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What Is DDT?. DDT the first of the chlorinated organic insecticides, was originally prepared in 1873
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What Is DDT? • DDT the first of the chlorinated organic insecticides, was originally prepared in 1873 • In 1939 Paul Muller of Geigy Pharmaceutical in Switzerland discovered the effectiveness of DDT as an insecticide he was awarded the Nobel Prize in medicine and physiology in 1948 for this discovery
The effectiveness of DDT •against the mosquito that spreads malaria and lice that carry typhus • The World Health Organization estimates that during the period of its use approximately 25 million lives were saved
Dangerous of DDT • problems related to extensive use of DDT began to appear in the late 1940s. Many species of insects developed resistance to DDT, and DDT was also discovered to have a high toxicity toward fish. • For humanbeing- cause cancer, chronic toxicity,freak.
The ban of DDT • The use of DDT was banned in the United States in 1973, although it is still in use in some other parts of the world. The buildup of DDT in natural waters is a reverisble process: the EPA reported a 90% reduction of DDT in Lake Michigan fish by 1978 as a result of the ban.