Contamination is a general word that means to taint, sully or defile an article or other substance. You can contaminate the air, water and land. Contamination includes two common environmental terms - pollution and waste.

Pollution refers to any direct or indirect alteration of the environment, that creates a hazard or potential hazard to any living creature. A pollutant can be any gas, liquid, solid contaminating a liquid, solid or gas.

Pollutants can have effects locally in the community, or nationally. Some travel long distances, when they are said to have "transboundary" effects.

Waste is anything that somebody wants to dispose of. By definition they are bound to be pollutants. While there is a lot of overlap with the two words, waste implies a deliberate act to get rid of, while other pollutants are lost from work processes.

Waste cannot be simply eliminated. It may dissappear, but it is still somewhere. Ideally it can be recycled, or transformed into a useful material. Otherwise it must be isolated permanently from the environment or released with controlled contamination.