The role of biological markers in toxicology.

Biological markers are tools that can be used to clarify the relationship, between exposure to a xenobiotic compound and health impairment and to indicate individual or population differences that affect the biologically effective dose. Biological markers, broadly defined, are indicators of variation in cellular or biochemical components or processes, structure, or function that are measurable in biological systems or samples. There is growing interest in the use of biological markers to study the health effects of exposure to environmental toxicants in occupational medicine, epidemiology, toxicology, and related biomedical fields.