State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, People's Republic of China.
Department of Lake Research, UFZ-Helmholtz Centre for Environmental Research, 39114, Magdeburg, Germany.
Environ Monit Assess. 2022 Sep 9;194(10):756. doi: 10.1007/s10661-022-10452-7.
The distribution of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn and their fraction characteristics (except Hg) were investigated in surface sediments of the Mwanza Gulf, Lake Victoria. The ecological risks, bioavailability, and mobility of the metals were also evaluated by using enrichment factor (EF), contamination factor (C), geo-accumulation index (I), potential ecological risk index (RI), risk assessment code (RAC), individual contamination factor (ICF), and global contamination factor (GCF). Results showed that there were moderate accumulations of heavy metals in sediments from the southern part of the gulf. The mean C of heavy metals ranged from 1.19 (Ni) to 2.85 (Hg) suggesting moderate contamination of heavy metals in the sediments while I results showed that the sediments are mainly contaminated by As, Cr, and Hg. The average potential ecological risk of heavy metals in sediments of the Mwanza Gulf is at moderate level (RI 205.49). Hg and Cd posed considerable or moderated risks with mean ecological risk of 114.18 and 44.16, which accounted for 51.08% and 21.54% of the total RI, respectively. High bioavailability and mobility of heavy metals were found in sediments near Mwanza city, particularly Zn and Cd, of which the bioavailability risks were at medium to high levels. Given the biological and environmental importance of the Mwanza Gulf and Lake Victoria, emission paths and bioaccumulation of heavy metals through food webs should be studied carefully to ensure the safety of food and the health and well-being of humans.
本研究调查了维多利亚湖姆万扎湾表层沉积物中砷（As）、镉（Cd）、铬（Cr）、铜（Cu）、汞（Hg）、镍（Ni）、铅（Pb）和锌（Zn）的分布及其分馏特征（Hg 除外）。利用富集因子（EF）、污染因子（C）、地积累指数（I）、潜在生态风险指数（RI）、风险评估码（RAC）、个体污染因子（ICF）和全球污染因子（GCF）评价了这些金属的生态风险、生物可利用性和迁移性。结果表明，海湾南部沉积物中重金属存在中度累积。重金属的平均 C 值范围为 1.19（Ni）至 2.85（Hg），表明沉积物中重金属受到中度污染，而 I 值表明沉积物主要受到 As、Cr 和 Hg 的污染。姆万扎湾沉积物中重金属的平均潜在生态风险处于中等水平（RI 205.49）。Hg 和 Cd 构成了相当大或中等的风险，其平均生态风险分别为 114.18 和 44.16，分别占总 RI 的 51.08%和 21.54%。在姆万扎市附近的沉积物中发现重金属具有较高的生物可利用性和迁移性，尤其是 Zn 和 Cd，其生物利用风险处于中等到高水平。鉴于姆万扎湾和维多利亚湖的生物学和环境重要性，应仔细研究重金属通过食物网的排放途径和生物累积，以确保食物安全以及人类的健康和福祉。
