Investigation in the United Kingdom of the risks of occupational exposure to radiation
Kendall GM., Muirhead CR.
This paper summarises the first analysis of the UK National Registry for Radiation Workers. Mortality in a cohort of about 100 000 radiation workers was compared with that expected in the general population of England and Wales. The standardised mortality ratio (SMR) for all causes of death was below 100, indicating that the expected healthy worker effect was present. SMRs from most specific causes were also below 100. Only for thyroid cancer was the SMR significantly above 100; later analysis will help determine whether this was a chance observation. Tests for trend with dose were carried out to see whether death rates were higher among those whose recorded radiation doses were greater. For all malignant neoplasms taken together there was a positive trend with dose, but this did not reach statistical significance. However, for the grouping of all leukaemias except chronic lymphatic leukaemia there was a positive trend with dose, which was statistically significant. The interpretation of these results is discussed.