title: Occupational and environmental exposures and risk of systemic lupus erythematosus: silica, sunlight, solvents.
abstract: OBJECTIVE
  We examined occupational and non-occupational exposures in relation to risk of SLE in a case-control study conducted through the Canadian Network for Improved Outcomes in SLE (CaNIOS).
  
  
  METHODS
  SLE cases (n = 258) were recruited from 11 rheumatology centres across Canada. Controls (without SLE, n = 263) were randomly selected from phone number listings and matched to cases by age, sex and area of residence. Data were collected using a structured telephone interview.
  
  
  RESULTS
  An association was seen with outdoor work in the 12 months preceding diagnosis [odds ratio (OR) 2.0; 95% CI 1.1, 3.8]; effect modification by sun reaction was suggested, with the strongest effect among people who reported reacting to midday sun with a blistering sunburn or a rash (OR 7.9; 95% CI 0.97, 64.7). Relatively strong but imprecise associations were seen with work as an artist working with paints, dyes or developing film (OR 3.9; 95% CI 1.3, 12.3) and work that included applying nail polish or nail applications (OR 10.2; 95% CI 1.3, 81.5). Patients were more likely than controls to report participation in pottery or ceramics work as a leisure activity, with an increased risk among individuals with a total frequency of at least 26 days (OR 2.1; 95% CI 1.1, 3.9). Analyses of potential respirable silica exposures suggested an exposure-response gradient (OR 1.0, 1.4. and 2.1 for zero, one and two or more sources of exposure, respectively; trend test P < 0.01).
  
  
  CONCLUSIONS
  This study supports the role of specific occupational and non-occupational exposures in the development of SLE.
authors.affiliation: Department of Environmental and Occupational Health, The George Washington University, School of Public Health and Health Services, Washington, DC, USA. cooper.glinda@epa.gov
authors.forename: Glinda S
authors.initials: GS
authors.lastname: Cooper
authors.forename: Joan
authors.initials: J
authors.lastname: Wither
authors.forename: Sasha
authors.initials: S
authors.lastname: Bernatsky
authors.forename: Jaime O
authors.initials: JO
authors.lastname: Claudio
authors.forename: Ann
authors.initials: A
authors.lastname: Clarke
authors.forename: John D
authors.initials: JD
authors.lastname: Rioux
authors.forename: Paul R
authors.initials: PR
authors.lastname: Fortin
mesh_terms: D000293:Adolescent; D000328:Adult; D002170:Canada / Q000453:epidemiology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects*; D012307:Risk Factors; D012822:Silicon Dioxide / Q000009:adverse effects*; D012997:Solvents / Q000009:adverse effects*; D013223:Statistics as Topic; D014466:Ultraviolet Rays / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D012997:Solvents; D012822:Silicon Dioxide