3. Evaluation of some heavy metal content in surface sediments in coastal areas of Quang Ninh province

Abstract

Coastal industrial activities, tourism, and aquaculture are exerting significant pressure on Vietnam's marine environment, particularly in Quang Ninh Province - a region characterized by rich ecosystems and robust marine economic development. This study aims to assess the concentrations of selected heavy metals (Pb, Cd, As, Cu, Zn) in surface sediments at the three representative coastal areas, namely Tra Co, Thanh Lan, and Cam Pha, reflecting different natural and economic conditions. The research methodology involved field surveys, sediment sampling, and laboratory analysis following standardized procedures. The results showed that heavy metal concentrations ranged from 0.054 to 137.62 mg/kg, with average accumulation following the order: Zn > Pb > Cu > Cd > As. Most of the measured concentrations were within the permissible limits set by QCVN 43:2017/BTNMT. However, the geological accumulation index (I_geo) showed pollution levels ranging from no pollution to heavy pollution for Zn at some locations in Tra Co and Cam Pha coastal areas. The findings provide a critical scientific basis for sediment quality monitoring and heavy metal pollution management in Quang Ninh coastal areas.