Mortality of aluminium reduction plant workers in France.

The mortality between 1950 and 1976 of 6455 French aluminium plant workers was analysed in order to assess occupational risks (especially lung cancer) associated with electrolysis, particularly with the Söderberg process. Mortality from all causes (SMR = 0.85), was lower in this cohort than in the French male population ('healthy worker effect'), and cancer mortality (SMR = 1.09) was only slightly higher. There was an excess of mortality from accidents (mainly non-occupational) in electrolysis workers (SMR = 1.38) and from cirrhosis of the liver in maintenance workers (SMR = 1.63). Among electrolysis workers, only those who had worked less than 10 years had a relative excess mortality from lung cancer (SMR = 1.94), but this did not seem to be associated with a particular electrolysis process. However a substantial underlying risk of lung cancer in Söderberg workers could not be excluded, although such a risk appeared unlikely for prebake workers.