Understanding PM_2.5 concentration and removal efficiency variation in urban forest park — Observation at human breathing height

Abstract

To increase our knowledge of PM2.5 concentrations near the surface in a forest park in Beijing, an observational study measured the concentration and composition of PM2.5 in Beijing Olympic Forest Park from 2015 to 2016. This study analyzed the meteorological factors and removal efficiency at 1.5 m above the ground (human breathing height) over the course of the day in the forest. The results showed that the average concentrations of PM2.5 near the surface peaked at 07:00–09:30 and reached their lowest at 12:00–15:00. In addition, the results showed that the annual concentration of PM2.5 in the forest was highest during winter, followed by spring and fall, and was lowest during summer. The main chemical components of PM2.5 near the surface in the forest were SO42− and NO3−, which accounted for 68.72% of all water-soluble ions that we observed. The concentration of PM2.5 in the forest had a significant positive correlation with relative humidity and a significant negative correlation with temperature. The removal efficiency near the surface showed no significant variation through the day or year. In the forest, the highest removal efficiency occurred between 07:00 and 09:30 in summer, while the lowest occurred between 09:30 and 12:00 in winter.

Pollution monitoring using the leaf-deposited particulates and magnetism of the leaves of 23 plant species in a semi-arid city, Northwest China

“…As one of the most important aspects of such efforts, urban vegetation plays a crucial role in optimizing the urban environment by regulating the microclimate, reducing noise and mitigating particulate matter (PM) pollution (Baldauf, 2017). The bene ts of vegetation have been demonstrated studies using model simulations (Gromke and Ruck, 2009;Selmi et al, 2016), wind tunnels (Gromke and Ruck, 2009;Wang et al, 2019) and eld experiments (He et al, 2020;Shao et al, 2019;Yan et al, 2019).…”