The mortality and cancer morbiidity experience of workers at the sellafield plant of British nuclearfuels plc, 1946-1998

We present preliminary results of the analysis of the Sellafield cohort of workers. The mortality and morbidity experience of these 28,973 employees to the end of 1998 is reported. These workers have accumulated 669,303 person-years of experience, with a mean follow-up time of 23.1 years. The low level of untraced workers, 0.27%, is indicative of the quality of the data set. The cohort has 21,537 radiation workers, 10,623 of which are classified as plutonium workers. The radiation workers have received 1,715 person-sieverts of external whole body radiation dose, 76% of which has been received by the plutonium workers. Of the plutonium workers that had been monitored, 77% (8,173) had provided sufficient urinalysis samples (i.e.≥ 5), for the calculation of the organ-specific plutonium doses using ICRP 60/66 dose models. Both the plutonium (SMR=93, p<0.001; 1,787 deaths) and other radiation workers (SMR=91, p<<0.001; 1,850 deaths) show the healthy worker effect, though this was not apparent amongst the non-radiation workers (SMR=102, p=0.37; 1,551 deaths,). Though there was no difference in the 'all causes' mortality experience when the plutonium workers were compared with the other radiation workers, the 'all causes' mortality experience for all radiation workers was significantly lower than that for the non-radiation workers (RR=0.88, p<0.001)