This study evaluates water quality, concentrations and health risks of heavy metals (HMs) in eight major lakes in Kenya namely Naivasha, Elementaita, Nakuru, Baringo, Bogoria, Turkana, Victoria and Magadi. Water quality was assessed using water quality index (WQI) and pollution evaluation index (PEI), while human health risk associated with ingestion and dermal contact of HMs was assessed using hazard quotients (HQ) and hazard index (HI). Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to deduce the probable sources of the HMs. The average concentration of aluminium (Al), molybdenum (Mo), manganese (Mn), nickel (Ni), arsenic (As), zinc (Zn), selenium (Se), lead (Pb), chromium (Cr), mercury (Hg), cobalt (Co) and cadmium (Cd) in the eight lakes was 824.6, 66.1, 58.9, 16.2, 8.40, 7.84, 6.91, 4.65, 2.66, 0.86, 0.78 and 0.46, respectively, all in μg/L. Al, Mn, As, and Mo were relatively high in Rift Valley lakes and exceeded the maximum permissible levels for drinking water. Notably, high HM concentrations were recorded at the entry points of rivers and areas with high human activities. Lake Magadi had the highest average WQI of 158.8 followed by lake Elementaita (128.4), Bogoria (79.5), Nakuru (73.3), Turkana (57.6), Victoria (52.3), Baringo (42.6) and Naivasha (25.5). Lake Magadi also had the highest average PEI of 40.0 followed by Elementaita (30.1), Bogoria (16.2), Nakuru (15.7), Victoria (10.8), Baringo (9.57), Turkana (9.53) and Naivasha (5.12). Based on WQI, Lake Naivasha water was excellent for drinking, Lake Victoria, Turkana, Baringo, Nakuru, and Bogoria had good water, but water from Lake Elementaita and Magadi was of poor quality. PEI classified the lakes as minimally polluted except Lake Magadi. Multivariate analysis concluded that Pb, Cr, Ni and Se had anthropogenic sources, mainly agricultural and urban runoff, but other HMs had natural influence. Although the HMs did not pose any health risks through dermal contact, HQingestion was >1 for adults and children consuming water from Lake Elementaita, Nakuru, Bogoria and Magadi due to non-carcinogenic risks associated with As, Zn and Mo. These results are important for formulating the necessary remediation policies to improve water quality in the eight lakes.

中文翻译：

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肯尼亚八个主要湖泊重金属的水质评估、多变量分析和人类健康风险。

该研究评估了肯尼亚八个主要湖泊（奈瓦沙、Elementaita、纳库鲁、巴林戈、博戈里亚、图尔卡纳、维多利亚和马加迪）的水质、重金属 (HMs) 浓度和健康风险。使用水质指数 (WQI) 和污染评价指数 (PEI) 评估水质，而使用危害商 (HQ) 和危害指数 (HI) 评估与摄入和皮肤接触 HMs 相关的人类健康风险。主成分分析（PCA）和层次聚类分析（HCA）被用来推断HMs的可能来源。铝（Al）、钼（Mo）、锰（Mn）、镍（Ni）、砷（As）、锌（Zn）、硒（Se）、铅（Pb）、铬（Cr）、汞的平均浓度(Hg)、钴(Co)和镉(Cd)在八个湖泊中分别为824.6、66.1、58.9、16.2、8.40、7.84、6.91、4.65、2.66、0.86、0。分别为 78 和 0.46，均为 μg/L。裂谷湖泊中的铝、锰、砷和钼含量相对较高，超过了饮用水的最大允许水平。值得注意的是，在河流入口点和人类活动频繁的地区记录到了高浓度的 HM。Magadi 湖的平均 WQI 最高，为 158.8，其次是 Elementaita 湖 (128.4)、Bogoria (79.5)、Nakuru (73.3)、Turkana (57.6)、Victoria (52.3)、Baringo (42.6) 和 Naivasha (25.5)。马加迪湖的平均 PEI 也最高，为 40.0，其次是 Elementaita (30.1)、Bogoria (16.2)、Nakuru (15.7)、Victoria (10.8)、Baringo (9.57)、Turkana (9.53) 和 Naivasha (5.12)。根据 WQI，奈瓦沙湖的水非常适合饮用，维多利亚湖、图尔卡纳、巴林戈、纳库鲁和博戈里亚的水水质良好，但 Elementaita 湖和马加迪湖的水水质较差。除了马加迪湖外，PEI 将这些湖泊列为污染程度最低的湖泊。多变量分析得出的结论是，Pb、Cr、Ni 和 Se 具有人为来源，主要是农业和城市径流，但其他 HMs 具有自然影响。尽管 HMs 不会通过皮肤接触造成任何健康风险，但由于与 As、Zn 和 Mo 相关的非致癌风险，成人和儿童饮用 Elementaita 湖、Nakuru、Bogoria 和 Magadi 水的 HQingestion 大于 1。这些结果很重要制定必要的整治政策以改善八个湖泊的水质。