The Expanding Role of Air Pollution in Cardiovascular Disease

Abstract

Scientific efforts to understand the health effects of air pollution and public policy efforts to control air pollution have a fascinating history. The early “killer smog” episodes in Meuse Valley, Belgium (1930), Donora, Pa (1948), and London, UK (1952) provided stark evidence of deleterious respiratory and cardiovascular health effects of severe air pollution exposure. This evidence motivated early public policy efforts to improve air quality. In the United States, Britain, and elsewhere, legislative, regulatory, and related efforts to control air pollution were initiated. Ambient air quality standards and guidelines were established. Severe air pollution episodes were largely mitigated, and concern about adverse air pollution-related health effects abated. Nearly all air pollution researchers agreed that air pollution at very high concentrations posed serious health hazards. By the late 1970s and through the 1980s, however, it was argued by many that air pollution, at levels then common to the United States and Britain, was no longer a significant threat and that the potential health effects of air pollution could not be disentangled from effects from other factors.1 Article see p 3118 In the mid-1990s, concerns about the health effects of air pollution were rekindled by several new epidemiological studies that reported health effects at unexpectedly low levels of exposure. These studies were highly controversial,2 but they prompted a reevaluation of relevant air quality standards and guidelines and a dramatic increase in health-related air pollution research. Much of the research has been focused on respiratory disease, but there is substantial and growing evidence that exposure to air pollution contributes to various cardiovascular diseases.3–5 Epidemiologically, the clinical cardiovascular health end points most compellingly linked to air pollution exposure include cardiovascular mortality, cardiovascular hospitalizations, and ischemic heart disease events. …