Mortality and cancer registration experience of the Sellafield employees known to have been involved in the 1957 Windscale accident

The mortality and cancer morbidity experience of the 470 male Sellatield employees known to be involved in the 1957 Windscale accident is reported. All these employees are known to have been involved in dealing with the fire itself, or in the clean-up operation afterwards. The size of the study population is small, leading to predicted low power to reveal any effects, but the cohort is of interest because of the involvement of the workers in the accident. For 1957-97, using rates for England and Wales to calculate the expected numbers, the all causes standardised mortality ratio (SMR) is 100 (observed - 258, expected = 258.80), and the all malignant neoplasms SMR is 79 (observed = 58, expected = 73.12) which is not significantly different from 100. For 1971-91, the all malignant neoplasms standardised registration ratio (SRR)of 85 (observed = 59, expected = 69.23) is not significantly different from 100. Significant excesses of deaths from diseases of lhe circulatory system (SMR = 121) and from ischaemic heart disease (SMR = 128), and a significant deficit of deaths from cancer of the genito-urinary organs (SMR = 31), were found. There were no significant differences in mortality rates between workers who had received high recorded external doses during the fire and those who had received low doses, though the power of this comparison was low. Comparison of the mortality rates of workers directly involved in the accident with workers in post, but not so involved, showed no significant differences. This study has been unable to detect any effect of the 1957 fire upon the mortality and cancer morbidity experience of those workers involved in it.