The biological effects of BPA are not completely understood. Large-scale studies of the biological effects of BPA are very few.
The plastic industry claimed that BPA does not have any significant effect on humans. They point to studies that suggest that BPA has a low toxicity. It should be noted that in these studies, participants are only exposed to BPA for a short time. In August 2008, after a public hearing, the FDA concluded that BPA is safe at current levels of exposure for both infants and adults
Researchers believed that BPA binds to estrogen receptors and mimic some functionalities of estrogen. BPA can affect normal development of the neurologic and reproductive systems and harm pancreatic beta cells and hepatocytes. Thus, BPA might have harmful biological and health effects. In a study published in the September 2008 issue of the Journal of the American Medical Association, a one-standard deviation in BPA concentration in urine was reported to be assocaited with a 60% increase in risk of coronary diseases, a 40% increase in risk of having had myocardial infarction (heart attack), and a 39% increase in risk of developing diabetes. BPA is also associated with higher concentration of liver enzymes. This is the first study of this type on the long term health effects of BPA. It is hoped that more research will be conducted to further investigate the biological effects of BPA.