title: Reference values for cobalt, copper, manganese, and nickel in urine among women of the general population in Japan.
abstract: OBJECTIVE
  The present study was initiated to establish the reference levels of Co, Cu, Mn, and Ni in urine of women in the general Japanese population.
  
  
  METHODS
  Stored urine samples were subjected to the analysis. The samples were collected from 1,000 adult women all over Japan, who had no occupational exposure to these elements. Co, Cu, Mn, and Ni in urine were analyzed by graphite furnace atomic absorption spectrometry. The concentrations were distributed log-normally, and were presented in terms of geometric mean (GM) and geometric standard deviation, as observed or after correction for creatinine concentration or a specific gravity of urine of 1.016.
  
  
  RESULTS
  The GM values of observed levels (i.e., with no correction for urine density) and of the levels after correction for creatinine (cr) concentration (values in parenthesis) were 0.68 g/l (0.60 microg/g cr) for Co, 13.4 g/l (11.8 g/g cr) for Cu, 0.14 microg/l (0.12 g/g cr) for Mn and 2.1 g/l (1.8 g/g cr) for Ni. There was a life-long age-dependent increase in Cu. Mn levels reached the maximum at 60 to 69 years of ages. In contrast, age-dependency was not substantial in Co and Ni.
  
  
  CONCLUSIONS
  Comparison with values reported in literatures for other areas showed that Co and Ni levels in urine of Japanese women are higher than, Cu level is comparable with, and Mn level is lower than others. The reasons for high Co and Ni levels deserve further study.
authors.affiliation: Kyoto Industrial Health Association, 67 Nishinokyo-Kitatsuboicho, Nakagyo-ku, Kyoto, 604-8472, Japan.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Ohashi
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Fukui
authors.forename: Shiro
authors.initials: S
authors.lastname: Takada
authors.forename: Jiro
authors.initials: J
authors.lastname: Moriguchi
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ezaki
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ikeda
mesh_terms: D000328:Adult; D003035:Cobalt / Q000652:urine; D003300:Copper / Q000652:urine; D004781:Environmental Exposure / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods* / Q000592:standards; D062665:Epidemiological Monitoring; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008345:Manganese / Q000652:urine; D019216:Metals, Heavy / Q000652:urine*; D008875:Middle Aged; D009532:Nickel / Q000652:urine; D012016:Reference Values; D016482:Urinalysis
chemical_list: D019216:Metals, Heavy; D003035:Cobalt; D008345:Manganese; D003300:Copper; D009532:Nickel