title: Hair Manganese as an Exposure Biomarker among Welders.
abstract: Quantifying exposure and dose to manganese (Mn) containing airborne particles in welding fume presents many challenges. Common biological markers such as Mn in blood or Mn in urine have not proven to be practical biomarkers even in studies where positive associations were observed. However, hair Mn (MnH) as a biomarker has the advantage over blood and urine that it is less influenced by short-term variability of Mn exposure levels because of its slow growth rate. The objective of this study was to determine whether hair can be used as a biomarker for welders exposed to manganese. Hair samples (1cm) were collected from 47 welding school students and individual air Mn (MnA) exposures were measured for each subject. MnA levels for all days were estimated with a linear mixed model using welding type as a predictor. A 30-day time-weighted average MnA (MnA30d) exposure level was calculated for each hair sample. The association between MnH and MnA30d levels was then assessed. A linear relationship was observed between log-transformed MnA30d and log-transformed MnH. Doubling MnA30d exposure levels yields a 20% (95% confidence interval: 11-29%) increase in MnH. The association was similar for hair washed following two different wash procedures designed to remove external contamination. Hair shows promise as a biomarker for inhaled Mn exposure given the presence of a significant linear association between MnH and MnA30d levels.
authors.affiliation: 1.Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA; reissb@uw.edu.
authors.forename: Boris
authors.initials: B
authors.lastname: Reiss
authors.affiliation: 1.Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA;
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Simpson
authors.affiliation: 1.Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA;
authors.forename: Marissa G
authors.initials: MG
authors.lastname: Baker
authors.affiliation: 1.Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA;
authors.forename: Bert
authors.initials: B
authors.lastname: Stover
authors.affiliation: 1.Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA; 2.Department of Biostatistics, University of Washington, Seattle, WA 98195, USA.
authors.forename: Lianne
authors.initials: L
authors.lastname: Sheppard
authors.affiliation: 1.Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA;
authors.forename: Noah S
authors.initials: NS
authors.lastname: Seixas
mesh_terms: D000293:Adolescent; D000328:Adult; D000388:Air / Q000032:analysis; D015415:Biomarkers / Q000032:analysis* / Q000097:blood / Q000652:urine; D004784:Environmental Monitoring / Q000379:methods; D005260:Female; D006197:Hair / Q000737:chemistry*; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis; D008137:Longitudinal Studies; D008297:Male; D008345:Manganese / Q000032:analysis*; D008875:Middle Aged; D016273:Occupational Exposure / Q000032:analysis*; D014896:Welding; D055815:Young Adult
chemical_list: D015415:Biomarkers; D008345:Manganese
keywords: biomarker of exposure; exposure assessment; exposure science; hair; manganese; welding