DISTRIBUTION AND GEOCHEMISTRY OF LEAD IN TIDAL CREEK SEDIMENT IMPACTED BY ANTHROPOGENIC ACTIVITIES

Abstract

Mangrove-dominated estuaries could play an important role in mitigating pollutants from the land to the sea. However, changes in the physicochemical characteristics of water and sediment could affect the spatiotemporal distribution of pollutants, including heavy metals which may induce ecological risks to organisms during tidal cycles and seasons. In the present study, we aimed to evaluate the lead (Pb) partitioning and its ecological risks in tidal creek sediments within the Can Gio mangrove estuary by using a method of sequential extraction. The results shown that the total lead content ranged from 16.92 – 24.55 mg/kg. We suggest that Pb originated mainly from natural sources during the weathering process that could be supported by Pb partitioning in residual fraction – silicate bonding i.e., F4 > F3 > F2 > F1 and geoaccumulation index (Igeo) < 0. The risk assessment code (RAC) was less than 10% at the sampling sites which indicated low ecological risks and anthropogenic activities were minor factors that may influence Pb geochemistry.