Biological monitoring, also called biomonitoring, is a process to prevent and assess health risk for individuals exposed to chemical products present in environment or through workplace exposure. Biomonitoring is most often a monitoring of exposure or of effect. The exposure monitoring is currently the most widespread in toxicology. It involves the determination in biological fluids of different biomarkers, most of which are biomarkers of internal dose. These biological indicators are typically measured in blood and urine, but other biological samples can be analyzed. They are used to assess the penetration of environmental pollutants into the body. Assay results are interpreted in relation to reference values which are adapted either to occupationally exposed populations, or to general population. This interpretation and the choice of appropriate biomarker of exposure are not always obvious. Biomonitoring has some limitations despite its many advantages. It is complementary to another health prevention approach: the monitoring of ambient air. To illustrate in practice the biomonitoring of exposure, several examples of toxics and their associated biomarkers are reviewed: benzene, toluene, styrene, polycyclic aromatic hydrocarbons, chloroform, 2-hexanone and hydrogen cyanide.
Keywords: biomarkers; biomonitoring; toxicology.