This paper reports concentrations of γ-emitter radionuclides (40K, 137Cs, 210Pb, 226Ra, 228Ra, 228Th and 234Th) and some metals (Al, Cr, Fe, Co, Ni, Cu, Zn, As, Sr, Cd, Sb, Cs, Pb, Th and U) in surficial sediments from the Ankobra, Pra and Volta estuaries, in Ghana. Artisanal gold-mining in the Ankobra and Pra basins promoted moderate enrichments of As, Sb, Cu, Cs and Cr in their estuarine sediments, with respect to the reference background of the Volta Estuary. Radionuclide concentrations were in the range found in the Earth's crust. Present data do not support any conclusion on their potential enrichments due to gold-mining activities. Radionuclide isotopic ratios revealed a transfer of 228Ra from sediments to the water column. Pearson correlation coefficient matrices showed different patterns, which were reasonably understood after novel approaches: i) inter-estuaries comparison of slopes in the linear regressions of element-concentrations vs Al, Fe and Cs; ii) study of Al-normalized concentrations of elements; iii) excess 210Pb informing on local sedimentary conditions. The metal enrichments observed in the Ankobra and Pra estuaries are associated with the Fe-rich compounds in sulphide ores (such as FeAsS) transported along the river course and deposited in the estuary.

中文翻译：

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加纳（赤道非洲）河口系统表层沉积物中的环境放射性和微量金属，受到手工金矿的影响。

本文报告了γ发射体放射性核素（40K，137Cs，210Pb，226Ra，228Ra，228Th和234Th）和某些金属（Al，Cr，Fe，Co，Ni，Cu，Zn，As，Sr，Cd，Sb，加纳Ankobra，Pra和Volta河口表层沉积物中的Cs，Pb，Th和U）。相对于伏尔塔河口的参考背景，安科布拉和Pra盆地的手工金矿开采促进了河口沉积物中砷，锑，铜，铯和铬的适度富集。放射性核素的浓度在地壳中发现的范围内。目前的数据并不支持有关由于金矿开采活动而导致的潜在富集的任何结论。放射性核素的同位素比表明228 Ra从沉积物中转移到水柱中。皮尔逊相关系数矩阵显示出不同的模式，通过新颖的方法得到了合理的理解：i）在元素浓度对Al，Fe和Cs的线性回归中，河口间坡度的比较；ii）研究Al标准化元素的浓度；iii）过量的210Pb告知当地的沉积条件。在安科布拉和普拉河口中观察到的金属富集与沿河道运输并沉积在河口中的硫化矿石（例如FeAsS）中的富铁化合物有关。