title: National job-exposure matrix in analyses of census-based estimates of occupational cancer risk.
abstract: OBJECTIVE
  The aim of this study was to increase the understanding of the alternative exposure metrics and analysis methods in studies applying job-exposure matrices in analyses of health outcomes, the association between crystalline silica and cancer being used as an example.
  
  
  METHODS
  Observed and expected numbers of cancer cases during 1971-1995 among Finns born in 1906-1945 were calculated for 393 occupational categories, as defined in the 1970 population census. According to the Finnish Cancer Registry, there were 43 433 lung and 21 444 prostate cancer cases. The Finnish job-exposure matrix (FINJEM) provided estimates of the proportion of exposed persons and the mean level of exposure among the exposed in each occupation.
  
  
  RESULTS
  The most comprehensive exposure metric included period- and age-specific estimates of exposure and an estimate of occupational stability, but also remarkably simpler metrics gave significantly elevated estimates of the risk ratio (RR) between 1.36 and 1.50 for lung cancer for occupations with the highest estimated cumulative silica exposure (> or = 10 mg/m3-years), allowing a lag time of 20 years. It proved important to adjust the risk ratios at least for the socioeconomic status and occupational exposure to asbestos. The risk ratios for prostate cancer were close to 1.0 in every model.
  
  
  CONCLUSIONS
  The results showed that the FINJEM-based analysis was able to replicate the well-known association between exposure to crystalline silica and lung cancer. The FINJEM-based method gives valid results, and it can be used to analyze large sets of register-based data on health outcomes.
authors.affiliation: Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research, Helsinki, Finland. eero.pukkala@cancer.fi
authors.forename: Eero
authors.initials: E
authors.lastname: Pukkala
authors.forename: Johannes
authors.initials: J
authors.lastname: Guo
authors.forename: Pentti
authors.initials: P
authors.lastname: Kyyrönen
authors.forename: Marja-Liisa
authors.initials: ML
authors.lastname: Lindbohm
authors.forename: Markku
authors.initials: M
authors.lastname: Sallmén
authors.forename: Timo
authors.initials: T
authors.lastname: Kauppinen
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D017632:Asbestos, Serpentine / Q000633:toxicity*; D019352:Censuses; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D008175:Lung Neoplasms / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology* / Q000209:etiology; D016273:Occupational Exposure / Q000009:adverse effects*; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000209:etiology; D012042:Registries; D012306:Risk; D012307:Risk Factors
chemical_list: D017632:Asbestos, Serpentine