The distribution of heavy metals (Cu, Zn, Cd, Pb) in surface sediments was examined in waters off the coast of Marang, Terengganu. A total of 20 samples were collected using Ponar grab and analysed by inductively coupled plasma-mass spectrometer after closed digestion with acid. The sediments were filtered using a dry sieving method to determine their particle size. The spatial distribution maps on the concentration of selected metals were drawn using the ArcGIS software. Results showed that the average concentration of Cu, Zn, Cd, and Pb were 2.33±0.38 µg/g dry weight, 28.4±3.78 µg/g dry weight, 0.09±0.01 µg/g dry weight and 8.35±1.48 µg/g dry weight, respectively. The level of pollution was also evaluated using the Index of Geoaccumulation (Igeo) and Pollution Load Index (PLI). All Igeo and PLI values obtained were low, which indicated low or no pollution. Meanwhile, the sediment mean size ranged between -0.77Ø and 3.18Ø, which characterised a sandy type of sediment. Correlation analysis showed a positive correlation between the heavy metals and sediment size. The results indicated that there was a common source of heavy metal pollution in the study area, possibly from shipping activities. Overall, there was no significant heavy metal pollution in the waters off Marang. This finding is important as the data could be used to evaluate the risk of metal contamination and the impact of anthropogenic activities on the marine environment.
The study examines the influence of temperature and pH on the leaching of six heavy metals (HMs) species: aluminum (Al), zinc (Zn), chromium (Cr), copper (Cu), lead (Pb) and arsenic (As) from transparent polyethylene pellets into seawater. The idea is to understand the potential influence of intensifying global warming and ocean acidification towards microplastic toxicity in the ocean. HMs leaching was obvious by 24th hours, with most HMs concentration decreased in water by 120th and 240th hours except Al. Nevertheless, we report that temperature and pH do not influence the overall HMs leaching from PE pellets with statistical analysis showing no significance (p