Haevy metal content (Cd, Mn,Cu, Zn, Pb) in oyster (Crassostrea iredalei) from Setiu Lagoon, Terengganu

Abstract

Heavy metals pollution in aquatic environments known as a major problem contributed to human health risks. The studies on this pollutant through bioindicators organisms such oyster from species Crassostrea iredalei is important to control their sources and to manipulate the pollutants. The concentrations of Cd, Mn, Cu, Zn and Pb in tissue of Crassostrea iredalei, sediment and surrounding water was measured and the data was analysed using one way ANOVA and correlation test to detect the relationship between sampling periods and between oyster tissue , sediment and water. The highest concentration of metals in oyster tissue was Zn (940.65 ± 531.4 μgig), followed by Cu (40.08 ± 24.35 μgig), Mn (22.56 ± 42.72μglg), Cd (2.42 ± 1.46 μgig) and Pb (1.15 ± 2.97 μgig). Concentrations of Cd, Cu and Zn were exceeded the maximum level allowed according to Food Act 1983. Metals in sediment were dominated by Mn (381.78 ± 237.56 μgig) and Zn (41.04 ± 17.24μglg), others were Pb (20.66 ± 8.95 μgig), Cu (7.02 ± 2.49 μgig) and Cd (0.41 ± 0.12 μgig). Concentrations of heavy metals in surrounding water were Zn (300.96 ± 492.08 μg/L), Pb (14.49 ± 19.75μglL), Cu (6.97 ± 8.6lμglL), Mn (5.43 ± 5.94μglL), Cd (1.96 ± 2.44 μglL). There was no correlation between metal concentration in oyster tissue and in sediment for all five metals. Otherwise only Zn represented strong positive (r = 0.650) (p < 0.05) relationship in oyster tissue and surrounding water.