Akoto Osei, Yakubu Salome, Ofori Linda A, Bortey-Sam Nesta, Boadi Nathaniel O, Horgah Jonathan, Sackey Lyndon N A
Departmentof Chemistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Heliyon. 2023 Jan 6;9(1):e12661. doi: 10.1016/j.heliyon.2022.e12661. eCollection 2023 Jan.
Mining generates large volumes of waste, which if not regulated can release toxic metals, causing widespread environmental contamination. This study focused on heavy metal contamination in topsoil within a mining area at Nangodi in the Northern Region of Ghana. A total of 24 soil samples were collected from the study area and control samples were analyzed for Hg, Pb, Cd, As, Cr, and Fe using atomic absorption spectroscopy. Results of Pollution Index estimations and Geo-accumulation index (Igeo) classified the soil samples as moderately contaminated to heavily contaminated. Soil samples were severely enriched with As and moderately enriched with b, and Hg. Multivariate analyses such as factor analysis and cluster analysis were employed to examine the relationship between the metals and also differentiate the influence of the natural background content of metals from that due to human activities. Factor analysis identified three polluted soil factor associations. Cadmium, Fe, As, and Pb associated with factor 1, were due to anthropogenic activities. The high intercorrelation revealed by As and Pb shows similarity in their sources. Factor two dominated by Hg is considered an anthropogenic component. Factor 3 correlated with Cr and can be considered a natural component. Correlation analysis and cluster analysis supported each other. Results from the bi-plots showed that sites S1, S8, S11, and S18, have similar metal composition as the control site. Heavy metal contents in soils sampled from Zones A and B have been influenced by the mining activities as seen from the associations of these sites in the bi-plots. The results are useful for metal source identification, and can contribute to monitoring and regulatory programs.
采矿产生大量废弃物，若不加以管控，这些废弃物会释放有毒金属，造成广泛的环境污染。本研究聚焦于加纳北部地区南戈迪一个矿区表层土壤中的重金属污染情况。从研究区域共采集了24个土壤样本，并采集了对照样本，采用原子吸收光谱法分析其中汞、铅、镉、砷、铬和铁的含量。污染指数估算结果和地累积指数（Igeo）将土壤样本分类为中度污染至重度污染。土壤样本中砷严重富集，硼和汞中度富集。采用因子分析和聚类分析等多变量分析方法来研究金属之间的关系，并区分金属自然背景含量的影响与人类活动造成的影响。因子分析确定了三个污染土壤因子组合。与因子1相关的镉、铁、砷和铅是由人为活动造成的。砷和铅之间的高相关性表明它们来源相似。以汞为主的因子2被认为是人为成分。与铬相关的因子3可被视为自然成分。相关性分析和聚类分析相互印证。双标图结果显示，S1、S8、S11和S18位点的金属组成与对照位点相似。从双标图中这些位点的关联可以看出，从A区和B区采集的土壤中的重金属含量受到了采矿活动的影响。这些结果有助于识别金属来源，并可为监测和监管计划提供参考。
