Findings Doses were accrued at very low rates (mean 1·1 mGy per year, SD 2·6). The excess relative risk of leukaemia
mortality (excluding chronic lymphocytic leukaemia) was 2·96 per Gy (90% CI 1·17–5·21; lagged 2 years), most
notably because of an association between radiation dose and mortality from chronic myeloid leukaemia (excess
relative risk per Gy 10·45, 90% CI 4·48–19·65).
mortality.