This document defines air pollution and classifies air pollutants according to their origin, chemical composition, and state of matter. It then discusses the various effects of air pollution, including damage to materials, vegetation, and farm animals. Air pollution also causes reduced visibility, impacts human health, and contributes to issues like acid rain and global warming. The key pollutants are gases like carbon monoxide, sulfur dioxide, and nitrogen oxides emitted from natural sources as well as human activities like industry, vehicles, and biomass burning.