pollutants in water bodies fall into the aquatic environment from both anthropogenic and natural sources.The latter include the destruction of rocks, volcanic activity, the waste products of aquatic organisms.Anthropogenic sources are population growth, the development of agricultural and industrial production.The surrounding waters are discharged, domestic, industrial and agricultural waste water.

anthropogenic pollution is divided into primary and secondary.During the initial quality of the water environment is deteriorating directly for fugitive emissions into water bodies.Secondary causes excessive concentration of decomposition products of dead aquatic animals, which occurred due to violation of the ecological balance.

The main sources of pollution include drainage water, domestic and in
dustrial waste water, storm drainage, waste water from areas of livestock farms, fields and settlements, convey of the forest along the rivers, water transport.

to human health is a particular danger of water pollution by organic substances with high toxicity - pesticides.Man uses them throughout his life.When a large forest and farmland treated with pesticides using aircraft, up to 70% of these toxic substances are carried by the wind for hundreds of kilometers, contaminating watercourses and ponds.After precipitation pesticides penetrate into the soil, ground water and then into lakes and rivers.

among the most dangerous pesticides are used persistent organochlorine compounds that accumulate in the tissues of various organisms.Engaging, for example, in the aquatic food chain, these compounds will be from one trophic level transmitted to another.For example, if a fisherman has caught and eaten the fish, which feed on planktonic crustaceans that live in polluted by pesticides pond in his body settles poison.From the body to bring it practically impossible, and large concentrations of poison can cause cancer.Also, have a high biochemical stability, synthetic detergents - detergents.Once in the water bodies with toxic effluents, they also accumulate in organisms, aquatic life, and then enter the body.

greatly affected by the radionuclides entering the reservoirs with waste plants, some plants and nuclear ships.Of the mineral most toxic compounds of lead, arsenic, zinc, mercury and copper.In the water they come through precipitation from the atmosphere, which are collected again as a result of human activity (industrial emissions).It is also rich in heavy metals mining effluents.Difficult to waste oil and its derivatives.A process and destroy the oil slurry is capable of only a few aquatic organisms.