Radon is a natural radioactive gas. You cannot see, hear, feel or taste it. It comes from the minute amounts of uranium that occur naturally in all rocks, soils, brick and concrete.
Radon is present in the soil in all parts of the UK to varying degrees. Most of it seeps from the ground harmlessly into the atmosphere. However, where it enters buildings, levels can build up and occasionally become a significant radiation risk to people inside. The highest levels are usually found in underground spaces such as basements, caves and mines.
The Health Protection Agency and the British Geological have undertaken a survey of the UK to identify radon affected areas. An atlas of radon areas in England and Wales can be obtained from www.ukradon.org.
Pembrokeshire is one of the areas in the UK which has generally higher levels of radon.