This document discusses air pollution and its major pollutants. It begins by defining air pollution and listing its sources such as agricultural activities, automobiles, industries, and natural phenomena. It then classifies air pollutants as either primary or secondary and organic or inorganic. The major pollutants discussed are sulfur oxides, nitrogen oxides, carbon dioxide, volatile organic compounds, particulate matter, carbon monoxide, ozone, and chlorofluorocarbons. Each pollutant's source and health effects are briefly described.