title: Global metabolomic profiling reveals an association of metal fume exposure and plasma unsaturated fatty acids.
abstract: BACKGROUND
  Welding-associated air pollutants negatively affect the health of exposed workers; however, their molecular mechanisms in causing disease remain largely unclear. Few studies have systematically investigated the systemic toxic effects of welding fumes on humans.
  
  
  OBJECTIVE
  To explore the effects of welding fumes on the plasma metabolome, and to identify biomarkers for risk assessment of welding fume exposure.
  
  
  METHODS
  The two-stage, self-controlled exploratory study included 11 boilermakers from a 2011 discovery panel and 8 boilermakers from a 2012 validation panel. Plasma samples were collected pre- and post-welding fume exposure and analyzed by chromatography/mass spectrometry.
  
  
  RESULTS
  Eicosapentaenoic or docosapentaenoic acid metabolic changes post-welding were significantly associated with particulate (PM2.5) exposure (p<0.05). The combined analysis by linear mixed-effects model showed that exposure was associated with a statistically significant decline in metabolite change of eicosapentaenoic acid [β(95% CI) = -0.013(-0.022 ≈ -0.004); p = 0.005], docosapentaenoic acid n3 [β(95% CI) = -0.010(-0.018 ≈ -0.002); p = 0.017], and docosapentaenoic acid n6 [β(95% CI) = -0.007(-0.013 ≈ -0.001); p = 0.021]. Pathway analysis identified an association of the unsaturated fatty acid pathway with exposure (p Study-2011 = 0.025; p Study-2012 = 0.021; p Combined = 0.009). The functional network built by these fatty acids and their interactive genes contained significant enrichment of genes associated with various diseases, including neoplasms, cardiovascular diseases, and lipid metabolism disorders.
  
  
  CONCLUSIONS
  High-dose exposure of metal welding fumes decreases unsaturated fatty acids with an exposure-response relationship. This alteration in fatty acids is a potential biological mediator and biomarker for exposure-related health disorders.
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Harvard University, Boston, Massachusetts, United States of America ; Department of Epidemiology and Biostatistics, Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, Jiangsu, China.
authors.forename: Yongyue
authors.initials: Y
authors.lastname: Wei
authors.forename: Zhaoxi
authors.initials: Z
authors.lastname: Wang
authors.forename: Chiung-yu
authors.initials: CY
authors.lastname: Chang
authors.forename: Tianteng
authors.initials: T
authors.lastname: Fan
authors.forename: Li
authors.initials: L
authors.lastname: Su
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.forename: David C
authors.initials: DC
authors.lastname: Christiani
mesh_terms: D015331:Cohort Studies; D005231:Fatty Acids, Unsaturated / Q000097:blood*; D053263:Gene Regulatory Networks / Q000187:drug effects; D006801:Humans; D008297:Male; D055432:Metabolomics; D008670:Metals / Q000737:chemistry* / Q000633:toxicity*; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D014835:Volatilization; D014896:Welding
chemical_list: D005231:Fatty Acids, Unsaturated; D008670:Metals