AMS Glossary of Meteorology
¥air pollution—The presence of substances in the atmosphere, particularly those that do not occur naturally.
¥These substances are generally contaminants that substantially alter or degrade the quality of the atmosphere.
¥The term is often used to identify undesirable substances produced by human activity, that is, anthropogenic air pollution.
¥Air pollution usually designates the collection of substances that adversely affects human health, animals, and plants; deteriorates structures; interferes with commerce; or interferes with the enjoyment of life.