title: Prospective risk of rheumatologic disease associated with occupational exposure in a cohort of male construction workers.
abstract: BACKGROUND
  The association between occupational exposure and autoimmune disease is well recognized for silica, and suspected for other inhalants. We used a large cohort to estimate the risks of rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, and dermatomyositis associated with silica and other occupational exposures.
  
  
  METHODS
  We analyzed data for male Swedish construction industry employees. Exposure was defined by a job-exposure matrix for silica and for other inorganic dusts; those with other job-exposure matrix exposures but not to either of the 2 inorganic dust categories were excluded. National hospital treatment data were linked for International Classification of Diseases, 10(th) Revision-coded diagnoses of rheumatoid arthritis (seronegative and positive), systemic lupus erythematosus, systemic sclerosis, and dermatomyositis. The 2 occupational exposures were tested as independent predictors of prospective hospital-based treatment for these diagnoses using age-adjusted Poisson multivariable regression analyses to calculate relative risk (RR).
  
  
  RESULTS
  We analyzed hospital-based treatment data (1997 through 2010) for 240,983 men aged 30 to 84 years. There were 713 incident cases of rheumatoid arthritis (467 seropositive, 195 seronegative, 51 not classified) and 128 cases combined for systemic lupus erythematosus, systemic sclerosis, and dermatomyositis. Adjusted for smoking and age, the 2 occupational exposures (silica and other inorganic dusts) were each associated with increased risk of rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, and dermatomyositis combined: RR 1.39 (95% confidence interval [CI], 1.17-1.64) and RR 1.31 (95% CI, 1.11-1.53), respectively. Among ever smokers, both silica and other inorganic dust exposure were associated with increased risk of rheumatoid arthritis (RRs 1.36; 95% CI, 1.11-1.68 and 1.42; 95% CI, 1.17-1.73, respectively), while among never smokers, neither exposure was associated with statistically significant increased risk of rheumatoid arthritis.
  
  
  CONCLUSIONS
  This analysis reaffirms the link between occupational silica and a range of autoimmune diseases, while also suggesting that other inorganic dusts may also impart excess risk of such disease.
authors.affiliation: Division of Occupational and Environmental Medicine, Department of Medicine, University of California, San Francisco. Electronic address: paul.blanc@ucsf.edu.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Blanc
authors.affiliation: Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
authors.forename: Bengt
authors.initials: B
authors.lastname: Järvholm
authors.affiliation: Section of Occupational and Environmental Medicine, Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden.
authors.forename: Kjell
authors.initials: K
authors.lastname: Torén
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000395:Air Pollutants, Occupational / Q000633:toxicity*; D001327:Autoimmune Diseases / Q000209:etiology*; D060389:Construction Industry; D004391:Dust; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009784:Occupational Diseases / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects*; D016012:Poisson Distribution; D011446:Prospective Studies; D012042:Registries; D012044:Regression Analysis; D012216:Rheumatic Diseases / Q000209:etiology*; D018570:Risk Assessment; D012307:Risk Factors; D012822:Silicon Dioxide / Q000633:toxicity*; D013548:Sweden
chemical_list: D000395:Air Pollutants, Occupational; D004391:Dust; D012822:Silicon Dioxide
keywords: Autoimmune disease; Dust; Occupation; Rheumatoid arthritis; Silica