Critical evaluation of current concepts in exposure assessment

The exploitation of natural resources and the improper use and disposal of thousands of chemicals have resulted in environmental pollution and a potential threat to human health on a global scale. Increasing public concern about environmental exposure to and consequent ill health from contaminants demands informed answers based on valid risk assessment. By assessing internal exposure to pollutants, human biomonitoring focuses on early markers of potential risks to prevent serious adverse effects. Exposure assessment may provide a rational basis for risk assessment, with knowledge of the adequacy of limit values; it may also uncover long-term changes in body burdens and thus help identify the sources and transfer pathways of environmental pollutants. The techniques of biological exposure assessment should be incorporated into epidemiological studies if suitable specimens are available, such as exhaled air, blood, urine, breast milk, or adipose or keratinous tissue. Special precautions must be taken in sampling, storage, and analysis if the findings are to be interpreted correctly and reliable conclusions drawn.