What are the hazards caused by water pollution?

The hazards of water pollution are as follows: \x0d\( 1) Harm to human health. After water pollution, pollutants enter \x0d\ human body through drinking water or food chain, causing acute or chronic poisoning. Arsenic, chromium, ammonium, benzopyrene, etc. It can also induce cancer. Water polluted by parasites, viruses or other pathogenic bacteria will cause various infectious diseases \x0d\ parasitic diseases. Water polluted by heavy metals is harmful to human health. Water and food contaminated by cadmium \x0d\ will cause kidney and bone diseases, and 20 mg cadmium sulfate will cause death. Lead poisoning, anemia and insanity. Hexavalent chromium is very toxic, which can cause skin ulcers and cause cancer. Drinking water containing arsenic can cause acute or chronic poisoning. Arsenic inhibits or deactivates many enzymes, causing metabolic disorder, skin keratinization \x0d\ skin cancer. Organophosphorus pesticides can cause neurotoxicity, while organochlorine pesticides can accumulate in fat, which is harmful to endocrine, immune and reproductive functions of human beings and animals. Most polycyclic aromatic hydrocarbons are carcinogenic. Cyanide is also a highly toxic substance. When it enters the blood, it will combine with cytochrome oxidase of cells, thus interrupting breathing, leading to respiratory failure, suffocation and death. We know that 80\x0d\% of diseases in the world are related to water. Typhoid fever, cholera, gastroenteritis, dysentery \x0d\ infectious liver disease are the five major diseases of human beings, all of which are caused by unclean water. \x0d\(2) Water pollution is harmful to industrial and agricultural production. Industrial water must be treated with more \x0d\ expenses, resulting in a waste of resources and energy. The food industry has stricter water requirements and will stop production if the water quality is unqualified. This is also the reason why the efficiency of industrial enterprises is not high and the quality and quantity are not good. The use of sewage in agriculture will reduce crop yield and quality, even harm people and animals, pollute large areas of farmland and reduce soil quality. The consequences of marine pollution are also very serious, such as oil pollution, which causes the death of seabirds \x0d\ marine life. \x0d\(3) Harm of water eutrophication Under normal circumstances, oxygen is dissolved in water to some extent. Dissolved oxygen is not only the survival condition of aquatic organisms, but also an important reason why natural water bodies have self-purification ability. It is the participation of oxygen in various redox reactions in water, which promotes the transformation and degradation of pollutants. The discharge of domestic sewage containing a large amount of nitrogen, phosphorus and potassium leads to the degradation of a large amount of \x0d\ organic matter in the water, releasing nutrients, promoting the excessive growth of algae in the water, making plants grow \x0d\, making the water body poorly ventilated, reducing dissolved oxygen and even appearing anaerobic layer. A large number of aquatic plants die, the water surface turns black, and the water stinks to form a "dead lake", "dead river" and "dead sea", and then turn into a swamp. This phenomenon is called water eutrophication. Eutrophicated water has a strong smell, dark color and many bacteria. The water quality is poor, so it can't be used directly, and water cut-off leads to a large number of fish deaths. \x0d\(4) Harm of drinking water pollution: impact of common drinking water quality items on human health \x0d\ Lead: harmful to kidney and nervous system, highly toxic to children, and confirmed carcinogenic \x0d\ Cadmium: acute harmful to kidney \x0d\ Arsenic: harmful to skin and nervous system, confirmed carcinogenic \ The main organs are kidney and central nervous system \ Nitrite: can cause cardiovascular diseases, especially blue baby disease, and has carcinogenicity \x0d\ Total trihalomethanes: chloroform has the greatest impact on health, and the most common carcinogenicity is bladder cancer \x0d\ trichloroethylene (organic matter): excessive inhalation will reduce the central nervous system and heart function, and long-term exposure will be harmful to the liver \x0d\ carbon tetrachloride (organic matter): Great influence on liver and kidney function \x0d\ In recent years, among 740 cases targeted by the US Environmental Protection Agency (EPA), *** 148 cases were caused by protozoa, and * * * 448486 people were affected, which was the highest among all the causes. 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. \x0d\\x0d\ Hope to help the landlord.