RADON IN PRIVATE WATER-SUPPLIES - THE UNKNOWN RISK

Radon gas, which is the main contributor to human radiation exposure, is easily dissolved in, and dissipated from, water. Problems with rado n occur because, in addition to being ingested, it (a) becomes attache d to particles which lodge in the lungs and (b) emits alpha radiation. Concentration has been found to increase inversely with the size of a water supply. Although of little problem in mains' water, private wat er supplies in the UK have been found to contain more than ten times t he recommended US levels. Despite this, very little monitoring is carr ied out for radon in private supplies. Local authorities, situated in areas where the geological conditions are such that high levels of rad on would be expected, should carry out a suitable sampling and monitor ing programme of their private water supplies.