Water pollutionWater pollution is a major problem in the global It has been suggested that it is the leading worldwide cause of deaths and diseases， and that it accounts for the deaths of more than 14，000 people An estimated 700 million Indians have no access to a proper toilet， and 1，000 Indian children die of diarrheal sickness every Some 90% of China's cities suffer from some degree of water pollution， and nearly 500 million people lack access to safe drinking In addition to the acute problems of water pollution in developing countries， industrialized countries continue to struggle with pollution problems as In the most recent national report on water quality in the United States， 45 percent of assessed stream miles， 47 percent of assessed lake acres， and 32 percent of assessed bay and estuarine square miles were classified as pollutedWater is typically referred to as polluted when it is impaired by anthropogenic contaminants and either does not support a human use， like serving as drinking water， and/or undergoes a marked shift in its ability to support its constituent biotic communities， such as Natural phenomena such as volcanoes， algae blooms， storms， and earthquakes also cause major changes in water quality and the ecological status of Causes of water pollutionThe specific contaminants leading to pollution in water include a wide spectrum of chemicals， pathogens， and physical or sensory changes such as elevated temperature and While many of the chemicals and substances that are regulated may be naturally occurring (calcium， sodium， iron， manganese， ) the concentration is often the key in determining what is a natural component of water， and what is a Oxygen-depleting substances may be natural materials， such as plant matter ( leaves and grass) as well as man-made Other natural and anthropogenic substances may cause turbidity (cloudiness) which blocks light and disrupts plant growth， and clogs the gills of some fish Many of the chemical substances are Pathogens can produce waterborne diseases in either human or animal Alteration of water's physical chemistry includes acidity (change in pH)， electrical conductivity， temperature， and Eutrophication is an increase in the concentration of chemical nutrients in an ecosystem to an extent that increases in the primary productivity of the Depending on the degree of eutrophication， subsequent negative environmental effects such as anoxia (oxygen depletion) and severe reductions in water quality may occur， affecting fish and other animal
水污染已对人类的生存安全构成重大威胁，成为人类健康、经济和社会可持续发展的重大障碍。据世界权威机构调查，在发展中国家，各类疾病有80%是因为饮用了不卫生的水而传播的，每年因饮用不卫生水至少造成全球2000万人死亡，因此，水污染被称作"世界头号杀手"。Water pollution has become a major threat to the survival and safety of human beings and has become a major obstacle to the sustainable development of human health， economy and According to surveys by authoritative institutions in the world， in developing countries， 80% of all kinds of diseases are spread by drinking unsanitary Every year， drinking unhygienic water causes at least 20 million deaths Therefore， water pollution is called "The world's number one "
Water pollution affects plants and organisms living in these bodies of water; and， in almost all cases the effect is damaging not only to individual species and populations， but also to the natural biological Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds水污染会影响水体里的植物和生物圈，基本所有的水污染不仅危害单一物种，所有自然界都会受到牵连。水污染是在污染物不受控制（直接或间接）流入水体，并且没有得到有效移除污染物。Water pollution is a major problem in the global It has been suggested that it is the leading worldwide cause of deaths and diseases， and that it accounts for the deaths of more than 14，000 people Some 90% of China's cities suffer from some degree of water pollution， and nearly 500 million people lack access to safe drinking In addition to the acute problems of water pollution in developing countries， industrialized countries continue to struggle with pollution problems as 水污染是现今国际大事。也是世界人口死亡的罪魁祸首。每天有14000人间接因水污染而死亡。我国90%的城市面临不同程度水污染，约5亿人缺少安全饮用水。发达国家也因为持续工业化加重水污染。可以了么？这是最最基本的概括了
