[Analytical quality in biological monitoring of workers exposed to chemicals: experience of the Prevention and Safety at the Workplace Service in Modena]. / Qualità del dato analitico nel monitoraggio biologico dei lavoratori esposti a sostanze chimiche: esperienza del Servizio Prevenzione e Sicurezza Ambienti di Lavoro della Azienda USL di Modena.

BACKGROUND: The quality of laboratory data is one of the main factors in guaranteeing efficacy of biological monitoring. OBJECTIVES: To analyze the quality of laboratory data used for biological monitoring of exposed workers. METHODS: A survey involving 18 companies employing 945 workers in the area of Modena, Italy, was carried out in 2008. RESULTS: Most of the 9 private laboratories receiving biological samples did not perform directly part or all of the laboratory assessments requested, but this was not indicated in the final report. Major problems were observed in the application of internal quality control, and only one laboratory participated in external quality assessment for blood lead measurements. CONCLUSIONS: Our results raise major concerns on the traceability and reliability of laboratory assessments performed for biomonitoring of exposed workers. Systematic evaluation of the quality of analytical data would be highly recommendable.