Basic concepts of monitoring human exposure.

Environmental and biological monitoring are two complementary approaches for evaluating human exposure to genotoxic agents. Environmental monitoring involves, usually, measurement of chemicals either by physico-chemical techniques or via biological activities (e.g., mutagenic activity of airborne pollutants). Biological monitoring relies on two groups of tests: those based on determination of the substances or their biotransformation products in various biological media and those based on detection and, possibly, quantification of those biological changes that result from the reaction of the organism to exposure. The application of tests for exposure and the interpretation of the results require a careful evaluation of several issues, mainly the sensitivity, specificity and health significance of the selected monitoring parameters, the precision and accuracy of the analytical technique and the ethical aspects.