Householders ignore the invisible invader - or rationalise the risk

YOU can't smell it, taste it or see it, but if enough of it seeps into your house for long enough it could kill you.

Faced with the prospect of an invisible invader, most householders are concerned. But that concern does not always translate into action, according to Dr Ann McGarry, of the Radiological Protection Institute of Ireland.

One man who runs a company offering an anti radon service said he gets more queries than customers. "People don't like the idea of labelling their house as a radon zone because they've installed a system," he said.

His company, Remedia Ltd, installs fan assisted sumps which eliminate the pressure difference between the house and the soil air underneath. When these are equalised, radon is no longer drawn into the house.

The other two firms known to the institute in the business of remedial work are Radon Care and Radon Remediation Ireland.

Most of Remedia's business is with developers, especially local councils in western counties, which install anti radon systems for new buildings in radon hotspots.

The system for existing houses costs between £500 and £1,500, depending on the size and structure of the house. The running costs work out at around £50 a year.

Apart from the stigma which might attach to a house and worries about property prices, Remedia has seen many people rationalising the risk.

People realise, I suppose, that the risk is a probability thing. It's like smoking. You could have radon in your house all your life and not be affected. I say to people if they're worried about lung cancer that one of the first things they should do is give up smoking."

According to Dr McGarry it is possible that one house might have a high radon level and a next door neighbour would be in the clear. Modern houses are more airtight, with energy saving measures like double glazing and better installation. However, keeping the heat in could also involve keeping the radon in.