What is particulate matter pollution?
Particulate matter (PM) pollution is composed of very small solid or liquid particles suspended in the air. Many man-made and natural sources emit PM directly or emit other pollutants that react in the atmosphere to form PM. PM is the most noticeable pollutant because it dramatically reduces visibility in urban areas. For more information, or to learn about the health effects from particulate matter, visit the Weather Underground’s particulate matter pollution page.
