地铁空气微生物研究进展

Advances in research of airborne microbes in subway systems

地铁已发展成为现代城市中最重要的交通工具之一,由于其环境的特殊性（相对封闭、人流量大等）,空气较易受微生物污染,对公众健康构成潜在威胁.通过比较多种空气微生物采样和分析方法,发现主动采样和基于聚合酶链式反应（Polymerase chain reaction,PCR）的分子生物学分析方法如16S rRNA基因测序、宏基因组学及定量PCR技术可为地铁空气微生物的污染特征提供更为准确、全面和细致的信息;通过分析全球范围内不同地区地铁空气微生物文献,发现地铁空气微生物的分布特征随时间和空间可发生较大变化,影响地铁内空气中细菌和真菌浓度及种类的主要因素包括环境温度、相对湿度、二氧化碳浓度、人流量、屏蔽门、通风系统等.建议尽快建立基于分子生物学分析的标准化采样和分析方法,获得地铁空气微生物污染水平的基线数据,并建立空气中致病菌浓度与人体健康风险的相关性.

Subway systems are indispensable for transportation in modern cities, with the air being easily polluted by microbes owing to the enclosed and crowded environment. The microbiological characteristics of subway aerosols have attracted the attention of researchers worldwide during recent years. This review aimed to evaluate the sampling and analyzing methods suitable for detecting airborne microbes in subway systems. Active air sampling methods and molecular biology techniques based on polymerase chain reaction（PCR） such as 16 S r RNA gene sequencing, metagenomics, and quantitative PCR demonstrated great potential in microbial analysis of aerosols because they can provide accurate and comprehensive information. Temporal and spatial distributions of airborne microbes, as well as the factors inf luencing their distribution characteristics, were also discussed by critically reviewing worldwide literature on subway microbiome studies. The concentration and composition of airborne bacteria and fungi in subway can vary dramatically with time and space. The critical factors determining microbial community structure and composition include temperature, relative humidity, carbon dioxide concentration, number of passengers, presence of platform screen door, ventilation systems, and so on. The review suggests that future studies on standardized sampling and analyzing protocols are required to obtain contamination levels of subway airborne microbes and to establish the relationship between microbial monitoring data and public health risks.