title: Incidence of cancer among Nordic airline pilots over five decades: occupational cohort study.
abstract: OBJECTIVE
  To assess the incidence of cancer among male airline pilots in the Nordic countries, with special reference to risk related to cosmic radiation.
  
  
  METHODS
  Retrospective cohort study, with follow up of cancer incidence through the national cancer registries.
  
  
  METHODS
  Denmark, Finland, Iceland, Norway, and Sweden.
  
  
  METHODS
  10 032 male airline pilots, with an average follow up of 17 years.
  
  
  METHODS
  Standardised incidence ratios, with expected numbers based on national cancer incidence rates; dose-response analysis using Poisson regression.
  
  
  RESULTS
  466 cases of cancer were diagnosed compared with 456 expected. The only significantly increased standardised incidence ratios were for skin cancer: melanoma 2.3 (95% confidence interval 1.7 to 3.0), non-melanoma 2.1 (1.7 to 2.8), basal cell carcinoma 2.5 (1.9 to 3.2). The relative risk of skin cancers increased with the estimated radiation dose. The relative risk of prostate cancer increased with increasing number of flight hours in long distance aircraft.
  
  
  CONCLUSIONS
  This study does not indicate a marked increase in cancer risk attributable to cosmic radiation, although some influence of cosmic radiation on skin cancer cannot be entirely excluded. The suggestion of an association between number of long distance flights (possibly related to circadian hormonal disturbances) and prostate cancer needs to be confirmed.
authors.affiliation: Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research, Liisankatu 21 B, FIN-00170 Helsinki, Finland. eero.pukkala@cancer.fi
authors.forename: Eero
authors.initials: E
authors.lastname: Pukkala
authors.forename: Rafael
authors.initials: R
authors.lastname: Aspholm
authors.forename: Anssi
authors.initials: A
authors.lastname: Auvinen
authors.forename: Harald
authors.initials: H
authors.lastname: Eliasch
authors.forename: Maryanne
authors.initials: M
authors.lastname: Gundestrup
authors.forename: Tor
authors.initials: T
authors.lastname: Haldorsen
authors.forename: Niklas
authors.initials: N
authors.lastname: Hammar
authors.forename: Jón
authors.initials: J
authors.lastname: Hrafnkelsson
authors.forename: Pentti
authors.initials: P
authors.lastname: Kyyrönen
authors.forename: Anette
authors.initials: A
authors.lastname: Linnersjö
authors.forename: Vilhjálmur
authors.initials: V
authors.lastname: Rafnsson
authors.forename: Hans
authors.initials: H
authors.lastname: Storm
authors.forename: Ulf
authors.initials: U
authors.lastname: Tveten
mesh_terms: D000328:Adult; D000368:Aged; D000401:Aircraft; D003359:Cosmic Radiation / Q000009:adverse effects*; D004812:Epidemiologic Methods; D005387:Finland; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology* / Q000209:etiology; D009784:Occupational Diseases / Q000453:epidemiology* / Q000209:etiology; D016273:Occupational Exposure / Q000009:adverse effects; D012537:Scandinavian and Nordic Countries / Q000453:epidemiology