超镁铁质和矿区土壤-植物系统的潜在有毒金属(PTM)富集是全球关注的问题,因为它会影响食物链。随着矿业的扩大,重要的是评估人为因素是否(即,与自然因素(即,地形)。Sekhukhuneland的地方,南非,沿着海拔梯度选择(即,地形:上坡,下坡,山谷和谷底)和土地利用概况(即,牧场,花园,尾矿和荒地)以调查Co的分布,Cr,Cu,Fe,Mg,Mn,Mo,Ni,天然的Sr和Zn(即,超镁铁质地质学)和人为(即,采矿)起源于表层土壤和植物叶片组织。植物生命形式被认为是评估叶片中PTM积累的附加因素。结果表明,表层土壤中Cr和Ni的分布范围更广。Co,Cu,Mg,Mo,Sr和Zn被积累(生物积累因子,BAF>1)在74%的被评估植物的叶组织中,其中83%是本地的。草,forbs,矮灌木和灌木的积累水平最高。尽管观察到PTM沿海拔梯度在土壤和植物叶片中的分布趋势,在地形位置之间没有确定显着差异。土地利用做法,然而,差异显着表明人为干扰是土壤植物系统PTM富集的主要决定因素。Sekhukhuneland的耐金属优势植物可归类为金属植物。土著物种,累加器和排除器,展示了植物修复和修复金属污染场地的前景,分别。食品和药用植物叶片中Cr和Co的浓度超过了国际允许的限值,其中强调了在含金属地点估计PTM的人类健康风险的必要性。
Potentially toxic metal (PTM) enrichment of the soil-plant system in ultramafic and mining regions is a global concern as it affects the food chain. With expanding mining industry, it is important to assess if anthropogenic factors (i.e., land use practices) have a greater influence in this regard compared to natural factors (i.e., topography). Localities in Sekhukhuneland, South Africa, were selected along an altitudinal gradient (i.e., topography: upper slope, footslope, valley and valley bottom) and a land use profile (i.e., rangelands, gardens, tailings and wastelands) to investigate the distribution of Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Sr and Zn of natural (i.e., ultramafic geology) and anthropogenic (i.e., mining) origin in surface soil and plant leaf tissue. Plant life form was considered as an additional factor to evaluate PTM accumulation in leaves. Findings revealed a wider distribution range for Cr and Ni in the surface soil. Co, Cu, Mg, Mo, Sr and Zn were accumulated (bioaccumulation factor, BAF > 1) in leaf tissue of 74% of the evaluated plants of which 83% were indigenous. Grasses, forbs, dwarf shrubs and shrubs showed the highest accumulation levels. Despite an observed trend in the distribution of PTMs in soils and plant leaves along the altitudinal gradient, no significant differences were determined among the topographic positions. Land use practices, however, differed significantly indicating anthropogenic interference as a predominant determinant of PTM enrichment of soil-plant systems. Metal tolerant dominant plants in Sekhukhuneland could be classified as metallophytes. Indigenous species, accumulators and excluders, showed prospects for
phytoremediation and rehabilitation of metal contaminated sites, respectively. Concentrations of Cr and Co in food and medicinal plant leaves exceeded the international permissible limits, which highlighted the necessity to estimate human health risks for PTMs in metalliferous sites.