pol ‧ lut ‧ ant /pəˈluːt ə nt/ BrE AmE noun [countable]
a substance that makes air, water, soil etc dangerously dirty, and is caused by cars, factories etc
air/environmental/water etc pollutants
New regulations will reduce hazardous air pollutants.
a dumping ground for toxic pollutants
chemical/industrial etc pollutants
industrial pollutants in the lake