Biomonitoring of chemicals on tropical ecosystems

Over the past years the environmental monitoring programmes have undergone rapid conceptual and technological advancement. Environmental monitoring (= Biomonitoring) plays an essential role in the evaluation and management of pesticides and other anthropogenic chemicals in the tropics. In the absence of effective biomonitoring, detection of serious environmental contamination and threats to human health caused by chemical pollutants may occur only after critical and irreversible damage has been done. Between 1976 and 1989 the ecosystematic effects caused by various herbicides and insecticides were analysed. The regenerative power of the tropical ecosystems, after having been treated with insecticides, does not only depend on the type of pesticide or its formulation and concentration, but also in a decisive way on the ecophysiological capacity of different organisms in the tropical food chains. Our experience in tropical South America, Africa and Europe has proved that the application of chemicals does not represent a serious environmental problem, provided the chemical inputs on the ecosystems have already been evaluated, and the whole procedure and organization are carried out in a professional manner. Concerning the elimination of pests, it has been observed that various forms of land utilization in the tropics have a much more adverse effect than those effects induced by pesticide usage. The cardinal question for the time being will be: What will happen to the ecosystems when they are free of pests? This is not a scientific but a political question. There is no free lunch in the world