Lung dose estimates from 222rn in arizona groundwater based on liquid scintillation measurements

Since August 1989, "'Rn groundwater samples from across the state of Arizona have been collected and analyzed using liquid scintillation. Of the 253 specimens acquired, 65% have "'Rn concentrations above 11 Bq L-' (300 pCi L-'), while 16% have "'Rn activities over 37 Bq L-' (1,000 pCi L-'). The geometric mean "'Rn concentration for all the wells tested is 13 Bq L-' 4; the arithmetic mean is 37 2 122 Bq L-'. Using the geometric mean, it is estimated that an additional tracheobronchial lung dose equivalent of 0.19 mSv y-' 13.9 is delivered to Arizona residents from the well water to home pathway.