Publications by authors named "Denis Moledo de Souza Abessa"

This study investigates the impact of environmentally relevant concentrations of azithromycin on Poecilia reticulata, through biomarkers at different levels. To this end, the somatic indexes of P. reticulata were evaluated, and liver and gill samples were collected and analyzed for biochemical and histopathological alterations.

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This study evaluated the effects of water-soluble fractions (WSF) of stranded oil sampled from the beaches of Trancoso and Massarandupió (Bahia, Brazil) following a mysterious oil spill along Brazil's northeast coast (2019-2020). The samples were characterized for aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs) and tested for chronic toxicity in the embryo-larval stages of the sea urchin Echinometra lucunter. The WSFs contained high levels of PAHs, some of which were above the acceptable levels for water in Brazil, and toxicity to sea urchin embryos tended to occur at higher concentrations.

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Two monophyletic Daphnia species (Daphnia magna and D. similis) were exposed to a sub-lethal concentration of Pb (50 µg/L) for nine generations under two food regimes (usual and restricted) and analyzed for acetylcholinesterase (AChE) activity, first reproduction delay, lifespan, and net reproductive rate (R0) at the subcellular, individual, and population levels, respectively. In the sixth generation, Pb-acclimated neonates were moved to clean media for three more generations to check for recovery.

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The synthetic hormone 17α ethinyl estradiol (EE2) is a molecule widely used in female contraceptives and recognized as a contaminant of attention (Watch List) in the European Union due to its high consumption, endocrine effects and occurrence in aquatic environments. Its main source of introduction is domestic sewage where it can be associated with other contaminants such as microplastics (MPs). Due to their characteristics, they can combine with each other and exacerbate their isolated effects on biota.

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In November 2015, the Fundão Dam break released millions of tons of metal-rich tailings into the Doce River Basin (DRB), causing catastrophic damage and potential ecological effects that reached the Atlantic Ocean. This study aimed to evaluate the geochemistry and toxicity of water and sediments collected in the DRB from 2015 to 2019 and to determine the spatial and temporal trends. Water and sediment samples were analyzed for metals and As by inductively coupled plasma optical emission spectrometry (ICP-OES), and acute toxicity for Daphnia similis or D.

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The most extensive oil spill ever recorded in tropical oceans occurred between August 2019 and March 2020, affecting approximately 3000 km of the Brazilian coast. This study assessed the chemical contamination and toxicity of sediments collected from affected reef areas during two sampling surveys conducted 17 and 24 months after the peak of oil slick inputs. Our results indicated that neither PAH levels nor measured toxicity showed a significant contribution from the spilled oil, with concentrations and biological effects indistinguishable from those in unaffected areas.

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Biocides used in antifouling (AF) paints, such as 4,5-dichlorine-2-n-octyl-4-isothiazole-3-one (DCOIT), can gradually leach into the environment. Some AF compounds can persist in the marine environment and cause harmful effects to non-target organisms. Nanoengineered materials, such as mesoporous silica nanocapsules (SiNCs) containing AF compounds, have been developed to control their release rate and reduce their toxicity to aquatic organisms.

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Marine Protected Areas (MPAs) are designed to conserve biodiversity and vulnerable ecosystems. This study aimed to assess the environmental quality of three Brazilian MPAs, based on the integrated analysis of biomarkers in pufferfish. The MPAs are differentiated by the degree of anthropogenic influences.

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Sedimentary aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) were studied in subtropical estuaries with distinct degrees of legal protection, located in the Southwestern Atlantic Ocean, São Paulo State, Brazil. A multivariate approach was adopted, using the Hierarchical cluster analysis followed by the Principal Matrix Factorization analysis to support the hydrocarbons sources findings using diagnostic ratios. In general, the sites with the highest values of hydrocarbons were in the vicinity of well-urbanized cities, where sewage discharge, harbor and industrial activities take place.

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Data-independent acquisition (DIA) mode in liquid chromatography (LC) high-resolution mass spectrometry (HRMS) has emerged as a powerful strategy in untargeted metabolomics for detecting a broad range of metabolites. However, the use of this approach also represents a challenge in the analysis of the large datasets generated. The regions of interest (ROI) multivariate curve resolution (MCR) approach can help in the identification and characterization of unknown metabolites in their mixtures by linking their MS1 and MS2 DIA spectral signals.

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Glitter particles are considered a model of microplastics, which are used in a wide range of products. In this study, we evaluated the toxicity of two types of glitter (green and white, with distinct chemical compositions) dispersions on the embryonic development of the sea urchins , , and the mussel . The Toxicity Identification and Evaluation (TIE) approach was used to identify possible chemicals related to toxicity.

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This study aimed to evaluate B[a]P and low-density polyethylene microplastics (MPs) toxicty, alone and in mixture (0.03 to 30 μg L of B[a]P; and 5, 50 and 500 mg L for MPs). Five mg L of MPs is considerably higher than commonly reported environmental concentrations, although it has been reported for marine environments.

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Organotin-based (OTs: TBT and TPT) antifouling paints have been banned worldwide, but recent inputs have been detected in tropical coastal areas. However, there is a lack of studies evaluating the toxicity of both legacy and their substitute antifouling booster biocides (e.g.

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Microplastics, including plastic pellets, get stranded on sandy beaches. They persist in the oceans for long periods and frequently carry contaminants. Acute and chronic toxicity has been observed when marine organisms are exposed to high densities of plastic pellets in laboratory assays.

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Biogenic silver nanoparticles (AgNPs) are considered a promising alternative to their synthetic versions. However, the environmental impact of such nanomaterials is still scarcely understood. Thus, the present study aims at assessing the antimicrobial action and ecotoxicity of AgNPs biosynthesized by the fungus Aspergillus niger IBCLP20 towards three freshwater organisms: Chlorella vulgaris, Daphnia similis, and Danio rerio (zebrafish).

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We analyzed per- and polyfluoroalkyl substances (PFAS) in aqueous film-forming foams (AFFFs) used to extinguish a major fire in a petrochemical terminal from the Port of Santos (Brazil). Eight AFFFs from seven known commercial brands and one unknown sample (AFFF-1 to AFFF-8) were evaluated. 17 PFAS were identified and quantified using high performance liquid chromatography (LC/MS).

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Sediments represent a major sink and also a main source of contaminants to aquatic environments. An environmental disaster from a mining dam breakage in 2015 in South-East Brazil re-suspended complex mixtures of chemicals deposited in the sediment, spreading contaminants along the Doce River Basin (DRB) major river course. While high levels of contaminants in sediment were well described, toxicological effects in aquatic organisms were poorly investigated.

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Article Synopsis
  • The study highlights the drawback of simplifying complex histopathological data into single indices, which can result in significant information loss regarding environmental quality.
  • The research aimed to assess the effectiveness of a multivariate approach that combines individual histopathological responses with contaminant levels, comparing it to the traditional univariate Bernet index.
  • Results showed that the multivariate analysis provided a clearer classification of environmental quality across various sites, while the univariate index was less reliable and primarily identified only the most severely impacted areas.
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Article Synopsis
  • Domestic sewage introduces pollutants like microplastics (MPs) and pharmaceuticals, posing risks to aquatic ecosystems, prompting this study on their combined biological impact using the swamp ghost crab Ucides cordatus as a model.
  • The research involved exposing crabs to various treatments (control, microplastics, microplastics with triclosan) for 7 days and analyzing tissue samples for multiple biomarkers indicative of biological stress and damage.
  • Results showed triclosan contamination in both water and crab tissues, with significant adverse effects observed from exposure to microplastics contaminated with triclosan, highlighting the role of microplastics as carriers for harmful substances in marine environments.
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The gastrointestinal tract and its enteric nervous system are the first routes of food and xenobiotics uptake. Considering the importance of this organ, this study evaluated intestinal biomarkers of Sphoeroides testudineus integrating the data to generate tools for pollution assessment. The fish were collected in three sites of São Paulo Coast and their intestines were analyzed for biochemical, histology, and neuronal density and morphometry biomarkers.

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Article Synopsis
  • Traditional methods for assessing contaminant effects on marine organisms often require euthanizing the species, but less invasive techniques may be better for threatened species.
  • This study focused on the biological responses of crabs (U. cordatus) exposed to microplastics and chemicals like Triclosan and 17α-Ethynylestradiol, analyzing effects like lipid peroxidation, DNA damage, and enzyme activity.
  • Results revealed that exposure to microplastics, whether alone or with additional contaminants, caused significant toxic effects such as oxidative stress, genotoxicity, and neurotoxic impacts, highlighting the effectiveness of non-lethal methods for studying environmental hazards.
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Recent advances in nanotechnology have allowed the encapsulation of hazardous antifouling (AF) biocides in silica mesoporous nanocapsules (SiNC) reducing their short-term toxicity. However, the chronic effects of such novel nanoadditives remain understudied. The present study aimed to assess short- and long-term sub-lethal effects of soluble forms (DCOIT and Ag) and nanostructured forms (SiNC-DCOIT and SiNC-DCOIT-Ag) of two AF biocides and the "empty" nanocapsule (SiNC) on juveniles of Crassostrea gigas after 96 h and 14 days of exposure.

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This study investigated the sublethal effects of environmentally relevant concentrations of DCOIT on the neotropical oyster Crassostrea brasiliana. Gills and digestive glands of animals exposed to increasing concentrations of DCOIT were analyzed for biochemical, cellular, and histopathological responses. Exposure to DCOIT (0.

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Accidents involving fuels and oil spills are among the main sources of hydrocarbons to the marine ecosystems and often damage the biota. Diesel and bunker oil are two examples of fuels with broad application that release hydrocarbons to the aquatic environment and little is known about their toxicity on tropical organisms. This study aimed to assess the toxicity of the water-soluble fraction (WSF) of diesel and bunker oils to neotropical marine invertebrates.

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