Abstract

During the last decades, the understanding of air pollution and its influence on health and environment has increased, but the actual knowledge is still limited. This entry is dedicated to airborne particulate matter (PM). According to the World Health Organization and the U.S. Environment Protection Agency, PM is one of the most important pollutants of the present times as its presence in the atmosphere has harmful effects on both human health and the environment. In this entry, a brief historical perspective of the problems related to PM is presented. A discussion on the various aspects of PM is given, covering its definitions, sources, chemical composition, and impacts on human health. Finally, an overview of the legislation related to air quality and PM emission abatement is presented to evaluate and understand the impacts of these policies concerning the current levels of this atmospheric pollutant.