Commuter exposure to particle matter and carbon dioxide inside high-speed rail carriages

Exposure to PM2.5 and CO2 inside standard high-speed Chinese rail carriages is examined. The concentrations, 0.07 mg/m3 and 1200 ppm, are found to be significantly affected by passenger numbers, ventilation systems, and the carriage class. As passengers increase from 10 to 80 in a carriage, the concentrations increases by up to 0.04 mg/m3 in the passenger-breathing zone, and are inversely proportional to the air exchange rate. The greatest in-carriage PM2.5 concentration are found in the dinning carriage, with lower but similar levels found in other carriage classes. More rapid air turnover leads to slightly higher PM2.5 removal.

► In-cabin PM2.5 is linearly proportional to a HSR’s load factor.
► PM2.5 concentrations are inversely proportional to the outside air exchange rates.
► PM2.5 concentrations inside the dinning cabin are much greater than in passenger carriages.