Dartmoor prisoners evacuated after radioactive gas detected

More than 180 cells closed down due to presence of radon, which can cause lung cancer

HMP Dartmoor has had to close down more than 180 cells and carry out prisoner transfers after the radioactive gas radon was detected.
Capacity at Dartmoor has been reduced by 184 places between November and February. In the same period until February, 194 prisoners have been moved out. While the reason for their removal is not recorded, the PA news agency understands the majority have been moved due to radon.
Radon, an odourless and colourless gas, is produced by decaying radioactive materials in rocks and soils, and is responsible for around 1,000 lung cancer deaths a year in the UK. It is thought to occur more often in areas with high concentrations of granite, such as Dartmoor.
The Prison Service said prisoners had been moved as a precautionary step, with efforts to reduce radon levels ongoing.
The Labour Party, which revealed the figures in a series of questions to ministers, said it was “shocking that the Government’s mismanagement of the prison estate means they are having to reduce the number of prison places during a capacity crisis”.
Ruth Cadbury MP, the shadow minister for prisons, said: “This dangerous gas was first detected in 2020, and yet the Ministry of Justice have said that measures weren’t put in place until 2022. Ministers need to explain why it has taken over two years for them to act.
“After 14 years in power and a dozen prison ministers, our prisons are out of control and the Government needs to get a grip.
“Labour will rebuild public confidence in the criminal justice system and we’ll restore law and order in Britain.”
Answering Labour’s questions on behalf of the Government, Edward Argar, the justice minister, said the Prison Service was “continually investing in the prison estate to ensure that prisons remain safe, decent and secure”.
He said: “Temporary mitigations have been in place at Dartmoor in those areas since 2022 following advice from specialist contractors, pending permanent mitigations that are near completion. Further specialist advice has been commissioned.”
A Prison Service spokesman said: “A number of prisoners have been relocated as a measure… This is a temporary measure while work to permanently reduce radon levels is completed and there are no safety implications to staff or prisoners who remain on site.”
The latest monthly bulletins for the prison population in England and Wales also appear to track a falling number of inmates and a decreased capacity at Dartmoor. January figures record an operational capacity of 583, with a population of 555, while in February the capacity was 505 with a population of 470.
In December, a report by Dartmoor’s independent monitoring board warned the prison was understaffed and overcrowded, and arguably “not fit for purpose”. It also pointed to radon first being detected in 2020, and claimed “it is only in this year that some actions have been taken while further monitoring is undertaken to inform future decisions”.