[Data quality and the interpretation of biological monitoring results]

Quality assurance criteria are not uniformly applied to routine biological determination, in particular with regard to the biomonitoring of exposure to organic solvents. Quality assurance is not an abstract concept but rather a flexible tool which can be adapted to different situations, such as the measurement of different exposure levels or the use of different analytical methods, for a range of purposes (routine determination, risk assessment procedures, research). The occupational health physician should be actively involved in the definition of quality objectives, as well as in checking that they have been implemented. This paper deals with some general issues regarding quality assurance, and in particular with certain requirements of analytical quality (analytical uncertainty, imprecision, bias) and its implementation (quality control, reference materials, standardization, reference values), contextualized to the biological monitoring of organic compounds and the relative metabolites.