Barde Bate Garba, Adeleye Adeniyi Olanrewaju, Oladeji Amoo Afeez, Duhu Yunana Bitrus
Department of Environmental Sciences, Federal University Dutse, Jigawa State, Nigeria.
Department of Biological Sciences, University of Maiduguri, Borno State, Nigeria.
Environ Anal Health Toxicol. 2024 Jun;39(2):e2024016-0. doi: 10.5620/eaht.2024016. Epub 2024 Jun 7.
Heavy metals pollution and potential ecological risk index were assessed in artisanal gold mining areas of Zamfara state, Nigeria. Soil samples were collected from three mines namely Kwali (05°45.49'E-11°59.66'N), Duke (06°19.56'E-12°21.45'N) and Maraba (06°22.43'E-12°20.26'N) while a non-mining area; Kadauri (06°08.71'E-12°13.56'N) was also chosen as a control. Samples were analysed using atomic absorption spectrophotometer and the results obtained showed that; the most abundant metal was Pb (148.59 mg/kg) in Kwali and the least was Ni (1.25 mg/kg) in Kadauri while the metals generally occurred in the order; Pb > Fe > Au > Al > Zn followed by other metals in an unspecified manner. All metal concentrations differed significantly (P<0.05) across sampling stations except Mn and Zn and they were all above the WHO limit which portrays a health risk. A strong positive correlation was found between metal pairs with r ≥ 0.5 (*p<0.05) in about 70% of them indicating commonality of source. Pb, Cd, Al and Au had contamination factors > 1in all sampling locations indicating increment in their concentrations above the pre-anthropogenic activities reference levels. Geoaccumulation index showed concentrations above background values of Pb, Cd, Al and Au while potential ecological risk index was highest (782.79) in Kwali and lowest (142.15) in Kadauri. Two principal components accounted for about 99.64% of the total variation in metals concentration with PC1 (95.21%) and PC2 (4.43%). This study showed the influence of artisanal gold mining on heavy metals concentration and suggested regulation of these practices.
对尼日利亚赞法拉州手工金矿开采区的重金属污染和潜在生态风险指数进行了评估。从三个矿区采集了土壤样本，分别是夸利（东经05°45.49′-北纬11°59.66′）、杜克（东经06°19.56′-北纬12°21.45′）和马拉巴（东经06°22.43′-北纬12°20.26′），同时选取了一个非矿区；卡道里（东经06°08.71′-北纬12°13.56′）作为对照。使用原子吸收分光光度计对样本进行分析，所得结果表明；夸利含量最高的金属是铅（148.59毫克/千克），卡道里含量最低的金属是镍（1.25毫克/千克），而金属的一般出现顺序为；铅>铁>金>铝>锌，其次是其他未明确顺序的金属。除锰和锌外，各采样点的所有金属浓度均存在显著差异（P<0.05），且它们都高于世界卫生组织的限值，这表明存在健康风险。在约70%的金属对中发现了强正相关，相关系数r≥0.5（*p<0.05），表明来源具有共性。铅、镉、铝和金在所有采样点的污染因子均>1，表明它们的浓度高于人为活动前参考水平。地累积指数显示铅、镉、铝和金的浓度高于背景值，而潜在生态风险指数在夸利最高（782.79），在卡道里最低（142.15）。两个主成分占金属浓度总变异的约99.64%，主成分1（PC1，95.21%）和主成分2（PC2，4.43%）。本研究显示了手工金矿开采对重金属浓度的影响，并建议对这些开采活动进行监管。
