Gbogbo Francis, Otoo Samuel D, Huago Robert Quaye, Asomaning Obed
Department of Animal Biology and Conservation Science, University of Ghana, P. O. Box LG 67, Legon, Accra, Ghana.
Environ Sci Pollut Res Int. 2017 Feb;24(6):5619-5627. doi: 10.1007/s11356-016-8309-2. Epub 2016 Dec 29.
Crustaceans, mollusks, and fish are wetland resources that constitute an important source of protein and foreign exchange for the Ghanaian population, and many species of these are sold in the open market and restaurants, yet studies on their heavy metal contents are generally scarce. This paper evaluates the levels of mercury in five species of crustaceans, two species of mollusks, and ten species of fish inhabiting three river basins with different catchment activities in Ghana. These include the Ankobra Basin, characterized with mining and agriculture, Densu Basin, associated with urban waste discharges and agriculture, and Lower Volta River Basin, associated with agricultural activities. Mercury concentration was highest in Ankobra (2.5 ± 2.59 μg g) followed by Densu (1.75 ± 1.35 μg g) and Volta (0.74 ± 1.46 μg g). The mercury load of the organisms range from <0.1 to 4 μg g with the highest load in Cynoglossus senegalensis at Ankobra. Except for Panaeus notialis from Densu and Ankobra, and three other species from Ankobra (Tympanotonus fuscatus, Cardisoma armatum, Callinectes amnicola) in which mercury was not detected, mercury loads of all the organisms were above the permissible limit of 0.5 mg kg established by Commission Regulation-EC (2006) for fishery products and muscle meat of fish. Weekly quantities of crustaceans and mollusks considered safe for consumption by adults ranged from 88 and 1000 g while that of the fishes were between 70 and 700 g (on a dry weight basis) depending on the species. It was clear that some caution needs to be exercised in the consumption of Ghana's fresh and brackish water fisheries.
甲壳类动物、软体动物和鱼类是湿地资源，是加纳人口重要的蛋白质来源和外汇来源，这些物种中有许多在露天市场和餐馆出售，但对它们重金属含量的研究普遍较少。本文评估了加纳三个流域中具有不同集水活动的五种甲壳类动物、两种软体动物和十种鱼类中的汞含量。这些流域包括以采矿和农业为特征的安科布拉河流域、与城市污水排放和农业相关的登苏河流域以及与农业活动相关的沃尔特河下游流域。汞浓度在安科布拉最高（2.5±2.59μg/g），其次是登苏（1.75±1.35μg/g）和沃尔特（0.74±1.46μg/g）。生物体的汞含量范围为<0.1至4μg/g，在安科布拉的塞内加尔舌鳎中含量最高。除了来自登苏和安科布拉的诺氏对虾以及来自安科布拉的其他三个物种（暗带笋螺、武装豆蟹、河生美青蟹）未检测到汞外，所有生物体的汞含量均高于欧盟委员会法规（2006年）规定的渔业产品和鱼肉0.5mg/kg的允许限量。成年人每周食用安全的甲壳类动物和软体动物的量分别为88至1000克，鱼类为70至700克（以干重计），具体取决于物种。显然，食用加纳的淡水和咸水渔业产品时需要谨慎。
