The occurrence and bioaccessibility of potentially toxic elements (PTEs) in soils and sediments are investigated by many studies, especially in territories exploited by mining and ore-processing activities, nearby agriculture-driven rural cities. Accordingly, the present study aimed at evaluating the geochemical properties, potential bioavailability, and risks for environment and human health of the most concerning PTEs of study area (Gafsa mining basin, Tunisia) such as Cd, Cr, and Zn in selected soil, sediment, and mining waste samples. The extraction of these solid matrixes by modified EU-BCR sequential extraction revealed that the most easily extractable fractions of each PTE were very low (first 2 steps, < 10%), Cd was mainly associated with the oxidizable phase (likely organic matter), and Cr and Zn were mostly found in residual mineral fraction (likely occluded in non-siliceous mineral phase). The total cumulative concentration of each metal was found to be higher in soil/sediment profiles and ore-processing wastes than in phosphate rocks, indicating a metal enrichment due to mining activities. The aqua regia extraction of representative sediment samples revealed that Cd, Cr, and Zn concentrations were higher than non-polluted sediment standards. In contrast, other elements as Cu, Mn, and Pb essentially arose from natural bedrocks. The Unified BARGE method was applied to assess the risk of ingestion by human beings and wild/domestic animals of contaminated sediment particulate prone to wind erosion and air dispersion in the arid conditions of study area. An higher oral bioaccessibility was found for Cd than Zn and Cr, most concerning in acid gastric phase than in sub-neutral intestinal environment.

中文翻译：

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对突尼斯西南部矿区土壤，沉积物和矿石加工废物中潜在有毒元素的环境和人类健康风险评估。

许多研究都对土壤和沉积物中潜在有毒元素（PTE）的发生和生物可及性进行了研究，尤其是在采矿和矿石加工活动开发的地区，附近农业驱动的农村城市。因此，本研究旨在评估研究区域（Gafsa矿床，突尼斯）中最相关的PTE（例如选定土壤，沉积物中的Cd，Cr和Zn）的地球化学特性，潜在的生物利用度以及对环境和人体健康的风险。 ，并收集废物样本。通过改进的EU-BCR顺序萃取对这些固体基质的萃取表明，每个PTE的最易萃取馏分非常低（前两个步骤，<10％），Cd主要与可氧化相有关（可能是有机物），Cr和Zn大多存在于残余矿物组分中（可能被非硅质矿物相吸收）。发现每种金属的总累积浓度在土壤/沉积物剖面和矿石加工废物中要比磷酸盐岩中的浓度高，这表明由于采矿活动导致金属富集。代表性沉积物样品的王水提取显示，Cd，Cr和Zn的浓度高于未污染的沉积物标准。相反，其他元素如Cu，Mn和Pb则主要来自天然基岩。统一BARGE方法用于评估人类和野生/家养动物在研究区域干旱条件下容易被风蚀和空气扩散的污染的沉积物颗粒摄入的风险。发现镉比锌和铬具有更高的口服生物可及性，