This document discusses air pollution, including its definition, classification, sources, and effects. It defines air pollution as the presence of unwanted particles and gases in the air that can adversely affect humans, plants, structures, and the environment. It then classifies air pollutants based on their origin (primary or secondary), state of matter (gaseous or particulate), and presence in the environment (indoor or outdoor). Common sources of air pollution are discussed, such as vehicles, industry, agriculture, and household activities. The document outlines some of the negative health, environmental, and infrastructure impacts of air pollution. Finally, it provides some potential solutions to control air pollution issues.