| Abstrakt: |
The rupture of the Fundão dam in Brazil released tons of mining tailings into the Doce River Basin (DRB). This investigation aimed to determine the bioaccumulation of metals in soft tissues of the bivalve Corbicula fluminea exposed to sediments collected in the DRB in four periods (just after, 1, 3, and 3.5 years after the dam rupture). In the exposure bioassays, the concentrations of Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn in sediments and bivalve soft tissues were quantified. The concentration of some elements (As, Cd, Mn, and Al) in sediments exceeded the federal limits or regional backgrounds at some sampling sites, but their concentrations tended to decrease over time. However, higher concentrations of many elements were detected in the winter of 2019. Several elements were detected in C. fluminea soft tissues, but the bioaccumulation factors were generally low or not related to those elements associated with the ore tailings, evidencing that the bioavailability of metals to bivalves, in laboratory conditions, was limited. Integr Environ Assess Manag 2024;20:87–98. © 2023 SETAC Key Points: The bivalve Corbicula fluminea exposed to sediments collected in the Rio Doce after the Fundão dam failure generally showed low bioaccumulation of metals, as evidenced by the low bioaccumulation factors; some bioaccumulated elements, such as Cu, were not related to the ore tailings.The concentrations of metals and As were high after the dam rupture, and the levels of As, Cd, Mn, and Al in sediments exceeded the federal limits or regional backgrounds at some sampling sites, but their levels tended to decrease over time.The concentrations of metals and As in soft tissues of C. fluminea did not correlate with the respective levels in the sediments, suggesting limited bioavailability of metals or the organisms' ability to cope with metals and metalloids. [ABSTRACT FROM AUTHOR] |
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