Comparison of the excess relative risks (ERR) per unit dose* estimated for solid cancers** and leukaemia excluding chronic lymphocytic leukaemia (CLL) in the French CEA-AREVA-EDF cohort, the third analysis of the UK National Registry for Radiation Workers (NRRW), the pooled cohort of U.S. nuclear workers, the INWORKS cohort and the Life Span study of Hiroshima and Nagasaki A-bomb survivors.