Evaluation of Heavy Metal Accumulation in Fish from Nguru LGA, Yobe State, Nigeria

Abstract

This study aimed to determine heavy metal contents in the fish of Nguru Local Government Area (LGA), Yobe State, Nigeria, and assess the potential health risks associated with their consumption. The work seeks to enhance public health awareness and promote environmental sustainability in the region. Heavy metals, including Lead, Cadmium, Chromium, Arsenic, and Copper, pose significant threats to aquatic ecosystems and human health. The study used a descriptive experimental design and collected fish samples from major fishing sites within the Hadejia-Nguru Wetlands.  A total of nine samples of common edible fish species, including African arowana, Tilapia, and Catfish, were analyzed for heavy metal concentrations using Atomic Absorption Spectrophotometry (AAS). Significant findings of environmental contamination and the accompanying health risks were highlighted. All three fish species contained varied amounts of heavy metals. Surprisingly, all of the samples contained very high levels of lead, cadmium, and copper, exceeding the World Health Organization (WHO) and Food and Agriculture Organization (FAO) permissible limits. Arsenic and chromium were found to be within permitted limits. The catfish had the highest lead content, followed by the African Arowana and the Tilapia. African Arowana had the greatest levels of cadmium, followed by Tilapia and Catfish.  Similarly, Tilapia has a greater copper level than Catfish and African Arowana. The findings raised major concerns regarding neurological and renal health risks for consumers, particularly in that region of the country, which is presently one of the epicenters for chronic kidney disease. The findings highlight the urgent need for regular monitoring of heavy metal levels in aquatic habitats, as well as the implementation of stronger industrial discharge laws and the promotion of ecologically friendly agricultural practices.