Indoor concentrations of radon in Cairo subway

Abstract The current study was going to detect radon concentrations in one of Cairo’s subways. The radon gas was detected in certain common positions chosen for thirteen stations. Plastic cans were prepared to hold the CR-39 samples and to be positioned at their destination in the stations. The cans were installed through two periods of one month and two months. Afterwards, the track density of radon gas was calculated for all the collected samples and then the concentration of radon was estimated in the stations. It was found that the average value of Rn concentration in the thirteen stations exceeds the average normal Rn concentration indoors. The measured values are less than the recommended maximum value of 300 Bq m −3 for radiation protection of residents according to ICRP Publ. 126. The indoor average radon concentrations were found less than the action level of 300 Bq m −3 , 100 Bq m −3 , and 148 Bq m −3 as recommended by ICRP, and WHO, respectively.