title: Characterization of Total and Size-Fractionated Manganese Exposure by Work Area in a Shipbuilding Yard.
abstract: BACKGROUND
  Shipbuilding involves intensive welding activities, and welders are exposed to a variety of metal fumes, including manganese, that may be associated with neurological impairments. This study aimed to characterize total and size-fractionated manganese exposure resulting from welding operations in shipbuilding work areas.
  
  
  METHODS
  In this study, we characterized manganese-containing particulates with an emphasis on total mass (n = 86, closed-face 37-mm cassette samplers) and particle size-selective mass concentrations (n = 86, 8-stage cascade impactor samplers), particle size distributions, and a comparison of exposure levels determined using personal cassette and impactor samplers.
  
  
  RESULTS
  Our results suggest that 67.4% of all samples were above the current American Conference of Governmental Industrial Hygienists manganese threshold limit value of 100 μg/m(3) as inhalable mass. Furthermore, most of the particles containing manganese in the welding process were of the size of respirable particulates, and 90.7% of all samples exceeded the American Conference of Governmental Industrial Hygienists threshold limit value of 20 μg/m(3) for respirable manganese.
  
  
  CONCLUSIONS
  The concentrations measured with the two sampler types (cassette: total mass; impactor: inhalable mass) were significantly correlated (r = 0.964, p < 0.001), but the total concentration obtained using cassette samplers was lower than the inhalable concentration of impactor samplers.
authors.affiliation: Department of Occupational and Environmental Health, Yong In University, Yongin, Republic of Korea.
authors.forename: Jee Yeon
authors.initials: JY
authors.lastname: Jeong
authors.affiliation: Korea Occupational Safety and Health Agency, Gunsan, Republic of Korea.
authors.forename: Jong Su
authors.initials: JS
authors.lastname: Park
authors.affiliation: Department of Occupational and Environmental Health, Yong In University, Yongin, Republic of Korea.
authors.forename: Pan Gyi
authors.initials: PG
authors.lastname: Kim
keywords: exposure; manganese; particle size; shipbuilding; welding fume