This is the first comprehensive report on the accumulation of Cr, Ni, As, and Ag in the fish species Nile tilapia Oreochromis niloticus and Nile perch Lates niloticus from Lake Victoria, complemented with recent data on Cu, Zn, Cd, and Pb. This also is the first report on Cr, Ni, As, and Ag levels in invertebrates: the shrimp Caridina nilotica, gastropod Pila ovata, and bivalve Mutela bourguignati. The study was conducted at five sites in the Kenyan part of Lake Victoria: four sites in Winam Gulf influenced by various anthropogenic pressures, including a site near Kisumu City, and one in the main lake, with lesser direct anthropogenic influence. Apart from Cu and Ag, which were highest in O. niloticus liver, the invertebrates had higher levels of trace elements than fish. Contamination of the gulf with trace elements was best mirrored by the invertebrates, whose mobility is limited; they accumulated Cr, Cd, Ag, and Pb corresponding to the levels in the surface sediment. The accumulation of trace elements in fish species and their bioindicative potential corresponded to their habitats and feeding behaviour. The tissue contents of most trace elements were higher in the inshore-dwelling, omnivorous O. niloticus compared to the pelagic, piscivorous L. niloticus. Cu (465 ± 689 mg/kg dw) and Ag (3.45 ± 1.49 mg/kg dw) in the liver of O. niloticus were up to 10 and 119 times higher than in L. niloticus, respectively. Oreochromis niloticus therefore has bioindicative potential for Cu and Ag contamination. Both the invertebrates and fish showed positive correlations between Cu and Ag concentrations, indicating similar source and/or uptake route. The target hazard quotients (THQ) show that there is no human health risk associated with the consumption of these fish. However, the levels of Zn, Cd, and Pb in P. ovata surpassed maximum food safety limits and are hence potentially unsafe for human consumption.

中文翻译：

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维多利亚湖肯尼亚部分甲壳动物，软体动物和鱼类中的微量元素：生物蓄积，生物指示和健康风险分析。

这是关于维多利亚湖鱼类尼罗罗非鱼和尼罗河鲈鱼中Cr，Ni，As和Ag积累的第一份综合报告，并补充了有关Cu，Zn，Cd和Pb的最新数据。这也是关于无脊椎动物中Cr，Ni，As和Ag含量的第一份报告：虾Caridina nilotica，腹足纲Pila ovata和双壳类Mutela bourguignati。这项研究是在维多利亚湖肯尼亚部分的五个地点进行的：Winam海湾的四个地点受到各种人为压力的影响，包括基苏木市附近的一个地点和主湖中的一个地点，直接人为影响较小。除了在O.niloticus肝脏中含量最高的Cu和Ag外，无脊椎动物的微量元素含量也高于鱼类。无脊椎动物最能反映出海湾对微量元素的污染，无脊椎动物的活动受到限制。它们积累了对应于表层沉积物含量的Cr，Cd，Ag和Pb。鱼种中微量元素的积累及其生物指示潜力与其栖息地和摄食行为相对应。与浮游的食鱼性尼罗罗非鱼相比，近海杂食性O. niloticus中大多数微量元素的组织含量更高。尼罗罗非鱼肝脏中的铜（465±689 mg / kg dw）和银（3.45±1.49 mg / kg dw）分别比尼罗罗非鱼高10倍和119倍。因此，尼罗罗非鱼具有对铜和银污染的生物指示潜力。无脊椎动物和鱼类都显示出铜和银浓度之间的正相关，表示相似的来源和/或吸收途径。目标危害商（THQ）表明，食用这些鱼没有人类健康风险。但是，卵形假单胞菌中的Zn，Cd和Pb含量超过了最大食品安全极限，因此对于人类食用而言可能是不安全的。