PCB Exposure Linked to Increased Risk of Hypertension
In a small study conducted in the Alabama city of Anniston, researches have linked exposure to polychlorinated biphenyls (PCBs) to an increased risk of having high blood pressure. Although the relationship was strong, according to study co-author David O. Carpenter, a direct cause-and-effect relationship was unclear.
Dr. Carpenter and colleagues from the Institute for Health and the Environment at the University at Albany in Rensselaer NY tested the blood of 758 Anniston residents, 407 of whom were white and 351 black. The subjects also had blood pressure and cholesterol levels checked. Of the total study group, the researchers focused on 394 who were not taking blood pressure medications.
After adjusting for risk factors such as gender and obesity, the researchers found that those with the highest levels of PCBs in their bodies were more than 3.5 times more likely to have high blood pressure than those in the lowest third.
Polychlorinated biphenyls were once used in hundreds of industrial products but have been banned in the US since 1979 because of fears about adverse health effects, including an increased risk of cancer. Products that may still contain PCB’s include transformers and other electrical equipment, oil used in motors and hydraulic systems, cable insulation, thermal insulation (fiberglass, felt, foam, and cork), oil-based paint, caulking, plastics, floor finish, and carbonless copy paper.
PCB’s may not still be in use, but still linger in the air, water, and soil because the chemicals do not break down. The chemicals can still be found in animal fats, including meat, dairy products, eggs, and fish.
It is not known how PCBs contribute to hypertension, but Carpenter theorizes that the chemicals could disrupt genes that regulate blood pressure or may disrupt cell functioning in the heart and blood vessels.
While we may not be able to change direct exposure to a chemical banned 30 years ago, Americans can still reduce indirect exposure by eating fewer animal fats, says Dr. Carpenter.
The study was published online in the Journal of Hypertension and was funded by the US Agency for Toxic Substances and Disease Registry, part of the US Centers for Disease Control and Prevention.