Department of Mechanical Engineering, Faculty of Engineering, Universiti Malaya, Kuala Lumpur, 50603, Malaysia.
College of Emergency Technology and Management, North China Institute of Science and Technology, Hebei 065201, China.
Environ Sci Process Impacts. 2021 May 26;23(5):642-663. doi: 10.1039/d1em00002k.
Nowadays, PM2.5 concentrations greatly influence indoor air quality in subways and threaten passenger and staff health because PM2.5 not only contains heavy metal elements, but can also carry toxic and harmful substances due to its small size and large specific surface area. Exploring the physicochemical and distribution characteristics of PM2.5 in subways is necessary to limit its concentration and remove it. At present, there are numerous studies on PM2.5 in subways around the world, yet, there is no comprehensive and well-organized review available on this topic. This paper reviews the nearly twenty years of research and over 130 published studies on PM2.5 in subway stations, including aspects such as concentration levels and their influencing factors, physicochemical properties, sources, impacts on health, and mitigation measures. Although many determinants of station PM2.5 concentration have been reported in current studies, e.g., the season, outdoor environment, and station depth, their relative influence is uncertain. The sources of subway PM2.5 include those from the exterior (e.g., road traffic and fuel oil) and the interior (e.g., steel wheels and rails and metallic brake pads), but the proportion of these sources is also unknown. Control strategies of PM mainly include adequate ventilation and filtration, but these measures are often inefficient in removing PM2.5. The impacts of PM2.5 from subways on human health are still poorly understood. Further research should focus on long-term data collection, influencing factors, the mechanism of health impacts, and PM2.5 standards or regulations.
如今，PM2.5 浓度极大地影响了地铁内的空气质量，威胁着乘客和工作人员的健康，因为 PM2.5 不仅含有重金属元素，而且由于其体积小、比表面积大，还可以携带有毒有害物质。探索 PM2.5 在地铁中的理化特性和分布特征对于限制其浓度和去除它是必要的。目前，世界上有许多关于地铁 PM2.5 的研究，但针对这一主题还没有全面和组织良好的综述。本文综述了近二十年来关于地铁站 PM2.5 的研究和 130 多篇已发表的研究，包括浓度水平及其影响因素、理化特性、来源、对健康的影响以及缓解措施。尽管当前的研究报告了许多影响车站 PM2.5 浓度的因素，例如季节、室外环境和车站深度，但它们的相对影响尚不确定。地铁 PM2.5 的来源包括外部来源（如道路交通和燃油）和内部来源（如钢轮和轨道以及金属刹车片），但这些来源的比例也不清楚。PM 的控制策略主要包括充分的通风和过滤，但这些措施在去除 PM2.5 方面往往效率不高。地铁 PM2.5 对人体健康的影响仍知之甚少。进一步的研究应集中在长期数据收集、影响因素、健康影响机制以及 PM2.5 标准或法规上。
