[en] A brief report is given of a study by the NRPB on the mortality and cancer incidence in UK participants in UK atmospheric nuclear weapon tests and experimental programmes. The results of 22,347 participants were compared with a population of 22,326 controls. It was concluded that participation in the nuclear weapons tests had no detectable effect on the participants' expectation of life or on their total risk of developing cancer, apart possibly from an effect on the risks from developing multiple myeloma and leukaemia. (U.K.)