Radon concentrations in underground public space environment in Shanghai City

Objective To survey and evaluate the concentration of radon in typical subway station platforms,underground malls(shopping streets) and underground garages and then make a scientific conclusion for the environmental management of underground public spaces.Methods Radon in underground spaces which measured as ²²²Rn was tested by electronic radon monitor (RAD-7).Results ① Among the 4 detected subway station platforms,Shanghai Railway Station showed a low concentration of radon,Zhongshan Park Station was next in that,and,People's Square Station and Yishan Road Station were higher in that; ② Among the 4 detected underground malls,the Shanghai Railway Station and Science & Technology Museum Station underground mall/shopping street had a low level of radon concentration,the People's Square station and Xujiahui station were next; ③ Radon concentration of underground parking garages in Shanghai Pudong International Airport was 6~10 times higher than that of Shanghai Railway station and Shanghai Hongqiao Railway station.Conclusion Data from similar underground public spaces in three compared cities showed that,the underground malls/shopping streets of Shanghai presented the minimum radon concentration. Radon concentrations of Shanghai subway station platforms gave a medium result in the four compared cities,and results from underground parking garages in Shanghai were below the average of some cities.Data from underground public spaces of the different type showed that,radon concentration in underground parking garage was below that of underground mall/shopping street which were also lower than that of subway station platform.Radon in the air of the underground place was beyond the testing results of indoor ground constructions but much lower than that in the basement of the country and the national occupational health limits.