Comprehensive Multi-Element and Isotopic Evaluation of Surface Water Quality in the Prestea Catchment, Ghana

Sammanfattning

Artisanal small-scale mining (ASM) significantly contributes to water pollution in many regions of the world, including the Prestea area in Ghana. This study comprehensively evaluates the surface water quality in the Asasre River, Prestea, a tributary of the Ankobra River, heavily impacted by ASM activities. The primary objectives were to analyse the distribution of trace elements, investigate isotopic fractionations of iron and lead, and assess the influence of ASM on rare earth elements and their anomalies. Water samples were collected in a sampling campaign conducted in November 2023. The samples were analysed in Sweden for concentrations of metals such as iron, arsenic, mercury,and rare earth elements. Isotopic ratios of iron and lead were analysed to trace contamination sources and environmental processes. The results revealed elevated concentrations of heavy metals, particularly arsenic and iron, near mining activities. Isotopic fractionation patterns indicated the influence of mining operations and natural processes on the distribution of iron and lead. Rare earth element anomalies, including negative cerium and europium anomalies,were also observed, suggesting altered redox conditions caused by ASM activities. The findings underscore the severe environmental impact of ASM on surface water quality inthe Prestea area, which could have long-term consequences for ecosystems and human health.This study highlights the need for improved environmental regulations and sustainable mining practices. Future research should focus on seasonal variations, sediment analysis, andexpanding the geographic scope to better understand ASM’s impact on water systems in Ghanaand West Africa.