Even coronary heart disease is, in part, caused by exposure to toxic chemicals. There is strong evidence from several studies that an association exists between elevated blood pressure and heart disease and elevated concentrations of polychlorinated biphenyls (PCBs) and other toxic chemicals. Researchers reporting in the journal Environmental Contamination and Toxicology noted in a study of pesticide-related jobs and human disease, “There were apparent associations between high serum pesticide [levels] . . . and the subsequent appearance of hypertension, arteriosclerotic cardiovascular disease, and possibly diabetes. This could imply a casual role of any of the pesticidal and other environmental stresses to which these workers were exposed.” How could industrial pollutants and pesticides cause coronary heart disease? Some may overstress the liver, which regulates cholesterol, such stress preventing the liver from keeping cholesterol at its proper level in the bloodstream.
Toxic chemicals may well play an even more significant role in the formation of arterial plaque in the human body, which leads to both stroke and coronary heart disease. Researchers have reported in Scientific American, “In the past 15 years it has become clear that [arterial] plaque is characterized by an accumulation of smooth muscle cells. The important question is: Why do the cells accumulate? Some of us now think the cells of a plaque are the progeny of a single mutated smooth-muscle cell from near the site of the plaque. If that is so, the plaque is comparable to a benign tumor of the artery wall. And if it is comparable then the search for initiating factors should be directed toward the genetic and environmental factors that cause mutation—the same kinds of agents and conditions that transform cells and thus initiate cancers.” It is known that atherosclerotic plaques can be produced in the arteries of laboratory animals by the administration of toxic chemicals such as dimethylbenz[a]anthracene. Other toxic chemicals, experts strongly suspect, play the same role.