title: Cancer incidence among workers in the asbestos-cement producing industry in Norway.
abstract: OBJECTIVE
  The incidence of cancer among employees of a Norwegian asbestos-cement factory was studied in relation to duration of exposure and time since first exposure. The factory was active in 1942-1968. Most of the asbestos in use was chrysotile, but for technical reasons 8% amphiboles was added.
  
  
  METHODS
  For the identification of cancer cases, a cohort of 541 male workers was linked to the Cancer Registry of Norway. The analysis was based on the comparison between the observed and expected number of cancer cases. Standardized incidence ratios (SIR) and 95% confidence intervals (95% CI) were estimated. Period of first employment, duration of employment, and time since first employment were used as indicators of exposure. Poisson regression analysis was used for the internal comparisons.
  
  
  RESULTS
  The standardized incidence ratio was 52.5 (95% CI 31.1-83.0) for pleural mesothelioma, on the basis of 18 cases. The highest standardized incidence ratio was found for workers first employed in the earliest production period (SIR 99.0, 95% CI 51.3-173). No peritoneal mesothelioma was found. The standardized incidence ratio for lung cancer was 3.1 (95% CI 2.14.3), but no dose-response effect was observed. The ratio of mesothelioma to lung cancer cases was 1:2.
  
  
  CONCLUSIONS
  This study showed a high incidence of mesothelioma and a high ratio of mesothelioma to lung cancer among asbestos-cement workers. The high incidence of mesothelioma was probably due to the fact that a relatively high proportion of amphiboles was used in the production process.
authors.affiliation: Cancer Registry of Norway, Institute of Population-based Cancer Research, Montebello, Oslo, Norway. bente.ulvestad@kreftregisteret.no
authors.forename: Bente
authors.initials: B
authors.lastname: Ulvestad
authors.forename: Kristina
authors.initials: K
authors.lastname: Kjaerheim
authors.forename: Jan Ivar
authors.initials: JI
authors.lastname: Martinsen
authors.forename: Grete
authors.initials: G
authors.lastname: Damberg
authors.forename: Axel
authors.initials: A
authors.lastname: Wannag
authors.forename: Gunnar
authors.initials: G
authors.lastname: Mowe
authors.forename: Aage
authors.initials: A
authors.lastname: Andersen
mesh_terms: D000368:Aged; D001194:Asbestos / Q000009:adverse effects* / Q000145:classification; D017636:Asbestos, Amphibole / Q000009:adverse effects; D017638:Asbestos, Crocidolite / Q000009:adverse effects; D017632:Asbestos, Serpentine / Q000009:adverse effects; D015331:Cohort Studies; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007221:Industry; D008175:Lung Neoplasms / Q000453:epidemiology / Q000209:etiology; D008297:Male; D008654:Mesothelioma / Q000453:epidemiology / Q000209:etiology; D008875:Middle Aged; D009369:Neoplasms / Q000145:classification / Q000453:epidemiology* / Q000209:etiology; D009664:Norway / Q000453:epidemiology; D016273:Occupational Exposure / Q000009:adverse effects*; D016012:Poisson Distribution; D012042:Registries; D012307:Risk Factors; D013995:Time
chemical_list: D017636:Asbestos, Amphibole; D017632:Asbestos, Serpentine; D017638:Asbestos, Crocidolite; D001194:Asbestos