As the side effects of organochlorines became known in the 1960s, most nations placed restrictions on their use. In South Africa and Namibia, DDT, widely applied from 1946, was prohibited in agriculture and is now used only by government for malaria mosquito control. Manufacture of these chemicals continues, however, and the main market has shifted from developed to developing countries. Zimbabwe, for example, imported 1000 tonnes of DDT in 1982. They are thought to be safer than organochlorines as they break down more rapidly.
Organophosphates are responsible for most acute pesticide related poisonings amongst humans.
In 1985, organophosphate poisonings were the second most common reason for Tygerberg Hospital's ICU admissions. These modern insecticides are usually not toxic to mammals, but are extremely toxic to birds. Carbamates are used in termite control and this can reasult in the secondary poisoning of birds that have eaten poisoned termites. Pesticides play an important role in the control of human and animal diseases, and crop pests. However, the continued use of organochlorines, for example, could seriously damage fish and wildlife resources as well as pose a health hazard to man.