Fine particulate matter (PM_2.5) is a common air pollutant that represents a significant threat to public health. In Dublin, a major source of PM_2.5 is diesel exhaust, brake dust, and rubber tire particles from vehicles. Particulate matter can be deposited onto the surface of vegetation thereby removing it from the atmosphere. The presence of trees can increase the amount of surface area on which deposition can occur, but they can also alter wind flow in a way that increases local pollutant concentrations. This study assesses the effect of urban trees on removing PM_2.5 using a novel combination of air quality monitoring and the i-Tree Eco (UFORE) deposition model during rush and non-rush hours with different traffic volumes. Monitoring was conducted in a tree alley and an area of no vegetation along the Drumcondra Road Lower in Dublin. Results indicated that there was no difference in PM_2.5 concentrations outside of rush hours, but concentrations were significantly lower in the tree alley during rush hours compared to the street section with no trees. The i-Tree Eco model calculated that the tree alley could remove approximately 3 kg of PM_2.5 on a yearly basis. Air monitoring found that the presence of trees resulted in a maximum air quality improvement of 126 %, more than double what was predicted by i-Tree Eco. While this study provides an initial exploration of trees and air quality in Dublin, further research combining these techniques with the measurement of local wind speed and direction would allow for a better understanding of how Dublin’s trees can affect its air quality. The results from this study suggest that they do cause a degree of air quality improvement and can be used to inform national clean air strategies aimed at reducing pollutant emissions.

细颗粒物（PM _2.5）是常见的空气污染物，对公众健康构成重大威胁。在都柏林，PM _2.5的主要来源是柴油机废气，制动粉尘和车辆产生的橡胶轮胎颗粒。颗粒物可以沉积在植被表面上，从而将其从大气中清除。树木的存在可以增加可能发生沉积的表面积，但是它们也可以通过增加局部污染物浓度的方式来改变风量。这项研究评估了城市树木对去除PM _2.5的影响在交通量不同的繁忙时间和非繁忙时间使用空气质量监测和i-Tree Eco（UFORE）沉积模型的新颖组合。监测是在都柏林Drumcondra Road Lower沿树胡同和无植被的地区进行的。结果表明，在高峰时间以外，PM _2.5浓度没有差异，但是与没有树木的路段相比，高峰时间树木胡同中的PM _2.5浓度显着降低。i-Tree Eco模型计算得出，树巷可以清除约3千克的PM _2.5每年一次。空气监测发现，树木的存在最大改善了126％的空气质量，是i-Tree Eco预测的两倍多。尽管这项研究提供了都柏林树木和空气质量的初步探索，但是将这些技术与当地风速和风向的测量结合起来进行进一步的研究可以使人们更好地了解都柏林的树木如何影响其空气质量。这项研究的结果表明，它们确实可以一定程度地改善空气质量，并可用于指导旨在减少污染物排放的国家清洁空气战略。