Some people say that the color of the earth is green, which breeds life and indicates the birth and future of mankind. I said, she is the cradle of life and the mother of mankind. She gave all her love selflessly to the children and grandchildren of mankind. She is indeed very big and has a vast territory, but it is not endless; She is really beautiful, beautiful, but she will not be young forever; She is indeed rich and rich in resources, but she is not inexhaustible. Nowadays, the ecological environment of the earth has been seriously damaged by human activities. In particular, water pollution is more prominent. First, let's look at a funny and sad story. A tractor in Gezhouba Reservoir stalled because there was no oil. When the driver saw pieces of oil slick in the tank, he scooped up the oil slick in a bucket and poured it into the tank. The tractor suddenly drove away. It can be seen that the seriousness of water pollution in China, our city is located in the subtropical monsoon region in the lower reaches of Jiulong River, and is rich in fresh water resources. 65,438+00 years ago, you could find drinking water not far from home. However, with the development of economy and the improvement of people's living standards, water pollution is becoming more and more serious. Now, most rivers in our city are not drinkable, and some rivers can't even be used for washing. People can only rely on waterworks to supply water for daily life. Once, water was one yuan and fifty cents. Water is the lifeblood of everything on earth. Water nourishes everything, breeds life and creates civilization. The distribution of water resources in China is extremely uneven. China's per capita water resources are less than 500 cubic meters, far below the internationally recognized critical value of per capita 1 000 cubic meters. Many large and medium-sized cities in the north stopped production or limited production due to lack of water, resulting in an annual loss of 654.38+0.2 billion yuan, and some cities in the south also experienced water shortage. At present, more than 300 cities in China are short of water, of which the serious water shortage is 108, and the water shortage is about100000 tons/day. Millions of people are short of domestic water ... Facing the water resource of "dripping water is as expensive as oil", it is sad for human beings to waste and pollute it. According to statistics, the global sewage discharge has reached 400 billion cubic meters, polluting water bodies 5.5 trillion cubic meters, accounting for more than 14% of the total global runoff. Water, air and food are the three elements of human life and health. 50% to 60% of human body weight is water, and the water content in children is as high as 80%. Without water, there is no life. The fresh water resources on the earth only account for 3% of the total water resources on the earth, and only 0.5% of these 3% fresh water can be directly drunk. Therefore, water is a precious resource for human beings and the source of life. However, water pollution is quite common and serious in the world. When harmful substances in water exceed the self-purification ability of water, pollution will occur. These harmful substances include toxic substances such as pesticides, heavy metals and their compounds, various waste gases and radioactive substances. The source of water pollution is mainly untreated industrial wastewater and domestic wastewater. Dead organic pollution comes from untreated urban domestic sewage, paper-making sewage, agricultural sewage and urban garbage. Dead organic matter will consume dissolved oxygen in water and endanger the survival of fish; It can also lead to lack of oxygen in water, leading to the death of microorganisms that need oxygen. It is these aerobic microorganisms that can decompose organic matter and maintain the self-purification ability of rivers and streams. The consequences of their death are: rivers and streams turn black and stink, and toxins accumulate, hurting people and animals. Pollution of organic and inorganic chemicals These chemicals come from wastewater from chemical plants, pharmaceutical factories, paper mills, printing and dyeing factories and tanneries, as well as building decoration, dry cleaning, chemical lotions, agricultural pesticides and herbicides. Most organic products will accumulate in aquatic organisms, leading to poisoning after eating. The water polluted by organic chemicals is difficult to purify, and the drinking water safety and health of human beings are threatened. Water pollution caused by human production activities. Water pollution caused by industry is the most serious. Such as industrial wastewater, which has many pollutants and complex components, is not only difficult to purify in water, but also difficult to treat. Industrial wastewater is the main cause of water pollution caused by industrial pollution. It accounts for most of the pollutants discharged by industry. Due to different types of factories, the pollutants contained in industrial wastewater vary widely. Even in similar factories, the quality and quantity of pollutants are different due to different production processes. In addition to the pollution caused by the direct injection of industrial wastewater into the water body, solid waste and waste gas will also pollute the water body ... Agricultural pollution is first caused by loose surface caused by farming or land reclamation. When the soil and terrain are unstable, it rains and a large amount of sediment flows into the water, which increases the suspended solids in the water. Another important reason is that the use of pesticides and fertilizers is increasing in recent years. Only a small amount of pesticides and fertilizers used are attached or absorbed, and most of the rest remain in the soil and float in the atmosphere. Through rainfall, they enter the surface water and infiltrate into the surface water to form pollution. Urban pollution sources are water pollution caused by urban population concentration and urban domestic sewage, garbage and waste gas. The pollution of urban pollution sources to water bodies is mainly domestic sewage, which is a mixture of various kinds of sewage produced in people's daily life, including sewage discharged from kitchens, bathrooms and toilets. In the world, the industrial and domestic wastewater discharged from urban areas alone is as much as 500 cubic kilometers every year, and each drop of sewage will cause several times or even dozens of times of pollution to the water body. A large number of pollutants are first discharged into rivers, causing inland water pollution. In the early 1980s, China investigated 53,000 kilometers of river. It was found that about 23.3% of the river sections could not be irrigated due to water pollution, and only 14% of the water quality met the drinking water standard. The pollution of lakes and bays is also quite serious. Even groundwater can't escape this fate. Water pollution does great harm to human health. Pathogenic microorganisms and viruses in sewage can cause the spread of infectious diseases. Some huge toxic substances in water can kill people and animals in a few minutes. The most dangerous are metal substances such as cadmium and lead, which can cause chronic poisoning after entering the human body. Once found, it can't be stopped. There are many unfavorable factors in the influence of polluted water on human body: 70%-80% of human body is water, and drinking inferior water for a long time will naturally weaken resistance, and various diseases are inevitable. Moreover, when the pollutants accumulated for a long time reach the body and cannot be tolerated, no matter how clever the doctor is, no matter how effective the drug is, it may not be effective. So the sentence "Water is the king of all medicines" is true. Effects of common drinking water quality items on human health: Lead: harmful to kidneys and nervous system, highly toxic to children, and carcinogenicity has been confirmed. Cadmium: Acute damage to kidney. Arsenic: It is harmful to skin and nervous system, and its carcinogenicity has been proved. Mercury: It is extremely harmful to human body. The main organs that are harmed are kidneys and central nervous system selenium: high concentration will harm muscles and nervous system nitrite: it will cause cardiovascular diseases, especially for infants (blue baby disease). Carcinogen total trihalomethane: chloroform has the greatest impact on health, and the most common carcinogen is bladder cancer trichloroethylene (organic matter): excessive inhalation will reduce the central nervous system and heart function. Long-term exposure to carbon tetrachloride (organic matter) is harmful to the liver: it has a wide impact on human health, is carcinogenic, and has a great impact on liver and kidney function. In recent years, the US Environmental Protection Agency (EPA) conducted an investigation on water-caused diseases during the period of 197 1- 1994. In 740 cases, protozoa caused * *. It is found that cryptosporidium and Giardia pyriformis are two protozoa that need special attention. They most often appear in leisure scenic spots and animal husbandry areas, among which pigs and ducks are the most common. Statistics also show that 89 deaths were caused in 23 years, and 70 deaths were caused by protozoa. According to the survey of the World Health Organization, 70% people in the world can't drink safe and hygienic drinking water. At present,150,000 children under the age of five die every year, most of which are related to drinking water. According to United Nations statistics, 250,000 people around the world get sick from drinking water or die from lack of water every day. Water pollution not only threatens human beings, but also brings huge losses to fisheries. It seriously kills fish and shrimp, interferes with fish reproduction and greatly reduces the yield and quality of fish. Sewage also pollutes farmland and crops and reduces agricultural output. Water pollution also causes other environmental degradation, affecting people's sightseeing, entertainment and recuperation. Water is not only the source of life, but also extremely important to human beings, and the pollution is so serious. Therefore, we should prevent and protect water resources and make rational use of them. The measures taken for pollution discharge mainly include: (1) financial, administrative and legal guarantee 1. Financial support is an indispensable condition. Obviously, financial support is one of the important conditions for pollution control. Without funds, all control measures cannot be implemented.