8 - Water Pollution

Abstract

There are virtually no sources of drinking water on earth that are not contaminated with xenobiotics. Rainwater cleanses the atmosphere as it forms and falls. As a result, it contains dissolved acids, organic compounds, and heavy metals such as mercury and selenium in many areas. Farming is responsible for the release of four categories of water pollutants into the water environment. Power production is responsible for the introduction of toxic chemicals into drinking water via several routes. These include petroleum production (drilling, pumping, transport, and refining), coal mining, petroleum combustion, and coal combustion. Household use of chemicals and chemical products is ultimately a major source of contamination of drinking water in the United States. The U.S. Environmental Protection Agency (EPA) has identified 13 major categories of water pollutants in this area. Water pollution causes the introduction of a very wide variety of toxic chemicals to those drinking, cooking, and bathing with impure water. Major sources of water pollutants include mining, manufacturing, farming, power production, and runoff from urban and suburban sprawl. Water pollution from each of these sources is discussed in this section. Mixtures of lipophilic and hydrophilic chemicals have been demonstrated to be causative for many of these unanticipated toxic effects. In a good portion of the world, groundwater and surface water are treated to disinfect biological agents and remove chemical pollutants prior to human consumption.