Bioaccumulation of Some Potentially Toxic Heavy Metals in Freshwater Fish of River Shah Alam, Khyber Pakhtunkhwa, Pakistan

The present study was designed to assess the concentrations of Cr, Ni, Cd and Pb in water, sediments and different fish species of River Shah Alam, a tributary of River Kabul in Khyber Pakhtunkhwa, Pakistan. The different environmental samples were collected from the river, downstream the city of Peshawar, and analyzed for the selected heavy metals by atomic absorption spectrophotometry. Heavy metal accumulation was studied in muscles of six fish species collected from the river. Heavy metal accumulation was also studied in other tissues such as skin, gills, liver and kidneys of two fish species i.e., Clupisoma naziri and Mastacembelus armatus. Cr concentrations in fish muscles ranged from 30.5 +/- 41.9 to 70.8 +/- 12.1 mg kg(-1) wet weight, Ni from 16.7 +/- 10.2 to 103.5 +/- 114.1 mg kg(-1) wet weight, Cd from 1.1 +/- 0.18 to 2.5 +/- 0.21 mg kg(-1) wet weight and Pb from 29.7 +/- 18.3 to 97.7 +/- 95.4 mg kg(-1) wet weight. Metal concentrations in muscle samples of the different six fish species showed random variations. Inter-species differences were statistically not significant, most probably due to more variance within samples. Comparative metal accumulation in the five different tissues of C. naziri and M. armatus did not show a consistent trend across the studied tissues.