Inorganic Geochemistry, Centre for Environmental Geochemistry, British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK.
School of Environmental Sciences, University of Eldoret, Eldoret, Kenya.
Environ Geochem Health. 2023 Aug;45(8):6137-6162. doi: 10.1007/s10653-023-01585-w. Epub 2023 Jun 2.
The impact of population expansion through economic growth and development has been identified as one of the key drivers of both water and sediment contamination from potentially harmful elements (PHEs). This presents a major hazard not only to aquatic ecosystems but local riparian communities and beyond who rely heavily on this natural resource for drinking water and fish-a valuable source of dietary micronutrients and protein. The present study measured biogeochemical concentration of PHEs in water, sediment and fish from locations pooled into four zones within Winam Gulf and Lake Victoria area of Kenya. Captured fish were used as a sentinel receptor of lake health to evaluate potential risks to fisheries and aquaculture food security. In water, concentrations of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu) and lead (Pb) were observed above the United States Environmental Protection Agency (US EPA) maximum contamination level drinking water guidelines (MCL), with aluminium (Al) observed above the Aquatic Life Criteria in all four zones. Similarly, sediment concentrations in all four zones exceeded the US EPA Effects range low (ERL) threshold guidelines for Cu, nickel (Ni), zinc (Zn) and Pb, with Cu, Zn and Pb classed at moderate contamination levels using the contamination factor. Fish tissue concentrations from the four zones were calculated using recommended daily intakes (RDI) and for PHEs as provisional maximum tolerable intakes (PMTIs) and indicated most macro- and micronutrients were at or below 10% RDI from aquaculture and wild fish, with Se indicating a greater RDI (16-29%) in all the zones. Contributions of PHEs to PMTIs were below threshold guidelines for both aquaculture and wild fish with only Cd, Cr and Pb levels being above the PMTI thresholds. There is a need to assess the long-term effects of persistent anthropogenic PHE input into Winam Gulf and the wider Lake Victoria basin. Continued monitoring of PHEs using both historical and more recent data will enable future management policies to be implemented through improved mitigation strategies to reduce their impact on water quality, fish health and subsequent human health.
人口增长通过经济增长和发展所带来的影响已被确定为导致潜在有害元素（PHEs）造成水和沉积物污染的关键驱动因素之一。这不仅对水生生态系统构成了重大危害，也对当地的河岸社区以及其他严重依赖这一自然资源获取饮用水和鱼类的地区构成了重大危害，因为鱼类是膳食微量营养素和蛋白质的宝贵来源。本研究对肯尼亚温亚马湾和维多利亚湖地区四个区域的水、沉积物和鱼类中的生物地球化学 PHE 浓度进行了测量。所捕获的鱼类被用作湖泊健康的哨兵受体，以评估对渔业和水产养殖粮食安全的潜在风险。在水中，砷（As）、镉（Cd）、铬（Cr）、铜（Cu）和铅（Pb）的浓度均高于美国环境保护署（USEPA）的最大污染饮用水水平指南（MCL），而在所有四个区域，铝（Al）的浓度均高于水生生物标准。同样，在所有四个区域，沉积物的浓度均超过了美国环境保护署的影响范围低值（ERL）阈值指南，用于铜、镍（Ni）、锌（Zn）和铅（Pb），其中 Cu、Zn 和 Pb 的污染程度被归类为中度污染，使用污染因子进行评估。使用建议的每日摄入量（RDI）和暂定最大耐受摄入量（PMTI）计算了四个区域的鱼类组织浓度，并表明来自水产养殖和野生鱼类的大多数宏量和微量元素均在 10%以下，所有区域的硒（Se）的 RDI 较高（16-29%）。水产养殖和野生鱼类的 PMTI 中 PHE 的贡献低于阈值指南，仅 Cd、Cr 和 Pb 的水平超过 PMTI 阈值。需要评估持久性人为 PHE 输入对温亚马湾和更广泛的维多利亚湖盆地的长期影响。通过使用历史数据和最近的数据持续监测 PHEs，将能够通过实施改进的缓解策略来减少它们对水质、鱼类健康和随后的人类健康的影响，从而实施未来的管理政策。
