Occupational and environmental exposures and risk of systemic lupus erythematosus: silica, sunlight, solvents.
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.
Cooper
Glinda S
GS
Department of Environmental and Occupational Health, The George Washington University, School of Public Health and Health Services, Washington, DC, USA. cooper.glinda@epa.gov
Wither
Joan
J
Bernatsky
Sasha
S
Claudio
Jaime O
JO
Clarke
Ann
A
Rioux
John D
JD
Fortin
Paul R
PR
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
D012997:Solvents; D012822:Silicon Dioxide