Abstract:
Estuarine ecosystems of the Bay of Bengal, India, are considered as the most productive environment, which have been persistently threatened by substantial anthropogenic activity. This study aims to investigate the metal contamination in the sediment of two estuaries and possible biomagnifications in the indigenous edible oyster Saccostrea cucullata and related health hazards due to its consumption. The accumulative ecological risks indicated that the sediment is moderate to strongly contaminated with cadmium and lead. The sediment pollution index and pollution load index suggested that the sediment possesses a little ecological stress on the exposed flora and fauna. The statistical interpretation highlights the most metals which have a similar source of origin and are bound to the finer fractions of the sediment, except nickel. Bioaccumulation of sediment-associated Cu and Zn in oyster reflects their potential biomagnifications through aquatic food chain. HPI range was below the critical limit of safe human consumption. The non-carcinogenic (THQ) and carcinogenic (CR) health hazards were estimated from the PTDI provided by USEPA. Except Cr, Hg and Zn, the THQ of all other metals was>1 suggesting detrimental non-carcinogenic health effects on humans. The TCR of Cr and Cd above safety limit indicates the exposed population might be under severe carcinogenic threat due to those metals.