POLLUTION, WATER (Social Science)

Water pollution exists when water is contaminated by impurities or its quality is otherwise adversely affected, for example, by solid matter or thermal discharges. Water pollution problems have a long history that can be traced to antiquity, and the attempts of communities to control such problems have an equally long track record. The nature of water pollution problems has changed over time, and their geographic scale has steadily increased, as has the scale of institutional solutions that have been adopted to control them. This entry explores the key changes in the nature and scale of water pollution and in the institutional solutions that have been adopted as a response to it.

Pollution of water by human wastes was a key public health problem when today’s developed countries urbanized in the 1800s. Urban life expectancies decreased because contaminated water supplies caused epidemics of cholera, typhoid fever, and other water-borne diseases and increased people’s susceptibility to all illnesses. These problems were initially local, when wells and ground water were used for water supplies, and communities responded to them with local public health and sanitation regulations. The construction of networked water supplies and sewer systems after the mid-1800s increased the scale of water pollution. Local regulations proved powerless when sources of pollution were increasingly outside the local jurisdiction. This situation gave rise to the first state and national water pollution policies, which successfully safeguarded public health but which largely failed to improve in-stream water quality.

The nature of water pollution changed in industrialized countries around the time of World War II (1939—1945) because the war effort and postwar reconstruction resulted in the rapid growth of industrial production and increased discharge of industrial effluents. New innovations such as organic pesticides and synthetic detergents also proved potent water pollutants. The decades after the war witnessed several widely publicized environmental disasters, including mercury pollution in Minamata, Japan, that caused "Minamata disease" in the 1950s; the Torrey Canyon (1967) and Amoco Cadiz (1978) supertanker disasters in Europe; and the Santa Barbara, California, oil spill in 1969. Furthermore, there was controversy over asbestos-containing discharges from Reserve Mining into Lake Superior in Silver Bay, Minnesota, in the 1970s; the leak of toxic chemicals from the Sandoz factory in Basel, Switzerland, in 1986; and the cyanide spill from a gold mine in Baia Mare, Romania, which polluted the Tisza and Danube rivers in 2000. More recently, in November 2005, an explosion in a chemical plant in Jilin, China, polluted the Songhua River with benzene and nitrobenzene.

Water pollution continues to be a public health problem in the developing world. Worldwide, one child out of six under five years of age dies of a diarrheal disease such as cholera, typhoid fever, dysentery, and gastroenteritis, which are caused by the contamination of water by human wastes. Moreover, weak enforcement or the nonexistence of environmental and safety regulations in developing countries means that agriculture, horticulture, and mining are major sources of toxic water pollutants such as pesticides and mercury. Such pollutants have caused grave public health consequences across the developing world, but particularly in severely polluted areas such as the Aral Sea region in Central Asia. In some places, such as in Bangladesh, naturally occurring arsenic pollutes certain layers of ground water on which many communities depend for their water supply.

Most developed countries have adopted water pollution policies that have reduced conventional water pollutants from point sources. Conventional pollutants include biochemical oxygen demand (BOD), total suspended solids (TSS), fecal coliform, oil and grease, and pH (acidity and alkalinity). Point sources include municipal sewage treatment plants, industrial establishments, and other facilities, which only contributed about half of all conventional pollutants in the United States when the Clean Water Act of 1972, with its focus on point sources, was adopted. Water pollution originating from nonpoint sources, such as agriculture, streets and roads, and storm sewers, was not originally controlled with the same level of effectiveness. National policies have also been less successful in reducing the amount of nonconventional pollutants, such as those of toxic chemicals. More recently, market-based instruments such as fertilizer, manure, and pesticide taxes have been used in many countries for controlling water pollution from nonpoint sources. Other market based instruments, particularly tradable effluent permits and sewerage charges, have increasingly been used also for controlling conventional water pollutants.

The incentives and capacity of states to control pollution from sources that lie outside their jurisdictions is limited, however. International environmental agreements have been negotiated to address this problem, including early agreements on the transportation of dangerous substances on the River Rhine in western Europe, which came into force between 1900 and 1902, and the Boundary Waters Treaty between the United States and Canada, which took effect in 1909. International agreements since 1970 have addressed, for example, the pollution of the marine environment by oil and dumping; the pollution of transboundary bodies of water such as the Baltic Sea, the North Sea, and the Mediterranean; the elimination of persistent organic compounds; and the international transport of hazardous materials and liability for damages caused by their transport. Some of these conventions, such as the 1992 Baltic Sea Convention, have been successful, while others have made little difference to the quality of the marine environment to date.

Next post:

Previous post: