Analysis of Dynamic Variation Characteristics and Influential Factors of PM2.5 on Subway Platforms under Air-Conditioning Condition and Ventilation Condition

The purpose of this study is to investigate the main influential factors of the subway Particulate Matter (PM) pollutants under the air-conditioning condition and ventilation condition, by an on-site field measurement in a subway station in Shanghai. It is found that the dust accumulation at fresh air shaft was the secondary dusting action under the influence of fresh air flow, leading to a higher concentration of the PM in the subway station than in the outdoor air even when the outdoor air quality was good. In addition, in the morning rush hour the PM 2.5 value near the platform screen door our is highest of the day