An investigation of the PM2.5and NO2concentrations and their human health impacts in the metro subway system of Suzhou, China.
This study measured the particle concentrations with an aerodynamic diameter smaller than 2.5 μm (PM2.5), nitrogen dioxide (NO2), and relative humidity (RH) at five metro subway stations in Suzhou's subway system (Lines 1 and 2). The real-time monitoring campaign was conducted from March 30thto April 10thand August 4thto August 21st, 2015. The monitoring practice was carried out during rush (7:00-9:00 AM and 17:00-19:00 PM) and regular hours (other times) at the ground and underground levels under different weather conditions with a purpose of obtaining representative data. The monitored results show that the concentrations of PM2.5in the train carriages were lower than the concentrations at the underground platforms during both spring and summer. The mean PM2.5concentrations at all the underground platforms in all the sub-stations monitored were significantly higher than those at the ground level. The human health impact was calculated to be 6300 annual DALYs (or 375 deaths) due to exposure to the subway system in Suzhou according to the UNEP-SETAC toxicity (USEtox) model. Linear regression models were applied to evaluate the relationships between the PM2.5, NO2concentrations, and RH. We found that a 10% increment in RH from the current average level of 50-60% can lead to a 9.8 μg m-3concentration decrease in PM2.5. This further results in the total human health impact being reduced to 2451 DALYs (150-4753 DALYs), representing a 20% decrease (1.2-38%).
Department of Civil and Environmental Engineering, School of Urban Rail Transportation, Soochow University, Suzhou, China. shijie.cao@suda.edu.cn yelin.deng@suda.edu.cn.
Shi-Jie
SJ
Cao
Xiang-Ri
XR
Kong
Linyan
L
Li
Weirong
W
Zhang
Zi-Ping
ZP
Ye
Yelin
Y
Deng
D000393:Air Pollutants / Q000032:analysis*; D002681:China; D004784:Environmental Monitoring / Q000379:methods*; D006801:Humans; D008962:Models, Theoretical; D009585:Nitrogen Dioxide / Q000032:analysis*; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D011890:Railroads
D000393:Air Pollutants; D052638:Particulate Matter; D009585:Nitrogen Dioxide