Heavy Metal Bioaccumulation in Wallago attu from Peshawar: A Public Health Risk Assessment

Abstract

Heavy metals are defined as any metallic element that is toxic or harmful at low concentrations and have an atomic weight greater than 40 and a sufficiently high density between 3.5 and 7 g/cm3. Aquatic ecosystems and human health are under great risk due to the substantial human-caused contamination of aquaculture systems and the environment with heavy metals. The purpose of this study was to determine the levels of heavy metals present in various organs- including intestine, liver, muscles and gills of freshwater fish Mulley (Wallago attu) that were purchased at the Board Bazar, a local fish market in Peshawar, Khyber Pakhtunkhwa, Pakistan as well as the potential health concerns to humans. In the current study, three samples (n=3) of Wallago attu have been collected from the local fish market (board bazaar) in Peshawar, Khyber Pakhtunkhwa, Pakistan to determine the accumulation of the Ni, Cd, Zn and Pb in key organs (gills, Liver, Intestine and muscles) by employing Atomic Absorption Spectrometry (AAS. To assess the health implications for both fish and humans, bioaccumulation factors and health assessments were performed. The findings revealed elevated concentrations particularly in the muscles and liver, the trend was Pb > Zn > Ni > Cd. On the other hand, gills show Zn > Ni > Pb > Cd trend and intestine shows Zn > Pb> Ni > Cd trend. Zinc was found to be the most bioaccumulated metal, while Cadmium had the minimum concentration across all the studied organs of Wallago attu. Muscles were the target organ for Ni, Cd, and Pb accumulations. Zn, however, exhibited higher concentration in the gills. Results indicated that elements accumulated in the tissues of Wallago attu typically didn’t surpass WHO/FAO recommendations maximum allowable level and implying no contamination and less potential risk to humans. However, it is recommended that heavy metals be continuously monitored to guarantee the safety and health of human consumption.