manufacture of plastics and adhesives, and can be found in the lining of canned foods, some plastic bottles and containers, cashier receipts and dental fillings.
The analysis was done using data from 244 mothers and their children up to age three years in the Cincinnati, Ohio area. The mothers’ urine samples were tested while pregnant at 16 and 26 weeks, and again at birth.
The children’s urine was tested at age one, two and three years. BPA was found in 85 per cent of the mothers’ urine and in 96 per cent of the samples from the children.
The higher the BPA levels were while the mother was pregnant, the more likely the daughters were to experience behavioural problems by age three.
The same correlation was not seen in boys, nor was there any apparent link between behaviour and levels of BPA in the children’s urine, according to the data derived from questionnaires on child behaviour filled out by the parents.
CHANGES ONLY SEEN IN GIRLS
“None of the children had clinically abnormal behaviour, but some children had more behaviour problems than others,” says lead author Joe Braun, research fellow in environmental health at the Harvard School of Public Health.
The study reported that “increasing gestational BPA concentrations were associated with more hyperactive, aggressive, anxious, and depressed behaviour and poorer emotional control and inhibition in the girls.”
The research appeared to support previous studies that have suggested a link between BPA exposure in the womb and child behaviour, but is the first to show that in utero exposure is the critical window when altering effects may occur.
However, due to the small size of the sample, the study authors – who also included scientists at Cincinnati Children’s Hospital and Medical Center, and Simon Fraser University in Vancouver, British Columbia – say more research is needed.
“There is considerable debate regarding the toxicity of low-level BPA exposure, and the findings presented here warrant additional research,” they write.
Funding for the study came from the National Institute of Environmental Health Sciences, the US Environmental Protection Agency and the National Institute of Environmental Health Sciences training.