Bioaccumulation of selected toxic heavy metals in mastacembelus armatus from three rivers of Malakand division, Pakistan

Abstract

Contamination of water bodies with toxic heavy metals is a genuine environmental problem. Bioaccumulation of toxic heavy metals in fish poses a potential health risk to fish consumers including humans. The aim of present research work was to study the bioaccumulation of Cr, Ni, Cd and Pb in the carnivorous fish Mastacembelus armatus at different sites of three rivers in Malakand Division, Pakistan. The study also investigated tissue-specific accumulation of these metals in M. armatus at one site of River Panjkora. Concentrations of Cr, Ni, Cd and Pb in the fish muscles ranged from 10.2 ± 3.5 to 29.8 ± 17.3, 24.7 ± 13.1 to 104.5 ± 27.1, 0.77 ± 0.17 to 2.4 ± 0.12 and 7.5 ± 5.3 to 75.2 ± 41.0 mg kg−1 wet weight, respectively. The order of metal accumulation in different tissues of M. armatus was: kidneys > liver ≅ skin > muscles > gills. Bioaccumulation factor (BAF) values of the metals in muscles of M. armatus were in the order: Cr > Pb > Ni > Cd. BAF values show that these metals are accumulated in the fish tissues and may pose a potential health risk to regular consumers.