[Biological monitoring of lead: system and quality control].

The assessment of health effects of lead exposure is based on the determination of lead blood concentrations. The correctness of predicting these effects depends on the reliability of determination results. The latter can be confirmed only if the laboratory participates in the quality assurance programme for chemical analyses. The aim of the present study was to investigate the systems in use for quality control, methods of determining lead blood concentration and the results of a project on quality control for lead determination in Poland (project coordinated by the Nofer Institute of Occupational Medicine, Lodz, Poland). The paper discusses the principles of the quality assurance programme implemented in Poland, elements of good laboratory practice with respect to blood sampling, analytical equipment and the use of flameless AAS for determining lead blood concentration. The quality assurance programme for lead determinations covers nine laboratories. The initial stage of its implementation revealed that only 50% of the determinations were correct. Consequently, a series of audits was made at the laboratories and some training provided for the staff. The last round indicated an increase in the percentage of correct results of up to 80%. Proper performance of lead determinations carried out routinely for the assessment of industrial exposure to lead is of extreme importance in view of the fact that lead determinations in blood are planned to be made compulsory and to replace urinary determinations of the metal.