Foliar Particulate Matter Distribution in Urban Road System of Beijing, China

• Published in: Chinese geographical science Vol. 29; no. 4; pp. 591 - 600
• Main Authors: Bao, Le, Ma, Keming, Xu, Xiaowu, Yu, Xinxiao
• Format: Journal Article
• Language: English
• Published: Heidelberg Science Press 01.08.2019; Springer Nature B.V
• Subjects: Air pollution; Earth and Environmental Science; Geography; Humidity; Load; Particulate matter; Regression analysis; Relative humidity; Roads; Roads & highways; Suburban areas; Urbanization; Vehicle emissions; Wind speed; Beijing China; China; number of lanes; relative humidity; roadside tree; wind speed; road cleanliness; distance from the urban centre; road width; road density
• ISSN: 1002-0063; 1993-064X
• DOI: 10.1007/s11769-019-1057-8

Particulate matter (PM), one of the most important pollutants of traffic emission, threatens the health of urban ecosystems and citizens. Roadside trees play an important role in trapping PM, and the foliar PM load is a useful indicator for air PM pollution in road systems. To detect the relationships of foliar PM load with road structures, urbanization, and meteorology in road systems, we studied a widely-planted tree Sophora japonica L. in 100 roads and 10 yards of Beijing, China, and found that the foliar PM loads increased with the distances from the urban centre (DUC) linearly, while decreased with the road density. All-subsets regression analysis indicated that DUC, average monthly relative humidity, average monthly wind speed, and mean annual wind speed were the most important factors in predicting foliar PM load, rather than general situation of buildings and road cleanliness. The monthly relative humidity and monthly wind speed had a negative correlation to foliar PM, while the annual relative humidity and annual wind speed had a positive correlation to foliar PM. Suburban areas and these effective factors should be highlighted in PM control in Beijing.