Occupational lead exposures biomarkers

Several other studies published in the last 5 years have reported adverse associations between occupational lead exposure and impaired renal function. A study in Nigeria described impaired creatinine clearance in 190 lead workers (mean BLL 50 pg/dL) compared with 80 controls but did not adjust for aity covariates (Alasia et al. 2010). A study of 87 industrial workers (mean BLL 29 pg/dL) and 61 controls in Pakistan reported statistically significant correlations between BLL and seram creatinine, uric acid, and several early biologic markers of renal dysfunction (Khan et al. 2008). Early biologic markers of tubular and glomeralar function were explored in 155 battery workers (mean BLL 20 pg/dL) and 36 controls in China (Sun et al. 2008). The study reported a dose-response relationship between BLL and renal function, biomarkers of bone metabolism, and the prevalence of osteoporosis. Those and many other studies summarized by EPA (2012) have been rather consistent in making the link between occupational lead exposure and impaired renal function. 

The efficacy of urinary porphyrin profiles as a biomarker of exposures to metals other than lead in human populations is less well established. Studies on dentists with occupational mercury exposure have provided preliminary evidence of the potential utility of urinary porphyrin changes as a biomarker of low-level mercury exposure in human subjects (Woods et al. 1993), and further studies have demonstrated their efficacy as a measure of cumulative effects of mercury on specific tests of neurobehavioral function (Echeverria... 

Roels HA, Hoet P, Lison D. Usefulness of biomarkers of exposure to inorganic mercury, lead, or cadmium in controlling occupational and environmental risks of nephrotoxicity. Ren Fail. 1999 May-Jul 21(3-4) 251-62. 

PbU has some interpretive features shared with other biomarkers of Pb exposure, especially PbB and PbP. Notably, single PbU measurements done in isolation do not offer helpful data on the nature of Pb exposures or their sources. Serial measurements are considerably more useful. Such an apphca-tion would be more of an advantage in occupational exposure monitoring for lead workers than in monitoring short-term or even chronic exposures in the very young. 

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