Chapter 8 – Biological Monitoring and Biomarkers

Biological monitoring (BM; synonym, biomonitoring) was developed for the assessment of the health risks from exposure to metals in the work environment, and the approaches and concepts of biomonitoring are derived from such exposures. At present, biomonitoring is increasingly used to assess exposure from the environment. Biomonitoring and the assessment of external exposure are complementary activities, where external exposure assessments are much more widely applied, especially when the number of chemicals concerned is considered; environmental analysis also offers the distinct advantage of speciation analysis, which is very poorly developed for biomonitoring. Biomonitoring, on the other hand, provides information on exposure from all sources and via all absorption routes, and also considers accumulation of the chemical in the body. Biomonitoring using exposure biomarkers thus considers interindividual differences in absorption, whereas the use of effect biomarkers also considers interindividual differences in susceptibility. Few effect biomarkers, however, have been validated. Biomarkers of susceptibility have so far not been adapted for routine use in metal toxicology. The major challenges of biomonitoring are the development of (preferably noninvasive) monitoring methods, which are inexpensive enough to be applied at a frequency that makes possible the meaningful biomonitoring of metals with a short half-time; the development of exposure biomarker guidance values specific to individual species of different metals; expansion of the repertoire of validated effect biomarkers; and the validation and application to effect monitoring of the “omic” technologies. Promotion of the scientifically sound use of biomonitoring in chemical risk management, for example as a tool to control the effectiveness of risk management measures, is also one of the today’s challenges.