Air quality risk assessment and management.

This article provides (1) a synthesis of the literature on the linkages between air pollution and human health, (2) an overview of quality management approaches in Canada, the United States, and the European Union (EU), and (3) future directions for air quality research. Numerous studies examining short-term effects of air pollution show significant associations between ambient levels of particulate matter (PM) and other air pollutants and increases in premature mortality and hospitalizations for cardiovascular and respiratory illnesses. Several well-designed epidemiological studies confirmed the adverse long-term effects of PM on both mortality and morbidity. Epidemiological studies also document significant associations between ozone (O3), sulfur (SO2), and nitrogen oxides (NO(x)) and adverse health outcomes; however, the effects of gaseous pollutants are less well documented. Subpopulations that are more susceptible to air pollution include children, the elderly, those with cardiorespiratory disease, and socioeconomically deprived individuals. Canada-wide standards for ambient air concentrations of PM2.5 and O3 were set in 2000, providing air quality targets to be achieved by 2010. In the United States, the Clean Air Act provides the framework for the establishment and review of National Ambient Air Quality Standards for criteria air pollutants and the establishment of emissions standards for hazardous air pollutants. The 1996 European Union's enactment of the Framework Directive for Air Quality established the process for setting Europe-wide limit values for a series of pollutants. The Clean Air for Europe program was established by the European Union to review existing limit values, emission ceilings, and abatement protocols, as set out in the current legislation. These initiatives serve as the legislative framework for air quality management in North America and Europe.