This study investigates ecological consequences from the combined provenance (natural and manmade) of fifteen metal(oid)s (Na, Al, K, Ti, Cr, Mn, Co, Zn, As, Rb, Sb, Cs, Ba, Th, and U) from a major Indo-Bangla transboundary river (Teesta). Instrumental neutron activation analysis has been performed to calculate the elemental concentration for a total of thirty sediment samples which accumulated from the upper, middle and downstream section of the Teesta River. In comparison with the crustal origin Rb, Th, and U were 1.5–2.8 times elevated. Elements from upstream and midstream sediments showed greater spatial variability than those from downstream sediments in terms of Na, Rb, Sb, Th, and U. Statistical approaches suggested the dominance of geogenic sources (Na, K, Al, Ti, Co, and Ba) of elements over anthropogenic sources (Cr and Zn). Alkali feldspar and aluminosilicates release lithophilic minerals into the sediments under the redox condition (U/Th = 0.18). Site-specific ecotoxicological indices advocated that some specific locations are highly hazardous relative to Cr and Zn. From SQG-based guidelines, Cr showed higher potential toxicity in some upstream locations relative to Zn, Mn, and As. In order to attain the knowledge limitation of northern transboundary rivers from Bangladesh, this study of origin and relative environmental impact will be beneficial for policy makers.

中文翻译：

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调查孟加拉国提斯塔河沉积物中元素综合来源的指数和统计方法：沉积物质量和生态风险评估

本研究调查了 15 种金属（类）（Na、Al、K、Ti、Cr、Mn、Co、Zn、As、Rb、Sb、Cs、Ba、Th、和 U) 来自一条主要的印度-孟加拉跨界河流 (Teesta)。已进行仪器中子活化分析，以计算从提斯塔河上游、中游和下游段累积的总共 30 个沉积物样品的元素浓度。与地壳起源相比，Rb、Th 和 U 升高了 1.5-2.8 倍。上游和中游沉积物中的元素在 Na、Rb、Sb、Th 和 U 方面表现出比下游沉积物更大的空间变异性。统计方法表明地质源（Na、K、Al、Ti、Co 和 Ba）占主导地位) 超过人为来源的元素（Cr 和 Zn）。碱性长石和铝硅酸盐在氧化还原条件下（U/Th = 0.18）将亲石矿物释放到沉积物中。特定地点的生态毒理学指标主张某些特定地点相对于 Cr 和 Zn 具有高度危险性。根据基于 SQG 的指南，相对于 Zn、Mn 和 As，Cr 在某些上游位置显示出更高的潜在毒性。为了了解孟加拉国北部跨界河流的知识局限性，这项起源和相关环境影响的研究将有利于决策者。相对于 Zn、Mn 和 As，Cr 在某些上游位置显示出更高的潜在毒性。为了了解孟加拉国北部跨界河流的知识局限性，这项起源和相关环境影响的研究将有利于决策者。相对于 Zn、Mn 和 As，Cr 在某些上游位置显示出更高的潜在毒性。为了了解孟加拉国北部跨界河流的知识局限性，这项起源和相关环境影响的研究将有利于决策者。