Bioconcentration of Cadmium and Nickel in Mud Clams (Polymesoda expansa) at Sungai Balok, Pahang

Abstract

Bioaccumulation of heavy metals in mollusc is one of the crucial topics in environmental pollution, toxicology and food safety as it gives great impact on the ecosystem and human health. This study was conducted to identify the level of Cadmium (Cd) and Nickel (Ni) in the soft tissues of mud clams (Polymesoda expansa) and in water samples at Sungai Balok, Pahang. The mud clams and water samples were collected from five sampling stations in Sungai Balok. Sampling was carried out during dry season (May 2018) and wet season (January 2019). The mud clams’ tissues were digested and analysed with inductively coupled plasma-mass spectrometry (ICP-MS). The obtained results revealed that the mean level of Cd and Ni in tissues of mud clams during wet season (0.127±0.104 and 0.909±0.482)mg/kg were higher compared to dry season (0.031±0.014 and 0.245±0.106)mg/kg respectively. Both of Cd and Ni concentrations in the mud clams were found below the limits stated by FAO/WHO (1984), MFA (1983) and FSANZ (2002). There was no significance different (p<0.05) between Cd and Ni in both seasons. Meanwhile, the concentration of Cd in water samples from Balok river during both seasons were the same, which were (0.0001±0.001)mg/kg respectively, whereas for Ni, the concentration in dry and wet season were slightly different with value of 0.0088±0.001mg/kg and in Jan 2019 is 0.0062±0.001ppm. All the water samples from both seasons had Cd and Ni concentrations within Malaysia’s National Water Quality Standard NWQS limits.