Mahlangeni Nomfundo T, Moodley Roshila, Jonnalagadda Sreekantha B
School of Chemistry & Physics, University of KwaZulu-Natal, Westville Campus, P. Bag X54001, Durban, 4000, South Africa.
Environ Monit Assess. 2016 Feb;188(2):76. doi: 10.1007/s10661-015-5044-y. Epub 2016 Jan 5.
Laportea peduncularis is a medicinal plant consumed by the native communities in South Africa. Due to its oral consumption, its potential for harming the human health and the distribution of metals in the leaves of L. peduncularis as a function of soil characteristics were evaluated. Broadly, the concentrations of metals in the soil were in decreasing order of Fe > Ca > Mg > Mn > Zn > Cr > Cu > Ni > As > Co > Cd > Pb. Low-molecular-weight organic acid, calcium chloride, and ethylenediaminetetraacetic acid extraction methods were employed to assess for exchangeable forms of metals in the soil. Geoaccumulation indices and enrichment factors showed no contamination or enrichment for most of the heavy metals studied except for Cd, which showed moderate contamination and significant enrichment at Mona, KwaZulu-Natal. Principal component and cluster analyses revealed that As, Cd, Fe, and Ni in the soil came from the same source, whilst Cu, Pb, and Zn in the soil were from a common origin. Correlation analysis showed significantly positive correlation between heavy metals As, Cd, Fe, and Ni in the soil, as well as between Cu, Pb, and Zn, confirming the metals' common origin. Concentrations of metals in plants and soil were influenced by site, but the availability and uptake of the metals solely depended on the plant's inherent controls.
柄花艾麻是南非当地社区食用的一种药用植物。鉴于其可口服，对其危害人体健康的可能性以及柄花艾麻叶片中金属含量随土壤特性的分布情况进行了评估。总体而言，土壤中金属浓度的递减顺序为：铁＞钙＞镁＞锰＞锌＞铬＞铜＞镍＞砷＞钴＞镉＞铅。采用低分子量有机酸、氯化钙和乙二胺四乙酸萃取法评估土壤中金属的可交换形态。地累积指数和富集因子表明，除镉外，所研究的大多数重金属均未受到污染或富集，在夸祖鲁 - 纳塔尔省的莫纳，镉显示出中度污染和显著富集。主成分分析和聚类分析表明，土壤中的砷、镉、铁和镍来自同一来源，而土壤中的铜、铅和锌则来自共同来源。相关性分析表明，土壤中的重金属砷、镉、铁和镍之间以及铜、铅和锌之间存在显著正相关，证实了这些金属的共同来源。植物和土壤中金属的浓度受地点影响，但金属的有效性和吸收仅取决于植物自身的调控。
