Assessment of Trace Metals in Surface Water and Sediment Collected from Polluted Coastal Areas of Bangladesh

抄録

Accumulation of trace metals in coastal ecosystem has become a prodigious problem in Bangladesh. This study was conducted to determine seven trace metals concentration (Cr, Ni, Cu, Zn, As, Cd and Pb) in water and sediment samples collected from coastal sites of Bangladesh. Water of Cox’s Bazar hatchery site showed the highest levels of Zn (1,390 µg/L), Cu (510 µg/L) and Pb (109 µg/L), which attributed to huge discharge of different chemical compounds from the hatcheries and fish processing industries. Trace metals in water samples were in the range of Cr (2.6 − 15.3 µg/L), Ni (5.1 − 77.5 µg/L), Cu (10.2 − 510 µg/L), Zn (5.0 − 1,390 µg/L), As (2.1 − 13.3 µg/L), Cd (0.006 − 0.09 µg/L), Pb (0.4 − 109 µg/L), respectively. The elevated concentration of As (13.3 µg/L) was observed in water sample of Chittagong ship breaking area. Some metals (Zn, Cu, Pb and As) in water exceeded the international quality guidelines. Sediment samples of Chittagong ship breaking area showed the highest level of Cr (56 mg/kg dw), Ni (37 mg/kg dw), Cu (28 mg/kg dw) and Pb (41 mg/kg dw) which exceeded the Canadian Sediment Quality Guidelines. The elevated level of trace metals in this Bangladeshi coastal ecosystem should not be ignored and immediate control measure is recommended.