The study determined the following heavy metals: cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), lead (Pb) and zinc (Zn) concentrations in surface water and in fish pond (water, sediments and farmed fish (Clarias gariepinus)) from a fish farm cluster with the view of assessing its pollution level and associated human health exposure risk to these heavy metals through fish consumption. Samples were digested with aqua regia and metal concentrations were determined with an atomic absorption spectrophotometer equipped with an air acetylene flame. Mean concentrations of the heavy metals (ppm) in surface and pond water ranged as follows: cadmium (below detection limit (bdl): 0.298); chromium (bdl: 0.257); copper (bdl: 0.067); manganese (bdl: 0.163); lead (bdl: 0.736) and zinc (bdl: 0.078) while in sediment, the ranges (mg/kg dry weight) were as follows: cadmium (1.156–3.329); chromium (9.439–14.373); copper (26.710–121.819); manganese (3.143–37.202); lead (0.340–1.537) and zinc (87.681–371.060). The mean concentrations of the metals in surface water were significantly different (p < 0.05) from those in sediment in all the sampling sites. The mean metal concentrations (mg/kg dry weight) in C. gariepnus were in the following ranges: cadmium (0.733–1.405); chromium (0.593–1.692); copper (175.882–245.321); manganese (bdl: 3.326); lead (0.221–0.263) and zinc (248.191–292.333). Some of the heavy metal concentrations obtained in water, sediment and catfish analyzed were above the permissible limit set by some National (DPR) and International organisations (WHO, FEPA and FAO). The pollution studies showed that lead, cadmium and chromium contaminated the surface water samples. Sediment from all sites showed low to considerable contamination by the heavy metals. The human exposure risk assessment of the metals showed that the total hazard index was less than one which indicates no probable adverse health effect from the consumption of fish from the ponds, although this case is different for Pb since there is no estimation of oral reference dose (RfDo) for lead according to EPA.

该研究确定了地表水和鱼塘（水、沉积物和养殖鱼（Clarias gariepinus)) 来自养鱼场集群，以评估其污染水平以及通过鱼类消费对这些重金属造成的相关人类健康暴露风险。用王水消解样品并用配备空气乙炔火焰的原子吸收分光光度计测定金属浓度。地表水和池塘水中重金属的平均浓度 (ppm) 范围如下：镉（低于检测限 (bdl)：0.298）；铬（bdl：0.257）；铜（bdl：0.067）；锰（bdl：0.163）；铅（bdl：0.736）和锌（bdl：0.078），而在沉积物中，范围（mg/kg干重）如下：镉（1.156-3.329）；铬 (9.439–14.373); 铜 (26.710–121.819); 锰 (3.143–37.202); 铅 (0.340–1.537) 和锌 (87.681–371.060)。p < 0.05）来自所有采样点的沉积物中。C. gariepnus中的平均金属浓度（mg/kg 干重）处于以下范围内：镉（0.733–1.405）；铬 (0.593–1.692); 铜 (175.882–245.321); 锰（bdl：3.326）；铅 (0.221–0.263) 和锌 (248.191–292.333)。在分析的水、沉积物和鲶鱼中获得的一些重金属浓度高于一些国家 (DPR) 和国际组织 (WHO、FEPA 和粮农组织) 设定的允许限值。污染研究表明，铅、镉和铬污染了地表水样本。所有地点的沉积物都显示出重金属的低至相当程度的污染。金属的人体暴露风险评估表明，总危害指数小于 1，表明食用池塘中的鱼不会对健康造成不利影响，