A silent killer, invisible, odourless and tasteless exists in hundreds of homes across Northamptonshire.
Nationally, it is responsible for more than 1,000 deaths a year yet few people take measures to protect themselves from radon gas.
The natural, radioactive gas is emitted from the soil every few seconds and collects in homes and workplaces, causing around five per cent of all lung cancer cases.
There is also research under way to establish its connection with Alzheimers and skin cancer.
Radon is more prevalent in some areas of the country than others and Northamptonshire, with its porous soil, has high levels of the gas emitted into the atmosphere.
Outdoors the gas quickly dissipates but it can collect in dangerous levels inside buildings particularly if there is good insulation preventing radon from escaping.
Awareness campaigns have been launched by the Government in the past but it is up to homeowners and businesses to tackle the problem and pay for work to reduce radon levels in their properties.
The gas has recently come into the public arena again after a University of Oxford team called for radon reduction membranes to be made compulsory in new houses and be funded by the Government.
However this was criticised by Professor Paul Phillips from the University of Northampton, which has the largest independent radon research department in the world.
Professor Phillips carried out research three years ago that revealed the membranes were ineffective in 60 per cent of cases.
He is also critical of politicians, planners and local authorities, who he believes are sweeping the widespread problem under the carpet.
Testing is vital, expert says
Radon may be a fatal gas but it is easy to keep out of properties if the correct measures are taken.
Many builders advocate membranes which are laid on a building's foundation and prevent the gas from seeping into the property.
However if these are not manufactured or laid properly, they can end up with piercings in the material which let the gas through.
Professor Paul Phillips, a radon expert at The University of Northampton, said: "They are a simplistic answer. Nobody really bothered to calculate if they work in practice. In a perfect world this would work perfectly.
"When builders lay the membranes down they are not always careful.
A shovel could have gone through them.
Houses also settle and move."
Professor Phillips has been in contact with West Northamptonshire Development Corporation to discuss alternatives to using membranes in new housing developments.
He said it would be the perfect opportunity for them to lead the way and eradicate the problem in the housing developments they oversee.
His solution is for all new properties to have radon tests on completion and then have a special pump fitted, if necessary, to reduce high levels.
Speaking to the Chron this week WNDC agreed they had held discussions with Professor Phillips but said it was not their responsibility and it should be taken up with individual local planning authorities.
According to radon experts an effective alternative to a membrane is the sump, which is a 400 pump which extracts the gas from the property.
Professor Phillips added: "There are some products that claim to use natural fibres to filter radon from the air. It is absolute nonsense.
You should use Radon Council validated systems. The environmental health officer at your local authority should be able to provide you with the names of local validated companies."
Radon Centres in Moulton is one such validated company which provides tests and radon solutions for commercial and domestic properties.
Director Roger Tornberg said homeowners were still slow to address the problem but Northamptonshire County Council took a responsible approach to its properties.
He explained: "All schools, fire stations and buildings they own are tested and they check them randomly every year."
And there is no property exempt from radon pollution.
During the 1990s Northamp-ton General Hospital discovered it had high levels of radon gas not associated with the radiological equipment.
The measurements were carried out by physicist Professor Tony Denman, who worked at the hospital at the time.
He said: "We found a number of rooms that had high risk radon levels.
The radon levels in offices were higher than the doses used by radiographers.
"We were able to reduce them down and found all the hotspots, so everyone is safe down there."
Testing a property, which costs around 40, is the only way to measure radon levels accurately.
Although there are maps and postcode reports that will indicate whether a property is in a radon affected area, they will not establish whether one particular property is at risk.
Radon levels can vary hugely from one house to the next due to a number of factors like insulation.
Professor Phillips explained: "The only way to really know is to have a test.
One house might have a level of 10 becquerels and the house next door might have 10,000."
When purchasing a property buyers must look carefully at the local search results which will reveal whether a property is in a radon affected area.
If it is, it is possible to negotiate a radon bond with the seller, meaning they have to pay for any remedial work to get rid of the problem, even after the sale goes through.
The new owner can then do a radon test, which takes three months, to see if the level in their home is above the safe amount of 200 becquerels.
If the level is above this the radon bond will come into force.
How to find out if your home is a health hazard ...
I have two reports sitting on my desk about the same property in Northampton.
Each asks the same question: Is this property in a radon affected area?
The 2005 report answers 'yes', and adds that more than one per cent of properties in this area are likely to be above the action level.
Meanwhile the 2007 report answers 'no' but in a contradictory guidance note adds that there is a zero to one per cent chance of the property being above the action level.
Both of these reports were carried out by the Health Protection Agency.
Confused? I am.
There is plenty of information available about radon gas but when you look at the fine details, none of it appears to make much sense to a lay person.
The message from radon experts is to get your property tested whether there is a one per cent or 100 per cent chance of it being in an affected area.
But confusion and lack of awareness are not the only problems as tests and solutions come at a price.
Professor Paul Phillips from The University of Northampton radon and health department thinks it is a disgrace that the public have to pay to find out if their home is potentially a health hazard.
In recent years the Government has commissioned and paid for a radon map of the country but in order to get the results for a specific area there is a fee of 3.45 (previously almost 30). This means taxpayers are effectively paying for the information twice.
Professor Phillips said: "Why isn't this free? It has already been funded by the Government and paid for by taxpayers.
The fee puts people off."
And even if a property is in an affected area, a further test costing 40 is needed to find out how high the levels are in one particular building.
Roger Tornberg, director of the Radon Council, believes the public should be made more aware and tests should be free.
He added: "Estate agents are pushing it under the carpet as they don't want a blight on the house and a problem for the sale.
Conveyancing is often the first time people hear about it.
"People also assume a new house has been tested for radon but it hasn't.
The electric and central heating and all those things will have been tested but not the radon levels.
"The Government don't want to deal with it because it will cost the country a fortune to fix it."
Physicist Tony Denman from Brixworth said even if people do test their houses they are reluctant to spend money on remedial work.
He added: "Perhaps people are not perceiving it as a risk as it is a natural gas."
In other European countries like Austria, the Government provides grants for people to do remedial work if radon levels are high in their homes.
"Northamptonshire on average is 6.3 per cent above the action level but this could vary from 17 per cent in Brixworth and one per cent in Corby," explained Professor Denman.
Targeting specific risks groups may be one way of dealing with the issue, he added.
Smokers are at a much higher risk of getting lung cancer if they are exposed to radon, and this is something Northamptonshire Primary Care Trust may promote in the future, he said.
For radon prevention advice visit www.radon.co.uk.