title: A longitudinal study on urinary cadmium and renal tubular protein excretion of nickel-cadmium battery workers after cessation of cadmium exposure.
abstract: OBJECTIVE
  This study aimed to predict the outcome of urinary cadmium (Cd) excretion and renal tubular function by analyzing their evolution through 10 years after Cd exposure ceased.
  
  
  METHODS
  Forty-one female, non-smoking workers were recruited from the year 2004 to 2009 when being removed from a nickel-cadmium battery factory, and they were asked to provide morning urine samples on three consecutive days at enrollment and in every follow-up year until 2014. Urinary Cd and renal tubular function biomarkers including urinary β2-microglobulin (β2-m) and retinol-binding protein (RBP) concentrations were determined with the graphite furnace atomic absorption spectrometry and the enzyme-linked immunosorbent assays, respectively.
  
  
  RESULTS
  The medians of baseline Cd, β2-m and RBP concentrations at enrollment were 6.19, 105.38 and 71.84 μg/g creatinine, respectively. Urinary β2-m and RBP concentrations were both related to Cd concentrations over the years (β absolute-β2-m = 9.16, P = 0.008 and β absolute-RBP = 6.42, P < 0.001, respectively). Cd, β2-m and RBP concentrations in the follow-up years were all associated with their baseline concentrations (β absolute-Cd = 0.61, P < 0.001; β absolute-β2-m = 0.64, P < 0.001; and β absolute-RBP = 0.60, P < 0.001, respectively), and showed a decreasing tendency with the number of elapsed years relative to their baseline concentrations (β relative-Cd = -0.20, P = 0.010; β relative-β2-m = -17.19, P = 0.002; and β relative-RBP = -10.66, P < 0.001, respectively).
  
  
  CONCLUSIONS
  Urinary Cd might eventually decrease to the general population level, and Cd-related tubular function would improve under the baseline conditions of this cohort.
authors.affiliation: Shenzhen Prevention and Treatment Center for Occupational Diseases, Buxin Rd. 2019, Luohu District, Shenzhen, 518020, China.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Shenzhen Prevention and Treatment Center for Occupational Diseases, Buxin Rd. 2019, Luohu District, Shenzhen, 518020, China.
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Shenzhen Prevention and Treatment Center for Occupational Diseases, Buxin Rd. 2019, Luohu District, Shenzhen, 518020, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Yi
authors.affiliation: Shenzhen Prevention and Treatment Center for Occupational Diseases, Buxin Rd. 2019, Luohu District, Shenzhen, 518020, China.
authors.forename: Jinpeng
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Shenzhen Prevention and Treatment Center for Occupational Diseases, Buxin Rd. 2019, Luohu District, Shenzhen, 518020, China.
authors.forename: Xianqing
authors.initials: X
authors.lastname: Huang
authors.affiliation: Shenzhen Prevention and Treatment Center for Occupational Diseases, Buxin Rd. 2019, Luohu District, Shenzhen, 518020, China.
authors.forename: Xinshan
authors.initials: X
authors.lastname: Shi
authors.affiliation: Shenzhen Prevention and Treatment Center for Occupational Diseases, Buxin Rd. 2019, Luohu District, Shenzhen, 518020, China.
authors.forename: Shunhua
authors.initials: S
authors.lastname: Xiao
authors.affiliation: Shenzhen Prevention and Treatment Center for Occupational Diseases, Buxin Rd. 2019, Luohu District, Shenzhen, 518020, China. david1385@foxmail.com.
authors.forename: Dafeng
authors.initials: D
authors.lastname: Lin
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000652:urine; D002104:Cadmium / Q000633:toxicity* / Q000652:urine*; D003404:Creatinine / Q000652:urine; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007684:Kidney Tubules / Q000187:drug effects / Q000378:metabolism*; D008137:Longitudinal Studies; D066192:Manufacturing Industry; D009532:Nickel / Q000633:toxicity; D016273:Occupational Exposure / Q000009:adverse effects*; D012177:Retinol-Binding Proteins / Q000652:urine; D013054:Spectrophotometry, Atomic / Q000379:methods; D001613:beta 2-Microglobulin / Q000652:urine
chemical_list: D015415:Biomarkers; D012177:Retinol-Binding Proteins; D001613:beta 2-Microglobulin; D002104:Cadmium; D009532:Nickel; D003404:Creatinine
keywords: Cadmium; Exposure cessation; Repeated measurement; Retinol-binding protein; β2-Microglobulin