Peculiarities of Particulate Matter Absorption by Urban Tree Species in the Major Cities of Armenia

Air pollution, including particulate matter (PM), impacts public health in urban areas. Vegetation acts as a natural filter, removing environmental pollution by absorbing large quantities of toxic substances on the foliage. Ambient air pollution problems are real in Armenia’s cities. This article presents the results of a study based on field sampling in July 2022 undertaken in urban parks and streets in the Armenian cities of Yerevan, Gyumri, and Vanadzor. The three cities have different climates and geographic conditions. The main research goal was a comparative study of the accumulation of PM by urban greenery. The most widespread tree species were selected for the study in each city: in Yerevan, Platanus orientalis and Quercus robur; in Gyumri, Fraxinus excelsior and Tilia caucasica; and in Vanadzor, Aesculus hippocastanum and Acer pseudoplatanus. The ecological status of trees was assessed through visual observation. Tree species with high PM uptake potential were identified and selected for inclusion in urban greening systems (Platanus orientalis, Fraxinus excelsior, and Quercus robur in Yerevan; Tilia caucasica, Sorbus persica, Fraxinus excelsior, and Populus alba in Grumri; Acer pseudoplatanus, Fraxinus excelsior, Aesculus hippocastanum, and Thuja occidentalis in Vanadzor.). High PM accumulation was found on the leaves of tree species in all of the investigated cities, with the largest amount recorded in Yerevan. In these cities, PM levels were higher in street plantations than in parks. All studied tree species have a high potential for PM absorption, demonstrating strong phytofilter properties. Therefore, they can be effectively used in their typical climatic zones and included in street plantings, gardens, and parks. These results can help urban planners and policymakers make informed decisions about urban greening initiatives to improve air quality and overall wellbeing.