In order to investigate the degree of contamination of heavy metals (As, Cd, Cr, Cu, Fe, Pb, and Ni) in the Aqyazi River in Iran, sediment samples were collected from the river receiving wastewater from an iron-manufacturing plant. For this study, contamination indices, geoaccumulation index (I_geo), contamination factor (CF), and pollution load index (PLI), were used to assess contamination by the heavy metals. The results of the I_geo indicated that the sediments were moderately contaminated by Cu and strongly to extremely contaminated by Cd. Based on spatial distribution of concentrations and the I_geo, mining activity was the source of Cu and Cd in the Aqyazi River. Furthermore, the elevated I_geo of Cd at upmost northern station was not influenced by the mining activity, suggesting that there may be another upstream anthropogenic source of Cd. The CF values indicated the same trend as the Igeo. The PLI was calculated using all the metals analyzed in this study, and displayed that the sediments were not polluted. However, the PLI was re-calculated using only Cu and Cd and indicated that the sediments were polluted. Our results suggest further studies to trace another source of Cd upstream of the Aqyazi River and to investigate influence of the river waters on accumulation of heavy metals in soils and vegetables downstream.

中文翻译：

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铁开采活动对伊朗阿克亚齐河沉积物中重金属污染的影响。

为了调查伊朗阿克亚齐河中重金属（As，Cd，Cr，Cu，Fe，Pb和Ni）的污染程度，从河流中收集了沉积物样本，该河流接受了一家钢铁制造厂的废水。在本研究中，污染指数，_地质累积指数（I _geo），污染因子（CF）和污染负荷指数（PLI）用于评估重金属污染。I _geo的结果表明，沉积物受到Cu的中等污染，而受到Cd的强烈污染。根据浓度和I _geo的空间分布，采矿活动是阿卡亚兹河中Cu和Cd的来源。此外，升高的I北部最北端的镉的_地理分布不受采矿活动的影响，这表明可能还有上游的人为来源的镉。CF值表示与I geo相同的趋势。使用本研究中分析的所有金属计算了PLI，显示出沉积物未受到污染。但是，仅使用Cu和Cd重新计算了PLI，表明沉积物受到了污染。我们的结果表明，需要进行进一步的研究以追踪阿卡亚兹河上游的另一种Cd来源，并研究河水对下游土壤和蔬菜中重金属积累的影响。