Assessment of heavy metals in seawater and fish tissues at Pulau Indah, Selangor, Malaysia

Abstract

This study focuses on the levels of heavy metals in seawater and selected fish tissue at Pulau Indah, Selangor, Malaysia. Pulau Indah primarily contains Westport (Malaysia’s major port), and a host of full scales factories. Therefore, it is important to monitor the levels of pollution in this water body and the aquatic organisms in the long term effects, due to the human activities in this area. Water samples in this study were taken from 8 locations along the coastal area. The water samples were collected using water sampler and sampling locations were determined using a Global Positioning system (GPS). Similarly, in situ water quality parameters including temperature, dissolve oxygen (DO), salinity, total suspended solid (TSS), pH and turbidity were measured by using portable multi probes meter. Then, the samples were acidified until pH 2 and filtered. Fish samples were purchased from local fisherman along the Pulau Indah coastal area and samples were digested using concentrated nitric acid in wet digestion method. The levels of selected heavy metals in four species of fish and seawater from Pulau Indah coastal area were determined using Inductive Coupled Plasma Mass Spectrometer (ICPMS) after dilution to the samples. In general, the quality of water at Pulau Indah is lower than Malaysia Marine Water Quality Standard except for few locations were higher than the maximum permissible levels. The concentration of heavy metals which are lead (Pb), copper (Cu), zinc (Zn) and uranium (U) in water samples are in the range of 0.36-5.43 µg/L, 75.20-621.58 µg/L, 11.92-30.52 µg/L, and 4.00-4.65 µg/L respectively. While the results of the four selected fish showed the following order of abundance Zn> U> Cu> Pb. Transfer factor (TF) of heavy metals in fish tissue of selected fish species from the water was discussed. However, the observed metal concentration in the sample tissue did not exceed the allowable limit of Malaysian Food Act (1983) and Regulation (1985). Therefore, it is safe for human consumption. Moreover, the pollution levels of these heavy metals were also compared with other studies. This present study can also be used to evaluate the safety dose uptake level of marine biota as well as to monitor environmental health.