The topic of water pollution is an extremely large one and this series of Information Notes is designed to provide a brief introduction to the subject highlighting the important sources of pollution and how they can be controlled.
Pollution is the presence of a substance which causes harm where it would not normally be found, or causes harm if present in larger than normal quantities. Paracelsus (1493-1541) wrote: ‘Dosis facit venenum’ (‘The dose makes the poison’). The same can be said for pollution. The relationship between dose (quantity) and response (effect) is still one of the most fundamental concepts of toxicology (the science of poisons).
A large number of substances have the potential to cause pollution in many different ways. Pollution can adversely affect the wildlife and plants that live near or in a watercourse, decrease fish stocks, reduce the aesthetic appeal of the water environment and affect the suitability of water for drinking water supply and industrial uses.