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Versie door Daphnisd (Overleg | bijdragen) op 23 jul 2009 om 16:08

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Definition of DDT:
dichlorodiphenyltrichloroethane (DDT), a persistant organochlorine pesticide [1]


DDT, like other organochlorine pesticides enter the marine environment mainly through inputs from water and air as a result of their use in agriculture. Although the use of DDT has been forbidden since the 1970's, they are still detected in the marine environment due to it's extreme stability, to illegal use or to use elsewhere (third world countries). DDT is metabolized into dichlorodiphenyldichloroethylene (DDE) which is equally toxic. Therefore, to asses the risk of DDT exposure, the sum both contaminants needs to be taken into account. This means that if you encounter a high percentage of DDT, the contamination must be a recent one.[2]. It's still possible to find recent contaminations of DDT, especially by use in third world countries, where use still isn't everywhere prohibited.[3] DDT affects the central nervous system of insects and other animals. This results in hyperactivity, paralysis and death. DDT also affects eggshell production in birds and the endocrine system of animals. [4]

DDT has a very high tenancy towards biomagnification. When in a simple ecosystem the background concentration is equal to 1, then zooplancton can accumulate concentrations of 13.000, small fish species concentrations of 170.000, large fishes up to 670.000 and finally birds will accumulate concentrations up to 8.300.000. [3] ALL biota: From algae to marine mammals,....

See also

Pesticides in harbour porpoises

Pollution and sea birds

PCBs and organochlorine pesticides in shrimp from the Belgian North Sea

