Spatial-Temporal Variations of Inorganic Contaminants and Associated Risks for Sediment of Felent Stream Basin Flowing Along with Silver Mines in the Midwestern Türkiye

Abstract

The Kütahya Silver Mine, located in the Felent Stream Basin, stands as Türkiye’s silver production site. Additionally, thermal tourism facilities in the upstream region are also degrading water quality of Felent Stream. This study meticulously examined the levels and spatial-temporal variations of 18 potentially toxic elements (PTEs) in the sediments of the Felent Stream Basin and evaluated their ecotoxicological risks during dry and wet seasons. The average sediments contamination levels of PTEs were ranked as follows: Fe > Al > Zn > Mn > Sr > Pb > Ba > Ni > Cu > As > Cr > V > Cd > Co > Sb > Se > Hg. Remarkably, during the wet season, sediment samples revealed an approximate threefold surge in the average concentrations of PTEs. Ecological risk assessment indicators highlighted that the basin experienced low pollution levels in the dry season, escalating to moderate pollution levels during the wet season. Non-carcinogenic risks for studied PTEs and carcinogenic risks for As remained below the threshold values in both seasons. Statistical analyses pinpointed the Yoncalı District, a prominent thermal tourism area, as the primary contributor to the sediment contamination of the Felent Stream Basin. The Enne Dam Lake, the region’s main stagnant water body, emerged as the least contaminated component, functioning as a natural filter for the basin and significantly mitigating the levels of PTEs in the sediment.