Waste disposal and pollution are inextricably linked. The term pollution describes both
the act of polluting and the consequences of that act. Waste describes unwanted residues
that are usually perceived to be of negative value. Pollution can be defined as the
introduction into the natural environment by humans of substances, materials or energy
that cause hazards to human health, harm to living resources and ecological systems,
damage to structures and amenities or that interfere with the legitimate uses of the
environment. It is implicit in the definition that pollution only describes situations where
unwanted effects occur (Royal Commission on Environmental Pollution, 1984). The
majority of waste disposal situations involve pollution of one kind or another.