Bioaccumulation of heavy metals in fish and shellfish from Rupsa River, Bangladesh, and risk assessment for human

Spatial variation of Pb, Hg, Cr, Cd and As concentrations between up- and downstream fish (river shad Tenualosa ilisha, silver jewfish Otolithoides pama) and shellfish (black tiger shrimp Penaeus monodon) collected from Rupsa River of the south-west coast of Bangladesh was studied in order to assess the potential health risks in human. Samples (n=18) were collected representing 3 species from two locations of the river system and muscle analyzed for heavy metal concentration. Mean concentration of the elements was significantly higher (p<0.05) in the downstream samples compared to those of the upstream with a high concentration in benthic fauna and interspecific variation at a trend: black tiger shrimp > Hilsa shad > silver jewfish and distribution As>Cr>Hg>Cd>Pb. Bioaccumulation of As and Hg was correlated well with fish size although their concentrations were well below the international legislation limits set by WHO and FAO. For potential human health risk, the estimated daily intake (EDI), target hazard quotient (THQ) and total target hazard quotient (TTHQ) for non-carcinogenic risk suggest that most of the values were within the acceptable limits for all species expect As. Besides, the carcinogenic risk (CR) values indicate less prone to cancer risk yet CR values of Cd and As in both black tiger shrimp and Hilsa shad were close to the unacceptable range.