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1.
Chemosphere ; 247: 125795, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31927181

RESUMO

The association of low concentrations of pyriproxyfen and Spinosad, a naturally-occurring insecticide, was evaluated as an environment-friendly strategy to rationalize Aedes aegypti control programs by reducing larvicide consumption, saving financial costs and increasing residual effect against mosquitoes development. Firstly, the ecotoxicological parameters of the mixture was performed on non-target species Daphnia magna and the results confirmed that the low concentrations used in this larvicide mixture were not able to alter the reproductive parameters of chronically exposed microcrustaceans. In contrast, the mixture altered the behavior and development of Aedes aegypti, effectively inhibiting the emergence of adult insects for a long period. The results confirm the hypothesis that even at very low concentrations, the combination of the Spinosad and Pyriproxyfen larvicides offers an opportunity for Aedes aegypti public control programs to be more efficient.


Assuntos
Aedes/efeitos dos fármacos , Inseticidas/farmacologia , Macrolídeos/farmacologia , Controle de Mosquitos/métodos , Piridinas/farmacologia , Animais , Daphnia/efeitos dos fármacos , Combinação de Medicamentos , Ecotoxicologia/métodos , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento
2.
Arch Environ Contam Toxicol ; 78(2): 216-229, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31897536

RESUMO

The evaluation of bioconcentration, toxicity, and hazard (BTH) of persistent lipophilic organic compounds (LOCs) are generally performed as separate rather than integrated assessments. There are adequate data sets in the literature for chlorobenzenes (CBs) consisting of (a) concentrations in aquatic biota (CB) and water (Cw) in the natural environment, (b) laboratory-derived bioconcentration factors (KB) and field concentration ratios (CR), the field equivalent factor of KB, (c) measured internal lethal concentrations (ILC50) and model estimated ILC50 calculated from KB and lethal concentrations (LC50), and (d) calculated hazard quotients in aquatic biota (HQB) and in water (HQW). However, there have been no integrated studies of those parameter values based on the respective lipid-based parameters (CBL, KBL, CRL, ILC50L, HQBL) performed. This study utilized the lipid-based parameters for CBs; a group of widely occuring, bioaccumulative, and toxic LOCs, and integrated those parameters into a bioconcentration-toxicity-hazard (BTHL) index. The values of the parameters were obtained from selected literature with known lipid contents of the aquatic biota. The results showed that the laboratory derived bioconcentration factors, KBLs, were comparable to the corresponding field based factors, CRLs, and the measured internal lethal concentrations, ILC50L, showed comparable values with the estimated ones. The integrated BTHL index was less than an order of magnitude or moderately acceptable for the assessment of variability, uncertainty, and predictive power of the index. This integrated assessment can be used to support decision making dealing with CBs in specific and LOCs in general, both in regional and global aquatic environments.


Assuntos
Clorobenzenos/análise , Clorobenzenos/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Animais , Bioacumulação , Clorobenzenos/farmacocinética , Ecotoxicologia/métodos , Dose Letal Mediana , Metabolismo dos Lipídeos/efeitos dos fármacos , Poluentes Químicos da Água/farmacocinética
3.
Chemosphere ; 242: 125231, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31704521

RESUMO

A large number of metals is present in aquatic ecosystems, often occurring simultaneously, however, the isolated toxicity of them are better well known than their mixtures. Based on that, for the first time we aimed to test the effects of zinc (Zn) and aluminum (Al) mixtures to the microalgae Raphidocelis subcapitata. Regarding isolated toxicity, the 96 h IC50 of Zn and Al based on specific growth rates occurred, respectively, at 0.40 and 27.40 µM, thus Zn was ≈70-fold more toxic than Al. Both Zn and Al altered the cell size and complexity of R. subcapitata at the highest concentrations, although only during Zn exposure was the chlorophyll a fluorescence significantly diminished. Microalgae exposed to Al produced more ROS than during Zn exposure. Moreover, algae produced less ROS at the highest Zn concentration than in the lower concentrations. According to species sensitivity curves (SSD), R. subcapitata was the most sensitive organism to Zn and one of the most sensitive to Al. With respect to mixture toxicity tests, there were significant deviations for both CA (concentration addition) and IA (independent action) models, although data best fitted the CA model and DL (dose level-dependence) deviation, in which metals showed synergic effects at low concentrations and antagonist effects at higher concentrations.


Assuntos
Alumínio/toxicidade , Ecotoxicologia/métodos , Microalgas/efeitos dos fármacos , Zinco/toxicidade , Clorofila A/metabolismo , Sinergismo Farmacológico , Metais/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Testes de Toxicidade/métodos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
4.
Chemosphere ; 238: 124604, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31450113

RESUMO

Accurate in silico predictions of chemical substance ecotoxicity has become an important issue in recent years. Most conventional methods, such as the Ecological Structure-Activity Relationship (ECOSAR) model, cluster chemical substances empirically based on structural information and then predict toxicity by employing a log P linear regression model. Due to empirical classification, the prediction accuracy does not improve even if new ecotoxicity test data are added. In addition, most of the conventional methods are not appropriate for predicting the ecotoxicity on inorganic and/or ionized compounds. Furthermore, a user faces difficulty in handling multiple Quantitative Structure-Activity Relationship (QSAR) formulas with one chemical substance. To overcome the flaws of the conventional methods, in this study a new method was developed that applied unsupervised machine learning and graph theory to predict acute ecotoxicity. The proposed machine learning technique is based on the large AIST-MeRAM ecotoxicity test dataset, a software program developed by the National Institute of Advanced Industry Science and Technology for Multi-purpose Ecological Risk Assessment and Management, and the Molecular ACCess System (MACCS) keys that vectorize a chemical structure to 166-bit binary information. The acute toxicity of fish, daphnids, and algae can be predicted with good accuracy, without requiring log P and linear regression models in existing methods. Results from the new method were cross-validated and compared with ECOSAR predictions and show that the new method provides better accuracy for a wider range of chemical substances, including inorganic and ionized compounds.


Assuntos
Ecotoxicologia/métodos , Aprendizado de Máquina , Poluentes Químicos da Água/toxicidade , Poluição Química da Água/análise , Animais , Simulação por Computador , Daphnia/efeitos dos fármacos , Peixes , Modelos Lineares , Modelos Teóricos , Relação Quantitativa Estrutura-Atividade , Medição de Risco/métodos , Software , Poluentes Químicos da Água/química
5.
Chemosphere ; 240: 124906, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31550587

RESUMO

Benzene homologues have significant toxic effects to aquatic organisms. In this study, the acute toxicity data of benzene, toluene, ethylbenzene and xylene (BTEX) were collected and screened, and the toxicity extrapolation model of paired BTEX was established. The results showed that except the correlation between benzene and xylene was not strong due to insufficient data, the linear correlation of the other five paired BTEX was good (p < 0.01), and R2 fitted by the four out of five paired BTEX was greater than 0.85. The cross validation showed that ethylbenzene-xylene model was optimal, and for most species (81.8%), the established five BTEX models had a prediction error of less than 10%. Also, these extrapolation models were validated by experimental results of Pseudorasbora parva. The difference between the predicted and measured values of the acute toxicity of BTEX was less than 1 fold, which indicated that the extrapolation model had high accuracy.


Assuntos
Benzeno/toxicidade , Ecotoxicologia/métodos , Tolueno/toxicidade , Poluentes Químicos da Água/toxicidade , Xilenos/toxicidade , Animais , Organismos Aquáticos , Derivados de Benzeno/toxicidade , Biodegradação Ambiental , Cyprinidae , Modelos Teóricos , Reprodutibilidade dos Testes , Testes de Toxicidade Aguda
6.
Chemosphere ; 239: 124731, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31499303

RESUMO

The fish bioconcentration factor (BCF) is an important aspect within bioaccumulation assessments. Several factors have been suggested to influence BCF values - including species, developmental stage, mixture exposure, and calculation method. However, their exact contribution to variance in BCF values is unknown. Within this study we assessed the relative impact of these test characteristics on BCF values and analyzed the reproducibility of aquatic exposure bioconcentration tests. Linear mixed effects analyses were performed on a newly develop database to investigate the relationship between the response variable (i.e. lipid normalized log BCF values) and several test characteristics as fixed effects. Lower BCF values were observed for substances that were simultaneously applied with high molecular weight polycyclic aromatic hydrocarbons compared to single substance exposure (with an average difference of -0.81 log BCF). Also, lower BCFs upon kinetic determination were observed compared to steady-state BCFs (log BCF -0.27), and lower BCFs for species from the Ostariophysi subcohort level (log BCF -0.17 to -0.15). In addition, data analysis showed high variation within BCF values for single substances (average SD = log BCF 0.21), which questions the robustness of the current bioaccumulation assessments. For example, the 95% confidence range of a BCF value of 2500 ranges from 953 ('not-bioaccumulative') to 6561 ('very bioaccumulative'). Our results show that the use of one single BCF leads to a high uncertainty in bioaccumulation assessments. We strongly recommend that within future bioconcentration studies, the used experimental design and test conditions are described in detail and justified to support solid interpretation.


Assuntos
Ecotoxicologia/métodos , Peixes , Poluentes Químicos da Água/farmacocinética , Animais , Bioacumulação , Exposição Ambiental/análise , Cinética , Peso Molecular , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/química , Hidrocarbonetos Policíclicos Aromáticos/farmacocinética , Reprodutibilidade dos Testes , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química
7.
Chemosphere ; 240: 124819, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31563723

RESUMO

The sea cucumbers are common members of marine benthic communities, widespread distributed, easily available and handled. Nevertheless, no data are available on embryo toxicity assays using sea cucumbers, despite some of these species could fully meet the requirements for model test organisms. Holothuria polii is a key species in soft sediments and seagrass meadows; the aim of the present study was the standardization of a new embryo bioassay with this species, as an ecologically relevant test to evaluate the effects of environmental stressors. Sequential experiments were carried out, allowing to define the test acceptability, and a minimum sample size of 240 embryos. Temperature of 26 °C, salinity at 36‰ and a density of 60 eggs/ml were identified as optimum experimental conditions for performing the bioassay. The EC50 calculated for Cd2+ and Cu2+ in dose-response experiments indicated a good sensitivity of H. polii, with comparable values with those obtained in embryo toxicity bioassays of other marine invertebrates. An Integrative Toxicity Index (ITI) was calculated by integrating the frequency of abnormal embryos with the severity of observed abnormalities. The index allows to better discriminate different levels of toxicity, appearing particularly relevant for validating the usefulness of H. polii in embryo assays and ecotoxicological studies on environmental quality.


Assuntos
Bioensaio/métodos , Ecotoxicologia/métodos , Pepinos-do-Mar/química , Pepinos-do-Mar/embriologia , Animais
8.
Chemosphere ; 240: 124966, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31726608

RESUMO

The hepatotoxic cyanotoxins microcystins (MCs) are emerging contaminants naturally produced by cyanobacteria. Yet their ecological role remains unsolved, previous research suggests that MCs have allelopathic effects on competing photosynthetic microorganisms, even eliciting toxic effects on other freshwater cyanobacteria. In this context, the bioluminescent recombinant cyanobacterium Anabaena sp. PCC7120 CPB4337 (hereinafter Anabaena) was exposed to extracts of MCs. These were obtained from eight natural samples from freshwater reservoirs that contained MCs with a concentration range of 0.04-11.9 µg MCs L-1. MCs extracts included the three most common MCs variants (MC-LR, MC-RR, MC-YR) in different proportions (MC-LR: 100-0%; MC-RR: 100-0%; MC-YR: 14.2-0%). The Anabaena bioassay based on bioluminescence inhibition has been successfully used to test the toxicity of many emerging contaminants (e.g., pharmaceuticals) but never for cyanotoxins prior to this study. Exposure of Anabaena to MCs extracts induced a decrease in its bioluminescence with effective concentration decreasing bioluminescence by 50% ranging from 0.4 to 50.5 µg MC L-1 in the different samples. Bioluminescence responses suggested an interaction between MCs variants which was analyzed via the Additive Index method (AI), indicating an antagonistic effect (AI < 0) of MC-LR and MC-RR present in the samples. Additionally, MC extracts exposure triggered an increase of intracellular free Ca2+ in Anabaena. In short, this study supports the use of the Anabaena bioassay as a sensitive tool to assess the presence of MCs at environmentally relevant concentrations and opens interesting avenues regarding the interactions between MCs variants and the possible implication of Ca2+ in the mode of action of MCs towards cyanobacteria.


Assuntos
Bioensaio/métodos , Ecotoxicologia/métodos , Microcistinas/toxicidade , Anabaena/efeitos dos fármacos , Anabaena/metabolismo , Cálcio/metabolismo , Cianobactérias/isolamento & purificação , Cianobactérias/metabolismo , Água Doce/microbiologia
9.
Chemosphere ; 239: 124799, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31518926

RESUMO

Terrestrial adult stages of freshwater insects may be exposed to pesticides by wind drift, over-spray, contact or feeding. However, studies addressing insecticide effects on freshwater invertebrates focus primarily on the impact of pesticides reaching the streams and potentially harming the aquatic juvenile stages. This is also reflected in the current risk assessment procedures, which do not include testing of adult freshwater insects. In order to assess the potential impact of insecticides on adult stages of freshwater insects, we exposed six common species to the insecticides Karate (lambda-cyhalothrin) and Confidor (imidacloprid). Dose-response relations were established, and LD50 estimates were compared to those of the honey bee, Apis mellifera L. (Hymenoptera: Apidae), which is the standard terrestrial test insect when pesticides are evaluated prior to commercial release. Generally, the tested species were more sensitive to the studied insecticides than the honey bee. In order to examine whether the sensitivity of adult stages of freshwater insects corresponds with the sensitivity of the juvenile stages of the same species, the ranking of the two life stages with respect to the toxicity of Karate was compared, revealing some correspondence, but also some dissimilarities. Our results strongly indicate that terrestrial adult stages of aquatic insects are not adequately protected by current risk assessment procedures.


Assuntos
Insetos/efeitos dos fármacos , Insetos/fisiologia , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Nitrilos/toxicidade , Nitrocompostos/toxicidade , Piretrinas/toxicidade , Animais , Abelhas/efeitos dos fármacos , Dinamarca , Relação Dose-Resposta a Droga , Ecotoxicologia/métodos , Inseticidas/administração & dosagem , Dose Letal Mediana , Neonicotinoides/administração & dosagem , Nitrilos/administração & dosagem , Nitrocompostos/administração & dosagem , Piretrinas/administração & dosagem , Rios , Especificidade da Espécie , Poluentes Químicos da Água/toxicidade
10.
Chemosphere ; 245: 125640, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31864043

RESUMO

The graphene oxide (GO) due to its exceptional structure, physicochemical and mechanical properties is a very attractive material for industry application. Even though, the unique properties of GO (e.g. structure, size, shape, etc.) make the risk assessment of this nanomaterial very challenging in comparison with conventional ecotoxicology studies required by regulators. Thus, there is a need for standardized characterization techniques and methodology to secure a high quality/reliable data on the ecotoxicology of GO, and to establish environmentally acceptable levels. Herein, authors address the crucial quality criteria when evaluating the ecotoxicology of GO using an algae (Raphidocelis subcapitata) and a shrimp (Paratya australiensis). This study provides a detail characterization and modification of the used GO, robust quantification and a suspension stability in different media for ecotoxicology studies. It was observed that under the same exposure conditions the behavior of GO and the estimated outcomes (IC50 values) in modified algae media differed in comparison to the referent media. Further to that, the adverse effects of GO on the algae cell structure and the potential uptake of GO by the algae cells were examined using the TEM with different staining techniques to avoid artefacts. Shrimps which were exposed to GO-algae aggregates via the food intake did not indicate stress or accumulation of GO. Our work presents an important insight to necessity of establishing a benchmark ecotoxicology assays for GO (e.g. characterization techniques, choice of media, etc.) and providing a reliable data to be used by regulators in risk assessment of two-dimensional (2D) nanomaterials.


Assuntos
Grafite/química , Poluentes Químicos da Água/química , Animais , Crustáceos , Ecotoxicologia/métodos , Cadeia Alimentar , Nanoestruturas , Óxidos
11.
Environ Monit Assess ; 192(1): 8, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31797148

RESUMO

Bisphenol-A (BPA) is a chemical used in the production of polycarbonate plastic and epoxy resins that may be related to the occurrence of human endocrine disorders. The present study aims to indicate a microalgae for use in ecotoxicological tests concerning BPA contamination of aquatic environments by analyzing its toxicity for the freshwater species Pseudokirchneriella subcapitata, and the two marine species Tetraselmis chuii and Skeletonema costatum. The standardization of the test involved determination of suitable nominal concentrations of BPA and the most appropriate species for use as biomarkers. S. costatum and P. subcapitata demonstrated resistance to BPA, features that are not of interest for toxicity markers. T. chuii presented an adequate sensitivity to BPA, compatible with parameters used in human toxicology for this substance, and is indicated as a potential biomarker for the presence of BPA in marine environments. The IC50 of T. chuii was 2.5 µM with R2 = 0.9, indicating reliability to demonstrate that low concentrations of BPA has significant toxicity to this species.


Assuntos
Compostos Benzidrílicos/toxicidade , Ecotoxicologia/métodos , Microalgas/efeitos dos fármacos , Fenóis/toxicidade , Poluentes Químicos da Água/toxicidade , Clorófitas/efeitos dos fármacos , Diatomáceas/efeitos dos fármacos , Água Doce/química , Reprodutibilidade dos Testes
12.
Mar Pollut Bull ; 143: 140-143, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31789149

RESUMO

In this study, the acute toxicity of microplastics (MPs) on unicellular organisms as marine decomposers and microalgae was assessed, by evaluating standards endpoints included in International Standard Organization (ISO) protocols. The bacteria Vibrio fischeri and the diatom Phaeodactylum tricornutum were exposed to different sizes (1-500 µm) of polyethylene MPs in order to evaluate bioluminescence inhibition and microalgal growth. No acute toxicity was found on bacteria or microalgae in an order of magnitude above environmentally relevant concentrations, suggesting that tested MPs did not affect the investigated biological processes. In conclusion, standard ecotoxicological endpoints are not sufficiently sensitive to assess the potential effects of MPs on decomposers and primary producers, conversely to nanoplastics. These findings highlight that the current approach for MP risk assessment in unicellular species should be revised, by providing alternative endpoints to be included in standardized protocols, able to monitor the fate and biological effects of MPs.


Assuntos
Aliivibrio fischeri/efeitos dos fármacos , Diatomáceas/efeitos dos fármacos , Ecotoxicologia/métodos , Poluentes Químicos da Água/toxicidade , Microalgas/efeitos dos fármacos , Polietileno/toxicidade , Testes de Toxicidade Aguda
13.
Ecotoxicol Environ Saf ; 186: 109754, 2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31606639

RESUMO

In (eco)toxicology, there is a critical need for efficient methods to evaluate the neurotoxic potential of environmental chemicals. Recent studies proposed analysis of early coiling activity in zebrafish embryos as a powerful tool for the identification of neurotoxic compounds. In order to demonstrate that the analysis of early tail movements of zebrafish embryos allows for the discrimination of neurotoxicants acting via different mechanisms, the present study investigated the effects of four different neurotoxicants on the embryogenesis (fish embryo toxicity test) and early tail coiling movements of zebrafish embryos. Cadmium predominantly increased the frequency of tail coiling at the late pharyngula stage. Dichlorvos delayed embryonic development and caused convulsive tail movements resulting in prolonged duration of tail coils. Embryos exposed to teratogenic concentrations of fluoxetine and citalopram displayed absence of spontaneous tail movements at 24 h post-fertilization. In contrast, a non-teratogenic test concentration of citalopram decreased coiling frequency at multiple time points. Results demonstrated that the analysis of tail coiling movements of zebrafish embryos has the potential to discriminate neurotoxic compounds with different primary modes of action. In addition, chemical-induced effects on coiling activity were shown to potentially overlap with effects on embryogenesis. Further studies are needed to clarify the interplay of unspecific developmental toxicity of neurotoxic chemicals and effects resulting from specific neurotoxic mechanisms.


Assuntos
Embrião não Mamífero/efeitos dos fármacos , Movimento/efeitos dos fármacos , Síndromes Neurotóxicas/etiologia , Testes de Toxicidade/métodos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/fisiologia , Animais , Cádmio/toxicidade , Citalopram/toxicidade , Diclorvós/toxicidade , Ecotoxicologia/métodos , Desenvolvimento Embrionário , Fluoxetina/toxicidade , Cauda , Peixe-Zebra/embriologia
14.
Mar Pollut Bull ; 145: 254-259, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31590784

RESUMO

Glassfish, Ambassis dussumieri (Cuvier, 1828), was used as a sentinel species to investigate the effects of the ingestion of environmentally relevant microplastic concentrations on juvenile fish growth and survival. Both virgin plastic and plastic collected from an urban harbour were fed to small juvenile fish daily for 95 days. Fish standard length, body depth and mass were recorded at intervals of 20 days, while survival was continuously recorded. All fish were fed tropical flakes, measured at 1.7% of the body mass per tank. Overall, fish in in plastic treatments grew less in body length and body depth compared to those control treatments. Fish mass was also lower in the virgin plastic treatment than control fish; however, the growth in mass was not significantly lower than fish in the harbour plastic treatment. The survival probability of fish in both plastic fed treatments was also lower than fish in controls.


Assuntos
Peixes/crescimento & desenvolvimento , Plásticos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Tamanho Corporal/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Ecotoxicologia/métodos , Mortalidade , Testes de Toxicidade Crônica
15.
Ecotoxicol Environ Saf ; 186: 109721, 2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31593825

RESUMO

Industrial wastewater discharge is one of major threats to the sustainability of aquatic environment. Rapid and sensitive detection of toxic wastewater discharge and appropriate control if necessary are therefore crucial. In the present study, a 1 h Daphnia magna exposure with heartbeat as an observation endpoint was developed and assessed for its utility as a rapid toxicity screening measure. Two types of metal-rich industrial wastewater, i.e., metal plating and the semiconductor industry were chosen as target samples, and the 1 h heartbeat assay was applied. Based on a literature search, four metals, i.e., Cu, Cr, Ni and Zn were identified as major chemicals of ecotoxicological concerns in these wastewaters. The effective concentrations determined for each metal from the D. magna 1 h heartbeat test were comparable to those derived from the conventional D. magna 48 h immobilization test. Copper sulfate (CuSO4) was determined as the most toxic, followed by potassium dichromate (K2Cr2O7), nickel sulfate (NiSO4) and zinc sulfate (ZnSO4). For ternary mixtures, the 1 h heartbeat test showed also comparable responses to those of the 48 h immobilization test, suggesting its utility for screening the toxicity of simple metal mixtures. For the site-sampled metal plating water, the rapid heartbeat assay showed similar responses to those of the 48 h immobilization assay. However, for the semiconductor industry wastewater, clearly different responses were observed in both the heartbeat and immobilization assays, probably due to the influence of other contaminants with different modes of action that are present in the wastewater. Our observations showed that the D. magna 1 h heartbeat test can be considered as a rapid ecotoxicity screening measure for certain wastewaters with simple metal mixtures.


Assuntos
Daphnia/efeitos dos fármacos , Ecotoxicologia/métodos , Resíduos Industriais , Metais/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Daphnia/fisiologia , Coração/efeitos dos fármacos , Metalurgia , Semicondutores , Testes de Toxicidade Aguda
16.
Chemosphere ; 235: 1097-1106, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31561300

RESUMO

Neonicotinoid insecticides show high persistence in the environment, and standard biological approaches such as biopurification systems have shown mostly inefficient removal of such compounds. In this work, soil pre-exposed to imidacloprid was used to obtain presumptive imidacloprid-degrading consortia. Cometabolic enrichment yielded a microbial consortium composed of eight bacterial and one yeast strains, capable of degrading not only this compound, but also thiamethoxam and acetamiprid, as demonstrated in cross-degradation assays. The biological removal process was scaled-up to batch stirred tank bioreactors (STBR); this configuration was able to simultaneously remove mixtures of imidacloprid + thiamethoxam or imidacloprid + thiamethoxam + acetamiprid, reaching elimination of 95.8% and 94.4% of total neonicotinoids, respectively. Removal rates in the bioreactors followed the pattern imidacloprid > acetamiprid > thiamethoxam, including >99% elimination of imidacloprid in 6 d and 17 d (binary and ternary mixtures, respectively). A comprehensive evaluation of the detoxification in the STBR was performed using different biomarkers: seed germination (Lactuca sativa), bioluminescence inhibition (Vibrio fischeri), and acute oral tests in honeybees. Overall, ecotoxicological tests revealed partial detoxification of the matrix, with clearer detoxification patterns in the binary mixture. This biological approach represents a promising option for the removal of neonicotinoids from agricultural wastewater; however, optimization of the process should be performed before application in farms.


Assuntos
Inseticidas/isolamento & purificação , Consórcios Microbianos , Neonicotinoides/isolamento & purificação , Purificação da Água/métodos , Agricultura , Animais , Abelhas , Ecotoxicologia/métodos , Inativação Metabólica , Inseticidas/análise , Neonicotinoides/metabolismo , Nitrocompostos/metabolismo , Águas Residuárias/química
17.
Environ Pollut ; 254(Pt B): 113082, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31472454

RESUMO

Growing production and consumption of pharmaceuticals is a global problem. Due to insufficient data on the concentration and distribution of pharmaceuticals in the marine environment, there are no appropriate legal regulations concerning their emission. In order to understand all aspects of the fate of pharmaceuticals in the marine environment and their effect on marine biota, it is necessary to find the most appropriate model organism for this purpose. This paper presents an overview of the ecotoxicological studies of pharmaceuticals, regarding the assessment of Mytilidae as suitable organisms for biomonitoring programs and toxicity tests. The use of mussels in the monitoring of pharmaceuticals allows the observation of changes in the concentration and distribution of these compounds. This in turn gives valuable information on the amount of pharmaceutical pollutants released into the environment in different areas. In this context, information necessary for the assessment of risks related to pharmaceuticals in the marine environment are provided based on what effective management procedures can be developed. However, the accumulation capacity of individual Mytilidae species, the bioavailability of pharmaceuticals and their biological effects should be further scrutinized.


Assuntos
Ecotoxicologia/métodos , Mytilidae/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , /métodos , Biota , Ecotoxicologia/instrumentação , Modelos Biológicos , Mytilidae/crescimento & desenvolvimento , Água do Mar/análise , Poluentes Químicos da Água/análise
18.
Chemosphere ; 236: 124406, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31545203

RESUMO

Pot experiments were conducted under abiotic conditions to investigate the interactive influence of decabromodiphenyl ether (BDE-209) and lead (Pb) on the seed germination, germ length, root exudation and physiological characteristics of tall fescue (Festuca arundinaceae), and the uptake, accumulation of Pb and BDE-209 in the plant tissues. Results show that seed germination and germ length were impacted by Pb but less influenced by BDE-209. BDE-209 spiking (10 and 50 mg/L) could alleviate the toxicity of high Pb concentration on seed germination and growth. The chlorophyll content was significantly increased at 500 mg/kg Pb but declined at 2000 mg/kg Pb. Low-level Pb contamination (500 mg/kg) activated antioxidase activity; however, 2000 mg/kg Pb significantly reduced the antioxidase activity. Plant biomass slightly decreased at 500 mg/kg Pb but significantly declined at 2000 mg/kg Pb. The addition of a moderate dosage of BDE-209 (10-50 mg/kg) lessened Pb phytotoxicity, leading to improved plant growth relative to the case of Pb spiking alone. The exudate secretion was significantly enhanced by Pb addition, but BDE-209 spiking only caused slightly increased secretion. Pb could interfere with BDE-209 adsorption and translocation of tall fescue by affecting physiological behavior of the plant, but BDE-209 exhibited little influence on the Pb fate in the plant. Overall, BDE-209 had slight interference on the impact of Pb towards tall fescue. The results demonstrate the complex interactive effects of organic pollutants and heavy metals in the soil-plant system.


Assuntos
Festuca/efeitos dos fármacos , Éteres Difenil Halogenados/toxicidade , Chumbo/toxicidade , Poluentes do Solo/toxicidade , Biomassa , Clorofila/metabolismo , Ecotoxicologia/métodos , Festuca/crescimento & desenvolvimento , Festuca/metabolismo , Germinação/efeitos dos fármacos , Éteres Difenil Halogenados/farmacocinética , Chumbo/farmacocinética , Exsudatos de Plantas/análise , Exsudatos de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Poluentes do Solo/farmacocinética
19.
Mar Pollut Bull ; 149: 110555, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31542597

RESUMO

Sediment metal concentrations were assessed in five different beach regions (n = 183) of KwaZulu-Natal (KZN) province in South Africa. Metal distribution revealed that Cr, Cu, Mo, Cd, Zn, Hg and As exceed the background upper continental crust values suggesting their anthropogenic origin (mining, agricultural and industrial) apart from natural geological inputs (gold placer deposits and heavy minerals). Various geochemical indices (Geoaccumulation index, Enrichment factor and Degree of contamination) confirmed that the sediment samples are extremely contaminated with Cr, Cd and Hg. Further, Hg and Cd were main contributors (60-90%) to the ecological threat in sediments. Hazard index estimated a high hazard potential of Hg in near future. Finally, present study together with our previous results portray the status of KZN coast with special significance to Hg contamination/enrichment. Thus, future researches are recommended to investigate the environmental and human health implications of mercury exposure in this coastal province.


Assuntos
Sedimentos Geológicos/análise , Metais/análise , Poluentes Químicos da Água/análise , Agricultura , Praias , Ecotoxicologia/métodos , Monitoramento Ambiental/métodos , Cadeia Alimentar , Sedimentos Geológicos/química , Humanos , Mercúrio/análise , Mercúrio/toxicidade , Metais/toxicidade , Mineração , África do Sul , Poluentes Químicos da Água/toxicidade
20.
Chemosphere ; 237: 124542, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31549655

RESUMO

The abuse of ciprofloxacin (CIP) may cause serious side effects and the mechanisms underlying these effects remain unclear. Here, we determinate the 48 h, 72 h and 96 h LC50 values of CIP to Drosophila melanogaster and demonstrate a series of adverse effects after D. melanogaster was exposed to CIP at a sublethal concentration (3.2 mg mL-1). Treated individuals showed shorter lifespan, delayed development and many of the treated larvae failed to pupate or hatch. Smaller body size was observed at every life stage when exposed to CIP and the size of pupae, the weight of third-instar larvae exhibited a perfectly dose-response relationship that the larger concentration exposed to, the smaller body size or lighter weight is. Moreover, reduction in fat body cell viability, elevated oxidative stress markers (SOD and CAT) and down-regulation of diap1, ex, two target genes of Yorkie (Yki), was observed in response to CIP exposure. Most importantly, we found two types of black spot in Drosophila and the proportion of larvae with a black spot was positively related to the treatment dose, which is new in the field. This study provides a scientific basis for the potential harm caused by abuse of quinolones with the goal of urging cautious use of antibiotics.


Assuntos
Ciprofloxacino/toxicidade , Drosophila melanogaster/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Animais , Antibacterianos/toxicidade , Tamanho Corporal/efeitos dos fármacos , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Ecotoxicologia/métodos , Biomarcadores Ambientais , Enzimas/metabolismo , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas Inibidoras de Apoptose/genética , Larva/efeitos dos fármacos , Masculino , Proteínas de Membrana/genética , Proteínas Nucleares/genética , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Pupa/efeitos dos fármacos , Transativadores/genética
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