The elemental distribution study of heavy metals (Fe, Cu, Cd, As, Cr, Ni and Hg) in various fish species at local market in Muar, Johor using SEM-EDX

Abstract

The polluted marine environment causes bioaccumulation of heavy metals particularly by fish, which is consumed by humans as sources of nutrients for humans, particularly as a source of protein. Thus, the investigation of the toxic heavy metals concentration levels in fish is essential. This study aimed to evaluate the heavy metals (Cd, Cr, As, Ni, Fe, Hg and Cu) contents in five different fish species, namely Rastelligar kanagurta, Selaroides leptolepis, Megalaspis cordyla, Decapterus ruselli and Euthynnus affinis. Each sample has been dried and grinds to 100 microns of powder form. The elemental composition of the heavy metals was determined using the rapid and versatile analytical technique, which is Scanning Electron Microscopy with Energy Dispersive X-ray analysis (SEM-EDX) and the results were expressed as an atomic percentage. The percentage concentrations of Cd, As, Cr and Ni were found to be higher in R. kanagurta which are 0.01%, 0.02%, 0.03% and 0.02%, while Cu was found to be higher in S. leptolepis which is 0.29%. For Hg element analysis, it was found that this element only exists in D. ruselli species with atomic percentage of 0.02%. The atomic percentage concentration of As in R. kanagurta and S. leptolepis are 0.02% and 0.01%. The element of Cr, Fe and Ni were detected in M. cordyla with atomic percentage of 0.01%, 0.02% and 0.02%. In E. affinis, Fe was the highest concentration of metals detected with 0.02%, while other elements such as Cr, Cu and Ni recorded similar the atomic percentages concentration at 0.01%. This study revealed that R. kanagurta species contributed most of the elements compared to other species. The accumulation of these toxic heavy metals from this fish species could contribute to the toxicity of heavy metals in the human body. However, since all heavy metal concentration measurements in this study are in atomic percentages level, hence it can be considered that the measurements are below the acceptable limit that suggested by WHO, FAO and UNSCEAR