Why does the country ban DDT?

DDT is also called DDT, 223, with the chemical name of dichlorochlorophenyl trichloroethane and the chemical formula of (ClC6H4)2CH(CCl3). Chinese name comes from English abbreviation DDT, which is white crystal, insoluble in water and soluble in kerosene. It can be made into emulsion and is an effective insecticide. In the first half of the 20th century, it played an important role in preventing agricultural pests and reducing the harm of mosquito-borne diseases such as malaria and typhoid fever.

However, in 1960s, scientists found that DDT was difficult to degrade in the environment, and it could accumulate in animal fat. Even DDT was detected in the blood of Antarctic penguins. DDT in birds will prevent soft-shelled eggs from hatching, especially carnivorous birds at the top of the food chain, such as the American national bird vulture, which is almost extinct. 1962, American scientist Carlson suspected that DDT entered the food chain in his book Silent Spring, which was the main reason for the near extinction of some carnivorous and fish-eating birds. Therefore, since 1970s, DDT has been banned from production and use by all countries in the world. DDT has also become the mother of environmental protection in China.

DDT, a toxic man-made organic substance, is a pollutant, which is easily soluble in human fat and can accumulate in it for a long time. It has been proved that DDT can interfere with the secretion of biological hormones. In the Journal of Epidemiology of 200 1, scientists first confirmed that the increase of DDT level in human body would lead to the decrease of sperm count by sampling the blood samples of 24 Mexican men aged 16 to 28. In addition, premature birth and weight gain of newborns are also related to DDT. The existing medical research also shows that it has an influence on the function and morphology of human liver and has obvious carcinogenicity.

Because of its low acute toxicity and long persistence, the use times of organochlorine pesticides have also decreased. However, this pesticide has a long persistence and accumulation time, which has caused many problems in the ecological environment. As far as toxicity is concerned, DDT pesticide has hepatotoxicity, which will cause necrosis of the central lobule of the liver with hepatomegaly. At the same time, activating microsomal monooxygenase can also change immune function, reduce antibody production and inhibit the ratio of embryonic germinal centers in spleen, thymus and lymph nodes. Other toxicity produced by ddt has no carcinogenic effect on mice or other animals, and it is also negative in epidemiological investigation and short-term mutagenicity test, which has been affirmed by many international organizations. However, DDT is banned because of its accumulation and persistence, which is potentially harmful to human health and ecological environment.