上海两地铁车站空气中PM_(10)和PM_(2.5)浓度分布特征

Distributions of PM_(10) and PM_(2.5) in Two Shanghai Metro Stations

[目的]了解上海轨道交通系统地下车站空气中可吸入颗粒物(PM10和PM2.5)浓度及其分布特征,为相关标准制定和环境改善提供科学依据。[方法]以上海地铁某两个地下车站为研究现场,在2013年3—5月期间,每两周监测一个工作日,每日监测早、中、晚3个时段。监测地点包括隧道、站台、站厅和室外风井,监测指标为PM10和PM2.5。[结果]隧道和站台PM10平均水平高于站厅和风井,差异别有统计学意义(P<0.05);PM2.5的浓度水平在不同监测地点比较差异无统计学意义(P>0.05)。不同时间段站内二者水平不同:PM10在隧道和站台表现为早晚高于中午,站厅为早上高于中晚;PM2.5在隧道和站厅与PM10的变化趋势相同,在站台则表现为早、晚、中依次降低;差异均有统计学意义(P<0.05)。[结论]上海市地下车站环境空气中的可吸入颗粒物水平在不同的地点和时间段有明显变化,提示颗粒物是上海市轨道交通系统需要重视的卫生学问题。

[Objective ] To investigate the concentrations and distributions of PM10 and PM2.5 in Shanghai metro stations so as to provide scientific basis for environmental improvement and establishment of relevant hygiene standard. [ Methods ] Two underground metro stations were selected for the study. The levels of PM10 and PM2.5 were measured on one workday in every two weeks from March to May, 2013. The measurement was conducted three times （morning, noon, and evening） a day. Sampling sites included tunnels, platforms, station halls, and outdoor air shafts. [ Results ] The average levels of PM10 in the tunnels and platforms were significantly higher than those in the station halls and air shafts （P〈0.05）. The levels of PM2.5 were even among different sites （P〉 0.05）. The particulate matter levels varied in different measuring time points： the PM10 levels in the tunnels and platforms were significantly higher in morning and evening than in noon （P〈0.05）, and those in the station halls were significantly higher in morning than in noon and evening （P 〈 0.05）. The time variation of PM2.5 was similar to PM10 in the tunnels and station halls, while in the platforms, the levels of PM2.5 in morning, evening, and noon were in a decreasing manner （P〈0.05）. [ Conclusion ] In the underground metro stations, the levels of particulate matter vary with time and location, indicating that the particulate matter pollution in Shanghai metro stations should be paid more attention to.