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GMDS 2012: 57. Jahrestagung der Deutschen Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie e. V. (GMDS)

Deutsche Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie

16. - 20.09.2012, Braunschweig

A cohort study on low dose exposure and mortality in nuclear power workers in Germany (NPW)

Meeting Abstract

  • Hiltrud Merzenich - Universitätsmedizin der Johannes Gutenberg Universität Mainz, Deutschland
  • Franz Fehringer - BG ETEM, Köln, Deutschland
  • Gaël Hammer - Universitätsmedizin der Johannes Gutenberg-Universität Mainz, Deutschland
  • Katrin Tröltzsch - Universitätsmedizin der Johannes Gutenberg Universität Mainz, Deutschland
  • Maria Blettner - Universitätsmedizin der Johannes Gutenberg Universität Mainz, Deutschland

GMDS 2012. 57. Jahrestagung der Deutschen Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie e.V. (GMDS). Braunschweig, 16.-20.09.2012. Düsseldorf: German Medical Science GMS Publishing House; 2012. Doc12gmds172

doi: 10.3205/12gmds172, urn:nbn:de:0183-12gmds1721

Published: September 13, 2012

© 2012 Merzenich et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Introduction: Standards in ionizing radiation protection rely mainly on the data obtained within the Life-Span-Study. The survivors of the A-bombs were exposed to ionizing radiation at high dose rates for a very short time. However, low and protracted doses are relevant for nuclear power workers. The investigation of health effects due to chronic exposure is an important research topic. A retrospective cohort study of German nuclear power workers included approximately 9,000 employees who worked in 17 nuclear power plants between 1991 and 2008. The main objective is the estimation of the overall mortality and cancer mortality related to external photon radiation.

Materials and Methods: The cohort includes occupationally exposed persons employed as category A radiation workers with an effective dose that may exceed 6 mSv (p.a.). Data on the personnel of German nuclear power plants are recorded at the Institution for Statutory Accident Insurance and Prevention (BGETEM). Information on name, address, date of birth, dates of employment and exposure data was provided for the cohort study. Employees were enrolled in a mortality follow up from January 1991 until December 2008. For every withdrawal or retirement the vital status was assessed through compulsory population registries. Death certificates were obtained from the local health authority of the place of death. The cohort members have been monitored by officially approved film badges. The exposure to external photon radiation was measured. Mortality was compared to that of the overall population. Standardized mortality ratios (SMR) and 95% confidence intervals (CI) were computed for all causes of death and all cancers.

Results: A total of 9,208 workers were exposed to external photon radiation. From these 1,219 persons had to be excluded (no DOB, withdrawal before 1991, no information about period of employment). The cohort includes 7,989 workers (7,809 men, 180 women). The mean follow up time was 14.4 years. The mean age was 49.7 years at the end of the follow up. During the follow up a total of 235 deaths’ occurred. No women died. The cause of death could be traced in 99.8%. Among 98 cancer cases the most frequent were lung cancer (n=23), colorectal cancer (n=12) and pancreatic cancer (n=11). Six leukaemia cases were observed. The all-cause SMR was 0.42 (95% CI 0.37–0.48) and the SMR for all-cancer diseases was 0.59 (95% CI 0.46–0.76).

Discussion: No increase in overall mortality and total cancer mortality was observed. The SMR values suggest a strong healthy worker effect. This is an expected result, since workers in the nuclear industry are relatively well-paid and educated. Individual information on socio-economic data were not available, but aggregated data on job titles confirm that 26% of the cohort members were higher educated, non-manual employees, 70% were skilled manual workers and 4% were trainees. A dose-response analysis will be the next step. Results will be available in September 2012.