Evaluating Air Pollution in Two Urban Alleys and Comparing Tree Capacity for PM Dust Absorption: A Case Study

The ongoing urbanization of cities worldwide contributes to escalating levels of air pollution, posing significant environmental and health concerns. The calculation of PM 2.5 air purification potential is commonly conducted for green spaces and trees within urban areas with models such as I Tee eco, as they play crucial roles in ecosystem functions, including the absorption of various air pollutants, but there is a deficiency of studies verifying the distribution of health-threatening concentrations of this pollutant for urban residents. This study presents the findings of research conducted in Warsaw, the capital of Poland, aiming to assess air pollution levels and compare the dust absorption capabilities of trees in two different alleys. The research comprised two main phases: initially, monitoring the concentration of PM2.5 in urban streets characterized by high and low tree density during peak traffic periods and post-peak traffic periods. Subsequently, the study focused on determining the pollution absorption parameters of trees in selected locations, utilizing the i-Tree Eco tool. The analysis revealed frequent exceedances of air quality standards in Warsaw within isolated time frames. Furthermore, it underscored the dependence of urban forest ecosystem services' efficiency on tree canopy cover (TCC), noting a nearly 14.5-fold lower pollutant uptake in areas with insufficient TCC. This issue warrants serious consideration, particularly as a significant number of samples surpassed the WHO standard of 15 µg/m ³ . Moreover, the study's outcomes emphasized the importance of researching urban trees and air pollution levels using dust sensors. In the case of Warsaw, relying solely on readily available models, commonly utilized in previous studies, may lead to underestimations, failing to accurately represent the actual concentration levels of air pollution.