bioaccumulation and human health risk assessment of heavy metals in fish cultured in metropolitan city lakes: a case study in bengaluru, south india

Food safety is a global concern, yet little research has focused on the heavy metal (hm) pollution and health risks associated with both cultured and captured fish. this study evaluates the bioaccumulation and human health risks of hm (cd, cu, zn, cr, and pb) in various tissues of aquacultured fish, oreochromis niloticus, from major lakes in bengaluru. over two years (august 2021 to july 2023), spanning different seasons, fish samples were collected and analyzed for heavy metal presence using atomic absorption spectrophotometry (aas). bioaccumulation levels were assessed, along with estimated daily intake (edi), target hazard quotients (thq), hazard index (hi), and target risk (tr). results showed varying bioaccumulation patterns across different tissues and lakes. the highest concentrations of heavy metals were found in gonad and liver tissues hi values for all muscle tissue were > 1, indicating potential health risks from metal consumption. tr levels were found to be unacceptable in the case of cd and cr which may lead to the risk of cancer and damages the normal functionality of the kidneys and liver. this study highlights the health threats associated with consuming freshwater fish from ulsoor and agara lakes in bengaluru, underscoring the importance of regular lake monitoring to mitigate heavy metal impacts on human health and the ecosystem.