Potential Harmful Effects of PM2.5 on Occurrence and Progression of Acute Coronary Syndrome: Epidemiology, Mechanisms, and Prevention Measures

The harmful effects of particulate matter with an aerodynamic diameter of <2.5 µm (PM2.5) and its association with acute coronary syndrome (ACS) has gained increased attention in recent years. Significant associations between PM2.5 and ACS have been found in most studies, although sometimes only observed in specific subgroups. PM2.5-induced detrimental effects and ACS arise through multiple mechanisms, including endothelial injury, an enhanced inflammatory response, oxidative stress, autonomic dysfunction, and mitochondria damage as well as genotoxic effects. These effects can lead to a series of physiopathological changes including coronary artery atherosclerosis, hypertension, an imbalance between energy supply and demand to heart tissue, and a systemic hypercoagulable state. Effective strategies to prevent the harmful effects of PM2.5 include reducing pollution sources of PM2.5 and population exposure to PM2.5, and governments and organizations publicizing the harmful effects of PM2.5 and establishing air quality standards for PM2.5. PM2.5 exposure is a significant risk factor for ACS, and effective strategies with which to prevent both susceptible and healthy populations from an increased risk for ACS have important clinical significance in the prevention and treatment of ACS.