Analysis of major heavy metals in the available fish species of the Dhaleshwari River, Tangail, Bangladesh

Abstract

Dhaleshwari is one of the most important rivers in Bangladesh for multi-species fisheries production. In this study, concentrations of major heavy metals (Pb, Cd, Cr, Hg and As) in the six available fish species (Channa punctatus, Mastacembelus armatus, Mystus vittatus, Puntius puntio, Amblyceps mangois and Metapenaeus spinulatus) of the Dhaleshwari river collected from three selected locations (Porabari, Katuli and Mahmudnagar) during the months from March to May 2016 were quantified using Atomic Absorption Spectrophotometer in order to estimate the present heavy metals pollution index in the available fish species of the river. The concentration of heavy metals in fishes of the study area ranged as Pb 0.086-0.288 mgkg-1, Cd 0.002-0.019 mgkg-1, Cr 0.006-0.159 mgkg-1, Hg 0.001-0.016 mgkg-1, As ˂0.005-0.128 mgkg-1. According to statistical analysis, heavy metals Cd, Cr, Hg and As in fishes show negative correlations among themselves and positive correlations with Pb. The level of these heavy metals in fishes of the river were found below the permissible limit. Thus, the study revealed that there is almost no heavy metal pollution in the Dhaleshwari river water fishes and the consumption of the available fish species of the river is not harmful to human beings.