This document discusses air pollution and is divided into several sections. It begins by describing the composition of the atmosphere and its importance. It then discusses the different types and sources of air pollution, including major classes of pollutants like particulate matter, nitrogen oxides, sulfur oxides, and others. Several effects of air pollution on health are outlined, and methods for controlling pollution like electrostatic precipitators are presented. The document also covers topics like photochemical smog, acid deposition, ozone depletion, and indoor air pollution.