Fluxes of settling sediment particles and associated mercury in a coastal environment contaminated by past mining (Gulf of Trieste, northern Adriatic Sea)

Historical mercury (Hg) mining at Idrija, Slovenia, continues to impact the Gulf of Trieste, with riverine inputs of suspended particles still introducing significant Hg into coastal waters. Research reveals that settling sediment particles (SSP), predominantly silt-sized, display Hg concentrations ranging from 0.61 to 6.87 µg g−1. Daily SSP fluxes vary dramatically—from as low as 7.05 ± 3.26 g m−2 day−1 under low river discharge to a peak of 92.4 ± 69.0 g m−2 day−1 during high flow events, with Hg fluxes reaching up to 245 µg m−2 day−1 in the bottom water column. These findings underscore that flood-driven river discharges are critical in transporting Hg into the Gulf, highlighting an ongoing environmental concern.

Pavoni, E., Petranich, E., Signore, S., Fontolan, G., Bezzi, A., & Covelli, S. (2023). Fluxes of settling sediment particles and associated mercury in a coastal environment contaminated by past mining (Gulf of Trieste, northern Adriatic Sea). Journal of Soils and Sediments, 23(12), 4098–4109. https://doi.org/10.1007/s11368-023-03451-9