title: Reduction in welding fume and metal exposure of stainless steel welders: an example from the WELDOX study.
abstract: OBJECTIVE
  In a plant where flux-cored arc welding was applied to stainless steel, we investigated changes in airborne and internal metal exposure following improvements of exhaust ventilation and respiratory protection.
  
  
  METHODS
  Twelve welders were examined at a time in 2008 and in 2011 after improving health protection. Seven welders were enrolled in both surveys. Exposure measurement was performed by personal sampling of respirable welding fume inside the welding helmets during one work shift. Urine and blood samples were taken after the shift. Chromium (Cr), nickel (Ni), and manganese (Mn) were determined in air and biological samples.
  
  
  RESULTS
  The geometric mean of respirable particles could be reduced from 4.1 mg/m(3) in 2008-0.5 mg/m(3) in 2011. Exposure to airborne metal compounds was also strongly reduced (Mn: 399 vs. 6.8 μg/m(3); Cr: 187 vs. 6.3 μg/m(3); Ni: 76 vs. 2.8 μg/m(3)), with the most striking reduction inside helmets with purified air supply. Area sampling revealed several concentrations above established or proposed exposure limits. Urinary metal concentrations were also reduced, but to a lesser extent (Cr: 14.8 vs. 4.5 μg/L; Ni: 7.9 vs. 3.1 μg/L). Although biologically regulated, the mean Mn concentration in blood declined from 12.8 to 8.9 μg/L.
  
  
  CONCLUSIONS
  This intervention study demonstrated a distinct reduction in the exposure of welders using improved exhaust ventilation and welding helmets with purified air supply in the daily routine. Data from area sampling and biomonitoring indicated that the area background level may add considerably to the internal exposure.
authors.affiliation: Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr-Universität Bochum (IPA), Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Lehnert
authors.forename: Tobias
authors.initials: T
authors.lastname: Weiss
authors.forename: Beate
authors.initials: B
authors.lastname: Pesch
authors.forename: Anne
authors.initials: A
authors.lastname: Lotz
authors.forename: Sandra
authors.initials: S
authors.lastname: Zilch-Schöneweis
authors.forename: Evelyn
authors.initials: E
authors.lastname: Heinze
authors.forename: Rainer
authors.initials: R
authors.lastname: Van Gelder
authors.forename: Jens-Uwe
authors.initials: JU
authors.lastname: Hahn
authors.forename: Thomas
authors.initials: T
authors.lastname: Brüning
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis*; D001774:Blood Chemical Analysis; D002857:Chromium / Q000032:analysis; D020378:Confined Spaces; D003430:Cross-Sectional Studies; D004784:Environmental Monitoring; D006260:Head Protective Devices; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis* / Q000517:prevention & control; D008345:Manganese / Q000032:analysis; D008670:Metals / Q000032:analysis* / Q000097:blood / Q000652:urine; D009532:Nickel / Q000032:analysis; D016273:Occupational Exposure / Q000032:analysis* / Q000517:prevention & control; D013193:Stainless Steel / Q000032:analysis; D016482:Urinalysis; D014896:Welding / Q000379:methods*
chemical_list: D000395:Air Pollutants, Occupational; D008670:Metals; D002857:Chromium; D013193:Stainless Steel; D008345:Manganese; D009532:Nickel