About a third of 98 people in the top third had elevated blood pressure, which is a major risk factor for cardiovascular disease and stroke.
If PCBs do contribute to high blood pressure in some way, it's not clear how they might do so. Carpenter said the chemicals could possibly disrupt genes that regulate blood pressure.
It's also possible that the chemicals could alter the way hormones work, encourage inflammation and disrupt cell functioning in the heart and blood vessels, added R. Thomas Zoeller, professor of biology at the University of Massachusetts.
Carpenter cautioned that factors other than PCBs could explain the higher rates of blood pressure in certain people. It's possible, for example, that high levels of PCB are a sign of exposure to other chemicals that actually may be at fault.
PCBs can still be found in animal fats, including fish, meat, dairy products, eggs and breast milk, according to the study.
What to do? Carpenter advised people to eat fewer animal fats, and Zoeller said the public should become more aware of the risks of the chemicals around them. "There are invisible pollutants like PCBs that can have very significant impact on our health," he said.
"These impacts are not trivial and should not be ignored," Zoeller said. "Because they are invisible, we don't have a choice but to be contaminated with them."
The U.S. Environmental Protection Agency has more details on PCBs.
SOURCES: David O. Carpenter, M.D., director, Institute for Health and the Environment, University at Albany, Rensselaer, N.Y.; R. Thomas Zoeller, Ph.D., professor of biology, University of Mass
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