贵阳地铁1号线氡浓度特征及其潜在健康效应评估

地铁轨道交通逐渐成为人们日常出行的首选，但作为较封闭的地下空间环境易导致氡积聚，对于工作人员和乘客存在潜在的电离辐射暴露风险，有必要进行监测评估。贵阳地铁1号线于2018年12月开通运营，所穿越地层主要为碳酸盐岩，该地层风化过程中常常产生氡异常，尤需引起关注。本研究利用RAD-7电子测氡仪，分别于2020年7月29日和2021年1月7日对该地铁全线20个地下站点及车厢中空气氡浓度进行监测，分析其时空变化特征及主要影响因素，估算人员暴露剂量，评估潜在健康效应。结果表明：贵阳地铁1号线氡浓度水平为9.6~257.5 Bq/m³，均值为38.9 Bq/m³，高于我国主要城市地铁氡平均值（28.9 Bq/m³），低于国外平均值（105.2 Bq/m³）；且不同站点存在较大差异，整体上氡浓度夏季低于冬季。计算发现，站内工作人员因氡及其子体暴露导致的有效剂量为0.28 mSv/a，小于天然背景辐射值（约为2.4 mSv/a），属于低剂量辐射范围，不存在健康风险。

Atmospheric Radon Concentration in Guiyang Subway Line 1 and the Potential Health Effects

Subway has gradually become the first choice for people''s daily travel, but the radon accumulation could not be ignored due to the closed underground environment. It is necessary to monitor and evaluate the potential risk of ionizing radiation exposure for staff and passengers. Guiyang subway line 1 was put into operation in December 2018, and the strata passed through are mainly carbonate rocks. Radon anomalies often occur in the process of weathering, which needs special attention. In this study, RAD-7 electronic radon detector was used to monitor the atmospheric radon concentration in 20 underground stations and the carriages of the subway on July 29, 2020 and January 7, 2021, respectively. The temporal and spatial variation characteristics and the main influencing factors were analyzed, in addition, the exposure dose was estimated, and the potential health effects were evaluated. The results show that the range of radon concentration in Guiyang subway line 1 is 9.6 to 257.5 Bq/m³, and the average value is 38.9 Bq/m³, which is higher than the average value of radon in major cities in China (28.9 Bq/m³), but is much lower than the foreign average (105.2 Bq/m³), and there are great differences among different stations, showing obvious seasonal variation with lower values in summer and higher ones in winter. The calculated effective dose of radon and its daughter elements exposure to the staff in the station was 0.28 mSv/a, which was less than the natural background radiation value (about 2.4 mSv/a), indicating it belongs to the low-dose radiation range, and there was no health risk.