Objectives To determine cancer mortality compared with the general population and to examine dose-response relationships between cumulative occupational radiation dose and specific cancer outcomes in the German aircrew cohort.
Methods For a cohort of 26 846 aircrew personnel, standardised mortality ratios (SMR) were calculated. Dose-response analyses were carried out using Poisson regression to assess dose-related cancer risks for the period 1960–2014. Exposure assessment comprises recently available dose register data for all cohort members and newly estimated retrospective cabin crew doses for 1960–2003.
Results SMR for all-cause, specific cancer groups and most individual cancers were reduced in all aircrew groups. The only increases were seen for brain cancer in pilots (n=23, SMR 2.01, 95% CI 1.15 to 3.28) and for malignant melanoma (n=10, SMR 1.88, 95% CI 0.78 to 3.85). Breast cancer mortality among female cabin crew was similar to the general population (n=71, SMR 1.06, 95% CI 0.77 to 1.44). Overall median cumulative effective dose was 34.2 mSv (max: 116 mSv) for 1960–2014. No dose-response associations were seen in any of the models. For brain cancer, relative risks were elevated across dose categories. An indicative negative trend with increasing dose category was seen for large intestine cancer in female cabin crew (n=23).
Conclusions There was no evidence for significant dose-response patterns for the considered cancer types. Interpretation of results remains difficult as cumulative dose is closely related to age. Future work should focus on investigating radiation jointly with other risk factors that may contribute to risks for specific cancers among aircrew.
- mortality studies
- retrospective exposure assessment
- ionising radiation
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Contributors MB and HZ conceived the initial study. TS was responsible for data management and follow-up implementation. SD and GPH were responsible for exposure data collection. SD and DW performed the statistical analyses, with assistance by GPH. SD drafted the manuscript with DW and HZ. All coauthors critically reviewed and approved the final manuscript.
Funding This work was funded by the employers' mandatory liability insurance Berufsgenossenschaft Verkehrswirtschaft Post-Logistik Telekommunikation (BG Verkehr).
Disclaimer The funder had no role in methods development, data collection, analysis and interpretation of results.
Competing interests None declared.
Patient consent for publication Not required.
Ethics approval The present study was approved by the Employee Representations of Lufthansa and Air Berlin. Ethical approval was obtained from Bremen Medical Council and University of Bielefeld’s institutional review board. In addition, authorisation from the data protection representative of the Federal Office of Radiation Protection was obtained for linking the cohort with the Federal Radiation Register database to obtain exposure data. Individual informed consent was not required for this retrospective study.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement No data are available.
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