Thursday 03 November 2011
Research has shown that fetal exposure to a chemical commonly used to make linings of plastic cans, may lead to behavioural problems in young girls.
There is a reason why some three-year-old girls are cranky. A team of researchers has found that baby girls who were exposed to bisphenol A (BPA) in the womb went on to demonstrate hyperactive, anxious, aggressive, and depressed behavior at age three.
BPA is used to harden plastic, and is found in consumer products, ranging from plastic cans to baby feeding bottles. The chemical has been shown to cause developmental defects and hormonal problems in animal studies, but its effects in humans are still debated. The latest study could be the first step towards settling that debate.
Scientists from Harvard School of Public Health (HSPH), Cincinnati Children’s Hospital and Medical Center, and Simon Fraser University in Vancouver in Canada examined urine samples of 244 mothers during pregnancy and at birth and their children for the first three years. BPA was detected in over 85 per cent urine samples in women and in 96 per cent in children's samples. The mothers were surveyed about their children's behaviour when they were three years old. “None of the children had clinically abnormal behaviour, but some children had more behaviour problems than others. Thus, we examined the relationship between the moms and children’s BPA concentrations and the different behaviours,” says lead author Joseph Braun, research fellow in environmental health at HSPH.
It was observed, after adjusting possible contributing factors, that increasing gestational BPA concentrations corresponded with more behavioural abnormalities like hyperactivity, anxiety and poor emotional control in girls, but not in boys. “Gestational, but not childhood BPA exposures, may impact neurobehavioural function, and girls appear to be more sensitive to BPA than boys,” Braun adds.
Giving reasons why the effects of the chemical were not noticed in young boys, Anoop Kohli, senior consulting neurologist with Indraprastha Apollo hospital in Delhi, says bisphenol was hitherto considered a weak environmental estrogen, the female hormone. "This could perhaps be one of the reasons that behavioural changes were seen in female children at the end of three years," he adds. But Kohli does not rule out the possibility of boys getting affected. "One cannot say that there may not be behavioural changes in boys in later years, he says
In the wake of studies that show the presence of BPA in baby foods and plastic feeding bottles, countries have been proactive in restricting its use. Canada imposed a ban on plastic baby bottles that contain BPA in March last year. The European Union and China followed suit with a similar ban in March this year. While there's no ban in place in the US, several states have passed laws to regulate the chemical's use. California recently passed a bill banning BPA from baby products.
India yet to act
India is yet to make any effort in this direction. The Food Safety and Standards Act, 2006, does not clearly address the issue of toxicity from food packaging. India has no law to regulate use of BPA, says Gopal Krishna, convenor of ToxicsWatch Alliance, a non-proft. “The health ministry's attention to environmental and occupational health has been minimal. They should be the ones looking at this.”
B Dinesh Kumar, senior scientist at National Institute of Nutrition in Hyderabad, says that the institute has received a request from the government for their comments on the issue of use of BPA in consumer products. However, it could be a while before there are any laws regarding regulation of BPA are passed. “There are no studies in the country to show whether or not BPA is present in baby bottles and other consumer products,” says J P Dadhich, national cooordinator of the non-profit, Breastfeeding Promotion Network of India. “To have regulations, we need to first ascertain whether our products have the chemical and to what extent. Most of the studies on the chemical have been done abroad.”
In the absence of any regulation on the use of the chemical, what precautions can mothers, who are at most risk from the chemical, take? “Typically, they could buy products with an ISI mark. However, since ISI has not determined any safe limits of BPA itself, there is no absolute guarantee the products will be safe.”
Dadhich says the best course of action for mothers is to breastfeed their babies.
The study was published in the October 24 issue of the journal Pediatrics.