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1.
Sci Total Environ ; 751: 141634, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32882550

RESUMO

Current research is increasingly focusing on the ecotoxicity of anthropogenic micro-pollutants and their degradation and transformation products resulting from biological and chemical treatment processes. These products enter the aquatic environment through various routes and may endanger aquatic organisms and plants. In this study, five neonicotinoids from the EU watchlist and their degradation products induced by UVC irradiation were examined. All identified photoinduced degradation or transformation products were subsequently submitted to Quantitative Structure Activity (QSAR) analysis. Among the investigated structures, 15 substances already identified in previous studies and eleven new transformation products were analyzed. By using QSAR analysis, it became possible to predict ecotoxicity of individual substances with mere computational effort. Starting from the chemical structure, lower toxicity against green algae and invertebrates was predicted for the transformation products in general. For other aquatic target organisms, such as branchiopoda, actinopterygii and fathead minnow, the residual hazardous effect as compared to the initial compound depends on the presence of specific structural elements. For the neonicotinoids investigated, the cleavage or elimination of the nitrile or nitro group through the degradation process, was predicted to increase toxicity.


Assuntos
Clorófitas , Cyprinidae , Poluentes Químicos da Água , Animais , Ecotoxicologia , Neonicotinoides , Relação Quantitativa Estrutura-Atividade , Poluentes Químicos da Água/toxicidade
2.
Bull Environ Contam Toxicol ; 105(5): 665-670, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33052433

RESUMO

A key step in deriving an Environmental Quality Standard (EQS) is assessing the reliability and relevance of the underpinning ecotoxicity data. While the assessment of data reliability is relatively well established, the detailed evaluation of data relevancy is a more recent development. We applied broadly accepted relevancy criteria to a series of non-standard ecotoxicity studies on diclofenac, focusing on some aspects that should be accounted for in studies used in EQS derivation. Specific relevancy issues include potential experimental bias, claimed 'significant effects' that are indistinguishable from controls, or within the range of normal, and lack of environmental applicability. We highlight that rigorous, comprehensive and, where necessary, specialist assessment of data relevancy for studies potentially applicable for EQS setting is critical if studies are to be appropriately used regulatory decision-making. We provide recommendations for researchers and environmental practitioners to ensure robust accounting of relevancy in non-standard studies is undertaken.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Diclofenaco/toxicidade , Ecotoxicologia/normas , Monitoramento Ambiental/normas , Poluentes Químicos da Água/toxicidade , Animais , Diclofenaco/análise , Ecotoxicologia/métodos , Monitoramento Ambiental/métodos , Humanos , Reprodutibilidade dos Testes , Testes de Toxicidade , Poluentes Químicos da Água/análise , Qualidade da Água/normas
3.
Chemosphere ; 261: 128160, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33113648

RESUMO

Up to now, complicated organoarsenicals were mainly identified in marine organisms, suggesting that these organisms play a critical role in arsenic biogeochemical cycling because of low phosphate and relatively high arsenic concentration in the marine environment. However, the response of marine macroalgae to inorganic arsenic remains unknown. In this study, Pyropia haitanensis were exposed to arsenate [As(V)] (0.1, 1, 10, 100 µM) or arsenite [As(III)] (0.1, 1, 10 µM) under laboratory conditions for 3 d. The species of water-soluble arsenic, the total concentration of lipid-soluble and cell residue arsenic of the algae cells was analyzed. As(V) was mainly transformed into oxo-arsenosugar-phosphate, with other arsenic compounds such as monomethylated, As(III), demethylated arsenic and oxo-arsenosugar-glycerol being likely the intermediates of arsenosugar synthesis. When high concentration of As(III) was toxic to P. haitanensis, As(III) entered into the cells and was transformed into less toxic organoarsenicals and As(V). Transcriptome results showed genes involved in DNA replication, mismatch repair, base excision repair, and nucleotide excision repair were up-regulated in the algae cells exposed to 10 µM As(V), and multiple genes involved in glutathione metabolism and photosynthetic were up-regulated by 1 µM As(III). A large number of ABC transporters were down-regulated by As(V) while ten genes related to ABC transporters were up-regulated by As(III), indicating that ABC transporters were involved in transporting As(III) to vacuoles in algae cells. These results indicated that P. haitanensis detoxifies inorganic arsenic via transforming them into organoarsenicals and enhancing the isolation of highly toxic As(III) in vacuoles.


Assuntos
Arsênico/toxicidade , Rodófitas/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Arseniatos/química , Arseniatos/toxicidade , Arsênico/química , Arsenitos/química , Arsenitos/toxicidade , Cromatografia Líquida de Alta Pressão , Ecotoxicologia , Regulação da Expressão Gênica/efeitos dos fármacos , Espectrometria de Massas , Monossacarídeos/química , Rodófitas/genética , Rodófitas/metabolismo , Alga Marinha/efeitos dos fármacos , Poluentes Químicos da Água/química
4.
Int J Nanomedicine ; 15: 8097-8108, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33116520

RESUMO

Background: Metallic nanoparticles (NPs) are highly exploited in manufacturing and medical processes in a broad spectrum of industrial applications and in the academic sectors. Several studies have suggested that many metallic nanomaterials including those derived by silver (Ag) are entering the ecosystem to cause significant toxic consequences in cell culture and animal models. However, ecotoxicity studies are still receiving limited attention when designing functionalized and non.-functionalized AgNPs. Objective: This study aimed to investigate different ecotoxicological profiles of AgNPs, which were analyzed in two different states: in pristine form uncoated AgNPs and coated AgNPs with the antimicrobial peptide indolicidin. These two types of AgNPs are exploited for a set of different tests using Daphnia magna and Raphidocelis subcapitata, which are representatives of two different levels of the aquatic trophic chain, and seeds of Lepidium sativum, Cucumis sativus and Lactuca sativa. Results: Ecotoxicological studies showed that the most sensitive organism to AgNPs was crustacean D. magna, followed by R. subcapitata and plant seeds, while AgNPs coated with indolicidin (IndAgNPs) showed a dose-dependent decreased toxicity for all three. Conclusion: The obtained results demonstrate that high ecotoxicity induced by AgNPs is strongly dependent on the surface chemistry, thus the presence of the antimicrobial peptide. This finding opens new avenues to design and fabricate the next generation of metallic nanoparticles to ensure the biosafety and risk of using engineered nanoparticles in consumer products.


Assuntos
Peptídeos Catiônicos Antimicrobianos/toxicidade , Organismos Aquáticos/efeitos dos fármacos , Ecossistema , Ecotoxicologia , Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Animais , Peptídeos Catiônicos Antimicrobianos/síntese química , Crustáceos/efeitos dos fármacos , Cucumis sativus/efeitos dos fármacos , Cucumis sativus/crescimento & desenvolvimento , Daphnia/citologia , Daphnia/efeitos dos fármacos , Germinação/efeitos dos fármacos , Lepidium/efeitos dos fármacos , Lepidium/crescimento & desenvolvimento , Alface/efeitos dos fármacos , Alface/crescimento & desenvolvimento , Nanopartículas Metálicas/ultraestrutura , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Testes de Toxicidade
5.
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
6.
Ecotoxicology ; 29(9): 1476-1485, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32936363

RESUMO

Increasing evidence suggests that phenotypic plasticity can play a critical role in ecotoxicology. More specifically, induced pesticide tolerance, in which populations exposed to a contaminant show increased tolerance to the contaminants later, has been documented in multiple taxa. However, the physiological mechanisms of induced tolerance remain unclear. We hypothesized that induced pesticide tolerance is the result of a generalized stress response based on previous studies showing that both natural stressors and anthropogenic stressors can induce tolerance to pesticides. We tested this hypothesis by first exposing larval wood frogs (Rana sylvatica) to either an anthropogenic stressor (sublethal carbaryl concentration), a natural stressor (cues from a caged predator), or a simulated stressor via exogenous exposure to the stress hormone corticosterone (125 nM). We also included treatments that inhibited corticosterone synthesis with the compound metyrapone (MTP). We then exposed the larvae to a lethal carbaryl treatment to assess time to death. We found that prior exposure to 125 nM of exogenous CORT and predator cues induced tolerance to a lethal concentration of carbaryl through a slight delay in time to death. Pre-exposure to sublethal carbaryl, as well as MTP alone or in combination with predator cues, did not induce tolerance to the lethal carbaryl concentration relative to the ethanol vehicle control treatment. Our study provides evidence that pesticide tolerance can be induced by a generalized stress response both in the presence and absence (exogenous CORT) of specific cues and highlights the importance of considering physiological ecology and environmental context in ecotoxicology.


Assuntos
Praguicidas/toxicidade , Ranidae/fisiologia , Estresse Fisiológico/fisiologia , Adaptação Fisiológica , Animais , Carbaril , Corticosterona , Tolerância a Medicamentos , Ecotoxicologia , Larva
7.
Mar Environ Res ; 161: 105110, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32977204

RESUMO

There is an increasing awareness of how damaging pollutants in the marine environment can be, however information on the effects of metal engineered nanoparticles (ENPs) on marine biota is still insufficient, despite an exponential rising in related publications in recent years. In order to provide an integrated insight on the present state of the art on metal ENP-related ecotoxicology studies on marine fauna, this review aimed to: (i) highlight the means of toxicity of metal ENPs in the marine environment, (ii) identify the principal biotic and abiotic factors that may alter metal ENP toxicity, and (iii) analyse and categorize results of these studies, including accumulation, molecular and histological biomarkers, genotoxicity and behavioural changes. Data retrieved from Scopus yielded 134 studies that met pre-established criteria. Most often, the target ENPs were titanium, zinc, copper or silver, and most studies (61.2%) focused on the phylum Mollusca. The degree of toxicity of metal ENPs was often dependent on the concentrations tested, length of exposure and the type of tissue sampled. Effects from simple tissue accumulation to DNA damage or behavioural alterations were identified, even when concentrations below environmentally available levels were used. It is proposed that other phyla besides the traditional Mollusca (and within it Bivalvia) should be used more often in this kind of studies, that exact pathways of toxicity be further explored, and lastly that co-stressors be used in order to best mimic conditions observed in nature. In this review, the current knowledge on engineered metal nanoparticles and their effects on marine fauna was summarized, highlighting present knowledge gaps. Guidelines for future studies focusing on under-developed subjects in ENP toxicology are also briefly provided.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Animais , Cobre , Dano ao DNA , Ecotoxicologia , Nanopartículas Metálicas/toxicidade , Moluscos , Prata/toxicidade , Titânio
8.
Chemosphere ; 254: 126909, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957299

RESUMO

Soil contamination by heavy metals (HMs) is an environmental problem, and nanoremediation by using zero-valent iron nanoparticles (nZVI) has attracted increasing interest. We used ecotoxicological test and global transcriptome analysis with DNA microarrays to assess the suitability of C. elegans as a useful bioindicator to evaluate such strategy of nanoremediation in a highly polluted soil with Pb, Cd and Zn. The HMs produced devastating effect on C. elegans. nZVI treatment reversed this deleterious effect up to day 30 after application, but the reduction in the relative toxicity of HMs was lower at day 120. We stablished gene expression profile in C. elegans exposed to the polluted soil, treated and untreated with nZVI. The percentage of differentially expressed genes after treatment decreases with exposure time. After application of nZVI we found decreased toxicity, but increased biosynthesis of defensive enzymes responsive to oxidative stress. At day 14, when a decrease in toxicity has occurred, genes related to specific heavy metal detoxification mechanisms or to response to metal stress, were down regulated: gst-genes, encoding for glutathione-S-transferase, htm-1 (heavy metal tolerance factor), and pgp-5 and pgp-7, related to stress response to metals. At day 120, we found increased HMs toxicity compared to day 14, whereas the transcriptional oxidative and metal-induced responses were attenuated. These findings indicate that the profiled gene expression in C. elegans may be considered as an indicator of stress response that allows a reliable evaluation of the nanoremediation strategy.


Assuntos
Caenorhabditis elegans/efeitos dos fármacos , Ferro/química , Metais Pesados/toxicidade , Nanopartículas/química , Estresse Oxidativo/efeitos dos fármacos , Poluentes do Solo/toxicidade , Transcrição Genética/efeitos dos fármacos , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Ecotoxicologia , Nanopartículas Metálicas , Metais Pesados/análise , Estresse Oxidativo/genética , Solo/química , Microbiologia do Solo , Poluentes do Solo/análise , Toxicogenética
9.
J Environ Manage ; 276: 111098, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32949842

RESUMO

This article aimed to demonstrate solution hospital wastewater due to more consumption of antibiotics, public concern has been significantly increased for usage, fates and occurrences of these emerging compounds in the environments and biota. Therefore, it does need more discoveries about occurrences and new treatment methods. Since the conventional treatment methods are low efficient on antibiotics, integration and combination of biological systems together or with an additional process has been shown that provided a better result. However, here, the potential of a full scale combined treating system with activated sludge-scoria biofilter (ASSB) was investigated for removal of ceftriaxone (CEF) and amoxicillin (AMX). To determine the potential biodegradability of proposed system, the solid-water distribution coefficient (Kd) was calculated. Overally, 118 samples were collected from three points; wastewater entering, exiting the activated sludge, and exiting the biofilter. To determine the amount of CEF and AMX antibiotics, the samples were analyzed using HPLC-UV. The results showed that the activated sludge system were able to eliminate the AMX and CEF antibiotics about 70.36 and 84.49%, respectively. In compare to activated sludge, the average mean of ASSB system for the removal efficiency were 87.53% (for AMX) and 93.17% (for CEF), respectively. As a result, it can be found that the efficiency of the combined activated sludge-biofilter system in removing of the low levels of antibiotics was more than individual activated system. The result of Kd revealed that AMX (with a Kd about 0.172) has lower tendency to biomass rather than CEF (with a Kd about 0.512). The ecological toxicity assessment guaranteed there is no risk for fish and daphnia when the activated sludge and also ASSB effluents to be discharged into the environment even without any diluting.


Assuntos
Esgotos , Águas Residuárias , Amoxicilina , Animais , Ecotoxicologia , Hospitais , Eliminação de Resíduos Líquidos
10.
Environ Pollut ; 265(Pt A): 115059, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32806429

RESUMO

Field survey-based ecological risk assessments for trace metals are conducted to examine the necessity and/or effectiveness of management intervention, such as setting of environmental quality standards. Observational datasets often involve confounders that may bias estimation of the effects of intervention (e.g., reduction of trace-metal concentrations through regulation). The field of ecotoxicology lags behind some other research fields in understanding proper analytical procedures for causal inference from observational datasets; there are only a few field survey-based ecotoxicological studies that have explicitly controlled for confounders in their statistical analyses. In the present study, we estimated the effect of intervention in nickel concentrations on Ephemeroptera, Plecoptera, and Trichoptera richness in rivers in Japan. We also provide detailed explanations for the backgrounds of spurious associations derived from confounders and on proper analytical procedures for obtaining an unbiased estimate of the targeted intervention effect by using regression analysis. We constructed a multiple regression model based on a causal diagram for aquatic insects and environmental factors, and on "the backdoor criterion," that enabled us to determine the set of covariates required to obtain an unbiased estimate of the targeted intervention effect from regression coefficients. We found that management intervention in nickel concentrations may be ineffective compared to intervention in organic pollution, and that analysis ignoring the confounders overestimated the effect of intervention in nickel concentrations. Our results highlight the fact that confounders can lead to misjudging the necessity for management of anthropogenic chemical substances. Confounders should be explicitly specified and statistically controlled to achieve a comprehensive assessment of ecological risks for various substances.


Assuntos
Ecotoxicologia , Níquel/análise , Japão , Análise de Regressão , Rios
11.
Mar Pollut Bull ; 158: 111385, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32753174

RESUMO

This study evaluated for the first time, the distribution, sources, and ecological risk assessment of 16 polycyclic aromatic hydrocarbons (PAHs) in sediments collected along the northern Patagonian shelf in the Argentine Sea -included in a Marine Protected Area (MPA). Total concentration of the PAHs varied from 19.47 to 183.17 ng/g dry weight and low molecular weight compounds, such as Anthracene and Naphthalene were the dominants. The selected PAHs ratios suggested a predominance of petrogenic sources and ecotoxicological risk evaluation based on the sediment quality guidelines model, indicated that some PAHs might cause occasional adverse biological effects in the study area.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , Ecotoxicologia , Monitoramento Ambiental , Sedimentos Geológicos
12.
Ecotoxicol Environ Saf ; 202: 110929, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800215

RESUMO

The aim of this study was to investigate the bioremediation potential of polychlorinated biphenyls (PCBs) in soil, mimicking three strategies: (a) mycoaugmentation: by the addition of Trametes sanguinea and Pleurotus sajor-caju co-cultures immobilized on sugarcane bagasse; (b) biostimulation: by supplementation of sugarcane bagasse; and (c) natural attenuation: no amendments. The experiments were done in microcosms using Ultisol soil. Remediation effectiveness was assessed based on pollutants content, soil characteristics, and ecotoxicological tests. Biostimulation and mycoaugmentation demonstrated the highest PCBs-removal (approx. 90%) with a significant toxicity reduction at 90 d. The studied strains were able to survive during the incubation period in non-sterilized soil. Laccase, manganese-peroxidase and endoxylanase activities increased significantly in co-cultures after 60 d. Sugarcane bagasse demonstrated to be not only a suitable support for fungal immobilization but also an efficient substrate for fungal colonization of PCBs-contaminated soils. Mycoaugmentation and biostimulation with sugarcane bagasse improved oxidable organic matter and phosphorous contents as well as dehydrogenase activity in soil. Therefore, biostimulation with sugarcane bagasse and mycoaugmentation applying dual white-rot fungal cultures constitute two efficient bioremediation alternatives to restore PCBs-contaminated soils.


Assuntos
Biodegradação Ambiental , Poluentes do Solo/metabolismo , Celulose , Ecotoxicologia , Lacase , Peroxidases , Fósforo , Bifenilos Policlorados , Saccharum , Solo/química , Microbiologia do Solo , Poluentes do Solo/análise , Trametes
13.
Ecotoxicol Environ Saf ; 202: 110910, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800245

RESUMO

Microplastics (MPs) are ubiquitous in the environment and more abundant in the marine environment. Consequently, increasing focus has been put on MPs in oceans and seas, while little importance has been attached to their presence in freshwaters and soils. Therefore, this paper aimed to provide a comprehensive review of the occurrence, analysis and ecotoxicology of MPs. The abundance and distribution of MPs in several typical freshwater systems of China were summarized. It suggested that the surface water of Poyang Lake contained the highest concentration of 34 items/L MPs among all the 8 freshwater systems, and the content of MPs in sediments were higher than that of the surface water. Net-based zooplankton sampling methods are the most frequently utilized sampling methods for MPs, and density separation, elutriation and digestion are three major pretreatment methods. Fourier transform infrared spectroscopy, Raman spectroscopy and pyrolysis-gas chromatography coupled to mass spectrometry are often used to identify the polymer types of MPs. Besides, MPs might damage the digestive tract of various organisms and negatively inhibit their growth, feeding and reproduction. The ways of human exposure to MPs are by ingestion, inhalation and dermal exposure, digestive and respiratory system might be adversely influenced. However, potential health risks of MPs to humans are remained insufficiently researched. Overall, by showing the presence of MPs in freshwaters and soils as well as possible ecotoxicological effects on the environment and humans, this paper provided a framework for future research in this field.


Assuntos
Monitoramento Ambiental , Poluentes Ambientais/análise , Microplásticos/análise , Animais , China , Ecotoxicologia , Monitoramento Ambiental/métodos , Poluentes Ambientais/toxicidade , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Lagos/química , Microplásticos/toxicidade , Oceanos e Mares , Plásticos/química , Solo , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/análise , Zooplâncton
14.
Environ Sci Pollut Res Int ; 27(30): 38360-38369, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32748353

RESUMO

Ecotoxicological bioassays have been widely applied to evaluate the toxicity of substances in standardized test organisms. Nevertheless, the main challenge for researchers is the use of native species to express the effects of pollutants on aquatic biota. Thirty years ago, Smith and collaborators evaluate the possible use of Pristina longiseta (as Pristina leidyi) in acute toxicity test, developing some experiments using cadmium and vanadium as toxicants. The present work aimed to update the use of P. longiseta, in acute bioassays, presenting the occurrence and general characteristics of the species; adaptation of cultivation to tropical conditions; sensitivity tests using potassium chloride (KCl) and copper sulfate (CuSO4) as reference substances standardized by OECD, USEPA, and ABNT; and acute exposure to zinc chloride (ZnCl2). The results showed a successful use of this species as tropical test organism, which presented easy laboratory rearing and responded to the classical ecotoxicological index. The present study can increase the utilization of P. longiseta in bioassays for tropical regions and improve the evaluation of environmental impacts using a native species in ecotoxicological studies.


Assuntos
Oligoquetos , Poluentes Químicos da Água , Animais , Bioensaio , Cádmio , Ecotoxicologia , Testes de Toxicidade Aguda
15.
J Environ Manage ; 273: 111176, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32763744

RESUMO

In the study, an attempt was made to create innovative mixtures based on bottom sediment and various types of waste to be tested for use as a substrate in the cultivation of consumer and non-consumer plants. The aim of the study was to assess the chemical and ecotoxicological properties of the growing medium prepared on the basis of bottom sediment (BS) and different carbon rich waste (cellulose waste (CW), biomass ash (BA), coffee hulls (CH), and sludge from water treatment (SW)) with a combination of 75% bottom sediment and 25% waste material. The mixtures had deacidifying properties, significant content of total organic carbon (TOC), the total quantities of macro- and micronutrients, and good sorption properties. The study showed a low total content of heavy metals in the mixtures. Moreover, a low share of the mobile fraction (F1) of metals indicated a low risk related to the metals mobility and potential bioavailability. The highest toxic effect was found in the mixture of bottom sediment and cellulose waste. Heterocypris incongruens was the most sensitive organism to substances present in the tested mixtures. Due to its low toxicity, the mixture of bottom sediment and water treatment sludge (BS+SW) constituted a potentially suitable substrate for its environmental application in agriculture, horticulture (for consumer crops) or land reclamation. Other mixtures exhibited valuable chemical properties (BS + BA, BS + CH BS + CW), but ended up being eco-toxic to the organisms, excluding them from agricultural or horticultural use for consumer crops. The proposed technology, which includes the production of growing medium based on the use of bottom sediment, is a promising way of transforming the sediment from a waste material to a valuable resource, thus enhancing the environmental benefits.


Assuntos
Ecotoxicologia , Metais Pesados/análise , Agricultura , Esgotos , Resíduos
16.
Environ Pollut ; 266(Pt 2): 115185, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32777698

RESUMO

Freshwater planarians have been gaining relevance as experimental animals for numerous research areas given their interesting features, such as high regeneration potential, shared features with the vertebrates' nervous system or the range of endpoints that can be easily evaluated in response to contaminants. Ecotoxicological research using these animals has been steadily increasing in the past decades, as planarians' potentialities for this research area are being recognized. In this work, we used polycyclic aromatic hydrocarbons (PAHs) as model contaminants and evaluated effects of exposure to phenanthrene, pyrene and benzo[a]pyrene (B[a]P) in planarians. The freshwater planarian Girardia tigrina was chosen and mortality, cephalic regeneration (during and post-exposure), behavioral endpoints and presence of PAHs in tissues, were evaluated. Mortality was only observed in planarians exposed to phenanthrene, with an estimated LC50 of 830 µg L-1. Results indicate that planarian behavioral endpoints were very sensitive in response to sub-lethal concentrations of PAHs, showing a greater sensitivity towards B[a]P and pyrene. Briefly, post-exposure locomotion and post-exposure feeding were significantly impaired by sub-lethal concentrations of all compounds, whereas regeneration of photoreceptors was only significantly delayed in planarians exposed to pyrene. Moreover, levels of PAH-type compounds in planarian tissues followed a concentration-dependent increase, showing uptake of compounds from experimental solutions. The present results highlight the importance of studying alternative and complementary endpoints, such as behavior, not only because these may be able to detect effects at lower levels of contamination, but also due to their ecological relevance. The simplicity of evaluating a wide range of responses to contaminants further demonstrates the utility of freshwater planarians for ecotoxicological research.


Assuntos
Planárias , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Animais , Ecotoxicologia , Água Doce
17.
Environ Pollut ; 266(Pt 2): 115251, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32814176

RESUMO

Sediments serve as both source and sink of contaminants (e.g., Cu) and biologically important materials (e.g., metals, nutrients). Bioturbation by benthic organisms is ecologically relevant as bioturbation affects the physio-chemical characteristics of sediments, thus altering nutrient and contaminant distribution and bioavailability. We examined the effects of sediment-associated Cu on T. tubifex with conventional toxicity endpoints, such as mortality and growth, and less commonly used non-destructive endpoints, such as bioturbation and feeding. An experimental approach was developed to examine the applicability of simple methods to detect effects on bioturbation and feeding. Two experiments were conducted with 7-day exposures to uncontaminated or Cu-spiked natural sediment at six Cu concentrations to examine Cu bioaccumulation and effects. Endpoints included worm mortality, feeding rate and growth (experiment A) and worm bioturbation (particle diffusion and maximum penetration depth, experiment B). A microparticle tracer was placed on the sediment surface and vertical particle transport was followed over time. Adverse effects were detected for all endpoints (bioturbation, feeding rate, growth and survival): a slight positive effect at the lowest Cu concentrations followed by adverse effects at higher concentrations indicating hormesis. These simple, non-destructive endpoints, provided valuable information and demonstrated that sediment-associated contaminants, such as Cu, can influence bioturbation activity, which in turn may affect the distribution of sediment-bound or particulate pollutants, such as the plastic microparticles studied here. Thus, we suggest to use simple endpoints, such as bioturbation and feeding rate, in ecotoxicity testing since these endpoint account for the influence of interactions between pollutants and benthos and, thus, increase ecological relevance.


Assuntos
Oligoquetos , Poluentes Químicos da Água/análise , Animais , Ecotoxicologia , Sedimentos Geológicos , Metais
18.
Mar Pollut Bull ; 159: 111493, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32736201

RESUMO

The consumption of anticancer agents has increased in the recent decades, and these substances may be present in sewage. Consequently, they may reach the environment when sanitation infrastructure is ineffective. This study evaluated the toxicity of three anticancer agents-Tamoxifen (TAM), Cisplatin (CisPt), and Cyclophosphamide (CP)-on the development of embryos of the sand-dollar Mellita quinquiesperforata. Adult individuals were collected in sandy beaches, and gametes were obtained. Freshly-fertilized eggs were exposed to increasing sets of concentrations of each compound, and the effective concentrations needed to cause a 50% effect in the organisms (EC50) were calculated. The three compounds were toxic, and their EC50 values were 16.78 ± 2.42 ng·L-1 (TAM), 27.20 ± 38.26 ng·L-1 (CisPt), and 101.82 ± 70.96 ng·L-1 (CP). There is no information on the environmental levels of these compounds in Brazil, but as they were already detected in ng·L-1 levels worldwide, it can be expected that these substances pose environmental risks to the marine biota.


Assuntos
Antineoplásicos , Poluentes Químicos da Água/análise , Animais , Brasil , Ecotoxicologia , Ouriços-do-Mar , Testes de Toxicidade
19.
Ecotoxicol Environ Saf ; 202: 110959, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800231

RESUMO

Long-term field experiments were performed to evaluate the phytotoxic properties of fungal metabolites in oil-contaminated soil and to assess the impact of contamination on the allelopathic activity of soil mycobiota. Two contrasting soils of Northwest Russia (sandy and loamy podzols) exposed to oil contamination underwent changes in abundance and allelopathic activities of soil fungi. Shifts within the microbial community caused by oil contamination affected not only oil-decomposition rates but also ecotoxicity of contaminated soil. There were significant differences in soil toxicity dynamics between sandy and loamy podzols. Four years after contamination, ecotoxicity of loamy podzol decreased, whereas sandy podzol remained highly toxic even nine years after contamination. The abundance and allelopathic activity of fungi is correlated with hydrocarbon degradation dynamics. The soil fungal community demonstrated high allelopathic activity which decreased over time in fertile loamy podzolic soil, whereas in poor sandy podzolic soil it remained high over the nine-year monitoring period. The results illustrate how oil contamination may influence allelopathic interactions in soil and demonstrate the advantage of using fungal metabolite toxicity test for testing of oil-contaminated soil samples.


Assuntos
Fungos/efeitos dos fármacos , Hidrocarbonetos/toxicidade , Micotoxinas/toxicidade , Petróleo/toxicidade , Microbiologia do Solo , Poluentes do Solo/análise , Animais , Biodegradação Ambiental , Daphnia/efeitos dos fármacos , Daphnia/crescimento & desenvolvimento , Ecotoxicologia , Fungos/metabolismo , Hidrocarbonetos/análise , Micotoxinas/metabolismo , Petróleo/análise , Federação Russa , Solo/química , Testes de Toxicidade , Triticum/efeitos dos fármacos , Triticum/crescimento & desenvolvimento
20.
Ecotoxicol Environ Saf ; 203: 110998, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32778532

RESUMO

Relative ecotoxicity of approved neonicotinoids (i.e. imidacloprid, clothianidin, acetamiprid, thiacloprid, thiamethoxam and dinotefuran) and diamides (i.e. chlorantraniliprole, cyantraniliprole and flubendiamide) was examined on population growth parameters of Zygogramma bicolorata Pallister on parthenium under laboratory conditions at 27 ± 1 °C, 65 ± 5% relative humidity and 10 L : 14D photoperiod. The dose of all tested insecticides in the bioassay procedure was within a minimum range of their recommended field rate. In acute toxicity trial, imidacloprid caused highest rate of mortality in treated adults of Z. bicolorata, however, it was lowest in flubendiamide treatment followed by cyantraniliprole and chlorantraniliprole. Further, based on toxicity coefficient (E) value in acute toxicity trial, all were classified as harmful (H) and diamides were classified as moderately harmful (MH) as per IOBC classification. Moreover, chronic toxicity trials were carried out through life table response experiments (LTREs) in the F1 progeny of acute toxicity experienced group. Prolonged development with the highest mortality was evident in as compared to diamides. Furthermore, population growth parameters i.e. potential fecundity (Pf), natality rate (mx), intrinsic rate of increase (rm), net reproductive rate (R0) and finite rate of increase (λ) was greatly reduced in Z. bicolorata treated with neonicotinoids as compared with diamides. However, mean generation time (Tc), corrected generation time (τ) and the doubling time (DT) was prolonged in neonicotinoids followed by diamides. Furthermore, proportion of females was greatly reduced (0.43-0.48 females) in neonicotinoids as comparison to diamides (0.53-0.55 females) and control (0.67 females). On the basis of ecotoxicity trials, the tested neonicotinoids were highly toxic to Z. bicolorata than diamides. Therefore, diamide insecticides could be used with Z. bicolorata, however, for validation experimentation need to be done under natural field conditions.


Assuntos
Besouros/efeitos dos fármacos , Diamida/toxicidade , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Animais , Besouros/fisiologia , Ecotoxicologia , Feminino , Crescimento Demográfico , Testes de Toxicidade Aguda
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