Rincon-Vasquez Ingrid Vanessa, Fohrer Nicola, Rosado Daniel
Department of Hydrology and Water Resources Management, Institute for Natural Resource Conservation, Kiel University, 24118, Kiel, Germany.
Department of Chemical and Environmental Engineering, Higher Technical School of Engineering, Universidad de Sevilla, Camino de los Descubrimientos s/n, 41092, Seville, Spain.
Environ Geochem Health. 2025 May 22;47(6):222. doi: 10.1007/s10653-025-02536-3.
Heavy metal toxicity risk assessments in sediments often rely on pseudototal concentrations, despite the higher theoretical predictive potential of bioavailable fractions. This study introduces the Bioavailable Fraction Toxicity Factor (BTf) and the Bioavailable Fraction Toxicity Index (BTI) to evaluate metal toxicity risks using a bioavailable fraction calculated as the sum of the first two steps of the Tessier sequential extraction procedure. Investigating heavy metal pollution (Cd, Cr, Cu, Mn, Ni, Pb, Zn) in the Vetas River catchment, a critical freshwater source in the Santurbán Páramo within the Tropical Andes biodiversity hotspot, the study identified artisanal and small-scale mining as the primary driver of contamination. Water and sediment of mining areas, particularly La Baja Creek and El Volcán Village, exhibited the highest concentrations of metals, with some sediment levels being categorized as strongly contaminated by the Geoaccumulation Index and Pollution Load Index and exceeding the Probable Effect Concentration threshold. Bioavailable fraction of metals in sediments were measured. Bioavailable fractions were higher in mining-affected areas, suggesting greater potential for metal release under acidic conditions. The BTf and BTI provided a more nuanced understanding of metal toxicity risks compared to pseudototal concentrations, with higher BTI values in mining-influenced sites. These findings underscore the need for mitigation measures to address heavy metal pollution and highlight the ecological importance of the Santurbán Páramo. Further research into bioremediation potential using local flora is recommended to support sustainable management practices.
沉积物中的重金属毒性风险评估通常依赖于伪总浓度，尽管生物可利用部分具有更高的理论预测潜力。本研究引入生物可利用部分毒性因子（BTf）和生物可利用部分毒性指数（BTI），以使用通过Tessier连续萃取程序的前两步之和计算得出的生物可利用部分来评估金属毒性风险。在热带安第斯生物多样性热点地区桑图尔班帕拉莫的关键淡水水源韦塔斯河流域调查重金属污染（镉、铬、铜、锰、镍、铅、锌）时，该研究确定个体和小规模采矿是污染的主要驱动因素。矿区的水和沉积物，特别是拉巴哈溪和埃尔火山村，金属浓度最高，一些沉积物水平根据地积累指数和污染负荷指数被归类为重度污染，并且超过了可能效应浓度阈值。测量了沉积物中金属的生物可利用部分。受采矿影响地区的生物可利用部分较高，表明在酸性条件下金属释放的潜力更大。与伪总浓度相比，BTf和BTI对金属毒性风险提供了更细致入微的理解，在受采矿影响的地点BTI值更高。这些发现强调了采取缓解措施应对重金属污染的必要性，并突出了桑图尔班帕拉莫的生态重要性。建议进一步研究利用当地植物进行生物修复的潜力，以支持可持续管理实践。
