Heavy metal concentrations in the macroalgae, seagrasses, mangroves, and crabs collected from the Tuticorin coast (Hare Island), Gulf of Mannar, South India

This study investigates the concentration of heavy metals in the macroalgae, seagrasses, mangroves, and crabs collected from Hare Island, Gulf of Mannar Marine Biosphere Reserve. The concentration of heavy metals ranged between 0.06 (Hg)-259 (Fe) mu g/g in macroalgae, 0.09 (Pb)-377 (Fe) mu g/g in seagrasses, 0.112 (Cd)-122 (Fe) mu g/g in mangroves, and 0.11 (Cd) -240 (Fe) mu g/g in crabs. The levels of heavy metals in the analyzed samples were found below the maximum residual limits (MRLs) prescribed by various National and International agencies. The result suggests that exposure to the analyzed metals through macroalgae consumption does not cause potential health risks to consumers (target hazard quotient (THQ), estimated exposure dose (EED), and hazard index (HI) <1). Hence, this study concludes that macroalgae that grow in the Gulf of Mannar regions are safe for human consumption and are suitable to prepare food supplements and bioceutical products.