Heavy Metal Concentrations in Hard Clam Meretrix lyrata and the Coastal Environment of Tien River Estuary, Mekong Delta

Abstract

The coastal area surrounding Mekong Delta-Vietnam (MDV) is one of the largest clam farming sites in Vietnam. Furthermore, previous studies showed that the rapid growth of urbanization, industrialization, and agriculture lead to the contamination of heavy metals in MDV. Therefore, this study is aimed to evaluate the presence of cadmium (Cd), cooper (Cu), lead (Pb) and zinc (Zn) in sea water, sediment, as well as hard clam (Meretrix lyrata) around coastal area of Tien River Estuary named Tan Thanh. The results showed that all studied metals’ concentrations in sediment were lower than the limits of marine sediment quality guidelines, except Zn. The levels of studied metals in clam samples were less than the maximum values of metals in food which regulated by Commission Regulation 1881/2006 and some countries. Concentrations of Cd, Cu, Pb and Zn in the clam flesh were ranging between 0.01 and 1.34 mg kg-1, 1.1 and 15.8 mg kg-1, not detected and 0.6 mg kg-1, as well as 9.9 and 192.5 mg kg-1, respectively. Among the studied metals, Cd is considered as the most influential parameter for the health risk assessment of local clam consumers. According to this study, the daily intake of 100 g clam flesh (wet weight) is recommended as the largest amount of clam for local consumers.