Assessment of Heavy Metals Content in Three Commercial Fish Feeds Found Within Awka Metropolis

Abstract

The study investigated the concentration of heavy metals in fish sold across selected Nigerian markets, focusing on public health implications and environmental safety. Fish is a major source of protein and essential nutrients for a vast majority of Nigerians, yet increasing industrialization, poor waste management and agricultural runoff have led to the contamination of aquatic ecosystems. The sample size was made up of three popular and commercially available fish feed brands in Awka metropolis, namely Pellet, Coppen, and Multi feeds. The samples underwent a wet digestion procedure before testing for heavy metal levels, specifically lead (Pb), cadmium (Cd), copper (Cu), iron (Fe), and chromium (Cr) concentrations. These results were then compared to the World Health Organization (WHO) safety standards. Cadmium and lead which are bio-accumulative and toxic had very minimal concentrations in all three feed samples, with Pellet feed showing the highest Cd level of 0.016 mg/kg and Multi feed showing the highest Pb level of 0.149 mg/kg, but the levels were still well below the WHO standard for Cd (0.050 mg/kg) and Pb (0.300 mg/kg). While Cu and Fe which are essential micronutrients had varying levels but were still under the maximum limit set by WHO. Notably, Cr was undetectable in all samples, prompting questions about nutritional adequacy. Overall, the feeds complied with international safety limits, yet the presence of Pb and absence of Cr underscore the need for improved quality control and nutritional optimization.