Biomonitors: Practice and Concepts

The usefulness of organisms as biomonitors of environmental quality has been demonstrated repeatedly during episodes of acute poisoning. Management goals now largely seek to avoid or mitigate these occurrences, concomitant with introduction of chemicals to the environment. Biomonitors have largely been adopted as sentinel organisms to warn of excess bioavailability of xenobiotics. Uptake and retention processes in any organisms, however, are only semi-passive, so that metabolic processes may influence both concentration ranges over which accumulation occurs, and mechanisms controlling it. Furthermore, the relationship between route and extent of accumulation is usually not known and cannot necessarily be inferred. Recently-proposed models use knowledge of a substance´s physicochemical properties to predict its disposition in environmental compartments, e. g. water, air, sediments and biota, based on related thermodynamic concepts of equilibrium partitioning or fugacity. It is not clear, however, that prediction of the behavior of chemicals not near equilibrium can adequately be made, at least for management purposes. These new concepts form the basis of a need for better understanding of physiological and biochemical attributes of biomonitor species and the significance of physicochemical behavior so that both the quality and limitations of entries in data bases created during monitoring programs is clearly understood.