Unveiling the path from sediment trace elements to bioaccumulation in edible mussels: Ecological and human health risk in Lake Singkarak, Indonesia

Lake Singkarak is one of the tectonic lakes on Sumatera Island and is classified as a national priority lake in Indonesia. Our study aimed to investigate the accumulation level of trace elements in the bottom sediments and edible bivalves Corbicula sumatrana in Lake Singkarak, Indonesia. The study also assessed the ecological and health risks associated with the presence of these elements. Surficial sediments and mussels were taken from seven sites of Lake Singkarak in September and November 2022. The levels of several elements were determined in sediments and mussel soft tissues. Our results suggest that the lake sediments were uncontaminated to moderately contaminated by Cd according to the Geoaccumulation index (Igeo). The Contamination Factor (CF) results exhibited moderate to considerable contaminated sediments in terms of Cd metal. Ecological risk evaluation posed by seven different trace elements identified Singkarak sediments as having low to moderate risk. Biota-sediment accumulation factor (BSAF) values indicated Corbicula sumatrana as a potential biomonitor for sediment chemical elements, especially Ag, Mo, Sb, Au, Pb, and Sn. Furthermore, human exposure to trace elements in sediments through dermal absorption poses no non-cancer risk, but lifetime exposure to Cr and Cd increases cancer risk (Cr: 29.04%-70.80%, Cd: up to 30.26%). Consumption of Pb-containing mussels poses a risk of non-cancer effects, while prolonged exposure to Cr, Cd, Pb, Ni, and As increases cancer risk. Our findings highlight the importance of educating the public about the risks of consuming contaminated mussels and implementing safer eating practices to reduce exposure to toxic elements.