Indoor radon concentration levels have been measured in a number of ci
ties in Jordan. CR-39 detectors were installed in randomly selected ho
uses and were exposed to radon for about 4 months. The detectors were
then etched in 6N NaOH at 70 degrees C. It was observed that the indoo
r radon concentration levels varied from similar to 7 to 123 Bq m(-3).