By Rebecca Jones

A new study finds that girls who are exposed to bisphenol-A (BPA) in the womb may be a t higher risk for behavioral problems.

What is BPA

BPA is commonly found in polycarbonate plastic. Being clear and virtually shatterproof BPA plastics are used in everything from baby bottles to the lining of food cans. For the last decade numerous studies have been conducted to determine the effects of long term exposure to BPA including its suspected links to obesity, neurological issues, and thyroid function. As of September 2010 Canada became the first country to declare BPA a toxic substance and, along with the European Union, ban the use of BPA in baby bottles.

The Study  

In the latest study the Harvard School of Public Health teamed up with the Centers for Disease Control and Prevention to see what the effects of pre-natal exposure are in young children. To conduct the study researchers tested BPA levels in the urine of 244 expectant mothers throughout their pregnancy and at the time of birth. Researchers also tested BPA levels in their children periodically after birth. Once the children reached the age of 3 the mothers filled out two questionnaires to assess whether their children were experiencing emotional or behavioral problems.

The Results

Researchers found that the higher a mothers BPA levels during pregnancy tended to have young girls that were more anxious and depressed and more likely to exhibit poor impulse and emotional control such as is common with attention deficit hyperactivity disorder. These effects seem limited solely to female children, the same study found no correlation between BPA levels and emotional and behavioral problems in young boys. They also found that exposure to BPA after birth did not cause any perceptible effects suggesting that it is the prenatal period where girls are most vulnerable.

How BPA Effects Development

While researchers insist that continuing studies need to be conducted before any real conclusions can be drawn from these findings they do have a few guesses as to why BPA exposure affects girls and not boys. Hormones play a large role in brain development in the womb and it hypothesized that BPA works as either an estrogen or an anti-estrogen and is an endocrine-disrupting compound. In tests conducted in rats, exposure to BPA in pregnant rats has caused females to be born more masculine. There is also evidence that BPA effects dopamine, a neurotransmitter that plays a role in the regulation of behavior.

While researchers insist that it is much too soon to draw any definitive conclusions they do recommend that women try to reduce BPA exposure during pregnancy by avoiding canned or packaged food.