The contamination of coastal environments by metallurgical wastes involves multiple biogeochemical processes; accordingly, understanding metal behavior and risk evaluation of contaminated areas, such as Sepetiba Bay (Rio de Janeiro, Brazil), remains challenging. This study coupled Zn isotopic analyses with sequential extractions (BCR) to investigate the mechanisms of Zn transfer between legacy electroplating waste and the main environments in Sepetiba Bay. This metallurgical waste showed a light bulk isotopic signature (δZnbulk = +0.30 ± 0.01‰, 2 s, n = 3) that was not distinct from the lithogenic geochemical baseline, but was different from signature of mangrove sediment considered as anthropogenic end member (δZn = +0.86 ± 0.15‰) in a previous isotopic study in this area. Zn isotopic compositions of sediment samples (ranging from +0.20 to +0.98‰) throughout the bay fit a mixing model involving multiple sources, consistent with previous studies. In the metallurgic zone, the exchangeable/carbonate fraction (ZnF1) exhibited high Zn concentrations (ZnF1 = 9840 μg g) and a heavy isotopic composition (δZnF1 = +1.10 ± 0.01‰). This finding showed that, in some cases, the bulk isotopic signature of waste is not the most relevant criterion for evaluating trace metal dispersion in the environment. Indeed, based on the BCR, it was observed that part of the anthropogenic metallurgical Zn was redistributed from the exchangeable/carbonate fraction in the waste to the surrounding mangrove sediment. Then, this contaminated sediment with heavy δZn values was exported to other coastal environments. In Sepetiba Bay, contaminated sediments revealed a large concentration of ZnF1 fraction (up to 400 μg g) with a heavy Zn isotopic signature. This signature also matched the Zn isotopic signature of oysters in Sepetiba Bay reported by other studies; hence, measurement of the isotopic exchangeable/carbonate fraction has important implications for tracing the transfer of anthropogenic Zn to biota.
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http://dx.doi.org/10.1016/j.scitotenv.2020.140610 | DOI Listing |
Arch Environ Contam Toxicol
November 2024
Jan Japenga Laboratory of Micropollutants (LMJJ), Biophysics Institute (IBCCF), Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil.
In general, mercury (Hg) undergoes biomagnification in aquatic systems. The absence of Hg biomagnification in a certain aquatic environment constitutes an exceptional finding and this seems to be the case for Sepetiba Bay, in Rio de Janeiro state (RJ), Brazil. There are three distinct ecological populations of Guiana dolphins in the Sepetiba Bay (SB)-Ilha Grande Bay (IGB) Complex, inhabiting: (1) the inner part of SB; (2) SB entrance; and (3) IGB.
View Article and Find Full Text PDFChemosphere
October 2024
Department of Pure and Applied Sciences, Università Degli Studi di Urbino "Carlo Bo", 61029, Urbino, Italy. Electronic address:
Animals (Basel)
June 2024
Laboratory of Marine Ecology and Conservation (ECoMAR), Department of Ecology, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil.
Sepetiba Bay, located in southwestern Rio de Janeiro state, in southeastern Brazil, is a region of extreme anthropogenic impact, and is home to a large population of Guiana dolphins, which face increasing and cumulative pressures on their physical health. Cetacean body condition provides a useful indicator for the evaluation of the conservation status of marine mammals. Given this, the present study quantified the proportion of dolphins with different body condition scores and assessed temporal variation in these scores between 2017 and 2022 through the analysis of photographic records.
View Article and Find Full Text PDFSci Total Environ
October 2024
Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, Pau, France. Electronic address:
Environ Pollut
May 2024
Laboratório de Mamíferos Aquáticos e Bioindicadores ''Prof(a). Izabel Gurgel'' (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier, 524, sala 4002, CEP 20550-013, Maracanã, Rio de Janeiro, RJ, Brazil; Programa de Pós-graduação em Oceanografia, Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro - UERJ. Rua São Francisco Xavier, 524 - sala 4018/bloco E, Maracanã, Rio de Janeiro, CEP: 20550-013, RJ, Brazil. Electronic address:
Organochlorine compounds (OCs) are persistent organic pollutants linked to damaging the immune and endocrine systems, leading to a greater susceptibility to infectious diseases at high concentrations. Sepetiba Bay, in the Southeastern Brazilian coast, historically presents anthropogenic activities and environmental contamination that could negatively impact resident populations. In this context, this study aimed to investigate the temporal trends in the accumulation of organochlorine compounds over a 12-year database in the Guiana dolphins' (Sotalia guianensis) resident population from Sepetiba Bay, including individuals collected before, during, and after an unusual mortality event triggered by morbillivirus (n = 85).
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