Shortly after the World Health Organization released its report warning of the potential hazards from exposure to synthetic chemicals, a new study from researchers at Columbia University College of Physicians and Surgeons, in New York City, has linked exposure to bisphenol A (BPA) to higher chances of developing asthma.
The chemical is found in various common goods, such as plastic containers and metal cans used to store food products. It has been linked to a number of conditions, especially in children, including obesity, increased blood sugar levels and behavioral problems. The latest research noted that exposure to BPA is a strong risk factor for developing asthma, even though it may not necessarily directly cause the disease, commented lead researcher Dr. Kathleen Donohue, an assistant professor of medicine at Columbia University College of Physicians and Surgeons.
Statistics reveal that the number of patients diagnosed with asthma has increased over the last three decades, suggesting that there might be an external factor in our environment that is contributing to the development of the disease, Donohue said. The study found that exposure to BPA may be an important environmental risk factor for asthma in children and results show that even routine exposure to low doses of BPA can boost the risk of wheezing and asthma.
Donohue, who is an investigator with Columbia's Center for Children's Environmental Health, and her team monitored 568 women who took part in the study with their newborns and looked into the effect of environmental exposures. Researchers measured the levels of a form of BPA that was found in urine, as a result of exposure to the chemical. They first measured those levels in the final trimester of the women's pregnancy and then the same measurements were taken when the babies were three, five and seven years old. All four measurements revealed that nine in ten children had BPA in their bodies — a proportion that is consistent with previous research.
Results from the study demonstrated that all children who were exposed to BPA after birth were at higher risk of wheezing and asthma, even after researchers took into account other factors related to asthma, such as secondhand smoke. However, there was no link found between asthma and exposure to BPA during the final stages of pregnancy, Donohue explained. This conclusion contradicts previous studies which found that exposure to the chemical in the second trimester of pregnancy led to increased risk of the disease.
According to Donohue, the connection between BPA and asthma is still unknown and so is the actual mechanism in which the chemical can trigger or contribute to the condition. She noted that not every child that has been exposed to BPA will develop asthma or wheezing, so other factors, such as the individual immune system, are likely to play a significant part.
The U.S. government has been put under pressure to ban the use of the chemical, especially in products intended for children. In July 2012 the U.S. Food and Drug Administration banned BPA in baby bottles and sippy cups. At present there are no indications that the ban could be extended to other products.