Ddt and Malaria

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  • Topic: Malaria, DDT, Anopheles
  • Pages : 6 (2300 words )
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  • Published : November 3, 2009
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Should DDT Be Used Against Malaria
DDT is an effective control mechanism for containing the spread of malaria. However, when used as a control mechanism for agriculture, it has been shown to cause environmental harm to ecosystems in the area. This has lead to many misconceptions that DDT is strictly a harmful chemical that only leads to negative outcomes. However, there is evidence that shows the opposite when DDT is used as a control mechanism in controlling the spread of malaria. DDT should be used as a control mechanism against malaria as long as the activity of spraying is closely monitored and contained. DDT should not be used as the only answer to solving the problem of malaria but should play an important role. The purpose of this paper will be to provide information on why DDT should be used as a control mechanism in the fight against malaria and to clarify misconceptions with support from quantitative and qualitative data. Malaria is a vector born disease that is transmitted to humans by four parasites which are: the Plasmodium falciparum which is found worldwide in tropical areas, the P. vivax which is found in Africa, Asia, and Latin America, and the other two less common species are the Plasmodium ovale, and P. malariae (Murrary). Mosquitoes are the main source of transmission of the disease to humans. It is most commonly spread by the bite of an infected female Anopheles mosquito (Murrary). The mosquitoes act as a vector for the disease through ingesting the plasmodium when biting an infected human. The infected mosquitoes can continue to spread the disease with each future bite on its next host (Malaria). The environmental factors that play the most important role on the transmission of malaria are temperature and humidity. These factors affect the growth and survival rates of the plasmodium and mosquitoes. Organisms cease to develop in the mosquito when the temperature falls below 16°C. At 20°-30°C, the parasites develop optimally in the vector (Malaria). One of the most disruptive changes affecting mosquito populations is deforestation. Deforestation is occurring throughout the world at large rates. During this time, cleared tropical forest is typically converted into grazing pastures, agricultural plots, and human settlements. In two independent case studies, it was found that more open treeless areas experienced warmer midday temperatures than those of forested areas. As a result, the gonotrophic cycle of female Anopheles gambiae (which is the egg production / laying cycle) was found to be shortened by 2.6 days (52%) and 2.9 days (21%) during the dry and rainy seasons compared to that of forested sites (Patz). As the reproductive cycles of the mosquitoes increases, the potential for mosquitoes to become infected and spread the disease goes up. These ecological disturbances allow for the proliferation of mosquitoes that prefer human habitation to natural settings. Malaria currently kills around one million people each year. Many of these people are young children in Africa. It is estimated that 3,000 children die each day from the disease. (Malaria Deaths Dropped To One Quarter Previous Level In Zanzibar, Tanzania). World efforts in fighting this disease first began in 1940’s by using a relatively new chemical called DDT. The next paragraph will provide a brief history of the use of DDT since its discovery.In 1874, Dichloro-diphenyl-trichloroethane (DDT) was created, with no specific purpose for it at the time by a German chemist named Othmar Zeidler. In its pure form, DDT is a white crystalline substance. Its chemical formula is C14H9Cl5 (DDT (dichlorodiphenyltrichloroethane)). In 1939, Dr. Paul Müller independently produced DDT. Müller found that DDT quickly killed flies, aphids, mosquitoes, walking sticks and Colorado potato beetles (Milloy). In the 1950’s DDT became commonly used throughout the world as an insecticide for agriculture and for control against diseases such as malaria. In...
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