Application of benchmark dose on renal injury in people chronically exposed to lead

Objective: To screen sensitive indicators of renal injury in lead workers using benchmark dose method. Methods: Of the 486 subjects,116 did not occupationally contact to lead as a control. The blood lead was considered as exposure biomarker, while Uβ2-MG and UNAG as effect biomarkers for renal injury. The BMD and BMDL of blood lead were estimated at the 10% benchmark response using BMDS Version 2.6. Results: There was statistical rise in blood lead between the lead group and control group (P<0.05) ; and the blood lead level was divided into four groups by quarterback spacing method, among which UNAG was statistically different (P<0.05) . There was an increased prevalence of abnormal rates of Uβ2-MG and UNAG with increasing blood lead concentration (P<0.05) , after trend chi-square test. BMD and BMDL of UNAG and Uβ2-MG were 602.784/431.838 μg/L and 130.398/100.981 μg/L caculated by Log-Probit model, respectively. Conclusions: Occupational lead exposure may cause kidney damage, and UNAG could be as a more sensitive marker for monitoring early renal injury than Uβ2-MG.