Pollution can be defined as a change in the physical, chemical, or biological characteristics of the air, water, soil, or other parts of the environment that adversely affects the health, survival, or other activities of humans or other organisms. After pollution occurs, the polluted resource is no longer suitable for its intended use. Most pollutants are solid, liquid, or gaseous chemicals created as byproducts of the extractive or manufacturing industries. Pollution can also take the form of excessive heat, noise, light, or other electromagnetic radiation.

Pollution is also a complex political problem and affects people's lives in numerous ways other than health. Determining an acceptable level of pollution is often more of a political problem than a scientific problem. This is especially true when jobs are at stake, as when a manufacturing plant is forced to close or to modify its operations.

Air Pollution

Air pollution is the...