title: Biological monitoring of cobalt in hard metal factory workers.
abstract: OBJECTIVE
  The main aim of this study was to investigate the cobalt (Co) concentrations in urine along 4 months and their relationship with Co concentrations in blood and haemoglobin (adducts) in 34 workers from a hard metal manufacturing plant where metallic Co and Co oxide were used. Furthermore, the excretion kinetics of Co was investigated and the half-lives of Co in blood, plasma and urine were calculated along 18 days of non-exposure in the same workers.
  
  
  METHODS
  Co was analysed, in all biological samples, by ICP/MS.
  
  
  RESULTS
  Wide fluctuations in the urinary Co concentration were observed throughout the work shift and during the work week. A highly significant linear correlation was found between Co concentration (geometrical mean) in urine samples provided each Thursday (end shift) during 16 subsequent weeks and levels of Co-haemoglobin adducts or blood Co concentrations at the end of the same period. The Co elimination kinetics in globin calculated along 18 days without Co exposure was slow, being related to the physiological metabolism of haemoglobin, while in blood, plasma and urine Co half-lives were 12.3, 9.1 and 5.3 days, respectively.
  
  
  CONCLUSIONS
  Co concentrations in haemoglobin or blood are highly related to the geometrical mean concentration of urinary Co when samples are collected weekly for several subsequent weeks. The biological monitoring of occupational exposure to Co in hard metal facilities provides reliable results by using the Co concentrations in haemoglobin or in whole blood. The urinary findings, though, do not show the same reliability because of their wide daily and weekly fluctuations.
authors.affiliation: University of Verona, Verona, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Princivalle
authors.affiliation: University of Naples Federico II, Napoli, Italy.
authors.forename: Ivo
authors.initials: I
authors.lastname: Iavicoli
authors.affiliation: University of Verona, Verona, Italy.
authors.forename: Marzia
authors.initials: M
authors.lastname: Cerpelloni
authors.affiliation: University of Verona, Verona, Italy.
authors.forename: Antonia
authors.initials: A
authors.lastname: Franceschi
authors.affiliation: University of Naples Federico II, Napoli, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Manno
authors.affiliation: University of Verona, Verona, Italy. luigi.perbellini@univr.it.
authors.forename: Luigi
authors.identifier: http://orcid.org/0000-0002-7518-2238
authors.initials: L
authors.lastname: Perbellini
mesh_terms: D000328:Adult; D003035:Cobalt / Q000097:blood* / Q000378:metabolism / Q000652:urine*; D004784:Environmental Monitoring / Q000379:methods*; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D008669:Metallurgy; D008875:Middle Aged; D016273:Occupational Exposure / Q000032:analysis*; D010087:Oxides
chemical_list: D006454:Hemoglobins; D010087:Oxides; D003035:Cobalt; C060728:cobalt oxide
keywords: Biomonitoring; Blood; Cobalt; Haemoglobin adducts; Hard metal workers; Urine