John Mark Steve B. Casas | Chate V. Casta | Dwayne Aaron C. Borja | Kate Maybelle R. Ramos | Justine Angelo M. Claveria | Marc Leoven C. Aquino | Nash Tristan H. Caures | Louie Ian B. Mariano | Maria Eliza Bello |
April 30, 2026
Heavy metal-contaminated water can threaten community health. This study assessed human exposure to four heavy metals: copper, nickel, chromium, and total mercury in the Agusan River via ingestion and dermal routes for adults and children. Using secondary sediment data. Chronic daily intakes (CDI) were computed, and US EPA reference doses were used to calculate hazard quotients (HQ) and hazard index (HI), as well as lifetime cancer risk (CR). All HQs and HIs were below <1. Ingestion HIs (10?6 for both age groups) indicate negligible oral risk. Dermal HIs reached 0.07–0.13 in adults and 0.08–0.16 in children at the downstream site, still well below 1. No HI exceeded 1. Cancer-risk show for Cr were below <10?6, far below EPA concern. These findings show that Agusan River water poses no significant non-cancer or cancer risk under current conditions. However, continued pollution control and monitoring are recommended due to the presence of bioaccumulation, which allows toxins such as heavy metals to reach hazardous levels in organisms over time.