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Studies have emphasized that the presence of heavy metals in freshwater fish represents a global public health issue. Nigeria, being a developing nation with less emphasis on the quality of seafood consumed by the residents, ranks this study very vital. The policy implication of this study is the advancement of a healthy population in contemporary Nigeria. Hence, this study assessed heavy metal concentration in two fish species, Clarias gariepinus (Catfish) and Oreochromis niloticus (Nile Tilapia), in the Anambra River. The sample included twenty fishes, of which eighteen were collected from the three sampling locations (the fish ports of Anambra River), namely Otu-nsugbe, Otuocha, and Ikemivite) while two control samples were collected from a pond about 200 m away from the river. The levels of heavy metals were determined using Varian AA 240 atomic absorption spectrophotometer (AAS). The results showed that the concentrations of heavy metals (cadmium and arsenic) in the sampled fishes from Anambra River exceeded the joint World Health Organization and Food and Agriculture Organization (FAO/WHO) standard for fish and fish product consumption, while the concentration of chromium, mercury, and lead are within the permissible limit. The study also showed the distribution of the heavy metals in the fish organ varies among fish species. Heavy metals occur higher in Clarias garepinus than in Oreochromis niloticus, while tissue preference for heavy metal accumulation is in the order of gill > liver > muscle. It was recorded from this study that the heavy metal concentration in the fish from the pond is generally higher than the fish from the river for some metals. The high level of heavy metals in the sampled fish was attributed to heavy metals contamination of the river as a result of various anthropogenic activities such as mining, burning of fossil fuel and emission from the exhaust of boats/vehicles, overuse of fertilizers and pesticides, discharge of effluent, sewage, and hospital waste. This study concluded that long-term consumption of fish from the river may pose health risks to the consumers due to the possible bioaccumulation of heavy metals, especially cadmium and arsenic. It was recommended that continuous monitoring of heavy metal levels in the fish and water, public awareness, and appropriate legislative provisions should be put in place to ensure that harvested fish and fish products may be safe for human consumption. [ABSTRACT FROM AUTHOR]

The occurrence of heavy metals in soil and selected edible plants (Manihot esculenta, Dioscorea rotundata, Ipomoea batatas, Telfairia occidentalis, and Chromolaena odorata) in the vicinity of major Lead-Zinc mining sites in Ebonyi State, Nigeria was investigated. The concentrations of the detected heavy metals in soil from the study sites ranged from 0.38-77830.99 (mg.kg-1). The limit values for all detected metals in soil from the mining sites were exceeded in most instances. The results showed that the plant species accumulated heavy metals near the mining sites to varying levels in their shoots and roots. The limit values for all detected heavy metals in the edible plants were not exceeded except in a few instances. The plant species demonstrated varying effectiveness for phytoextraction, indicating their appropriateness in the phytoremediation of heavy metal-contaminated soil. Therefore, examining the environmental consequences of uncontrolled mining activity in the vicinity of the mining sites with a scientific approach has helped to increase our knowledge of the pollution problem in the mining sites, reveal the ferocity of the situation, and contribute to the techniques presently in use for monitoring chemical pollution in a mining-impacted ecosystem. [ABSTRACT FROM AUTHOR]