title: Environmental epidemiological study and estimation of benchmark dose for renal dysfunction in a cadmium-polluted area in China.
abstract: We have performed a study aimed at investigating the critical concentration of urinary cadmium (UCd) required for the development of renal dysfunction. We studied population groups (totally 790 persons) living in two cadmium exposed areas and one control area in China. UCd, was determined as an indicator of cadmium exposure and accumulation, while the concentrations of N-acetyl-beta-D-glucosaminidase (NAG), its iso-form B (NAG-B), beta2-microglobulin (B2M), retinol binding protein (RBP), and albumin (ALB) in urine were measured as indicators of the renal effects caused by cadmium. There was a significantly increased prevalence of hyperNAGuria, hyperNAG-Buria, hyperB2Muria, hyperRBPuria and hyperALBuria with increasing levels of Cd excretion in urine. We used the benchmark dose (BMD) procedure to estimate the critical concentration of urinary cadmium in this general population. The lower confidence limit of the BMD (LBMD-05) of urinary cadmium for a 5% level of risk above the background level was estimated for each of the renal effect indicators. The BMD-05/LBMD-05 were estimated to be 4.46/3.99, 6.70/5.87, 8.36/7.31, 7.98/6.98 and 15.06/12.18 microg/g creatinine for urinary NAG-B, NAG, B2M, RBP and ALB, respectively. Our findings suggest, based on the present study, that the Lower Confidence Limit of the Population Critical Concentration of UCd (LPCCUCd-05) of tubular dysfunction for 5% excess risk level above the background may be ca. 3-4 microg/g creatinine, and that cadmium concentration in urine should be kept below this level to prevent renal tubular damage. This report is the first to use the BMD method in this field and to define the concept of critical concentration in urine.
authors.affiliation: Department of Occupational Health, School of Public Health, Fudan University, Shanghai, 200032 Shanghai, PR China.
authors.forename: Taiyi
authors.initials: T
authors.lastname: Jin
authors.forename: Xunwei
authors.initials: X
authors.lastname: Wu
authors.forename: Yinqi
authors.initials: Y
authors.lastname: Tang
authors.forename: Monica
authors.initials: M
authors.lastname: Nordberg
authors.forename: Alfred
authors.initials: A
authors.lastname: Bernard
authors.forename: Tingting
authors.initials: T
authors.lastname: Ye
authors.forename: Qinhu
authors.initials: Q
authors.lastname: Kong
authors.forename: Nils-Göran
authors.initials: NG
authors.lastname: Lundström
authors.forename: Gunnar F
authors.initials: GF
authors.lastname: Nordberg
mesh_terms: D000118:Acetylglucosaminidase / Q000652:urine; D000419:Albuminuria / Q000652:urine; D002104:Cadmium / Q000633:toxicity / Q000652:urine*; D002105:Cadmium Poisoning / Q000150:complications*; D002681:China / Q000453:epidemiology; D016001:Confidence Intervals; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000652:urine; D007678:Kidney Glomerulus / Q000187:drug effects; D007684:Kidney Tubules / Q000187:drug effects; D008297:Male; D015995:Prevalence; D051437:Renal Insufficiency / Q000139:chemically induced / Q000453:epidemiology*; D012177:Retinol-Binding Proteins / Q000652:urine; D012306:Risk; D001613:beta 2-Microglobulin / Q000652:urine
chemical_list: D007527:Isoenzymes; D012177:Retinol-Binding Proteins; D001613:beta 2-Microglobulin; D002104:Cadmium; D000118:Acetylglucosaminidase