Noel V Stanton1, Tracy Fritsch. 1. Wisconsin State Laboratory of Hygiene, Toxicology Section, University of Wisconsin-Madison, Madison, Wisconsin 53707-7996, USA. nvstox@mail.slh.wisc.edu
Abstract
BACKGROUND: A new blood lead testing instrument has qualities that make the instrument attractive for on-site testing of occupational lead exposures. This study evaluated the accuracy of the instrument when used in a manufacturing setting, and examined the impact of blood storage and shipment on results. METHODS: Venous blood specimens (n=121) were obtained and immediately analyzed on-site using the new instrument. They were then shipped to a reference laboratory and analyzed using electro-thermal atomization atomic absorption spectrometry (ETAAS), and retested using the new instrument. RESULTS: The cohort blood lead concentration averaged 40.1 microg/dl. Results obtained on the new analyzer with freshly collected blood averaged 38.7 microg/dl. The mean difference of 1.2 microg/dl on paired samples was not statistically significant. Following blood shipment and storage, results on the analyzer increased to an average of 42.4 microg/dl. The mean increase of 3.0 microg/dl on stored blood samples also failed to reach statistical significance. Under OSHA proficiency test acceptability requirements, 94% of the results had satisfactory agreement. CONCLUSIONS: The new analyzer might be a useful tool for on-site monitoring of occupational lead exposures. The manufacturer's instructions should be adhered to with respect to specimen age and storage requirements.
BACKGROUND: A new blood lead testing instrument has qualities that make the instrument attractive for on-site testing of occupational lead exposures. This study evaluated the accuracy of the instrument when used in a manufacturing setting, and examined the impact of blood storage and shipment on results. METHODS: Venous blood specimens (n=121) were obtained and immediately analyzed on-site using the new instrument. They were then shipped to a reference laboratory and analyzed using electro-thermal atomization atomic absorption spectrometry (ETAAS), and retested using the new instrument. RESULTS: The cohort blood lead concentration averaged 40.1 microg/dl. Results obtained on the new analyzer with freshly collected blood averaged 38.7 microg/dl. The mean difference of 1.2 microg/dl on paired samples was not statistically significant. Following blood shipment and storage, results on the analyzer increased to an average of 42.4 microg/dl. The mean increase of 3.0 microg/dl on stored blood samples also failed to reach statistical significance. Under OSHA proficiency test acceptability requirements, 94% of the results had satisfactory agreement. CONCLUSIONS: The new analyzer might be a useful tool for on-site monitoring of occupational lead exposures. The manufacturer's instructions should be adhered to with respect to specimen age and storage requirements.