School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Department of Building Science, School of Architecture, Tsinghua University, Beijing 100084, China; Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Tsinghua University, Beijing 100084, China.
Environ Pollut. 2022 Jul 15;305:119279. doi: 10.1016/j.envpol.2022.119279. Epub 2022 Apr 8.
Air in subway stations is typically more polluted than ambient air, and particulate matter concentrations and compositions can vary greatly by location, even within a subway station. However, it is not known how the sources of particulate matter vary between different areas within subway stations, and source-specific health risks in subway stations are unclear. We analyzed the spatial characteristics of particulate matter by source and calculated source-specific health risks on subway platforms and concourses and in station offices by integrating source apportionment with health risk assessments. A total of 182 samples were collected in three areas in six subway stations in Nanjing, China. Enrichment factors and the positive matrix factorization receptor model were used to identify major sources. The carcinogenic and non-carcinogenic health risks to subway workers and passengers were evaluated to determine control priorities. Seven sources of particulate matter were identified in each area, with a total of four subway sources and six outdoor sources over all the areas. The source contributions to total element mass differed significantly from the source contributions to human health risks. Overall, subway sources contributed 48% of total element mass in the station office and 75% and 60% on the concourse and platform, respectively. Subway-derived sources accounted for 54%, 81%, and 71% of non-carcinogenic health risks on station platforms, concourses, and office areas, respectively. The corresponding values for carcinogenic risks were 51%, 86%, and 86%. Among the elements, cobalt had the largest contributions to carcinogenic and non-carcinogenic risks, followed by manganese for non-carcinogenic risks and hexavalent chromium for carcinogenic risks. Reducing emissions from subway sources could effectively protect the health of subway workers and passengers.
地铁站内的空气通常比环境空气污染更为严重，即使在地铁站内，颗粒物浓度和成分也因位置而异。然而，我们并不清楚颗粒物的来源在地铁站的不同区域之间有何差异，也不清楚地铁站内特定来源的健康风险。我们通过源解析与健康风险评估相结合的方法，分析了不同区域内颗粒物的空间分布特征，并计算了地铁站台、站厅和站务办公室的源特异性健康风险。在中国南京的 6 个地铁站的 3 个区域共采集了 182 个样本。我们使用富集因子和正定矩阵因子受体模型来识别主要来源。评估了地铁工人和乘客的致癌和非致癌健康风险，以确定控制优先级。在每个区域都确定了 7 种颗粒物来源，总共有 4 种地铁源和 6 种室外源。各区域元素总质量的源贡献与对人体健康风险的源贡献差异显著。总体而言，地铁源在站务办公室占总元素质量的 48%，在站厅和站台分别占 75%和 60%。地铁源造成的非致癌健康风险分别占站台、站厅和站务办公室的 54%、81%和 71%，对应的致癌风险分别为 51%、86%和 86%。在这些元素中，钴对致癌和非致癌风险的贡献最大，其次是锰对非致癌风险，六价铬对致癌风险。减少地铁源的排放可以有效保护地铁工人和乘客的健康。
