Epidemiology of fine particulate air pollution and human health: Biologic mechanisms and who's at risk?

This article briefly summarizes the epidemiology of the health effects of f ine particulate air pollution, provides an early, somewhat speculative, dis cussion of the contribution of epidemiology to evaluating biologic mechanis ms, and evaluates who's at risk or is susceptible to adverse health effects . Based on preliminary epidemiologic evidence, it is speculated that a syst emic response to fine particle-induced pulmonary inflammation, including cy tokine release and altered cardiac autonomic function, may be part of the p athophysiologic mechanisms or pathways linking particulate pollution with c ardiopulmonary disease. The elderly, infants, and persons with chronic card iopulmonary disease, influenza, or asthma are most susceptible to mortality and serious morbidity effects from short-term acutely elevated exposures. Others are susceptible to less serious health effects such as transient inc reases in respiratory symptoms, decreased lung function, or other physiolog ic changes. Chronic exposure studies suggest relatively broad susceptibilit y to cumulative effects of long-term repeated exposure to fine particulate pollution, resulting in substantive estimates of population average loss of life expectancy in highly polluted environments. Additional knowledge is n eeded about the specific pollutants or mix of pollutants responsible for th e adverse health effects and the biologic mechanisms involved.