pollutant /pəlo̅o̅′tənt/ [L, polluere, to defoul] , an unwanted substance that occurs in the environment, usually with health-threatening effects. Pollutants may exist in the atmosphere as gases or fine particles that may be irritating to the lungs, eyes, and skin; in drinking water as dissolved or suspended substances; and in foods or beverages as carcinogens or mutagens.
