Particle Emission from Outdoor and Indoor Sources

Abstract

Aerosols, by their nature, are somewhat unstable in the sense that concentration and particle properties change with time. The sources of aerosols may be either natural or anthropogenic. However any source may be described as either primary (particles emitted directly into the atmosphere) or secondary (formed by chemical reactions of gaseous components). With industrialisation and urbanisation increasing, man emits substantial quantities of particulate material although, globally, natural contributions far exceed emissions from man's activities.