Causes of death of Cogema active workers, 1980-1995

Background: Populations exposed to risks at work show a deficit in deaths in comparison with the national population, the 'healthy worker effect'. This effect has been observed among former nuclear workers. The aim of our- cross-sectional study was to evaluate the mortality in a metallurgy worker population, and to study the impact of the choice of the reference population on the estimation of the Standardized Mortality Ratio (SMR). Methods: The studied population was the COGEMA Metallurgy Department workers, aged 25 years to 64, during the period 1980-1995 in two regions of France (North - La Hague; South - Cadarache, Marcoule, Miramas and Pierrelatte). In order to account for geographical variability and the difference in mortality between the working population and the non-working population, we used several reference populations: national population, regional population, 'working' national population (farmer snot present in COGEMA and non-workers excluded), and 'working' regional population. Results: All SMRs were increased when we used a 'working' regional reference compared with the national reference population. Among men, eight pathologies presented a significant deficit with a national reference, whereas only two pathologies showed a deficit with the 'working' regional reference. Conclusion: The use of a reference population close to the study population enabled us to reduce the Healthy Worker Effect among metallurgy workers at COGEMA plants. (author)