The most important harbor of Brazil is located in Santos Estuary. In the 1970s, this area was one of the major examples of coastal degradation and although the quality of the environment has improved, the sediment is still contaminated with polycyclic aromatic hydrocarbons (PAHs) and mutagenic activity. Because of sediment dredging and consequently contaminants resuspension, it is useful to have reliable methods to monitor the water quality. Considering that blue rayon (BR) has been successfully used in evaluation of mutagenicity and PAHs content the objective of this work was to verify the applicability and adapt the methodology to monitor the water for mutagenic activity using the BR associated with the Salmonella assay. Analysis of three sites with different levels of contamination was performed using a modification of the BR hanging method denominated in this work BR anchored technique. The microsuspension protocol of the Salmonella/microsome assay was employed with the strain YG1041. The water from the site 1 the most contaminated and under influence of the steel mill discharge presented the highest potency reaching 36,000 revertants/g of BR with S9. Sites 2 and 3 showed less mutagenicity than site 1 with values approximately 1000 revertants/g of BR. We conclude that the BR anchored technique associated with Salmonella assay using YG1041 is a reliable alternative to monitor estuarine waters, especially in regions where sediment resuspension or acute pollution episodes can occur.
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http://dx.doi.org/10.1016/j.mrgentox.2006.06.003 | DOI Listing |
Environ Pollut
January 2025
Federal Institute of Maranhão, Campus Barreirinhas, Rodovia MA-225, KM 04, CEP:65590-000, Barreirinhas, Maranhão, Brazil.
Dredging in estuarine systems significantly impacts phytoplankton communities, with suspended particulate matter (SPM) and dissolved aluminum (Al) serving as indicators of disturbance intensity. This study assessed the effects of dredging in the São Marcos Estuarine Complex (SMEC), Brazil, over three distinct events (2015, 2017, 2020), involving varying sediment volumes and climatic influences. Prolonged dredging operations and increased sediment volumes led to a pronounced 43.
View Article and Find Full Text PDFSci Adv
January 2025
Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden.
Coastal ecosystems play a major role in marine carbon budgets, but substantial uncertainties remain in the sources and fluxes of coastal carbon dioxide (CO). Here, we assess when, where, and how submarine groundwater discharge (SGD) releases CO to shallow coastal ecosystems. Time-series observations of dissolved CO and radon (Rn, a natural groundwater tracer) across 40 coastal systems from 14 countries revealed large SGD-derived CO fluxes.
View Article and Find Full Text PDFWater Res
December 2024
Programa de Pós-Graduação em Química Tecnológica e Ambiental (PPGQTA), Universidade Federal do Rio Grande (FURG), Rio Grande, RS 96203-900, Brazil; Instituto de Oceanografia, Universidade Federal do Rio Grande (IO-FURG), Av. Itália s/n, Rio Grande, RS 96203-900, Brazil. Electronic address:
Organotin compounds (OTs) used to be the most widely used biocide in antifouling paint systems, but the International Maritime Organization (IMO) banned them because of their high environmental toxicity to non-target organisms. Currently, at least 25 active ingredients are being employed as biocides in antifouling paint formulations. In the present study, silicone rubber-based passive sampling was used to determine the freely dissolved concentrations (C) of 6 OTs and 4 booster biocides in the water column at the entrance of Santos Port's main navigation channel, the largest Port of South America (southeastern Brazil).
View Article and Find Full Text PDFMar Pollut Bull
December 2024
Instituto de Ciências do Mar (LABOMAR), Universidade Federal do Ceará (UFC), Fortaleza, Brazil. Electronic address:
Estuaries are the main pathway for the microplastics (MPs) to enter into the oceans. However, factors that drive river-sea transport of MPs are not yet fully understood. Therefore, our research investigated the influence of the tidal cycle on the abundance and characteristics of MPs in an urban estuary, through high-frequency sampling (every 2-3 h) using a plankton net (120 μm mesh size) in two seasons (rainy and dry seasons).
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2025
Laboratório de Química Analítica E Ecotoxicologia (LAEC), Federal University of Maranhão (UFMA), Av. Dos Portugueses, 1966, São Luís, Maranhão, 65080-805, Brazil.
Pesticide contamination remains a significant environmental concern globally, with important implications for aquatic ecosystems. Despite being one of the world's largest pesticide consumers, monitoring and assessment of pesticide pollution are limited in Brazil, especially in sensitive regions like the Amazon. In this study, the occurrence and environmental risks of 8 pesticides of different classes, namely alachlor, atrazine, chlorfenvinphos, isoproturon, irgarol, simazine, diuron, and its transformation product DCPMU (1-(3,4-dichlorophenyl)-3-methyl urea) were analysed in surface water of the São Marcos Estuarine Complex (SMEC) in two consecutive years.
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