Kebede Mathewos Temesgen, Geleta Lemi
Department of Biology, College of Natural Sciences, Ambo University, Ambo, Ethiopia.
Adea Berga District Environment, Forest and Climate Change Authority Office, Adea Berga, Ethiopia.
Heliyon. 2023 Mar 14;9(3):e14560. doi: 10.1016/j.heliyon.2023.e14560. eCollection 2023 Mar.
Heavy metal pollution is a serious problem in Ethiopian rift valley lakes, including Lake Koka, as a result of unmanaged industrial waste pollution. However, the bioaccumulation level in common carp (), a commercially important fish species, are unknown. The aim of this research was, therefore, to assess the heavy metal bioaccumulation in edible parts of common carp in Lake Koka and the associated health risks. Three sampling sites were selected randomly for primary data collection. Four heavy metals (Cd, Cr, Pb and Zn) were analyzed in water and the edible part of the fish using Atomic Absorption Spectroscopy (AAS). The mean concentrations of Zn, Cr and Cd in the edible part of fish ranged from 0.07 to 0.36 mg kg, Not Detected (ND)-0.24 mg kg and ND-0.03 mg kg, respectively. Site 2 had the highest Zn and Cd content, while Site 3 had the highest Cr content. Pb was however not identified. The amount of Cr was above the permissible limit of FAO and the bioaccumulation showed marked differences among the sampling sites (p < 0.05). The concentrations of Cd, Pb and were below the maximum permissible limit. Cr and Zn had the highest and lowest transfer factor values, respectively. The carcinogenic hazard ratio values were below the threshold value (<1). The estimated weekly intake of heavy metals from fish muscles ranked as Cr > Zn > Cd, but the values were lower than the Reference Dose limit (RfDo). The carcinogenic risk value also indicated a low health risk associated with individual metals intake. Furthermore, the hazard index of the edible part of fish was less than unity. Generally, the water quality is not a risk for the survival and reproduction of fish and the heavy metal contents in the edible parts of fish exhibited low carcinogenic risk through the food chain.
由于工业废物污染管理不善，重金属污染在包括科卡湖在内的埃塞俄比亚裂谷湖是一个严重问题。然而，商业上重要的鱼类品种鲤鱼体内的生物累积水平尚不清楚。因此，本研究的目的是评估科卡湖鲤鱼可食用部分的重金属生物累积情况以及相关的健康风险。随机选择了三个采样点进行原始数据收集。使用原子吸收光谱法（AAS）分析了水中和鱼的可食用部分中的四种重金属（镉、铬、铅和锌）。鱼的可食用部分中锌、铬和镉的平均浓度分别为0.07至0.36毫克/千克、未检出（ND）至0.24毫克/千克和ND至0.03毫克/千克。2号采样点的锌和镉含量最高，而3号采样点的铬含量最高。然而，未检测到铅。铬的含量高于粮农组织的允许限量，且生物累积在各采样点之间存在显著差异（p<0.05）。镉、铅的浓度低于最大允许限量。铬和锌的转移因子值分别最高和最低。致癌风险比数值低于阈值（<1）。从鱼肌肉中估计的重金属每周摄入量排序为铬>锌>镉，但这些数值低于参考剂量限值（RfDo）。致癌风险值也表明与个体金属摄入量相关的健康风险较低。此外，鱼可食用部分的危害指数小于1。总体而言，水质对鱼类的生存和繁殖没有风险，鱼可食用部分中的重金属含量通过食物链表现出较低的致癌风险。
