title: Occupational exposure to solar ultraviolet radiation and the risk of prostate cancer.
abstract: OBJECTIVE
  Preventable risk factors for prostate cancer are poorly understood; sun exposure is a possible protective factor. The goal of this study was to investigate prostate cancer risk in outdoor workers, a population with high sun exposure.
  
  
  METHODS
  Prostate cancer cases and controls from a large study (conducted between 1994 and 1997) were used for this analysis. A job exposure matrix (JEM) was used to assign solar ultraviolet radiation (UVR) at work as moderate (2 to <6 hours outside/day) or high (≥6 hours). Average daily satellite UV-B measures were linked to the latitude/longitude of the residences of each participant. Several other exposure metrics were also examined, including ever/never exposed and standard erythemal dose by years (SED×years). Logistic regression was used to evaluate the association between solar UVR exposure and the odds of prostate cancer.
  
  
  RESULTS
  A total of 1638 cases and 1697 controls were included. Men of Indian and Asian descent had reduced odds of prostate cancer (ORs 0.17 (0.08 to 0.35) and 0.25 (0.15 to 0.41), respectively) compared with Caucasian men, as did single men (OR 0.76 (0.58 to 0.98)) compared with married men. Overall, no statistically significant associations were observed between sun exposure and prostate cancer with 1 exception. In the satellite-enhanced JEM that considered exposure in high category jobs only, prostate cancer odds in the highest quartile of cumulative exposure was decreased compared with unexposed men (OR 0.68 (0.51 to 0.92)).
  
  
  CONCLUSIONS
  This study found limited evidence for an association with prostate cancer, with the exception of 1 statistically significant finding of a decreased risk among workers with the longest term and highest sun exposure.
authors.affiliation: Department of Health Sciences, Carleton University, Ottawa, Ontario, Canada.
authors.forename: Cheryl E
authors.initials: CE
authors.lastname: Peters
authors.affiliation: Occupational Cancer Research Centre, Toronto, Ontario, Canada.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Demers
authors.affiliation: Dermatology & Skin Science, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Sunil
authors.initials: S
authors.lastname: Kalia
authors.affiliation: College of Public Health and Human Sciences, Oregon State University, Corvallis, Oregon, USA.
authors.forename: Perry
authors.initials: P
authors.lastname: Hystad
authors.affiliation: Department of Health Sciences, Carleton University, Ottawa, Ontario, Canada.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Villeneuve
authors.affiliation: Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada.
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Nicol
authors.affiliation: Department of Prevention and Cancer Control, Cancer Care Ontario, Toronto, Ontario, Canada.
authors.forename: Nancy
authors.initials: N
authors.lastname: Kreiger
authors.affiliation: School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Mieke W
authors.initials: MW
authors.lastname: Koehoorn
mesh_terms: D000368:Aged; D002170:Canada / Q000453:epidemiology; D016022:Case-Control Studies; D004784:Environmental Monitoring; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology* / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects*; D009790:Occupations; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000209:etiology*; D012307:Risk Factors; D016082:Solar System; D013472:Sunlight / Q000009:adverse effects; D014466:Ultraviolet Rays / Q000009:adverse effects*
keywords: Outdoor workers; Prostate cancer; Solar radiation