Radon mapping in cluj-napoca city-a radon prone area from romani

Cluj Napoca City is the most important city from northwestern part of Romania, having about 350,000inhabitants. The Somes river, also the most important river of this country region crosses the city fromwest to east, but before it crosses a granite massive, named Maguri-Racatau, a region located at 35Km on the upper part of this water course. The first indicators of a possible radon prone area for Cluj-Napoca city and its neighboring was the water radon concentration from the old power supply of thecity with about 37 Bq/L (1nCi/L).