The information about concentration, sources, and pollution degree of heavy metals belong to deposited dust (DS) can be used for decision-making in air quality control, removal role of green space, and urban forest management. The objectives of the study were to identify and evaluate DS pollution degree with the introduction of a new index. DS samples were collected from five tree species. The concentration of heavy metals and pollution degree of DS were evaluated by enrichment factors (EF), geoaccumulation index (I_geo), modified degrees of contamination (mC_d), and a new comprehensive index as weighted degree of contamination factor (wC_d). The values of EF showed that all samples were significant to extremely high enrichment and DS samples were emitted from anthropogenic activities. I_geo values indicated that DS samples were polluted by Cd (80–97%) and Pb (100%). In addition, mC_d results showed more than 67% of samples were unpolluted. There was a clear fact that I_geo results showed high pollution levels for Pb, Cd, and low for Ni, and the mCd results were incompatible with them. When all heavy metals were used without their importance to mC_d, calculation can cause bias from reality. For this reason, the new index was suggested as wC_d for all heavy metals that its results showed high to very high degree of pollution and that it was compatible with other indices results.

中文翻译：

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德黑兰绿色空间中尘埃的来源识别和污染程度。

有关重金属的浓度，来源和污染程度的信息属于沉积粉尘（DS），可用于空气质量控制，绿地的清除作用和城市森林管理的决策。该研究的目的是通过引入新指标来识别和评估DS污染程度。从五个树种中收集了DS样品。重金属的浓度和DS的污染程度通过富集因子（EF），_地质累积指数（I _geo），修正的污染程度（mC _d）和新的综合指数作为污染因子的加权程度（wC _d）进行评估）。EF值表明，所有样品都具有极高的富集度，而DS样品则来自人为活动。I _geo值表明DS样品被Cd（80-97％）和Pb（100％）污染。此外，mC _d结果表明超过67％的样品未被污染。有一个明显的事实，我_地理结果显示铅，镉高污染水平，对低镍和MCD结果与他们格格不入。当使用所有重金属而对mC _d不重要时，计算可能会引起与实际的偏差。因此，建议将新索引设为wC _d 对于所有重金属，其结果均显示出极高的污染程度，并且与其他指数结果兼容。