Heavy Metal Concentrations in Mollusks and Crustaceans Harvested from Eastern Samar’s Taft River in the Philippine and the Health Risks Posed to Consumers

Heavy metal (HM) contamination from mining activities poses a health risk to humans who consume mollusks and crustaceans from mine-affected environments. One such example is the Taft River, which receives drainage water and sediments from the Bagacay mines in Samar, Philippines. To assess the accumulation of HM in mollusks and crustaceans and the associated risks to the humans, a comprehensive analysis was conducted on representative specimens, which were gathered from different sections of the river. The concentrations of Cu (97.67 mg kg–1), Ni (29.30 mg kg–1), Pb (0.59 mg kg–1), and Sr (14.67 mg kg–1) in the flesh of “bebe” (Batissa violacea Lamarck) were significantly higher than those in “tangili” (Telescopium telescopium Linn.), “tuway” (Mercenaria mercenaria Linn.), and “sihi” (Nerita albicilla Linn.); whereas for crustaceans, the flesh of mud crabs (Scylla serrata) contained higher concentrations of As (17.67 mg kg–1), Cu (118.67 mg kg–1), Ni (25.79 mg kg–1), Rb (31.33 mg kg–1), Sr (60.67 mg kg–1), and Zn (331.00 mg kg–1) compared with giant freshwater prawns (Macrobrachium rosenbergii). The consumption of T. telescompium, N. albicilla, and B. violacea may result in an estimated daily intake (EDI) that is greater than the provisional tolerable daily intake (PTDI) for As [2.03–4.48 μg kg–1 body weight (BW) d–1], while all mollusks may have an EDI for Cr of between 124.59–136.23 48 μg kg–1 BW d–1. This may subsequently lead to a high target hazard quotient (THQ), high hazard index (HI), and high target cancer risk (TCR) for adults. With respect to crustaceans, the consumption of S. serrata exceeds the PTDI index for As. Both S. serrata and M. rosenbergii exceed the PTDI for Cr by 20–21 times, as well as the elevated health risk values of 22.36 and 28.57 48 μg kg–1 d–1 for M. rosenbergii and S. serrata, respectively. Overall, current results indicate that human consumption of the Taft River mollusks and crustaceans may inadvertently lead to an increased intake of As and Cr that could negatively impact human health.