The impact of polluted water on the human body has many unfavorable factors: 70%-80% of the human body is water, so long-term drinking of poor water quality, resulting in poor physical resistance naturally weakened, then the occurrence of all diseases is inevitable, and long-term When the accumulated pollutants reach the body and cannot be tolerated, the doctors who are more sophisticated and the more effective drugs may not work. Therefore, the statement that "water is the king of medicine" is not false.

Water pollution is caused by harmful chemicals that reduce or lose the use of water and pollute the environment.

Water pollution affects industrial production, increases equipment corrosion, affects product quality, and even prevents production from proceeding. The pollution of water affects people's lives and destroys ecology. It directly harms people's health and causes great damage.

(1) Hazard of eutrophication of water Under normal conditions, oxygen has a certain solubility in water. Dissolved oxygen is not only a condition for the survival of aquatic organisms, but also the various oxidation-reduction reactions of oxygen in water to promote the conversion and degradation of pollutants, which is an important reason for the self-purification ability of natural water bodies. The discharge of domestic sewage containing a large amount of nitrogen, phosphorus and potassium, a large amount of organic matter degraded in water to release nutrients, promote the accumulation of algae in the water, the plant grows wild, the water body is poorly ventilated, the dissolved oxygen is reduced, and even an anaerobic layer appears. As a result, a large number of aquatic plants die, the water surface is black, and the water body is stinky to form a "dead lake", a "dead river", a "dead sea" and then become a swamp. This phenomenon is called eutrophication of water. Eutrophic water has a large odor, deep color, and many bacteria. The water quality of this water is poor and cannot be directly used.

(2) Harm to industrial and agricultural production After water pollution, industrial water must be invested in more processing costs, resulting in waste of resources and energy. The food industry requires more stringent water quality, and unqualified water quality will stop production. This is also a factor in the low efficiency and poor quality of industrial enterprises. The use of sewage in agriculture has reduced crop yields, reduced quality, and even victimized humans and animals. Large areas of farmland have been polluted and soil quality has been reduced. The consequences of marine pollution are also very serious, such as oil pollution, causing the death of seabirds and marine life.

(3) After harming people's healthy water pollution, pollutants enter the human body through drinking water or food chain, causing acute or chronic poisoning. Arsenic, chromium, ammonium, stupid (a) sputum, etc., can also induce cancer. Water contaminated with parasites, viruses, or other pathogens can cause a variety of infectious and parasitic diseases. Water contaminated by heavy metals is harmful to human health. Water and food contaminated with cadmium will cause kidney and bone disease after eating, and the intake of 20 mg of cadmium sulfate will cause death. Poisoning caused by lead, causing anemia, nervous disorder. Hexavalent chromium is highly toxic, causing skin ulcers and carcinogenic effects. Drinking arsenic-containing water can cause acute or chronic poisoning. Arsenic inhibits or inactivates many enzymes, causing metabolic disorders in the body, keratinization of the skin, and skin cancer. Organophosphorus pesticides cause neurotoxicity, and organochlorine pesticides accumulate in fat, causing harm to endocrine, immune, and reproductive functions of humans and animals. Most of the polycyclic aromatic hydrocarbons have carcinogenic effects. Cyanide is also a highly toxic substance. When it enters the bloodstream, it binds to the pigment oxidase of the cell, causing the breathing to be interrupted, causing respiratory failure and suffocation. We know that 80% of the world's diseases are related to water. Typhoid fever, cholera, gastroenteritis, dysentery, and infectious liver disease are the five major diseases of human beings, all caused by the uncleanness of water.

Acids, alkalis, oxidants in sewage, and compounds such as copper, cadmium, mercury, arsenic, organic poisons such as benzene, phenol, dichloroethane and ethylene glycol will poison aquatic organisms and affect drinking water sources and scenic spots. . When the organic matter in the sewage is decomposed by microorganisms, the dissolved oxygen in the water is consumed, affecting the life of aquatic organisms such as fish. After the dissolved oxygen in the water is exhausted, the organic matter is anaerobicly decomposed to generate unpleasant gases such as hydrogen sulfide and mercaptan, and the water quality is further advanced. deterioration. It will also affect the life of aquatic organisms due to the floating of oil, causing fires.