ABSTRACT
Since the 1940s the use of pesticides has grown steadily at about 11 percent a year, reaching five million T in 1995. Pesticides and fertilizers play a central role in agriculture and contribute to an enhanced food production worldwide. Agrochemical use, mainly in developed countries, is being reduced while organic (no synthetic chemicals) farming methods are being reinvented. However, in most countries, agrochemicals remain an essential component of agricultural practice and will remain so for the foreseeable future. Pesticides, especially insecticides and fungicides, are more heavily applied to tropical cash crops, e.g. banana, coffee, cotton, and vegetables, than to crops in temperate regions. For example, the application of pesticides to banana plantations in Costa Rica reached 45 kg a.i. per ha, whereas the comparable average application of pesticides in Japan to crops is 10.8 kg. Only a minor fraction of applied pesticides actually reaches the target pest species – less than 0.1 percent; the excess pesticide moves through the environment potentially contaminating soil, water, and biotic matrices. It is critical, especially in the tropics where use patterns lead to much higher loads of pesticides than in temperate zones, to characterize the fate and non-target toxicity of these pesticides to confidently assess the risk associated with their use.
