Department of Earth Sciences, College of Sciences, Shiraz University, Shiraz, 71454, Iran.
Medical Geology Center, Shiraz University, Shiraz, Iran.
Environ Geochem Health. 2018 Aug;40(4):1187-1208. doi: 10.1007/s10653-017-0035-2. Epub 2017 Oct 28.
This study investigates the occurrence and spatial distribution of potentially toxic elements (PTEs) (Hg, Cd, Cu, Mo, Pb, Zn, Ni, Co, Cr, Al, Fe, Mn, V and Sb) in 67 road dust samples collected from urban industrial areas in Ahvaz megacity, southwest of Iran. Geochemical methods, multivariate statistics, geostatistics and health risk assessment model were adopted to study the spatial pollution pattern and to identify the priority pollutants, regions of concern and sources of the studied PTEs. Also, receptor positive matrix factorization model was employed to assess pollution sources. Compared to the local background, the median enrichment factor values revealed the following order: Sb > Pb > Hg > Zn > Cu > V > Fe > Mo > Cd > Mn > Cr ≈ Co ≈ Al ≈ Ni. Statistical results show that a significant difference exists between concentrations of Mo, Cu, Pb, Zn, Fe, Sb, V and Hg in different regions (univariate analysis, Kruskal-Wallis test p < 0.05), indicating the existence of highly contaminated spots. Integrated source identification coupled with positive matrix factorization model revealed that traffic-related emissions (43.5%) and steel industries (26.4%) were first two sources of PTEs in road dust, followed by natural sources (22.6%) and pipe and oil processing companies (7.5%). The arithmetic mean of pollution load index (PLI) values for high traffic sector (1.92) is greater than industrial (1.80) and residential areas (1.25). Also, the results show that ecological risk values for Hg and Pb in 41.8 and 9% of total dust samples are higher than 80, indicating their considerable or higher potential ecological risk. The health risk assessment model showed that ingestion of dust particles contributed more than 83% of the overall non-carcinogenic risk. For both residential and industrial scenarios, Hg and Pb had the highest risk values, whereas Mo has the lowest value.
本研究调查了伊朗西南部阿瓦兹大都市城区工业区 67 个道路灰尘样本中潜在有毒元素（PTEs）（Hg、Cd、Cu、Mo、Pb、Zn、Ni、Co、Cr、Al、Fe、Mn、V 和 Sb）的发生情况和空间分布。采用地球化学方法、多元统计、地统计学和健康风险评估模型研究了空间污染模式，并确定了优先污染物、关注区域和研究 PTEs 的来源。此外，还采用受体正矩阵因子模型来评估污染源。与当地背景相比，中值富集因子值显示出以下顺序：Sb>Pb>Hg>Zn>Cu>V>Fe>Mo>Cd>Mn>Cr≈Co≈Al≈Ni。统计结果表明，不同区域之间 Mo、Cu、Pb、Zn、Fe、Sb、V 和 Hg 的浓度存在显著差异（单变量分析，Kruskal-Wallis 检验 p<0.05），表明存在高度污染点。综合源识别与正矩阵因子模型表明，交通相关排放（43.5%）和钢铁工业（26.4%）是道路灰尘中 PTEs 的前两个来源，其次是自然来源（22.6%）和管道及石油加工公司（7.5%）。高交通区的污染负荷指数（PLI）值算术平均值（1.92）大于工业区（1.80）和居民区（1.25）。此外，结果表明，总灰尘样本中 41.8%和 9%的 Hg 和 Pb 的生态风险值高于 80，表明它们具有相当大或更高的潜在生态风险。健康风险评估模型表明，粉尘颗粒的摄入对非致癌风险的贡献超过 83%。对于住宅和工业两种情况，Hg 和 Pb 的风险值最高，而 Mo 的风险值最低。
