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A. Radon is a radioactive gas, which comes from the minute particles of uranium naturally present in all rocks and soils. It is, and always has been, a part of the world we live in.

Although exposure to particularly high levels of radon may pose a health risk, particularly to smokers, the gas disperses quickly and easily in the open air, and as a result, background levels are barely detectable. In an enclosed space – like a house – levels tend to be higher, for the simple reason that the gas cannot escape so quickly into the atmosphere. Nevertheless, in most parts of the country, even indoor radon levels remain extremely low – detectable only by the most sensitive instruments.

Radon levels are measured in something called “becquerels per cubic metre.” Most homes in the UK register a score of around 20. However, geological conditions in certain parts of the country can lead to higher than average levels. In such areas, the Health Protection Agency (HPA), which conducts radon surveys for government departments and local councils as well as private householders, recommends that indoor radon levels above an “Action Level” of 200 should be reduced. This is normally tackled by installing a “radon sump,” which vents the gas harmlessly into the atmosphere with the aid of a small electric fan under the floor. In the case of older properties, these can usually be fitted from the outside, without any internal disruption. To conform with current building regulations, all new homes in these areas have to be equipped with them.

If you are buying a property in a high-radon area, then your survey or mortgage valuation will generally mention the fact. However, this is basically no more than a standard paragraph inserted as a matter of course. It does not necessarily mean that the property concerned is actually affected. Indeed, many homes in so-called high-radon areas display levels no higher than the national average.

However, if you are concerned, and would like to check things out, the HPA produces a free radon information pack which explains all you need to know – including how you can go about obtaining a radon measurement. To request a pack, go to the HPA’s website, www.UKradon.org