Impact and Environmental Risk Assessment of Hazardous Metal Pollution in the Sediment at Shipbreaking Yard Chattogram

Abstract

The shipbreaking area of Chattogram is one of the ecologically important regions in Bangladesh. To assess the possible ecological harm, sediment samples were collected and analyzed using the atomic absorption spectroscopy following standard methods from different locations of the shipbreaking yard at Chattogram. A decreasing trend in the amount of trace elements is present in sediment (average values): Pb (52.55 mg/kg) > Cr(VI) (45.97 mg/kg) > As (6.99 mg/kg) > Cd (0.218 mg/kg). The levels of harmful metals were higher than what was considered acceptable. According to the measured mean geo-accumulation index (I_geo), the research region was moderate to somewhat polluted, with the exception of Cd. The sediment samples were moderately to highly contaminated by Pb, Cr(VI), and As, according to the contamination factor (CF). Again, the pollution load indices (PLI) ranged from 1.91 to 3.10 (PLI > 1), indicating that the shipbreaking sites were moderately polluted with heavy metals and pose a risk to the ecosystem.