Factors affecting the exposure of passengers, service staff and train drivers inside trains to airborne particles.

This study investigated train air conditioning filters, interior ventilation systems, tunnel environments and platform air quality as factors affecting the concentrations of airborne particles inside trains and provides information on the exposure of passengers, train drivers and service staff to particles. Particle sampling was done inside the passenger cabin, the driver cabin and the service staff cabin during on-board measurement campaigns in 2016 and 2017. The results show that interior ventilation plays a key role in maintaining cleaner in-train air. Noticeable increases in PM10 and PM2.5 levels were observed for all of the measured cabins when the train was running in the newly opened tunnel. The increases occurred when the doors of the passenger cabin and the service staff cabin were open at underground stations. The door to the driver cabin, which remained closed for the entire measurement period, acted as a filter for coarse particles (PM2.5-10). The highest particle exposure occurred in the passenger cabin, followed by the service staff cabin, while the driver had the lowest exposure. The highest deposition dose occurs for the service staff and the lowest for commuters.