This work considers dust deposition and the heavy metal (HM) content on leaves of urban trees (Acer platanoides L. ‘Globosum,’ Fraxinus excelsior L. ‘Westhof’s Glorie’ and Tilia tomentosa Moench.) in order to estimate the trees’ capacity to remove dust and HM from the air. Leaves were collected from the Buda Arboretum and from different streets of heavy traffic in Budapest, Hungary, during 2015 and 2016. At each site, five trees were sampled by collecting 6 leaves from each tree from the height of 2–3 m. Dust deposits on the leaves were removed by soaking the fresh foliage in distilled water for 20 h and then washed with ultrasound shaking. Afterward, the leaves were dried to constant weight and then they were digested in nitric acid–hydrogen peroxide treatment, and their Pb, Fe, Ni, Zn and Cu contents were measured using an inductively coupled plasma (ICP AS) spectrometer. The removed dust deposit was dried, and after a similar digestion treatment the Pb, Fe, Ni, Zn and Cu contents were measured using an AURORA AI 1200 AAS appliance. The HM deposit was calculated in mg m^–2 leaf surface area. In 2015, the amount of foliar dust deposit from spring to autumn increased from 86.3 to 270.2 mg m^–2. The most efficient tree species in trapping dust on their leaves was the silver linden (98.5–123.5 mg m⁻²), followed by the Norway maple (74.2–84.8 mg m⁻²) and the common ash (62.8–74.6 mg m⁻²). The deposit of HM elements showed seasonal differences: the quantity of Fe and Pb deposit on autumnal leaves increased five- to tenfold, while other heavy metals did not show accumulation. Silver linden with its pubescent (hairy) leaf surface proved to be most efficient in entrapping and retaining dust and heavy metals. The 60–100% higher Pb and Fe content of autumnal leaves indicate that over the season leaves may absorb Fe and Pb from the foliar dust. Our results confirmed that the foliar dust is a potential indicator for monitoring the HM content in the air. We also show that foliar dust deposits should be considered when estimating the capacity of urban trees to clean the air.

这项工作考虑了城市树木（Acer platanoides L.'Globosum，Fraxinus excelsior L.'Westhof's Glorie'和Tilia tomentosa）叶片上的灰尘沉积和重金属（HM）含量。Moench。），以评估树木清除空气中灰尘和HM的能力。在2015年至2016年期间，从布达植物园和匈牙利布达佩斯交通繁忙的不同街道上收集叶子。在每个站点，从每棵树的2-3 m高度采集6片叶子，对五棵树进行了采样。将新鲜的叶子在蒸馏水中浸泡20小时，然后去除叶子上的灰尘，然后用超声波摇动清洗。然后，将叶片干燥至恒重，然后在硝酸-过氧化氢处理中进行消化，并使用电感耦合等离子体（ICP AS）光谱仪测量其铅，铁，镍，锌和铜的含量。将去除的粉尘沉积物干燥，并在进行类似的消化处理后，将Pb，Fe，Ni，锌和铜含量是使用AURORA AI 1200 AAS设备测量的。HM沉积物以mg·m计算^–2叶表面积。2015年，春季至秋季的叶面粉尘沉积量从86.3增至270.2 mg m ^–2。在它们的叶子捕集粉尘的最有效的树种是银椴（98.5-123.5毫克米^-2），接着由挪威枫木（74.2-84.8毫克米^-2）和共用灰（62.8-74.6毫克米^{- 2}）。HM元素的沉积表现出季节差异：秋天叶子上的Fe和Pb沉积量增加了5到10倍，而其他重金属则没有积累。带有菩提叶表面（有毛）的银菩提树被证明在捕获和保留灰尘和重金属方面最有效。秋季叶片中铅和铁的含量高出60-100％，表明在整个季节中叶片可能会从叶面灰尘中吸收铁和铅。我们的结果证实，叶面灰尘是监测空气中HM含量的潜在指标。我们还表明，在估算城市树木清洁空气的能力时，应考虑叶面灰尘的沉积。