Generally, the presence of a substance in the environment that because of its chemical composition or quantity prevents the functioning of natural processes and produces ...
Undesireable change in the physical, chemical, or biological characteristics of the air, water, or land that can harmfully affect the health, survival, or activities of human or ...
Air pollution usually refers to the presence of any chemical or particulate that alters the normal make-up of our atmosphere, causing direct threats to human health (such as ...