Comparative studies of indoor radon concentration levels in Jordan using CR-39 based bag and cup dosimeters

Indoor radon concentration levels have been measured in 9 major cities of Jordan using CR(-3)9 detectors placed in punched polyethylene bags to measure both radon and thoron, and in cups to measure radon only. The average value of indoor radon and thoron concentration levels measured with bag dosimeters vary from 32 to 107 Bq m(-3) and the indoor radon concentration levels measured with cup dosimeters vary from 27 to 88 Bq m(-3). The indoor radon concentration levels in Irbid and Zaraka are comparable to the world average of 27 Bq m(-3). In Ajloun, Jerash, Salt, Tafilah and Amman, the indoor radon levels are greater than the world average by a factor of up to 2, and in Madaba and Karak these levels are greater than the world average by a factor of more than 3. The large variation in the measured radon levels may be attributed to the large variation in the 226Ra activity in the soil of the region.