THE INFLUENCE OF 222RN-BEARING WATER USE ON INDOOR RADON LEVELS AT SOME HOT SPRING HOTELS IN GUANGDONG, CHINA

摘要

This study selected seven hot spring hotels in Guangdong to investigate the influence of indoor use of 222Rn-bearing water on indoor radon levels. Radon in tap hot spring waters, as well as in indoor and outdoor air,was determined by using Scintillation Cell method, NR-667A and RAD-7 continuous radon detector, respectively.Radon concentrations ranged 53.4-292.5 BqL-1 in the hot spring waters, and 18-56 Bqm-3 in outdoor air.Systematic diurnal variation of radon concentration in the investigated hotel rooms was determined. The rising of radon levels in the rooms was largely attributed to the guests' bathing with hot spring water and the inefficient ventilation. Spring water use in the hotel rooms had radon transfer coefficients from 1.6×10-4 to 5.0×10-3. The results of this study show that hot spring water flow during bath filling is by far the dominant mechanism by which 222Ra is released into the air of the hotel rooms.