RESIDENTS in more than eight thousand homes across the Cotswolds are believed to be at increased risk of developing lung cancer because their home is in a radon gas hotspot.

Public Health England, an executive agency of the Department of Health, says it has an accurate map of the district showing where scientists estimate there is a higher than usual chance that homes will have high radon levels through the gas seeping into their houses through the ground.

It is now going to write to each household inviting them to take part in a free test to identify a potential hazard.

"It has long been known that the Cotswolds and parts of Gloucestershire are radon hotspots," said Neil McColl, head of dosimetry services at the PHE's Centre for Radiation, Chemicals and Environmental Hazards.

He said parts of West Oxfordshire - including the Chipping Norton area - also have high levels and they have already worked with people there to help them find out if their home is affected and if it is, to take action to reduce their radon levels.

On that occasion about 3,200 households were offered a test. Some 53 per cent took up the offer and 1,500 completed it. Of that total around 15 per cent had a radon level at or above the recommended level for action which is what the PHE had predicted.

"It's important people do act because long term exposure to high levels of radon can lead to lung cancer," he said.

People are exposed to radon all the time to differing levels. It cannot be seen, heard, smelled or tasted, but each year it is believed to lead to over 1000 lung cancer death.

The worst affected areas in the remainder of the Cotswolds have been identified as east of Shipston and north of Chipping Campden.

Testing involves placing two plastic detectors, about the size of a biscuit, in key positions around the home. After three months the detectors are returned and the radon level is calculated. If levels are high as suspected, PHE will recommend householders take steps to reduce levels.

Dr Peter Brambleby, director of public health for Gloucestershire, said: "Testing for radon is easy and important. Although you may live in a radon affected area it's important to remember that every home is different. Just because your neighbour isn't exposed to high levels doesn't mean you won't be. Testing is the only way you can know for sure if radon is a real risk to your health."

If a home is found to be above the accepted levels then remedial work to reduce the contamination is recommended. This may involve fitting a radon sump fitted with a fan and estimated to cost between £1,000 and £2,000.

The PHE also states anyone can find out if a property is in a radon affected area by searching on

Radon occurs naturally through the break-down of uranium in the ground which is released as a gas and escapes into the atmosphere depending on the type of rock in that area. The danger occurs when the gas gets trapped in buildings and cannot escape.

Most homes in the UK have fairly low radon levels, with an average of about 20 becquerels per cubit metre of air. Some, though, have levels of 200 becquerels or more which is the level action should be taken.

The highest recording in the Chipping Norton area was 2,200 becquerels.