Studies Report More Harmful Effects From BPA

June 11 -- WEDNESDAY, June 10 (HealthDay News) -- More potentially harmful health effects have been discovered for the chemical bisphenol A, found in clear plastic bottles and other everyday items, according to several new animal studies.

Not only are humans probably being exposed to generally unsafe levels of BPA, as the chemical is commonly called, but it could be causing arrhythmias, or irregular heartbeats, research shows. That could be especially problematic for women, who may be at higher risk for this type of cardiac threat.

In addition, other researchers say that they have found the mechanism by which BPA, a synthetic hormone with estrogen-like properties, might affect later fertility of babies whose mothers were exposed to the chemical.

These findings are being reported this week at the Endocrine Society's annual meeting, in Washington, D.C.

BPA, a chemical used to harden plastics, is in myriad items, including CDs, sunglasses and dental sealants. It is also in the lining of metal cans and bottle tops. Some studies have linked it to cancer, diabetes, heart disease and developmental problems in children. Health advocates say exposure to the chemical could present a particular problem to developing fetuses.

The U.S. Food and Drug Administration agreed in early June to reconsider its position that BPA is safe at levels found in baby bottles and other common products.

Researchers for one of the studies to be presented this week concluded that estrogen and BPA cause heartbeat irregularities in heart cells isolated from rats and mice.

"Basically, it's very clear that BPA is acting like estrogen," said study co-author Scott Belcher, an associate professor of pharmacology at the University of Cincinnati. "If we give estrogen at physiological concentrations, then add BPA, it's actually a synergistic effect. It's not like adding the two together. It's worse."

Women are more likely to die after a heart attack than men, and Belcher suspects an increased rate of arrhythmia might bear some of the responsibility for that trend.