Air pollution and cardiovascular disease.

An escalating body of epidemiologic and clinical research provides compelling evidence that exposure to fine particulate matter air pollution contributes to the development of cardiovascular disease and the triggering of acute cardiac events. There are 3 potential mediating pathways that have been implicated, including "systemic spillover," autonomic imbalance, and circulating particulate matter constituents. Further support that the increased morbidity and mortality attributed to air pollution comes from studies demonstrating the adverse cardiovascular effects of even brief periods of exposure to secondhand smoke. Accordingly, persons with known or suspected cardiovascular disease, the elderly, diabetic patients, pregnant women, and those with pulmonary disease should be counseled to limit leisure-time outdoor activities when air pollution is high. Recognizing the insidious and pervasive nature of air pollution, and the associated odds ratios and population attributable fractions for this widely underappreciated chemical trigger of acute cardiovascular events, may serve to maximize the potential for cardiovascular risk reduction by addressing at least a portion of the 10%-25% incidence of coronary disease that is unexplained by traditional risk factors.