Department of Pure and Applied Chemistry, Masinde Muliro University of Science and Technology, Kakamega, Kenya.
Centre of Excellence in Water and Environmental Resource Management (CEWERM), Masinde Muliro University of Science and Technology, Kakamega, Kenya.
Environ Monit Assess. 2019 Oct 16;191(11):646. doi: 10.1007/s10661-019-7858-5.
A major ecological challenge facing freshwater resources such as rivers is the influx of chemical contaminants from anthropogenic sources. A report on the levels of heavy metals, namely Zn, Cu, Cr, Cd and Pb in benthic macroinvertebrates, sediments and water along River Isiukhu, within Lake Victoria catchment area in Kenya is presented. Families of benthic macroinvertebrates that were investigated included Gerridae, Baetidae and Unionidae. Samples were digested using the appropriate acid combination and analysed using Spectra AAS Varian 200. Physicochemical parameters were measured on-site using mobile Hydrolab Quanta. Pearson's correlation matrix and post hoc Tukey's test were used to show the relationship between metal concentrations in the various matrices at significant differences accepted at p ≤ 0.05. Positive correlations were obtained for heavy metal concentrations in sediments and benthic macroinvertebrates with significant correlations observed for Zn (r = 0.655, p = 0.029) and Cu (r = 0.641, p = 0.034). Sediments presented the highest range of heavy metal concentrations compared to water and benthic macroinvertebrates and presented the only matrix with quantifiable Pb levels. The range in heavy metal concentration in benthic macroinvertebrates samples were as follows: Zn, 30.73-46.64, 21.93-38.17, and 26.85-41.69 mg/kg, Cu, 1.17-6.54, 1.11-3.87 and 1.15-5.79 mg/kg, Cr, 0.47-1.61, 0.22-0.74 and 0.25-0.92 mg/kg, for families Unionidae, Baetidae and Gerridae respectively. Heavy metal concentration profile along the river indicated an influx of pollutants from anthropogenic sources due to rapid urbanization along the river.
河流等淡水资源面临的一个主要生态挑战是人为来源的化学污染物的涌入。本文介绍了肯尼亚维多利亚湖集水区伊西乌库河的底栖大型无脊椎动物、沉积物和水中重金属（锌、铜、铬、镉和铅）水平的报告。调查的底栖大型无脊椎动物科包括 Gerridae、Baetidae 和 Unionidae。使用适当的酸组合对样品进行消解，并使用 Spectra AAS Varian 200 进行分析。使用移动 Hydrolab Quanta 在现场测量理化参数。使用 Pearson 相关矩阵和事后 Tukey 检验显示各种基质中金属浓度之间的关系，显著差异接受 p ≤ 0.05。在沉积物和底栖大型无脊椎动物中观察到重金属浓度之间存在正相关，锌（r = 0.655，p = 0.029）和铜（r = 0.641，p = 0.034）之间存在显著相关性。与水和底栖大型无脊椎动物相比，沉积物中的重金属浓度范围最高，并且是唯一具有可量化 Pb 水平的基质。底栖大型无脊椎动物样本中的重金属浓度范围如下：Zn，30.73-46.64，21.93-38.17，和 26.85-41.69 mg/kg，Cu，1.17-6.54，1.11-3.87 和 1.15-5.79 mg/kg，Cr，0.47-1.61，0.22-0.74 和 0.25-0.92 mg/kg，分别为 Unionidae、Baetidae 和 Gerridae 家族。河流沿线的重金属浓度分布表明，由于河流沿岸的快速城市化，人为来源的污染物大量涌入。
