A dozen of the sites, which include current and former air and naval bases, have not been identified before by the MoD. Some are accessible by the public or being developed for homes or businesses, though the potential risks are unclear.
The contamination comes from radium that was used to coat the dials of aircraft and other equipment so that they could be seen in the dark. It was in scrap burnt and dumped in the 1940s and 1950s, and remains radioactive for thousands of years.
The contaminated sites include the old SAS headquarters at Stirling Lines in Hereford, a former naval air base near Portsmouth, a previous home to the Red Arrows in Gloucestershire and a former RAF base at Machrihanish on the Mull of Kintyre (see table below).
The MoD has revealed the list of sites in response to a series of freedom of information requests in the wake of the discovery of dangerous levels of radium contamination at Dalgety Bay in Fife. It was home to a busy Second World War air base.