A THIRD of homes most at risk of a deadly cancer causing gas have taken up a free testing offer.

Last month the Oxford Mail revealed the Health Protection Agency (HPA) had written to more than 9,000 homes across West Oxfordshire offering a free test of the property to determine the level of radon present.

Now it is writing again to the 6,000 homes that have not taken up the offer.

Radon is an odourless, colourless natural gas which seeps into homes from the ground.

High levels of radon have been linked to an increased risk of lung cancer.

It occurs naturally and is present all over the UK, but high levels are linked with Cotswold stone, a limestone which allows the gas to seep to the surface more easily.

According to HPA figures, 3,000 of the 9,000 homes at risk applied for a test.

Residents in Ledwell, Charlbury and Hailey are leading the response rate.

Neil McColl, head of radon projects team at the agency, said it should be taken seriously. He said: “Days after the story appeared in the Oxford Mail we received thousands of slips from people who had been offered tests – a much quicker response than we usually get.

“But we are aware that this is holiday season and as such testing for radon may not be at the forefront of people’s minds.”

HPA scientists have been running testing campaigns where levels of the gas are believed to be high, including Scotland and Cornwall, for years.

About ten years ago, 8,500 homes in the Cherwell area were also told they were in potential danger.

Radon is measured in becquerels per metre cubed of air (Bq m3). The HPA recommends steps are taken to reduce exposure at a concentration of 200 Bq m3.

Mr McColl added: “Testing is very easy, you simply place one detector in a living room and another in a bedroom. After three months you post them to us, we then analyse them and contact you to say what your result is.”

He said HPA would hold an event later to explain what people with high readings can do to protect their properties and families from the effects of radon.

Householders can choose to install a sump under their homes to pump out the gas, but that can cost several hundreds of pounds.

Last night Associated Surveyors, of Abingdon, said homeowners, if asked for the information, were legally obliged to reveal the radon reading if their home had been tested.

In some areas of West Oxfordshire and Cherwell the reading has topped 2,500 Bq m3.

West Oxfordshire councillor Warwick Robinson, who represents Hailey, Minster Lovell and Leafield, said he was glad residents in his area were taking up the test.

TAKE-UP - THE percentage of people in each area (by postcode) who have taken up the offer to get radon testing: * Witney (OX28) 32.8 * Witney (OX29) 25.0 * North Leigh 32.8 * Stonesfield/ Coombe/ Long Hanborough 33.5 * Hailey 39.4 * Charlbury/ Chadlington/ Fawler 36.5 * Great Tew/ Little Tew/ Swerford/ Lidstone /Enstone 30.4 * Chipping Norton/ Over Norton/ Great Rollright 30.7 * Ascott- and Shipton-under-Wychwood/ Fifield 32.5 * Ledwell / Over Worton 39.0 * Chastleton 26.9 * Burford 28.8 * Woodstock 32.6 * Rousham 33.3 * All 32.5