Comparative Metabolism of Mixtures of Chemicals by Animals, Plants, and Microorganisms and Their Significance in Alteration of Pollutants in the Environment

To assess the overall metabolic alteration of organic pollutants through biological systems in the environment, the basic characteristics of metabolic systems in microorganisms, plants, and animals have been examined. While most of their metabolic activities contribute to reduce the levels of pollutant residues and their toxicities, certain of their activities result in the formation of stable, toxic residues (i.e. 'terminal residues'). Conditions which are likely to promote formation of terminal residues are described. There is no single satisfactory microcosm approach to enable scientists to predict overall metabolic fates of pollutants at present. Thus metabolic activities are currently studied by using single species or at best a mixture of related species of organisms. Integration and interpretation of individually collected information, therefore, become rather important tasks. The use of microbial model ecosystems coupled with knowledge on the role of plant and animal systems has provided valuable predictive tools for assessing the nature of toxic residues that accumulate in the environment.