[The environment, knowledge and preventive medicine. 2. Reductionism and holism--a dichotomy in thinking].

The usual theories and methods of biological sciences and medicine are of important rank to valuate the potential risks of environmental pollutions. Because in notice of the represented system model the consideration of ecotoxicological processes shows, that a complete assessement of these risks and the effects of environmental pollutions against human health can only be attainable when holostic mode of thinking is integrated.