Present status and trends in biological monitoring of exposure to industrial chemicals.

This paper describes the current practice of biological monitoring of populations exposed to occupational or environmental pollutants. The three types of monitoring are ambient monitoring, biological monitoring of exposure, and health surveillance (also called biological monitoring of effects). The trend in biological monitoring today is to develop tests that provide information on the amount of chemical bound to the critical sites of action (target dose). Ambient monitoring and biological monitoring assess the health risk by comparing the current exposure with the permissible exposure limits. They are essentially preventive activities. By contrast, health surveillance or biological monitoring of effects assesses the health status and aims at detecting the early adverse health effects. Health surveillance is part of the medical screening program for the early detection of health impairment due to industrial chemicals.