The activity of fish monooxygenases has been extensively used as a monitoring tool to detect contamination of water bodies by cytochrome P450-inducing agents. In this study we evaluated the activities of ethoxy- (EROD), methoxy- (MROD) and pentoxy- (PROD) resorufin-O-dealkylases in the liver of Nile tilapias (Oreochromis niloticus) collected at the Guandu river, at a reference clean site (Lake 1) and at two other sampling sites (Lakes 2 and 3) in Rio de Janeiro state, Brazil. Alkoxyresorufin-O-dealkylases were measured fluorimetrically in the hepatic S9 fraction. EROD (17.7-fold), MROD (14.2-fold) as well as PROD activities were considerably higher in tilapias from Guandu river. A moderate increase of EROD (5.0-fold) and MROD (5.4-fold) was also found in tilapias from Lake 3. These findings suggest that Guandu river watershed, the main source of urban drinking water supply in Rio de Janeiro, is polluted with CYP1A-inducing xenobiotics. Furthermore, we also found a good linear relationship between EROD and MROD, a finding that agrees with the hypothesis that the two reactions are catalysed by the same CYP1A isoform in O. niloticus.
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http://dx.doi.org/10.1016/j.chemosphere.2003.09.027 | DOI Listing |
Environ Monit Assess
August 2023
Department of Agricultural and Biological Engineering, Mississippi State University, Starkville, 39759, USA.
Environmental vulnerability is an important tool to understand the natural and anthropogenic impacts associated with the susceptibility to environmental damage. This study aims to assess the environmental vulnerability of the Doce River basin in Brazil through Multicriteria Decision Analysis based on Geographic Information Systems (GIS-MCDA). Natural factors (slope, elevation, relief dissection, rainfall, pedology, and geology) and anthropogenic factors (distance from urban centers, roads, mining dams, and land use) were used to determine the environmental vulnerability index (EVI).
View Article and Find Full Text PDFSci Total Environ
December 2022
Department of Civil Engineering, National Taiwan University, Taiwan.
The mangrove ecosystem is significantly affected by human activities, climate change, and rising sea level. The propagules of mangroves dispersal with tide and river currents that extend upstream habitats are why mangroves are the dominant species in the tidal area. Bridging critical knowledge gaps can help to create restoration plans for mangrove extension.
View Article and Find Full Text PDFMicrob Ecol
July 2022
CSIRO Land and Water, Perth, WA, Australia.
Sci Total Environ
August 2022
Programa de Pós-Graduação em Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande (FURG), Av. Itália, s/n, Carreiros, Rio Grande, RS, Brazil; Fundação Espírito-santense de Tecnologia - FEST, Av. Fernando Ferrari, 845 - Goiabeiras, Vitória, ES, Brazil.
This study investigates the ecotoxicological impacts of the Fundão dam rupture, one of the major environmental disaster that occurred in Brazil and in the world mining industry history, through multi-biomarkers responses and metals bioaccumulation in the fish community of different trophic levels. Specimens of the fishes (omnivorous/herbivorous and carnivorous) were collected along the Doce River channel and its affluent Guandú River, and in different lakes and coastal lagoons adjacent to the river channel, in the Espirito Santo State, Southeast of Brazil. Four sampling collections were carried out over two years (2018 to 2020, during dry and rainy seasons).
View Article and Find Full Text PDFEnviron Toxicol Pharmacol
January 2022
Universidade Vila Velha, Av. José Dantas de Melo, 21, Boa Vista, Zip Code 29102-770, Vila Velha, ES, Brazil. Electronic address:
This study aimed to evaluate the harmful effects of metal accumulation on Astyanax lacustris and their biochemical response when exposed to the metals contained in the Doce River water, Brazil. The study was carried out in the Baixo Guandu region of the Doce River, Espírito Santo state. Samples were collected during the dry and wet seasons.
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