Radon exhalation rate in building materials using plastic track detectors

The radon flux emitted from building material samples and from the surface of building materials could be determined using a simple and reliable metho d. This method was based on the use of cellulose nitrate films (LR-115 II). The samples and the detectors were placed in a closed can of known dimensi ons. Tracks due to alpha-particles of radon that migrate from the building material into the air space in the chamber were registered on the LR-115 fi lm. The detectors were chemically etched in 2.5N NaOH solution at 60+/-1 de grees C for 115 minutes. Exhalation rates of various building material samp les and of building surfaces of various building components were determined . The results obtained by this technique could be used to establish a datab ase for average radon exhalation rates for all available building materials and walls or floors.