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Biomagnification and Bioaccumulation

The effects of DDT

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The effects of DDT
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Bioaccumulation and Biomagnification
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A briefe history about DDT
 
DDT actually means dichlorodiphenyltrichloroethane. I was first introduced in WWII along with penicilian. Before the introduction of DDT in Sri Lanka the number of cases of Malaria were more than 1 million. After DDT was intorduced, by 1963 almost all of this disease were eliminated. This led scientists to belive that the hazards of DDT were too much. So DDT was not used in the mid 1960's in which cases of malaira were growing.

How DDT becomes concentrated in a food chain
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http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/D/DDTandTrophicLevels.html

DDT is one of the most common sources of a toxin that is a threat to organisms in a food chain. DDT is a threat because it affects the nervous system. If DDT is accidentally swallowed in a large amount DDT can cause the person to become excitable, have Tremors and seizures. In animals, short-term exposure to large amounts of DDT in food affected the nervous system, while long-term exposure to smaller amounts affected the liver. Also in animals, short-term oral exposure to small amounts of DDT can cause harmful affects in reproduction. DDT that was exposed to workers did not show any signs of DDT causing cancer however DDT exposed to animals showed that animals could develop liver cancer. How DDT can end up in a food chain is very simple. When DDT used extensively in the 1970’s it was used as a pesticide control as well it was used to eliminate diseases such as malaria. DDT is white in colour and tasteless as well as odorless. When DDT entered the environment for its use as pesticide it stuck to the soil and therefore a plant that grew out of the soil might have had a very little concentration of DDT but as a result animal that ate that plant had a concentration of DDT higher of that than the plant. As this process keeps on repeating the animals in the high trophic levels  which consume an organism containing DDT are more at risk of having problems in the nervous system or in more severe cases death. One good thing about DDT is that the DDT that is in the air is broken down by sunlight. Also only very little amounts of DDT will dissolve in groundwater as they do not dissolve easily in water.