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.
Influence of common drinking water quality engineering on human health
Lead: harmful to the kidney and nervous system, highly toxic to children, and its 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, and the main organs are kidney and central nervous system.
Selenium: High concentration will harm muscles and nervous system.
Nitrite: It causes cardiovascular diseases, especially infants (blue infant disease), and is carcinogenic.
Total trihalomethane: chloroform has the greatest impact on health, and the most common carcinogenicity is bladder cancer.
Trichloroethylene (organic matter): Excessive inhalation will reduce the central nervous system and heart function, and long-term exposure will be harmful to the liver.
Carbon tetrachloride (organic matter): 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. Of the 740 cases, *** 148 cases were caused by protozoa, and * * * 448486 people became ill. 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.
Water is not only the source of life, but also extremely important to human beings, and the pollution is so serious. Therefore, scientists should prevent and protect water resources and make rational use of them.
Also: human birth defects are also called congenital malformations. Although genetic factors play an important role in the occurrence of human birth defects, acquired environmental factors play an important role in the damage of genetic material of germ cells, the direct damage to embryo development and the occurrence of birth defects. With the development of industry, a large number of chemicals are discharged into the environment, and many researchers have observed that the incidence of fetal malformation caused by pregnancy poisoning has increased significantly. In fact, for example:
(A) the incident of fetal Minamata disease
In the epidemic areas of Minamata disease in Japan, sometimes mothers have little or no symptoms of Minamata disease, while babies suffer from congenital paralytic dementia or other malformations. According to animal experiments and human observation, alkyl mercury compounds can enter the fetus through the placenta, and the content of fetal blood and brain is 20% higher than that of the mother. Pregnant women exposed to a large number of alkyl mercury compounds may cause mental retardation and even dementia, and some of them are accompanied by symptoms of fetal Minamata disease such as convulsive cerebral palsy.
(2) 2 4 5 snuff incident
During the Vietnam War, the defoliant 2,4,5-nasal drops were widely used in the United States. The survey shows that among people who have lived in the area where 2,4,5-snot spread for more than 2 months, three of the four mothers of adult women gave birth to deformed children except acute and chronic symptoms. It was also found that there were obvious chromosomal abnormalities (2 1- trisomy) in 2 cases of deformed children. The structural abnormalities such as chromosome breakage and defect were 1. 14% in the control group, 5.88% in scattered children and 3.55% in deformed children.
The teratogenic effect of 2,4,5-nasal secretions is mainly impurities containing dioxins, which are difficult to remove. Even after recrystallization and purification, it can still cause teratogenicity in mice, rats and chickens at high dose (100mg/kg). 2,4,5-snot can be decomposed into 2,4,5-trichlorophenol in soil, and dioxins can be generated by condensation of two molecules of trichlorophenol to remove two molecules of hcl. Among the pesticide compounds, there are many derivatives based on ortho-phenol, such as sodium pentachlorophenol, ibiphos, chlorpyrifos, rice blast, 2,4,5-bis, herbicide, herbicide and so on.