Thousands of UK personnel were involved in the UK's atmospheric nuclear weapons test programme in Australia and the South Pacific in the 1950s and 1960s.
In the 1980s scientists from the National Radiological Protection Board, which became part of the Health Protection Agency in 2005, established a study to investigate whether the radiation that UK personnel were exposed to during those tests had detrimentally affected their health.
NRPB created a major epidemiological study to compare the health of those exposed with a similar sized group of personnel who were not exposed to radiation. Three statistical analyses have been conducted and reported since the 1980s, the most recent in 2003.
Based on this work the HPA conclude that nuclear weapons test participants had, in general, a better life expectancy than members of the general UK population. When compared with the control group, the test participant group had similar overall patterns of mortality and cancer incidence indicating no significant cause for concern.
The statistical analyses also provided a slight indication that test participation may have caused a very small increased risk of leukaemia but there was not enough evidence to confirm this as a fact and there was evidence to suggest that this finding should be treated with caution.