A pollutant is any substance, chemical or other factors that:
Changes the natural balance of our environment
A pollutant is a substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource. A pollutant may cause long or short-term damage by changing the growth rate of plant or animal species, or by interfering with human amenities, comfort, health, or property values. Hence, a pollutant changes the natural balance of the environment.