Natural Radioactivity and Radon Exhalation from Building Materials in Underground Parking Lots

The change of natural ionizing radiation and the radon exhalation rates from typical building materials in underground parking lots are presented article. activity concentration radionuclides 232Th, 226Ra, 40K six important types construction materials, which mostly used Lithuania, were analyzed using high-resolution gamma spectroscopy. highest values found concrete ferroconcrete samples: 226Ra 44 90 Bq kg−1; 232Th 29 34 581 603 kg−1. A strong positive correlation (0.88) was observed between radium concentration. indexes (Iα Iγ) equivalent (Req) evaluating suitability for such constructions view safety determined. average calculated absorbed dose rate samples ranged 18.24 nGy h−1 sand to 87.26 ferroconcrete. annual effective below limit 1.0 mSv y−1. external internal hazards index (Hex Hin) all unity, Iγ Iα recommended levels 0.5 1. Dosimetric analysis carried out. It determined that caused by 222Rn progeny car varies 17 30% total rate.