Analysis of Heavy Metal (Hg, Pb, Ni) Content in Marsh Clam, Polymesoda expansa Collected from Butuan Bay, Philippines

Butuan Bay is an amalgamation of resources and wastes, with the Agusan River as its main river source. Multiple industrial operations near the area make it susceptible to pollution, thereby affecting the aquatic organisms and the people who depend on the bay for food and livelihood. Thus, the main objective of the study was to determine the Mercury (Hg), Lead (Pb), and Nickel (Ni) concentration in the flesh of Marsh clam (Polymesoda expansa) in different mangroves wetlands across Butuan Bay. Heavy metal concentration was assessed using cold vapor atomic absorption spectroscopy for Hg and Atomic Absorption Spectrophotometry for Pb and Ni. The results revealed that Hg and Pb concentrations were below the detection limits (BDL), while Ni concentrations were within the tolerable limits established for bivalves. Human health risk via the consumption of P. expansa was calculated using the estimated daily intake (EDI) and Target Quotient Hazard (THQ). Results show that the EDI of Ni exceeded the oral reference dose, but its THQ was below the standard THQ value. In conclusion, the consumption of P. expansa does not pose any adverse health effects on human health. Still, further investigation and monitoring of the mangrove ecosystems are encouraged to secure the environment's health and the communities that depend on it.