Air pollution and health: Evidence from epidemiological studies and population impact

Outdoor air pollution —in particular particulate matter, nitrogen dioxide and ozone— can exert its effects on health after acute (short-term) and chronic (long-term) exposures. Short-term exposures increase the probability of the onset of acute diseases within a few days, such as myocardial infarction or stroke, or even death in the case of susceptible individuals. Long-term exposures are associated with decreased survival and incidence of several non-communicable diseases, including cardiorespiratory conditions and lung cancer. In Europe, the large ESCAPE project (European Study of Cohorts for Air Pollution Effects — www.escapeproject.eu) evaluated the chronic effects of air pollution in the cohorts of adult subjects. The results of ESCAPE show an association between chronic exposure to air pollutants and natural mortality, cardiovascular events, lung, brain, breast and digestive tract cancer. The recent joint statement of the European Respiratory Society and the American Respiratory Society clarifies the wide spectrum of adverse effects of pollution, including "new" diseases such as neurological and metabolic syndrome previously not studied. The estimates by the Global Burden of Disease provide nowadays indications that air pollution causes illness and mortality, just after diet, smoking, hypertension and diabetes: 4.2 million premature deaths a year worldwide. Ischemic heart disease, stroke, chronic obstructive pulmonary disease, acute lower respiratory infections are the main conditions associated with air-pollution–related mortality.