BIOACCUMULATION OF POTENTIALLY RISKY HEAVY METALS IN COMMONLY CONSUMED FRESHWATER FISH IN AMPARA DISTRICT

Abstract

Fish are pivotal in ensuring global food and nutrition security, given their abundance of essential nutrients. Nevertheless, their habitats face many challenges due to the proliferation of diverse malpractices, resulting in various forms of pollu- tion. As fish ascend through higher trophic levels within the food chain, they emerge as prominent bio-indicators of increased heavy metal contaminations. Consequently, the human body becomes particularly susceptible to heightened levels of heavy met- als, leading to a spectrum of health risks. In the present study, Oreochromis nilot- icus species were collected to determine the accumulated metal content in their mus- cles and the impact on consumers’ health risk. Fish samples were collected from the Irakkamam tank, Ampara district, which is believed to be polluted by extensive pol- lutants from agricultural and natural sources. The heavy metals including Cr, Pb, As, Cd, and Hg were determined using ICP-MS. The estimated daily intake (EDI), and hazard index (HI) were determined to determine the health hazard levels. The mean concentration (ppm) of Cr, Pb, As, Cd and Hg in fish muscles were 7.98±3.03, 0.75±0.34, 0.03±0.03, 0.1±0.06 and 0.10±0.08, respectively and Cr, Cd, and Pb ex- ceeded the recommend levels prescribed by FAO. Except for As, the EDI (mg/day/person) of all metals exceeds the recommended daily dietary allowance. Moreover, HI through consumption of Oreochromis niloticus is above the standard threshold of one indicating a non-carcinogenic risk to consumers. Continuous con- sumption of Oreochromis niloticus species of the Irakkamam tank may cause chronic health hazards to consumers.