Also called: atmospheric particulate matter or particulates (Show more) Particulate matter is a type of air pollution that consists of airborne suspensions of extremely small solid or liquid particles, such as soot, dust, smokes, fumes, and mists. Particulate matter—especially those particulates less than 10 micrometers (μm; millionths of a meter) in diameter—are significant air pollutants because of their very harmful effects on human health, including increased risk of cancer, lung and cardiovascular disease, and decreased life expectancy. Particulate pollution is a leading cause of reduced visibility (haze) in many places and is responsible for atmospheric brown clouds, including the annual Asian brown cloud associated with slash-and-burn agriculture in southern ...(100 of 1120 words) Access the full article Help support true facts by becoming a member. Subscribe today!