Potential heavy metal health risk via consumption of rastrelliger kanagurta from selected wet markets in Hulu Langat district

Due to its remarkable nutritional properties, fish especially Indian Mackerel (Rastrelliger kanagurta) is regarded as an important source of a healthy, well-balanced diet. However, anthropogenic environmental impacts have contributed to a significant increase in the amount of naturally occurring heavy metals in the environment, notably in the marine ecosystem. The fact that marine species like fish can accumulate these metals to potentially toxic concentrations is concerning since food containing toxic metals above permitted levels considered harmful to human health. Therefore, the aim of this study was to determine the concentration of heavy metals (chromium, cadmium, copper and zinc) in R. kanagurta and to calculate potential health risk based on previously estimated fish intake among adult and children population in Malaysia. 15 samples of R. kanagurta were collected from Bandar Baru Bangi wet market, Kajang wet market and Semenyih wet market which are located in Hulu Langat district. The concentration of heavy metals was measured using Atomic Absorption Spectroscopy (AAS) (Perkin Elmer). The concentration of heavy metals was found to vary and in order of Zn > Cu > Cr > Cd in all samples. All the heavy metals were within the permitted level of the FAO, WHO, and Malaysian Food Act 1983. Further statistical analysis using Kruskal-Wallis test revealed that only mean concentration of cadmium and zinc were significantly different from different wet markets (p<0.05). For the health risk assessment, formula of THQ and TCR were used to calculate the noncarcinogenic risk and carcinogenic risk respectively. The cumulative effect of all metals in this study was found not to exceed the value of 1 for THQ in all samples for adult and children (THQ<1), which indicates that non-carcinogenic health effects are not expected to occur. However, the TCR value for adult and child were found to be exceeding 10⁻⁶ of acceptable TCR value which may present with carcinogenic risk to consumers. Therefore, it can be concluded that consuming R. kanagurta species from wet markets in Hulu Langat district presently poses carcinogenic health risks to humans. Therefore, it is suggested that regular heavy metals surveillance of marine fish should be carried out by environmental health authorities to ensure that the metal content does not exceed the set standards. For the future studies, as HMs are the only focus of pollutant in the study, it is recommended that other pollutants such as pesticides, insecticides, or micro plastics to be analysed which are also known to be accumulated in fish and possess health risk to human.