Abstract：Objective To investigate the radon concentration and occupational radon exposure doses in Hangzhou Metro Line 1 and Line 5, so as to provide a basis for assessing potential health risks of radon exposure and protecting the occupational health of metro workers. Methods From March 2022 to March 2023, radon concentration monitoring was conducted at 53 stations on Hangzhou Metro Lines 1 and 5. Four sampling points were set up at each station: train control room, customer service center, security checkpoint area, and platform. Continuous monitoring was conducted for one year at the train control room, while continuous monitoring at the other sampling points lasted for one quarter. CR-39 cumulative radon detection cups were used to measure radon concentrations, while RAD7 radon detectors were used to measure instantaneous radon concentrations. The annual effective dose to workers from radon and its progeny was estimated. Radon concentrations across different lines, sampling points, and seasons were analyzed. Results The median radon concentration was 26.8 (interquartile range, 11.2) Bq/m3 in Line 1, and the median instantaneous radon concentration was 4.7 (interquartile range, 8.5) Bq/m3. In Line 5, the radon concentration was (26.1±6.1) Bq/m3, and the median instantaneous radon concentration was 4.7 (interquartile range, 7.4) Bq/m3. No significant differences were found between the two lines in either radon or instantaneous radon concentrations (both P>0.05). The control rooms in both lines showed relatively high radon levels, with a median of 42.5 (interquartile ranges, 24.3) Bq/m3 in Line 1 and a median of 26.8 (interquartile ranges, 6.1) Bq/m3 in Line 5. In the Line 1 control room, the median radon concentrations across four quarters were 37.7 (interquartile range, 27.5), 42.5 (interquartile range, 24.4), 46.8 (interquartile range, 26.0), and 34.9 (interquartile range, 29.0) Bq/m3, respectively. No significant seasonal variation was observed (P>0.05). In the Line 5 control room, the values were 24.8±6.7, 26.6 (5.9), 33.8±7.9, and 22.8 (8.7) Bq/m3, respectively. A significant seasonal difference was found (P<0.05), with the third quarter showing higher radon levels than the first and fourth quarters (both P<0.05). The annual effective doses to workers from radon and its progeny were relatively high in the Line 1 control room (0.305 2 mSv) and the Line 5 platform (0.255 9 mSv). Conclusions The radon concentrations in Hangzhou Metro Lines 1 and 5 were within the low-dose radiation range and met the national standard limits. No significant health risks were identified. However, attention should be paid to radon levels in control rooms and during the third quarter. Enhanced monitoring and ventilation management are recommended.
郝小吉, 俞顺飞, 郭佳娣, 赖忠俊, 曹艺耀, 王东航, 宣志强. 地铁环境氡浓度调查及工作人员暴露剂量评估[J]. 预防医学, 2026, 38(5): 483-487.
HAO Xiaoji, YU Shunfei, GUO Jiadi, LAI Zhongjun, CAO Yiyao, WANG Donghang, XUAN Zhiqiang. Investigation of radon concentration and assessment of occupational exposure dose in the metro environment. Preventive Medicine, 2026, 38(5): 483-487.
