Radon in domestic water supplies in the UK

In a novel experiment carried out by school children the level of naturally occurring 222 Rn has been measured in domestic tap water at 504 locations throughout the UK. Most values were close to 1 Bq.1 −1 and none were above the limit suggested by the UK National Radiological Protection Board of 100 Bq.1 −1 . The values are considerably lower than in many US tap waters and provide a negligible contribution to the level of inhaled radon in room air