Little attention has been given to the nature and sources of airborne dust affecting northeastern Iran. The objectives of this study were to examine the concentrations of selected potentially toxic elements (i.e., Cr, Cu, Fe, Mn, Ni, Pb, and Zn), distinguish geogenic from anthropogenic sources, and assess the pollution intensity. A total of 600 samples were collected at 50 locations 12 times between May 2014 and April 2015 for fallout rate; 250 of these samples were selected for geochemical analysis. Mean dust concentrations of Cu, Pb, and Zn were found to be higher in autumn compared to spring as well as higher in the most populous cities. Results suggested that Ni, Cr, Mn, and Fe have come from mainly natural geologic sources, while concentrations of Cu, Pb, and Zn in the dust were associated with anthropogenic sources. Enrichment factors showed minimal to significant enrichment for Cu and Pb and moderate to very high enrichment for Cr, Ni, and Zn. The mean geo-accumulation index revealed that the contamination levels for Cu, Pb, and Zn peaked during autumn. In addition to industrial and traffic sources, seasonal differences in meteorological conditions can create frequent and persistent thermal inversions that at ground level can result in increases in Cu, Ni, Pb, and Zn concentrations during autumn. Because of the diversity of geology and terrain in combination with significant seasonal shifts in winds over this region, this study highlights the need to consider both geogenic and anthropogenic sources in evaluating pollution risks in northeastern Iran.

对于影响伊朗东北部的空气尘埃的性质和来源，人们几乎没有给予任何关注。这项研究的目的是检查选定的潜在有毒元素（即Cr，Cu，Fe，Mn，Ni，Pb和Zn）的浓度，区分人为和人为来源，并评估污染强度。2014年5月至2015年4月期间，在50个地点共采集了600个样本，共12次，以求出落尘率；从这些样品中选择了250个进行地球化学分析。与春季相比，秋天的铜，铅和锌的平均粉尘浓度要高于春季，而在人口最多的城市中，粉尘的浓度较高。结果表明，镍，铬，锰和铁主要来自自然地质来源，而粉尘中铜，铅和锌的浓度与人为来源有关。富集因子显示出对Cu和Pb的富集最小至显着富集，对Cr，Ni和Zn的中等至非常高的富集。平均地积累指数显示，秋季铜，铅和锌的污染水平达到峰值。除了工业和交通资源外，气象条件的季节性差异还会造成频繁且持续的热反转，这在地面上会导致秋季Cu，Ni，Pb和Zn浓度增加。由于该地区地质和地形的多样性以及该地区大风的季节性变化，本研究强调在评估伊朗东北部的污染风险时需要同时考虑地源和人为源。平均地积累指数显示，秋季铜，铅和锌的污染水平达到峰值。除了工业和交通资源外，气象条件的季节性差异还会造成频繁且持续的热反转，这在地面上会导致秋季Cu，Ni，Pb和Zn浓度增加。由于该地区地质和地形的多样性以及该地区大风的季节性变化，本研究强调在评估伊朗东北部的污染风险时需要同时考虑地源和人为源。平均地积累指数显示，秋季铜，铅和锌的污染水平达到峰值。除了工业和交通资源外，气象条件的季节性差异还会造成频繁且持续的热反转，这在地面上会导致秋季Cu，Ni，Pb和Zn浓度增加。由于该地区地质和地形的多样性以及该地区大风的季节性变化，本研究强调在评估伊朗东北部的污染风险时需要同时考虑地源和人为源。气象条件的季节性差异会造成频繁且持续的热逆转，这在地面上会导致秋季Cu，Ni，Pb和Zn浓度增加。由于该地区地质和地形的多样性以及该地区大风的季节性变化，本研究强调在评估伊朗东北部的污染风险时需要同时考虑地源和人为源。气象条件的季节性差异会造成频繁且持续的热反转，这在地面上可能导致秋季Cu，Ni，Pb和Zn浓度增加。由于该地区地质和地形的多样性以及该地区大风的季节性变化，本研究强调在评估伊朗东北部的污染风险时需要同时考虑地源和人为源。