pollution
Introduction
pollution, contamination of the environment as a result of human activities. The term pollution refers primarily to the fouling of air, water, and land by wastes (see air pollution; water pollution; solid waste). In recent years it has come to signify a wider range of disruptions to environmental quality. Thus litter, billboards, and auto junkyards are said to constitute visual pollution; noise excessive enough to cause psychological or physical damage is considered noise pollution; and waste heat that alters local climate or affects fish populations in rivers is designated thermal pollution.