ABSTRACT
DDT (trichloro-bis-p-chlorophenylethane), the proto type of the chlorinated hydrocarbons and of the chlori nated ethanes, was discovered during World War II and used with great success for controlling insect vectors of diseases such as typhus, malaria, and bubonic plague (8 ). The compound is credited with making as important contribution to human health as antibiotics (9). Exten sive agricultural use of DDT did not begin until the late 1940s, when the compound became available for civil ian use and was found to be effective for the control of a wide range of insects of agricultural importance. DDT has a wide margin of safety when used properly; and
despite its previous widespread use, there is no docu mented, unequivocal report of a fatal human poisoning (9). Nevertheless, because of the accumulation of DDT in the animal kingdom and the environment, in 1972, DDT was banned in the United States for all but essen tial public health use and for a few minor uses in pro tecting crops for which there are no effective alterna tives (10). A major reason for the Environmental Protection Agency ban of DDT was that it caused can cer in animals. DDT has been reported to induce liver tumors, lymphomas, and lung tumors in mice and liver tumors in some experiments with rats.
