Visible air pollutants consisting of particles appearing in smoke or mist emitted by the combustion of fossil fuels, primarily in the transportation, industrial, or electric utility sectors, or consisting of naturally occurring substances such as airborne dust particles.
(Particulate matter) Tiny pieces of solid or liquid matter that float in the air. Particulates come from smoke, dust, ash and vapours, and can cause serious health problems.
Very small liquid and solid particles floating in the air. A component of smog.