title: Pollution in the working place and social status: co-factors in lung cancer carcinogenesis.
abstract: BACKGROUND
  Apart from the association with tobacco consumption, other factors of importance for prevention and early diagnosis of lung cancer have received little attention. We present a case-control study focusing on professional exposure to carcinogens and social status.
  
  
  METHODS
  A written questionnaire was completed by 551 consecutive patients with lung cancer and 494 patients with large bowel cancer. The groups were balanced regarding gender and age distribution. The questionnaire included data on place of birth, education, smoking history, diet and alcohol intake, body weight and height, occupation, housing conditions and family income. According to standard epidemiological criteria, professional exposure to carcinogens was classified as professions with exposure to confirmed lung cancer carcinogens, professions with exposure to suspected lung cancer carcinogens and other professions.
  
  
  RESULTS
  As expected, there were significant differences between the two groups regarding smoking status. While there were no significant differences in educational levels, more immigrants were among patients with lung cancer (17.9% vs 11.6%, p=0.005). On average, lung cancer patients had a lower body mass index (BMI) at 24.77, as compared to 26.14 for large bowel cancer (p=0.000). Lung cancer patients had lower income and poorer housing conditions; the bivariate difference was significant both for income levels (p=0.046) and type of residence (p=0.009). The proportion of patients working in professions with exposures to known carcinogens was 33.5% for lung cancer, and 17.1% for large bowel cancer (p=0.000). In the multivariate analysis, smoking (p=0.000), BMI (p=0.000) and type of occupation (p=0.001) were significant factors.
  
  
  CONCLUSIONS
  While there is no doubt about smoking in lung cancer carcinogenesis, professional exposure to carcinogens and belonging to lower socio-economic strata also play an important role.
authors.affiliation: Institute of Oncology Ljubljana, Zaloska 2, 1000 Ljubljana, Slovenia. Electronic address: mrajer@onko-i.si.
authors.forename: Mirjana
authors.initials: M
authors.lastname: Rajer
authors.affiliation: Institute of Oncology Ljubljana, Zaloska 2, 1000 Ljubljana, Slovenia; Department of Medical Ethics, Medical School, University of Maribor, Taborska ulica 8, 2000 Maribor, Slovenia.
authors.forename: Matjaz
authors.initials: M
authors.lastname: Zwitter
authors.affiliation: University of Ljubljana, Kongresni trg 12, 1000 Ljubljana, Slovenia.
authors.forename: Borut
authors.initials: B
authors.lastname: Rajer
mesh_terms: D016022:Case-Control Studies; D002471:Cell Transformation, Neoplastic; D004787:Environmental Pollution / Q000009:adverse effects*; D006801:Humans; D008175:Lung Neoplasms / Q000453:epidemiology* / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects*; D016017:Odds Ratio; D062486:Public Health Surveillance; D012307:Risk Factors; D012923:Social Class; D011795:Surveys and Questionnaires
keywords: Colon cancer; Epidemiology; Logistic regression; Lung cancer; Professional exposure to carcinogens; Socio-economic strata