Radon exposure at drinking water supply plants in Slovenia.

Radon was measured at ten drinking water supply plants in Slovenia, in rooms attended by workers. Concentrations ranged from 40 to 2600 Bq x m(-3) resulting in annual effective doses of the personnel, calculated according to the ICRP 65 methodology, of below 0.5 mSv at 6 places, and of 0.6-3.0 mSv at the others. In addition, at each plant water was analyzed for 222Rn and 226Ra and ranges of 0.5-33 kBq x m(-3) and 5-34 Bq x m(-3), respectively, were obtained.