Heavy Metal Concentration in Water, Sediments, Freshwater Mussels and Fishes of the River Shitalakhya, Bangladesh

This study was undertaken to study the concentration of some heavy metals in the water and sediment samples and their bioaccumulations in freshwater fish and mussels of the Shitalakhya River. In water samples, concentration of Ni ranged from 4.31 to 7.83 micro mu g/L, Pb 41.24 to 63.15 micro mu g/L, Cd 7.12 to 10.11 micro mu g/L, Cr 192.18 to 234.32 micro mu g/L, and Cu 156.38 to 254.07 micro mu g/L at different sampling stations during pre-monsoon, monsoon and post-monsoon. In sediment samples, Ni ranged from 120.96 to 131.94 mg/kg, Pb 54.52 to 65.90 mg/kg, Cd 1.71 to 2.17 mg/kg, Cr 60.09 to 91.02 mg/kg, and Cu 56.07 to 91.51 mg/kg in dry weight basis at different stations during different seasons. In Puntius sophore, Ni ranged from 9.07 to 13.01 mg/kg, Pb 8.01 to 10.09 mg/kg, Cd 0.85 to 1.13 mg/kg, Cr 2.94 to 4.01 mg/kg, and Cu 4.92 to 5.27 mg/kg in dry weight basis during different seasons. In Glossogobius giuris, Ni ranged from 10.53 to 11.32 mg/kg, Pb 7.17 to 9.17 mg/kg, Cd 0.81 to 1.07 mg/kg, Cr 3.13 to 3.37 mg/kg, and Cu 5.19 to 6.03 mg/kg in dry weight basis during different seasons. In the muscles of the freshwater mussels (Lamellidens marginalis), Ni ranged from 8.19 to 9.07 mg/kg, Pb 9.16 to 13.09 mg/kg, Cd 1.09 to 1.21 mg/kg, Cr 8.12 to 9.07 mg/kg, and Cu 5.47 to 8.19 mg/kg in dry weight basis during different seasons. These variations of metal concentrations in fish and freshwater mussels in our study are likely to be due to the different sampling locations, seasons, weight and age of the organisms. The present study found much higher concentration of heavy metals in water, sediment and aquatic animals than standard value of WHO and EQS.