Claude Viau, D.Sc.
Professor
Department of Environmental and
Occupational Health
Université de Montréal
Tel: 1-514-343-7817
Fax: 1-514-343-2200
claude.viau@umontreal.ca
Web: http://www.mapageweb.umontreal.ca/viauc

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Our environment, just like our own body, is made of chemicals. Those we usually fear most are man-made chemicals despite the fact that some of the most toxic ones have a natural origin such as the botulinum toxin or certain mushroom toxins. There are two major approaches to monitoring exposure to “environmental chemicals”. We can quantify their presence in the media we are in contact with such as the air we breathe and the food we eat. Alternately, we can measure the chemicals or their biotransformation products in biological media such as blood, urine and hair. The substance thus measured in a biological matrix is called a biomarker. The extent of our knowledge on biomarkers varies. Consequently, the interpretation we make of a biomarker measurement cannot be identical for all biomarkers. Some reveal the mere presence of the chemical in an organism without any further possible interpretation whereas others can contribute to a full-scale risk assessment. For biomonitoring to be fully exploitable as a health prevention tool, we need to establish guideline values for the biomarkers. These values can derive from the distribution of biomarker concentrations in a reference population, from the knowledge of the relationship between the exposure dose and the resulting biomarker concentration, or from the relationship between a health outcome and the biomarker concentrations. Some of the biomarkers success stories in the establishment of public health policies include blood lead and serum cotinine. The first was key to stopping the use of lead tetraethyl as an antiknock agent in gas. The second contributed to the various antismoking policies established over the recent years. As such they were instrumental to improving public health.