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1.
Chemosphere ; 262: 127772, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32799140

RESUMO

This study utilized the freshwater amphipod (Hyalella azteca) for the indication of contamination risk levels of sediment-associated contaminants in the Erren (ER1∼ER10) and Sanye Rivers (SY1∼SY5) which were contaminated by metal scrap and smelting industries for decades. Toxicity identification evaluations involving the manipulation of pore water and whole-sediment samples were conducted to identify causative pollutants. Impacts on the aquatic environment were then evaluated in order to explore how industrial development led to contaminant accumulation in sediments and resulted in biological effects. A whole-sediment TIE indicated that the major toxicant at sampling sites ER8 and SY5 was ammonia and that its toxicity was significantly reduced by the addition of zeolite. Toxicity at sampling sites ER4 and ER9 was induced by ammonia and heavy metals (Zn, Cd, Cr, As), whereas Cr was at toxic levels at ER6. ∑PAHs was another major class of contaminants at site ER2. Metals (Zn, Ni, Pb, Cd, Cr, and As) were identified as major toxic contaminants at three sites (ER3, SY1, and SY3). The application of TIEs confirmed that a causative toxicant can be identified and that its measured toxicity correlated with its concentration. In conclusion, a TIE approach was successful in demarcating most effective contaminant groups (ammonia, heavy metals, and non-polar organic compounds) in whole-sediment cores, their porewaters and potential toxicities from a highly polluted river after remediation in southern Taiwan to an invertebrate animal model H. azteca.


Assuntos
Anfípodes/efeitos dos fármacos , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Rios/química , Poluentes Químicos da Água/toxicidade , Amônia/análise , Amônia/toxicidade , Animais , Água Doce/química , Metais Pesados/análise , Metais Pesados/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Taiwan , Clima Tropical , Poluentes Químicos da Água/análise , Zeolitas/química
2.
Chemosphere ; 261: 127888, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33113669

RESUMO

Besides anthropogenic contamination, freshwater environments can also be affected by the presence of natural toxins. Mycotoxins, plant toxins and cyanotoxins are the most relevant groups that can be found in the aquatic system. However, until now, only cyanotoxins have been more carefully studied. In the present work, single workflow for the assessment of natural toxins in waters, based on suspect screening and target screening of a selected group of toxins is presented. The approach is based on a triple-stage solid-phase extraction (SPE) able to isolate a wide range of natural toxins of different polarities, followed by liquid chromatography coupled to high-resolution mass spectrometry (HPLC-ddHRMS2) using a Q-Exactive Orbitrap analyser. The acquisition was performed in full-scan (FS) and data-dependant acquisition (ddMS2) mode, working under positive and negative mode. For the tentative identification, different on-line databases such as ChemSpider and MzCloud and an in-house natural toxins list with 2384 structures, that includes cyanotoxins, plant toxins and mycotoxins, were used. Also, thanks to the MS2 data, it was possible to achieve a high level of tentative identification confidence, but confirmation was only possible comparing the standards of the suspected compounds. For those, the analytical parameters of the developed method were also validated, and the quantification was possible by external calibration. Validation showed recoveries in the range between 53 and 95%, and method limits of detection (MDL) between 0.02 and 1.22 µg/L. This approach was applied to study natural toxins in 4 sampling sites along the Ter River in Catalonia (NE Spain). In this preliminary study 23 natural toxins were tentatively identified, and 9 of them confirmed (aflatoxin B1, anatoxin-a, nodularin, microcystin-LR, baicalein, kojic acid, cinchonine, B-asarone and atropine). The results of the quantification of these compounds showed concentrations below 1 µg/L in all cases, that is considered safe according to the actual legislation. This suspect screening approach allows a more comprehensive assessment of natural toxins in natural waters.


Assuntos
Toxinas Bacterianas/análise , Água Potável/química , Água Doce/química , Micotoxinas/análise , Poluentes Químicos da Água/análise , Cromatografia Líquida de Alta Pressão/métodos , Água Potável/normas , Limite de Detecção , Espectrometria de Massas/métodos , Microcistinas/análise , Peptídeos Cíclicos/análise , Extração em Fase Sólida/métodos , Espanha , Tropanos/análise
3.
Aquat Toxicol ; 228: 105646, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33011648

RESUMO

2,4-dinitrophenol (2,4-DNP) is a phenolic compound used as a wood preservative or pesticide. The chemical is hazardous to freshwater organisms. Although 2,4-DNP poses ecological risks, only a few of its aquatic environmental risks have been investigated and very limited guidelines for freshwater aquatic ecosystems have been established by governments. This study addresses the paucity of 2,4-DNP toxicity data for freshwater ecosystems and the current lack of highly reliable trigger values for this highly toxic compound. We conducted acute bioassays using 12 species from nine taxonomic groups and chronic assays using five species from four taxonomic groups to improve the quality of the dataset and enable the estimation of protective concentrations based on species sensitivity distributions. The acute and hazardous concentrations of 2,4-DNP in 5% of freshwater aquatic species (HC5) were determined to be 0.91 (0.32-2.65) mg/L and 0.22 (0.11-0.42) mg/L, respectively. To the best of our knowledge, this is the first report of a suggested chronic HC5 for 2,4-DNP and it provides the much-needed fundamental data for the risk assessment and management of freshwater ecosystems.


Assuntos
2,4-Dinitrofenol/análise , Ecossistema , Monitoramento Ambiental , Água Doce/química , Praguicidas/toxicidade , Poluentes Químicos da Água/análise , Animais , Organismos Aquáticos/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Chlamydomonas/efeitos dos fármacos , Clorofíceas/efeitos dos fármacos , Embrião não Mamífero/efeitos dos fármacos , Euglena/efeitos dos fármacos , Oryzias , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Especificidade da Espécie , Testes de Toxicidade Aguda , Testes de Toxicidade Crônica , Qualidade da Água
4.
Bull Environ Contam Toxicol ; 105(5): 699-704, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33006036

RESUMO

Transportation of crude oil across North America's boreal ecozone creates the potential for spills in freshwater where less is known about the sensitivity of resident fish than for marine systems. The sensitivity of wild fathead minnows (FHM) to residual concentrations (ppb range) of the water accommodated fraction (WAF) of diluted bitumen (dilbit) was assessed by exposing them for 21 days followed by a 14 days depuration. Target concentrations were well below detection limits for GC-MS, but were estimated by dilution factor (1:100,000 and 1:1,000,000 WAF:water) to contain less than 0.0003 µg/L of polycyclic aromatic compounds. Confinement and handling stress caused by transfer of wild fish into tanks much smaller than their natural range resulted in mortality and lower body condition among all groups, but interactive effects of oil exposures still resulted in females with smaller cortical alveolar oocytes, and males with larger testicular lobe lumen sizes. Additional studies examining the compounded effects of stress and environmentally relevant oil exposures in wild fishes are needed.


Assuntos
Cyprinidae/crescimento & desenvolvimento , Exposição Ambiental/análise , Hidrocarbonetos/análise , Poluição por Petróleo/análise , Petróleo/análise , Poluentes Químicos da Água/análise , Animais , Exposição Ambiental/efeitos adversos , Feminino , Água Doce/química , Hidrocarbonetos/toxicidade , Masculino , América do Norte , Óvulo/efeitos dos fármacos , Óvulo/patologia , Petróleo/toxicidade , Poluição por Petróleo/efeitos adversos , Testículo/efeitos dos fármacos , Testículo/patologia , Poluentes Químicos da Água/toxicidade
5.
Aquat Toxicol ; 228: 105626, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32992088

RESUMO

Increasing salinity in freshwater environments is a growing problem due both to the negative influences of salts on ecosystems and their accumulation and persistence in environments. Two major sources of increased salinity from sodium chloride salts (NaCl) are saline wastewaters co-produced during energy production (herein, wastewaters) and road salts. Effects of road salts have received more attention, but legacy contamination from wastewaters is widespread in some regions and spills still occur. Amphibians are sensitive to contaminants, including NaCl, because of their porous skin and osmoregulatory adaptations to freshwater. However, similarities and differences between effects of wastewaters and road salts have not been investigated. Therefore, we investigated the relative influence of wastewaters and NaCl at equivalent concentrations of chloride on three larval amphibian species that occur in areas with increased salinity. We determined acute toxicity and growth effects on Boreal Chorus Frogs (Pseudacris maculata), Northern Leopard Frogs (Rana pipiens), and Barred Tiger Salamanders (Ambystoma mavortium). We posited that wastewaters would have additive effects on amphibians compared to NaCl because wastewaters often have additional toxic heavy metals and other contaminants. For NaCl, toxicity was higher for frogs than the salamander. Toxicity of wastewaters was also similar between chorus and leopard frogs. Only chorus frog survival was lower when exposed to wastewater compared to NaCl. Mass and length of leopard and chorus frog larvae decreased with increasing salinity after only 96 hours of exposure but did not for tiger salamanders. Size of leopard frogs was lower when exposed to NaCl compared to wastewater. However, growth effects were similar between wastewater and NaCl for chorus frogs. Taken together, our results suggest that previous studies on effects of road salt could inform future studies and management of wastewater-contaminated ecosystems, and vice versa. Nevertheless, effects of road salts and wastewaters may be context-, species-, and trait-specific and require further investigations. The negative influence of salts on imperiled amphibians underscores the need to restore landscapes with increased salinity and reduce future salinization of freshwater ecosystems.


Assuntos
Água Doce/química , Larva/efeitos dos fármacos , Cloreto de Sódio/toxicidade , Águas Residuárias/química , Poluentes Químicos da Água/toxicidade , Animais , Anuros , Ecossistema , Pradaria , Salinidade , Testes de Toxicidade Aguda
6.
Ecotoxicol Environ Saf ; 205: 111291, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32956865

RESUMO

The purpose of this study was to determine the acute toxicity in aquatic organisms of one biocidal active substance and six metabolites derived from biocidal active substances and to assess the suitability of available QSAR models to predict the obtained values. We have reported the acute toxicity in sewage treatment plant (STP) microorganisms, in the freshwater microalgae Pseudokirchneriella subcapitata and in Daphnia magna following OECD test methods. We have also identified in silico models for acute toxicity of these trophic levels currently available in widely recognized platforms such as VEGA and the OECD QSAR ToolBox. A total of six, four and two models have been selected for Daphnia, algae and microorganisms, respectively. Finally, we have compared the in silico and in vivo data for the seven compounds plus two previously assayed biocidal substances. None of the compounds tested were toxic for Daphnia and STP microorganisms. For microalgae, CGA71019 (1,2,4 triazole) presented an ErC50 value of 38.3 mg/L. The selected in silico models have provided lower EC50 values and are therefore more conservative. Models from the OECD QSAR ToolBox predicted values for 7 out of 9 and for 4 out of 9 chemicals for Daphnia and P. subcapitata, respectively. No predictive models were identified in such platform for STP microorganism's acute effects. In terms of models's specificity, biocide-specific models, developed from curated datasets integrated by biocidal active substances and implemented in VEGA, perform better in the case of microalgae but for Daphnia an alternative, non biocide-specific has revealed a better performance. For STP microorganisms only biocide-specific models have been identified.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Desinfetantes/toxicidade , Modelos Biológicos , Poluentes Químicos da Água/toxicidade , Animais , Clorofíceas/efeitos dos fármacos , Simulação por Computador , Daphnia/efeitos dos fármacos , Desinfetantes/química , Desinfetantes/metabolismo , Água Doce/química , Microalgas/efeitos dos fármacos , Relação Quantitativa Estrutura-Atividade , Poluentes Químicos da Água/química , Poluentes Químicos da Água/metabolismo
7.
Ecotoxicol Environ Saf ; 203: 111022, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888608

RESUMO

To evaluate the aquatic hazards of the insect juvenile hormone analogue fenoxycarb, a single application (0, 48.8, 156.3, 500, 1600, and 5120 µg/L) of it was done in indoor freshwater systems dominated by Daphnia carinata (daphnid) and Dolerocypris sinensis (ostracoda). The responses of zooplankton (counted by abundance and the activity and immuno-reactive content of free N-Acetyl-ß-D-glucosaminidase (NAGase)), phytoplankton (counted by chlorophyll and phycocyanin), planktonic bacteria and fungi, and some water quality parameters were investigated in a period of 35 d. Results of the study showed that the ostracoda was more sensitive than daphnid, with time-weighted average (TWA)-based no observed effect concentrations (NOECs) to be 8.45 and 12.66 µg/L in systems without humic acid addition (HA-) and to be 6.37 and 9.54 µg/L in systems with humic acid addition (HA+). The duration of treatment-related effects in the ostracoda population was longer than the daphnid population (21 vs. 14 days). Besides, the data analysis indicated that the toxicity of fenoxycarb was significantly enhanced in the HA+ systems. Owing to the reduced grazing pressure, the concentrations of chlorophyll and phycocyanin increased in the two highest treatments. The increase in photosynthesis along with a reduced animal excretion led to an increase in pH and a decrease in nutrient contents. These changes seemed to have an effect on the microbial communities. For example, the abundances of some opportunistic pathogens of aquatic animals (e.g. Aeromonas and Cladosporium) and organic-pollutant-degrading microorganisms (e.g. Ancylobacter and Azospirillum) increased significantly in microbial communities, but the abundances of Pedobacter, Candidatus Planktoluna, and Rhodobacter (photosynthetic bacteria) markedly decreased. This study provides useful information to understand the ecotoxicological impacts of fenoxycarb at the population and community levels while integrating the effects of HA on toxicity.


Assuntos
Crustáceos/efeitos dos fármacos , Daphnia/efeitos dos fármacos , Água Doce/química , Fenilcarbamatos/toxicidade , Fitoplâncton/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Zooplâncton/efeitos dos fármacos , Animais , Ecotoxicologia , Substâncias Húmicas/efeitos adversos , Substâncias Húmicas/análise , Microbiota/efeitos dos fármacos
8.
Bull Environ Contam Toxicol ; 105(5): 715-720, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32970224

RESUMO

Genotoxic potential of herbicide bispyribac-sodium was evaluated in fish Clarias batrachus using micronucleus (MN) test and comet assay. Fish were exposed to three environmentally relevant test concentrations of the herbicide for 20, 25 and 30 days. Significant effects (p < 0.05) for both concentration and duration of exposure were observed in herbicide exposed fish. Similar trend of DNA damage was observed through MN test and comet assay. Maximum DNA damage was observed in fish exposed to highest concentration of herbicide at all duration. Maximum damage was observed on day 25 at all concentrations followed by a decline. This study established C. batrachus as an ecotoxicological model for bispyribac-sodium induced genotoxicity testing. It further confirmed that both MN test and comet assay are useful tool for assessment of genotoxicity induced by water pollutants.


Assuntos
Benzoatos/toxicidade , Peixes-Gato/genética , Dano ao DNA , Herbicidas/toxicidade , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Pirimidinas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Ensaio Cometa , Relação Dose-Resposta a Droga , Água Doce/química , Dose Letal Mediana , Testes para Micronúcleos , Testes de Mutagenicidade , Fatores de Tempo
9.
Aquat Toxicol ; 227: 105569, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32916319

RESUMO

Pharmaceuticals are widespread contaminants across the aquatic systems and despite the role that these compounds play in society today, little is known about their effects in aquatic organisms once they are released into the environment. This study aims to provide quantitative insight on the effects of antidepressants on the reproduction of fish and crustaceans with a multilevel meta-analysis. A systematic literature search identified 19 studies investigating effects of antidepressant exposure in fish or crustaceans' reproduction, according to specific selection criteria. Heterogeneity analysis was performed and the moderating effect of the range of exposure concentrations, exposure time, organism group and toxicant was tested. Additionally, publication bias was also addressed. The results showed that, overall, there is no significant association between antidepressant exposure and the reproduction of fish and crustaceans, however, moderator analysis revealed that the range of concentrations is a significant moderator for fish and crustacean fecundity, showing contrary results between the two groups. Antidepressant concentration had a small, yet positive effect on fish fecundity, meaning that increased concentrations resulted in increased fish fecundity, whilst a negative effect on crustaceans' fecundity was apparent with increasing concentrations. This difference could be related to data artifacts, or, more likely, evidencing a hormetic dose-response curve, with different ranges of exposure concentrations considered in studies on fish and crustaceans. Antidepressants have shown effects on reproductive outcomes in aquatic organisms, based on individual studies and narrative reviews. However, our results show that other factors can have an important role. Additionally, data available for a quantitative assessment is scarce, focusing mainly on a few freshwater species, low concentration ranges and one SSRI compound, fluoxetine. Thus, more research on the subject is needed since meta-analysis are only as statistically powerful as the number of, good quality, studies they include.


Assuntos
Antidepressivos/toxicidade , Organismos Aquáticos/efeitos dos fármacos , Fluoxetina/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/fisiologia , Crustáceos/efeitos dos fármacos , Peixes/crescimento & desenvolvimento , Água Doce/química , Reprodução/efeitos dos fármacos
10.
Arch Environ Contam Toxicol ; 79(3): 298-309, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32860087

RESUMO

Aquatic environments are constantly exposed to a cocktail of contaminants mainly due to human activities. As polluted ecosystems may simultaneously present other multiple natural stressors, the objective of the present study was to evaluate joint effect of stressors (natural and anthropogenic) on life history traits of the Neotropical cladoceran, Ceriodaphnia silvestrii. For this purpose, the effects of water conditioned with predator kairomones (fish) and environmental concentrations (sublethal) of two pesticides widely used in sugarcane monoculture in Brazil, the insecticide Regent® 800 WG (active ingredient-a.i. fipronil) and the herbicide DMA® 806 BR (a.i. 2,4-D) were evaluated using chronic toxicity testing, isolated and in mixture, for this cladoceran species. The environmental risks of pesticides for tropical freshwater biota were also estimated from the risk quotient MEC/PNEC. Among the characteristics of the life history of C. silvestrii evaluated after 8 days of exposure, compared with the mean value of control, the age of primiparous females was not affected by any evaluated treatment. However, species average survival decreased in the treatment of kairomones mixed with fipronil (FK) and in the treatment with a mixture of fipronil, 2,4-D, and kairomones (MFKD). The body length of maternal females was shorter than in the control after exposure in treatments with only kairomones (K) and FK. Fecundity of this cladoceran was reduced when exposed to FK and MFKD treatments, and the intrinsic rate of population increase significantly decreased for organisms exposed to treatment with fipronil (F) and to mixtures of fipronil and 2,4-D (MFD), MFDK, and FK. The results indicated that the combination of anthropogenic and natural stressors causes changes in C. silvestrii life history traits, which can contribute to the decline in populations, and our preliminary risk assessment results are a matter of concern regarding biota conservation.


Assuntos
Ácido 2,4-Diclorofenoxiacético/toxicidade , Cladóceros/efeitos dos fármacos , Traços de História de Vida , Feromônios/toxicidade , Pirazóis/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Brasil , Ecossistema , Feminino , Fertilidade/efeitos dos fármacos , Peixes/metabolismo , Água Doce/química , Testes de Toxicidade Crônica
11.
Ecotoxicol Environ Saf ; 202: 110944, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800225

RESUMO

Bisphenol A (BPA), a weak estrogenic endocrine disruptor and a well-known plasticizer, has the potential to perturb diverse physiological functions; however, its impact on immune and metabolic function in aquatic vertebrates is relatively less understood. The present study aims to investigate the impact of BPA on hepatotoxicity, metabolic and immune parameters vis-à-vis estrogen receptor expression modulation in a freshwater teleost, Labeo bata (Cyprinidae, Cypriniformes). The 96-h median lethal concentration of BPA in L. bata has been determined as 4.79 mg/L. Our data demonstrate that congruent with induction of plasma vitellogenin (VTG), chronic exposure to sub-lethal BPA (2 and 4 µM/L) attenuates erythrocyte count, hemoglobin concentration, packed cell volume, mean corpuscular hemoglobin, but not leukocyte number. Further, a significant increase in MDA, concomitant with diminished catalase and heightened GST activity corroborates well with hepatic dystrophic changes, appearance of fatty liver (macrovesicular steatosis) and elevated serum lipids (triglyceride, cholesterol, LDL, VLDL) in BPA-treated groups. Interestingly, a differential regulation of estrogen receptor (ER) subtypes at transcript and protein level signifies negative influence of BPA on hepatic ERα/ERß homeostasis in this species. While at a lower dose it promotes Akt phosphorylation (activation), BPA at the higher dose attenuates ERK1/2 phosphorylation (activation), suggesting potential alteration in insulin sensitivity. Importantly, dose-dependent decrease in hepatic TNF-α, IL-1ß, iNOS (NOS2) expression and nitric oxide (NO) level corresponds well with progressive decline in p-NF-κB, p-p38 MAPK, albeit with differential sensitivity, in BPA-exposed groups. Collectively, BPA exposure has wide-spread negative influence on hematological, biochemical and hepatic events in this species.


Assuntos
Compostos Benzidrílicos/toxicidade , Cyprinidae/metabolismo , Disruptores Endócrinos/toxicidade , Fígado/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Fenóis/toxicidade , Receptores Estrogênicos/genética , Animais , Cyprinidae/imunologia , Citocinas/metabolismo , Relação Dose-Resposta a Droga , Receptor alfa de Estrogênio/genética , Receptor beta de Estrogênio/genética , Água Doce/química , Expressão Gênica/efeitos dos fármacos , Homeostase , Inflamação , Fígado/imunologia , Fígado/metabolismo , Redes e Vias Metabólicas/efeitos dos fármacos , Vitelogeninas/metabolismo
12.
Ecotoxicol Environ Saf ; 204: 111059, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32791357

RESUMO

Exploring the Manganese (Mn) removal prediction with several independent variables is tremendously critical and indispensable to understand the pattern of removal process. Mn is one of the key heavy metals (HMs) stipulated by the WHO for the development of many attributes of the ecosystem in controlled quantity. In the present paper, an extreme gradient model (XGBoost) is proposed for Mn prediction. A compressive statistical analysis reveals the stochastics behaviour of the data prior to the prediction investigation. The main goal is to determine the Mn predictability of XGBoost algorithm with influencing factors such as D2EHPA (M), Time (min), H2SO4 (M), NaCl (g/L), and EDTA (mM). The PCA biplot signifies the importance of the predictors. The XGBoost model validated against a diversity of data-driven models such as multilinear regression (MLR), support vector machine (SVM), and random forest (RF). The order of the applied models' performance are XGBoost > RF > SVM > MLR as per their R2 and RMSE metrics over testing phase i.e. 20.88, 0.75, 0.61, 0.40, and 2.23, 3.01, 3.51, 6.38, respectively. Moreover, the Taylor diagram and Radar chart have drown to emphasize the XGBoost model efficiency, stability, and reliability. In respect of XGBoost model prediction, 'Time' predictor outperforms D2EHPA, EDTA, H2SO4, and NaCl predictors in order.


Assuntos
Água Doce/química , Manganês/análise , Modelos Teóricos , Máquina de Vetores de Suporte , Poluentes Químicos da Água/análise , Algoritmos , Ecossistema , Previsões , Aprendizado de Máquina
13.
Ecotoxicol Environ Saf ; 205: 111157, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32829211

RESUMO

The fungicide carbendazim (CBM) has been applied all around the world but its potential adverse effects other than its recognized activity as endocrine disruptor in non target organisms have been scarcely studied. The aims of this work were (1) to use a battery of biomarkers that can reflect potential negative effects such as oxidative stress, genotoxicity, neurotoxicity or altered immune response; and (2) to examine biomarkers of detoxification by analyzing the gene expression of cytochrome P4501A1 (CYP1A1) and the multi-xenobiotic resistance protein P-glycoprotein (P-gp) in the freshwater fish Jenynsia multidentata exposed to environmentally relevant concentrations of CBM during 24 h. Fish exposed to 5 µg/L showed inhibition of GST activity and an increase of TBARs contents in gills, the organ of direct contact with waterborne contaminants. Genotoxicity - measured in peripheral blood-was evidenced by the increases of micronuclei frequency when fish were exposed to 5, 10 and 100 µg/L CBM and of nuclear abnormalities (NA) frequency at 0.05, 0.5, 5, 10 and 100 µg/L CBM. The expression inhibition of interleukin (IL-1ß) and tumor necrosis factor a (TNF-α) at 10, and 5 and 10 µg/L CBM, respectively, indicated an altered immune response. The expression of CYP1A1 was down regulated in liver at 10 µg/L and of P-gp at 5 µg/L CBM, indicating a possible slow on CBM metabolization. On the other hand, in gills CYP1A1 decreased at 5 and 10 µg/L while P-gp was induced at 5 and 100 µg/L CBM. Overall, most of these significant effects were detected below 10 µg/L CBM, in a range of realistic concentrations in aquatic ecosystems worldwide.


Assuntos
Benzimidazóis/toxicidade , Carbamatos/toxicidade , Ciprinodontiformes/metabolismo , Citocinas/metabolismo , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Animais , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Ciprinodontiformes/genética , Ciprinodontiformes/imunologia , Citocromo P-450 CYP1A1/genética , Ecossistema , Água Doce/química , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Estresse Oxidativo/genética , Estresse Oxidativo/imunologia
14.
Nanotoxicology ; 14(8): 1082-1095, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32810409

RESUMO

Since nanomaterials (NMs) are particulate contaminants, their first contact with organisms is a physical encounter ruled by physic-chemical processes that can determinate the potential NMs accumulation, toxicity, and trophic transfer. Freshwater ecosystems often become a final depository for NMs, so they can get in contact with the biota, especially primary organisms as algae. There are almost none comparative studies of this interaction using various NMs in the same conditions. This work identifies, analyzes, and compares the algae-NMs interaction by flow cytometry after a short-term contact test in which three freshwater algae (Raphidocelis subcapitata, Desmodesmus subspicatus, and Chlorella vulgaris) interact individually with a set of twelve metallic oxide NMs. Dose-response profiles and differences in the algae-NMs interaction were found according to each algae species (C. vulgaris had the most affinity, starting the interaction from 0.5 mg/L and D. subspicatus had the less affinity starting at 5 mg/L). Flow cytometry results were confirmed by optical microscopy. Some NMs characteristics were identified as key-factors that govern the algae-NMs interaction: NMs composition (no interaction for SiO2 NMs), surface electric charge (higher interaction for the positively charged NMs and lower interaction for the negatively charged ones) and crystalline form (for TiO2 NMs). The presented method can be useful for a rapid determination of the interaction between free cells organisms as microalgae and (nano)particulate substances.


Assuntos
Cério/toxicidade , Microalgas/efeitos dos fármacos , Nanoestruturas/toxicidade , Dióxido de Silício/toxicidade , Titânio/toxicidade , Poluentes Químicos da Água/toxicidade , Óxido de Zinco/toxicidade , Relação Dose-Resposta a Droga , Ecossistema , Citometria de Fluxo , Água Doce/química , Propriedades de Superfície
15.
Aquat Toxicol ; 227: 105587, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32841885

RESUMO

Among the various environmental disturbances caused by wildfires, their impacts within burnt areas and on the downhill aquatic ecosystems has been receiving increased attention. Post-fire rainfalls and subsequent runoffs play an important role in transporting ash and soil to aquatic systems within the burnt areas. These runoffs can be a diffuse source of toxic substances such as metals. The present work aims at assessing the effects of ash-loaded runoff on feeding rates of three representative aquatic invertebrates (Daphnia magna, Corbicula fluminea and Atyaephyra desmarestii) and the mosquitofish, Gambusia holbrooki, through post-exposure feeding inhibition bioassays carried out in-situ and in the laboratory using water collected from the experimental field sites. Four sites were selected in a partially burnt basin for bioassay deployment and sample collection: one site upstream of the burnt area (RUS); three sites receiving runoff directly from the burnt area, one immediately downstream of the burnt area (RDS) and two in permanent tributary streams within the burnt area (BS1 and BS2). The in-situ exposure lasted four days and began following the first post-fire major rain events. At sites affected by the wildfire, post-exposure feeding rates for D. magna, A. desmarestii and G. holbrooki were lower, which is consistent with the highest levels of metals found at these sites compared to the unaffected site, although the individual concentrations of each metal were generally below corresponding ecological safety benchmarks. Thus, interactions between metals and/or between metals and other environmental parameters certainly played a role in modulating the ecotoxic effects of the runoffs; this was further supported by a Toxic Units Summation exercise. Even if direct causal links between the ecotoxicological effects observed in D. magna, A. desmarestii and G. holbrooki and the physicochemical parameters of the water samples could not be established, the results suggest an important role of major and trace elements in explaining post-exposure feeding rate variation.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Cinza de Carvão/toxicidade , Comportamento Alimentar/efeitos dos fármacos , Metais Pesados/toxicidade , Poluentes Químicos da Água/toxicidade , Incêndios Florestais , Animais , Organismos Aquáticos/fisiologia , Bioensaio , Corbicula/efeitos dos fármacos , Ciprinodontiformes/fisiologia , Daphnia/efeitos dos fármacos , Ecossistema , Ecotoxicologia , Água Doce/química , Modelos Teóricos , Portugal , Oligoelementos/toxicidade
16.
Ecotoxicol Environ Saf ; 204: 111096, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32805503

RESUMO

The hepatopancreas is the digestive organ of crustaceans, and plays important roles also in the synthesis and secretion of sexual hormones, immunological defenses and xenobiotic detoxification. Although the importance of this organ in crustaceans cannot be underestimated, the effects of ultraviolet B (UVB) radiation on hepatopancreas are poorly understood. Moreover, Macrobrachium prawns, have a transparent carapace, which make them more susceptible to UVB radiation, since their internal organs, such as hepatopancreas, are easily reached by solar radiation. Therefore, we aimed to evaluate UVB radiation toxicity on the morphology and morphometry of hepatopancreatic epithelial cells, and to investigate these UVB effects in subcellular compartments of the ecologically-important freshwater decapod, Macrobrachium olfersii. Hepatopancreas from the UVB-irradiated group showed a granular cytoplasm, with non-defined cell limits. Morphometric analyses revealed that the UVB-irradiated group exhibited a higher frequency of fibrillar (F-cell), resorptive (R-cell) and midget (M-cell), and decreased the blister-like (B-cell). It was also observed increased vacuole frequencies and increased F-, B- and R-cell volumes in the UVB-irradiated group. In addition, it was observed increased B-cell vacuolar volumes and decreased R-cell vacuolar volumes. Ultrastructural alterations occurred in subcellular compartments in F- and R-cells, e.g. loss of mitochondrial crests, morphologically compatible with mitochondrial fission, rough endoplasmic reticulum cisternae dilation, dilation of Golgi lamellar sacs, and increased vacuole and concentric membrane formation in the UVB-irradiated group. Our data showed that the hepatopancreas is an important target of UVB radiation, as demonstrated by a series of organ-specific morphological and morphometric impairments. Therefore, cell damage caused by UVB radiation can compromise metabolic functions in epithelial cells from the hepatopancreas, potentially affecting absorption, secretion and digestion processes, vitellogenin synthesis, immune responses and xenobiotic detoxification.


Assuntos
Decápodes/efeitos da radiação , Hepatopâncreas/efeitos da radiação , Raios Ultravioleta , Animais , Decápodes/ultraestrutura , Células Epiteliais , Epitélio , Água Doce/química , Hepatopâncreas/efeitos dos fármacos , Hepatopâncreas/ultraestrutura , Dinâmica Mitocondrial , Palaemonidae/efeitos dos fármacos , Vitelogeninas/metabolismo , Xenobióticos/metabolismo
17.
Bull Environ Contam Toxicol ; 105(3): 460-467, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32839840

RESUMO

A green, sensitive and accurate dispersive liquid-liquid microextraction (DLLME) method was used to preconcentrate four selected pesticides in dam lake water samples for determination by gas chromatography-mass spectrometry (GC-MS). Conditions of the DLLME method were comprehensively investigated and optimized according to type/volume of extraction solvent, type/volume of dispersive solvent, and type/period of mixing. The developed method was validated according to the limits of detection and quantitation, accuracy, precision and linearity. Under the optimum conditions, limit of detection values calculated for alachlor, acetochlor, metolachlor and fenthion were 1.7, 1.7, 0.2 and 7.8 µg/kg (mass based), respectively. The method recorded 202, 104, 275 and 165 folds improvement in detection power values for acetochlor, alachlor, metolachlor and fenthion, respectively, when compared with direct GC-MS measurements. In order to evaluate the accuracy of the developed method, real sample application with spiking experiments was performed on dam lake water samples, and satisfactory percent recovery results in the range of 81%-120% were obtained.


Assuntos
Microextração em Fase Líquida/métodos , Praguicidas/análise , Poluentes Químicos da Água/análise , Acetamidas/análise , Fention/análise , Água Doce/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Limite de Detecção , Solventes/análise , Toluidinas/análise
18.
Aquat Toxicol ; 226: 105563, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32673887

RESUMO

Climate warming and nitrate pollution are pervasive aquatic stressors that endanger the persistence of fishes prevailing in anthropogenically disturbed habitats. Individually, elevated nitrate and temperature can influence fish energy homeostasis by increasing maintenance costs and impairing oxygen transport capacity. However, it remains unknown how fish respond to simultaneous exposure to elevated temperature and nitrate pollution. Hence, we examined the combined effects of nitrate and elevated temperatures on aerobic scope (AS, maximum-standard metabolic rates) and cardiorespiratory attributes (haemoglobin HB, haematocrit HCT, relative ventricle mass RVM, and somatic spleen index SSI) in a freshwater salmonid, Thymallus thymallus. A 3 × 2 factorial design was used, where fish were exposed to one of three ecologically relevant levels of nitrate (0, 50, or 200 mg NO3- l-1) and one of two temperatures (18 °C or 22 °C) for 6 weeks. Elevated temperature increased AS by 36 % and the improvement was stronger when coupled with nitrate exposure, indicating a positive synergistic interaction. HB was reduced by nitrate exposure, while HCT was independent of nitrate pollution and temperature. Stressor exposure induced remodeling of key elements of the cardiorespiratory system. RVM was 39 % higher in fish exposed to 22 °C compared to 18 °C but was independent of nitrate exposure. SSI was independent of temperature but was 85 % and 57 % higher in fish exposed to 50 and 200 mg NO3- l-1, respectively. Taken together, these results highlight that simultaneous exposure to elevated temperatures and nitrate pollution offers cross-tolerance benefits, which may be underscored by cardiorespiratory remodeling.


Assuntos
Metabolismo Energético/efeitos dos fármacos , Água Doce/química , Temperatura Alta , Nitratos/toxicidade , Salmonidae/metabolismo , Poluentes Químicos da Água/toxicidade , Aclimatação/efeitos dos fármacos , Animais , Ecossistema , Eutrofização , Hematócrito , Consumo de Oxigênio/efeitos dos fármacos , Salmonidae/sangue
19.
Chemosphere ; 260: 127594, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32673874

RESUMO

Salinization of freshwater ecosystems caused by human activities and climate change is a global problem that threatens freshwater resources and aquatic organisms. The aggravation of salinization and the presence of cyanobacterial blooms may pose a serious threat to crustacean zooplankton Daphnia. To test the consequences of these effects, we exposed Daphnia magna to the combined treatments of different chloride concentrations and three food compositions (100% Chlorella pyrenoidosa, 90% C. pyrenoidosa + 10% toxic Microcystis aeruginosa, 80% C. pyrenoidosa + 20% toxic M. aeruginosa) for 21 days, recorded relevant life history indicators, and fitted them using Sigmoidal and Gaussian model if appropriate. Results showed that both increased chloride and the presence of toxic M. aeruginosa in the food had significantly negative effects on key life history traits and clearance rate, and the two factors also had a significant interaction on the survival, development, and reproduction of D. magna. The maximum values of the key life-history traits and clearance rate, the median effect chloride concentrations, and the optimal chloride concentrations derived from the models showed that the survival, reproduction, and clearance rate of D. magna were threatened by high chloride concentrations, which were exacerbated by the presence of toxic M. aeruginosa, but lower concentration of chloride was beneficial to D. magna to resist toxic M. aeruginosa. In conclusion, the combined effects of increasing chloride concentration and cyanobacterial blooms have severely adverse impacts on cladocerans, which may cause cladocera population to decline more rapidly and potentially disrupt the food webs of aquatic ecosystems.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Daphnia/efeitos dos fármacos , Água Doce/química , Microcystis/crescimento & desenvolvimento , Cloreto de Sódio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Chlorella/crescimento & desenvolvimento , Daphnia/crescimento & desenvolvimento , Daphnia/fisiologia , Ecossistema , Cadeia Alimentar , Humanos , Traços de História de Vida , Reprodução/efeitos dos fármacos
20.
PLoS One ; 15(7): e0235225, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32649660

RESUMO

Freshwater wetlands of the temperate north are exposed to a range of pollutants that may alter their function, including nitrogen (N)-rich agricultural and urban runoff, seawater intrusion, and road salt contamination, though it is largely unknown how these drivers of change interact with the vegetation to affect wetland carbon (C) fluxes and microbial communities. We implemented a full factorial mesocosm (378.5 L tanks) experiment investigating C-related responses to three common wetland plants of eastern North America (Phragmites australis, Spartina pectinata, Typha latifolia), and four water quality treatments (fresh water control, N, road salt, sea salt). During the 2017 growing season, we quantified carbon dioxide (CO2) and methane (CH4) fluxes, above- and below-ground biomass, root porosity, light penetration, pore water chemistry (NH4+, NO3-, SO4-2, Cl-, DOC), soil C mineralization, as well as sediment microbial communities via 16S rRNA gene sequencing. Relative to freshwater controls, N enrichment stimulated plant biomass, which in turn increased CO2 uptake and reduced light penetration, especially in Spartina stands. Root porosity was not affected by water quality, but was positively correlated with CH4 emissions, suggesting that plants can be important conduits for CH4 from anoxic sediment to the atmosphere. Sediment microbial composition was largely unaffected by N addition, whereas salt amendments induced structural shifts, reduced sediment community diversity, and reduced C mineralization rates, presumably due to osmotic stress. Methane emissions were suppressed by sea salt, but not road salt, providing evidence for the additional chemical control (SO4-2 availability) on this microbial-mediated process. Thus, N may have stimulated plant activity while salting treatments preferentially enriched specific microbial populations. Together our findings underpin the utility of combining plant and microbial responses, and highlight the need for more integrative studies to predict the consequences of a changing environment on freshwater wetlands.


Assuntos
Microbiota/fisiologia , Nitrogênio/química , Plantas/metabolismo , Cloreto de Sódio/química , Solo/química , Ciclo do Carbono , Connecticut , Água Doce/química , Sedimentos Geológicos/microbiologia , Nitrogênio/análise , Cloreto de Sódio/análise , Microbiologia do Solo , Qualidade da Água , Áreas Alagadas
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