Bioaccumulation of Trace Metals in Selected Plants within Amin Bazar Landfill Site, Dhaka, Bangladesh

Abstract

The presence of trace metals in landfill soil and plants pose a risk to the environment and human health. This study was conducted to determine trace metal concentrations in soil and different plant parts that grow in the Amin Bazar landfill, Bangladesh, to evaluate the possible human health risk on consumer. The collected soil and plant samples were analyzed for trace metals using a Flame Atomic Absorption Spectrophotometer. The mean concentrations of trace metal found in the soil were in the following order: zinc (Zn) > manganese (Mn) > lead (Pb) > copper (Cu) > chromium (Cr) > nickel (Ni). Considering all selected plant species, the mean concentrations of trace metals were in the following order: Zn > Ni > Mn > Cu. On the other hand considering all measured trace metals, the accumulation trend in plant species were in the following order: Carica papaya > Enhydra flactuans > Amaranthus gangeticus > Ipomoea aquatica > Sesbania cannabina > Musa sapientum. Pb and Cr were not accumulated in the studied plant species. Translocation factor (TF), bioaccumulation factor (BAF) and bioaccumulation coefficient (BAC) were calculated for the assessment of mobility of trace metals from root to shoot, soil to shoot and soil to whole plant, respectively. TF values showed that the plant species effectively translocate trace metals from roots to the shoots, suggesting that they are suitable for phytoextraction. According to BAF all studied plants were excluders for all metals except Ni, and according to BAC, all studied plants were hyperaccumulators of Ni. The daily metal intake and health risk index values of the studied metals, except of Ni, indicated that there is a relative absence of health risks associated with the ingestion of contaminated edible parts of plants.