TAILIEUCHUNG - Pesticide Residues in Coastal Tropical Ecosystems: Distribution, fate and effects - Chapter 3

Zimbabwe nằm trong vùng nhiệt đới châu Phi (Lat. 15 ° đến 22 ° S và ° Long. 26 tới 34 ° E), chiếm một diện tích km2 và có dân số khoảng 11 M. sông Zambezi các hình thức ranh giới với Zambia ở phía bắc, và sông Limpopo hình thức ranh giới với Nam Phi ở phía nam. Vùng cao nguyên phía đông đã hình thành vành cao nguyên châu Phi (trước khi gốc các đồng bằng ven biển Mozambique), tạo thành phần lớn biên giới với Mozambique. Ở phía tây, ranh giới với Botswana theo giới. | Chapter 3 Pesticide use in Zimbabwe Impact on Lake Kariba a tropical freshwater ecosystem Mark F. Zaranyika INTRODUCTION Zimbabwe is situated within the African tropics Lat. 15 to 22 S and Long. 26 to 34 E occupies an area of 390 580 km2 and has a population of about 11 M. The Zambezi River forms the boundary with Zambia to the north and the Limpopo River forms the boundary with South Africa to the south. The eastern highlands that form the rim of the African Plateau before descent to the Mozambique Coastal Plain constitute the greater part of the border with Mozambique. In the west the boundary with Botswana follows the eastern limit of the Kalahari Desert. Zimbabwe is a landlocked country. Its GDP for 1990 and 1994 was Z 14 643 M and Z 39 775 M respectively. The agriculture sector contributes about 13 percent of GDP while the export of agricultural products contributes 50 percent of the country s total annual export earnings Central Statistical Office 1990 . The use of pesticides plays a major role in maintaining these high levels of agricultural production. As in most tropical countries in Africa pesticides are also extensively used in the public health arena to control diseases such as malaria a nonhemorrhagic fever caused by protozoans of the genus Plasmodium Marchiafava and Celli and vectored by Anopheles Meigen spp. Diptera Culicidae mosquitoes African trypanosomiasis African sleeping sickness a nonhemorrhagic fever caused by protozoans of the genus Trypanosoma Gruby and vectored by tsetse flies Glossina spp. Diptera Glossinidae and typhoid a bacterial illness caused by Salmonella typhi spread in contaminated food and water . Of late there has been concern about the possible effects the use of pesticides has on tropical environments including tropical marine and fresh water ecosystems. The effect of pesticides on the environment depends on several factors such as climate in particular temperature and rainfall soil type and the nature of the vegetative cover

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