There is substantial epidemiological evidence that inhalation of air pollution particles results in increased morbidity and mortality from heart conditions, such as heart attacks, cardiac arrhythmia, and heart failure. Recent research has shown that air pollution causes the development and progression of atherosclerosis, the underlying disease in vessels responsible for stroke and heart attacks. However, the biological mechanisms of air pollution-induced heart disease remain unclear. Dr. Stephan van Eeden is exploring at the cellular level the connection between the inhalation of air pollution particles and the development and progression of blood vessel disease (atherosclerosis). His hypothesis is that chronic lung inflammation caused by exposure to particulate matter air pollution and cigarette smoke cause a persistent, low-grade systemic inflammatory response that contributes to the development of atherosclerosis. He is conducting a series of studies to determine whether inhalation of air pollution particles destabilizes atherosclerotic plaques and trigger clot formation. This information will provide researchers and policy makers with a greater understanding of the adverse effects of air pollution on individuals’ health.