"No one would choose to eat polychlorinated biphenyls, or PCBs -- yet we unwittingly do. And a new study finds that the cost of their pervasive contamination of our food supply can be high blood pressure, a major risk factor for heart disease.

PCBs comprise a family of 209 related, colorless and oily compounds. Discovered more than a century ago, they quickly won widespread adoption as the electrical insulator of choice throughout the electric power industry. Being chemically stable and heat resistant, PCBs also found use in other applications: as lubricants, as additives to make plastics more pliable, in adhesives, even as a component of some inks.

Over the years, the toxicity of PCBs has slowly emerged. Some have been designated not only as probable carcinogens, but also as agents that diminish immunity and pollutants that lower birth weight and IQ. Now, researchers with the Anniston, Ala., Environmental Health Research Consortium report that these toxic pollutants also appear to impair vascular health."

Janet Raloff reports for Science News November 17, 2009. [2]