Thursday, July 25, 2019
Environmental Engineering Essay Example | Topics and Well Written Essays - 2000 words
Environmental Engineering - Essay Example Pesticides are used widely for domestic purposes such as rat killers, mosquito and ant repellents etc. In agricultural sector, pesticide became a main aspect for improving yields. They are used to control insects, weeds, fungal diseases in plants. Pesticides are also used to kill rats, flies which destroy crops and to prevent food from being contaminated. The pesticide era started before 2000 B.C. Around 4500 years ago, ancient Sumerians used elemental sulphur, Compounds of Arsenic, Lead, and Mercury was applied in 15th century. The tobacco product, nicotine sulphate was used in 17th century. Natural products such as pyrethrum and rotenone are obtained from chrysanthemums and vegetables respectively. In 1890s, Lead Arsenate and compounds of di-nitro phenol were used. The 20th century saw introduction of many pesticides such as Arsenic compounds, sulphur products, cyanides and nicotine compounds. In 1932, ethylene was first used as plant growth regulator to promote flowering in pineap ples. In 1939, DDT was discovered. DDT was a powerful insecticide. During 1960, herbicides based on lead and nitrogen, carboxylic acids such as di-chloro phenoxy acetic acid etc. were used. The 20th century saw the use of large amount of pesticides. The developing countries are still using increased amount of pesticides for pest control and crop yield. Every advantage has a disadvantage associated with it. Use of pesticides for crop yield and killing of pests in turn affected the environment, wild life and humans. The use of pesticide increased enormously in 20th century. It was discovered traces of DDT was found in many fish-eating birds and it hindered their reproduction. This was the finding which shocked the world because it hindered bio-diversity. Even though DDT was banned in some nations, it is still used in developing countries as an insecticide. The uses of pesticides cause problems
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