title: Absence of adverse effect on thyroid function and red blood cells in a population of workers exposed to cobalt compounds.
abstract: BACKGROUND
  Hypothyroidism has been observed in the fifties and sixties as an undesirable side-effect of cobalt therapy used for its erythropoietic properties in the treatment of anemia.
  
  
  OBJECTIVE
  This study aims at evaluating the possible impact of both cumulative (long-term) and recent occupational exposure to cobalt on thyroid function and red blood cells.
  
  
  METHODS
  A cross-sectional survey was conducted from February 2008 to August 2009 in a population of 249 male workers from a cobalt production department in the North of Belgium. The possible effect of cobalt exposure on thyroid and red blood cells was investigated through multiple regression analyses.
  
  
  RESULTS
  Blood cobalt ranged from undetectable to 3.20 μg/100ml (median 0.10); urinary cobalt from 0.30 to 204.30 μg/g(creat) (median 3.90) and long-term exposure to cobalt ranged from 0.15 to 6990.46 μg/g(creat) · years (median 106.09). No effect of cobalt exposure on thyroid or red blood cell parameters was observed at these levels of exposure.
  
  
  CONCLUSIONS
  The results support the absence of effects on the thyroid and red blood cells when occupational exposure to cobalt is kept below the recommended biological limit of occupational exposure (15 μg Co/g(creat) in urine).
authors.affiliation: Louvain Centre for Toxicology and Applied Pharmacology (LTAP), Université catholique de Louvain, Avenue E. Mounier 53.02, 1200 Brussels, Belgium.
authors.forename: A-C
authors.initials: AC
authors.lastname: Lantin
authors.forename: A
authors.initials: A
authors.lastname: Mallants
authors.forename: J
authors.initials: J
authors.lastname: Vermeulen
authors.forename: N
authors.initials: N
authors.lastname: Speybroeck
authors.forename: P
authors.initials: P
authors.lastname: Hoet
authors.forename: D
authors.initials: D
authors.lastname: Lison
mesh_terms: D000328:Adult; D003035:Cobalt / Q000097:blood / Q000633:toxicity*; D003430:Cross-Sectional Studies; D004912:Erythrocytes / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D012044:Regression Analysis; D013961:Thyroid Gland / Q000187:drug effects*
chemical_list: D003035:Cobalt