Why did the study need a control group?
Participants in the nuclear weapons test programme would have differed in some ways from men of the same age in the general UK population. For example, test participants needed to have been fit enough to be selected for overseas service, and they would have experienced a different lifestyle during their period in a tropical or desert environment. Consequently, as well as comparing mortality and cancer rates among test participants with the corresponding national rates, comparisons were also made with the control group.
