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Leukaemia, brain tumours and exposure to extremely low frequency magnetic fields: cohort study of Swiss railway employees
  1. Martin Röösli1,
  2. Manfred Lörtscher2,
  3. Matthias Egger1,
  4. Dominik Pfluger3,
  5. Nadja Schreier1,
  6. Emanuel Lörtscher4,
  7. Peter Locher5,
  8. Adrian Spoerri1,
  9. Christoph Minder1
  1. 1Department of Social and Preventive Medicine, University of Berne, Switzerland
  2. 2Federal Office of Transport, Berne, Switzerland
  3. 3Datametrix AG, Zürich, Switzerland
  4. 4LOITS, Bonstetten, Switzerland
  5. 5ENOTRAC AG, Thun, Switzerland
  1. Correspondence to:
 Dr M Röösli
 Institut für Sozial- und Präventivmedizin, Finkenhubelweg 11, CH-3012 Bern, Switzerland; Roeoesli{at}


Aims: To investigate the relationship between extremely low frequency magnetic field (ELF-MF) exposure and mortality from leukaemia and brain tumour in a cohort of Swiss railway workers.

Methods: 20 141 Swiss railway employees with 464 129 person-years of follow-up between 1972 and 2002 were studied. Mortality rates for leukaemia and brain tumour of highly exposed train drivers (21 μT average annual exposure) were compared with medium and low exposed occupational groups (i.e. station masters with an average exposure of 1 μT). In addition, individual cumulative exposure was calculated from on-site measurements and modelling of past exposures.

Results: The hazard ratio (HR) for leukaemia mortality of train drivers was 1.43 (95% CI 0.74 to 2.77) compared with station masters. For myeloid leukaemia the HR of train drivers was 4.74 (95% CI 1.04 to 21.60) and for Hodgkin’s disease 3.29 (95% CI 0.69 to 15.63). Lymphoid leukaemia, non-Hodgkin’s disease and brain tumour mortality were not associated with magnetic field exposure. Concordant results were obtained from analyses based on individual cumulative exposure.

Conclusions: Some evidence of an exposure–response association was found for myeloid leukaemia and Hodgkin’s disease, but not for other haematopoietic and lymphatic malignancies and brain tumours.

  • ELF-MF, extremely low frequency magnetic field
  • HR, hazards ratio
  • ICNIRP, International Commission on Non-Ionizing Radiation Protection
  • leukaemia
  • lymphoma
  • brain tumours
  • electromagnetic fields
  • cohort study

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  • Published Online First 24 May 2007

  • Competing Interests: None.