In addition to the traditional risk factors for cardiovascular disease (CVD), studies have indicated that exposure to inhalation of particulate matter (PM) contribute to CV morbidity and mortality. The 2010 American Heart Association Scientific Statement on Particulate Matter Air Pollution and Cardiovascular Disease provided compelling evidence of increased risk due to air pollution. Although the exact mechanisms by which PM cause these toxic effects are not adequately understood, and it is likely that different mechanisms are responsible for acute and chronic effects. In addition, PM consists of many different components, and different components may affect CVD by different mechanisms, such as electrophysiologic changes, inflammation, coagulation, endothelial cell function effects and atherosclerosis. In summary, thousands of WTC responders sustained exposure to thousands of tons of coarse and fine PM, cement dust, glass fibers, asbestos, lead, hydrochloric acid, polychlorinated biphenyls, organochlorine pesticides, and polychlorinated dioxins and furans. It is unknown to what extent the exposure to PM modified risk of developing atherosclerotic disease, in addition to the pulmonary effects and effects on cardiac function.