(1), water is the source of life. The earliest life in the world was born in water, with 70% adult tissues, 60% middle-aged tissues and 50% aged tissues, including 90% blood, 85% brain tissues, 75% muscles and 50% bones. If the proportion of water in human body is less than 50%, it will endanger people's lives.
Water is very important to people's health, but now the water quality in our country is seriously polluted. The Chinese Academy of Sciences 1996 national report pointed out that the investigation on the pollution situation of 532 rivers in China showed that 436 rivers had been polluted to varying degrees. More than 63.6% of lakes in China have reached the level of eutrophication. China's densely populated areas, lakes and reservoirs have been polluted.
Due to the pollution of water quality, sewage has become an invisible killer of human health. A survey by the World Health Organization (WHO) shows that:
80% of diseases in the world are caused by polluted drinking water;
50% of child deaths in the world are caused by polluted drinking water;
Every year, 25 million children in the world die of diseases caused by drinking polluted water;
* 12 There are 2 billion people in the world who suffer from various diseases because of drinking polluted water.
In a word, water is the source of life, and health is the foundation of everything in life. Love life and pay attention to health!
(2) Introduction of water environmental pollution knowledge
Studies show that pollutants in water can usually be divided into three categories: biological, physical and chemical pollutants.
1. Biological pollutants include bacteria, parasites and viruses. There are good ways to kill pathogenic bacteria and parasites. However, the research on pathogenic virus is not enough, and there is no recognized standard for virus killing. There are more than 100 kinds of viruses excreted by human feces, which pollute water sources through different ways. Through routine purification and disinfection, poliovirus, coxsackie virus, rotavirus and hepatitis A virus can partially survive. With the deterioration of water pollution, the original viruses in water may also change and new viruses appear.
2. Physical pollutants include suspended solids, thermal pollution and radioactive pollution. Mainly from the tap water station to the civil and public taps, there are several kilometers of iron pipes and valves, which are corroded all the year round. A large number of suspended sediments are deposited in various electric water heaters, thermos bottles, teacups and our bodies all the year round. Radioactive pollution is the most harmful and generally exists in local areas.
3. Chemical pollutants include organic and inorganic compounds. With the development of analytical technology, more than 2500 kinds of chemical pollutants have been detected from source water. At present, we should pay close attention to: (1) Water-borne infectious diseases are caused by living pollutants in water. Drinking unclean water or eating contaminated food can cause typhoid fever, cholera, bacillary dysentery, amebic dysentery, hepatitis A and other infectious diseases. In addition, people move in unclean water, and pathogens in water can also invade the body through skin and mucosa, such as schistosomiasis and leptospirosis.
(2) Mutagenic, carcinogenic and teratogenic effects. Common mutagenic pollutants in water, such as methyl chloride and acrylonitrile, will have a sudden and heritable impact on the genetic material of organisms; Inorganic substances such as asbestos, arsenic, nickel and chromium, and organic pollutants such as nitrosamines and aniline can all induce the formation of tumors. Methylmercury, sodium pentachlorophenol and other teratogenic pollutants can interfere with the normal fetal development process through pregnant mothers, make the fetal development abnormal and cause congenital malformation, and can also directly act on germ cells, affecting reproductive function and birth defects.
(3) The hazards of endocrine disruptors in water environment. Some chemical pollutants, such as dibutyl phthalate, parathion and synthetic pyrethroids, can interfere with the synthesis, metabolism or action of some hormones in the body, thus affecting the normal physiological, metabolic, reproductive and reproductive functions of the body.
The serious harm of unclean drinking water to individuals is as follows:
Excessive heavy metals and impurities: various strange diseases and tumors.
Escherichia coli: gastroenteritis, diarrhea, urinary system infection, cholecystitis, etc.
Salmonella: typhoid fever, paratyphoid fever, etc.
Shigella: bacillary dysentery, etc.
Hemolytic Streptococcus: Water-borne epidemic of hemolytic jaundice still occurs.
(3) the drinking water revolution in human society
The first revolution:1From the beginning of the 9th century to the 1960s, in order to remove turbidity of raw water and eliminate infectious sources in water, the coagulation sedimentation-sand filtration-chlorination-ordinary pure water disinfection process was adopted.
The second revolution: In the 1960s, pollution from non-pollution sources caused refractory or non-biodegradable organic matter. Organic halides produced by chlorination disinfection are more toxic. Remove turbidity and pathogenic bacteria; Removing a variety of organic and inorganic trace pollutants is called advanced purification technology.