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1.
Ecotoxicol Environ Saf ; 208: 111634, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396154

RESUMO

The Quantitative Structure-Activity Relationship (QSAR) has been used to investigate organic mixtures but QSAR in the nanomaterial field (QNAR) is still new. Toxicity is a result of the interaction of many substances. QNAR research focuses on a single nanomaterial in the long-term. It is difficult to find an appropriate descriptor to build a model due to the complexity of the mixture. Here, we attempt to build a QNAR model to predict cell viability for HK-2 cells exposed to a mixture containing nano-TiO2 and heavy metals. HK-2 cells were exposed to four groups of mixtures containing heavy-metals and nanomaterials and CCK8 was added to obtain the number of living cells. At the same time, ROS was investigated to study this mechanism. Each descriptor of the components and mixtures were obtained using the formula Dmix= [Formula: see text] respectively. We used the Multiple Partial Least Squares Regression (PLS) and Random Forest Regression (RF) to build a QNAR model. Both models reliably predict and assess viability of HK-2 cells exposed to the mixture. The RF model showed greater stability and higher precision in toxicity predictability and can be applied to environmental nano-toxicology.


Assuntos
Ecotoxicologia/métodos , Metais Pesados/toxicidade , Nanoestruturas/toxicidade , Relação Quantitativa Estrutura-Atividade , Titânio/toxicidade , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Metais Pesados/química , Nanoestruturas/química , Espécies Reativas de Oxigênio/metabolismo , Titânio/química
2.
Ecotoxicol Environ Saf ; 208: 111639, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396159

RESUMO

Cnesterodon decemmaculatus is a Neotropical teleost fish frequently used in ecotoxicological evaluations, whose biology has been thoroughly studied. Although there is considerable information on its response to different toxicants, no range of reference values has been so far established for the different biological parameters proposed as biomarkers of effect or exposure. Moreover, no study has yet examined the possible influence of the metabolic status of the exposed animals on their response to toxic stress. Therefore, the aim of this work was to provide a first baseline for a set of bioenergetic biomarkers in C. decemmaculatus adults exposed to a control medium under previously standardized conditions, and to assess their possible intrinsic seasonal variability. The responses of the biomarkers obtained from the controls were contrasted with those from the reference toxicant (Cadmio-Cd) and receiving waters (surface waters of the Reconquista River RR, Buenos Aires Province, Argentina). We conducted four 12-day assays (one in each season) of exposure to control media, (reconstituted moderate hard water, MHW) and two assays of exposure to Cd in MHW and surface river water (RR) in both summer and autumn. The variables recorded were: Food intake (In), fecal production (F), specific assimilation (A) and cumulative mortality, oxygen extraction efficiency (OEE), specific metabolic rate (SMR), ammonia excretion (N), ammonia quotient (AQ) and scope for growth (SFG). The seasonal variation shown by some physiological parameters, points to the need for establishing a baseline obtained from standardized media, preferably on a seasonal basis. Moreover, SFG and A appeared as the most sensitive biomarkers, emphasizing the importance to consider the metabolic status of the test organisms for the appropriate interpretation of results from ecotoxicological studies performed under controlled experimental conditions. The obtained results provide useful information on C. decemmaculatus as model species in ecotoxicological bioassays involving biomarkers of early effect.


Assuntos
Ciprinodontiformes/metabolismo , Ecotoxicologia/métodos , Metabolismo Energético/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Argentina , Cádmio/toxicidade , Ciprinodontiformes/crescimento & desenvolvimento , Ecotoxicologia/normas , Biomarcadores Ambientais/efeitos dos fármacos , Rios/química , Estações do Ano
3.
Chemosphere ; 262: 127724, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32805653

RESUMO

Earthworms are common organisms in soil toxicity-testing framework, and endogeic species are currently recommended due to their ecological role in agroecosystem. However, little is known on their pesticide metabolic capacities. We firstly compared the baseline activity of B-esterases and glutathione-S-transferase in Allolobophora chlorotica and Aporrectodea caliginosa. Secondly, vulnerability of these species to pesticide exposure was assessed by in vitro trials using the organophosphate (OP) chlorpyrifos-ethyl-oxon (CPOx) and ethyl-paraoxon (POx), and by short-term (7 days) in vivo metabolic responses in soil contaminated with pesticides. Among B-esterases, acetylcholinesterase (AChE) activity was abundant in the microsomal fraction (80% and 70% of total activity for A. caliginosa and A. chlorotica, respectively). Carboxylesterase (CbE) activities were measured using three substrates to examine species differences in isoenzyme and sensitivity to both in vitro and in vivo exposure. CbEs were mainly found in the cytosolic fraction (80% and 60% for A. caliginosa and A. chlorotica respectively). GST was exclusively found in the soluble fraction for both species. Both OPs inhibited B-esterases in a concentration-dependent manner. In vitro trials revealed a pesticide-specific response, being A. chlorotica AChE more sensitive to CPOx compared to POx. CbE activity was inhibited at the same extent in both species. The 7-d exposure showed A. chlorotica less sensitive to both OPs, which contrasted with outcomes from in vitro experiments. This non-related functional between both approaches for assessing pesticide toxicity suggests that other mechanisms linked with in vivo OP bioactivation and excretion could have a significant role in the OP toxicity in endogeic earthworms.


Assuntos
Inibidores Enzimáticos/toxicidade , Oligoquetos/efeitos dos fármacos , Oligoquetos/enzimologia , Organofosfatos/toxicidade , Praguicidas/toxicidade , Poluentes do Solo/toxicidade , Acetilcolinesterase/metabolismo , Animais , Carboxilesterase/metabolismo , Citosol/enzimologia , Ecotoxicologia/métodos , Esterases/metabolismo , Glutationa Transferase/metabolismo , Oligoquetos/metabolismo , Paraoxon/análogos & derivados , Paraoxon/toxicidade , Solo/química , Especificidade da Espécie , Testes de Toxicidade
4.
Ecotoxicol Environ Saf ; 207: 111278, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32979841

RESUMO

Information on soil antimony (Sb) toxicity to earthworm Eisenia fetida (Savingy) is limited. This ecotoxicology study was designed to quantify the soil Sb toxicity to earthworm E. fetida before and after aging process, establishing dose-effect relationship between Sb content and mortality. Results of the avoidance test and acute test showed that the values of net avoidance response, escape rate and mortality were generally decreased in aged treatment compared to that in fresh treatment, respectively from 93.33% to 66.67%, 36.67% to 13.33% and 100% to 53.33% (15 d) taking TL800 (treatment level of 800 mg/kg) for example, meanwhile the values of median lethal content (LC50) at 72 h, 7 d and 15 d were respectively increased from 355.27 mg/kg to 2324.55 mg/kg, 322.19 mg/kg and 1743.19 mg/kg and 282.74 mg/kg to 745.94 mg/kg, indicating that aging process could reduce the Sb acute toxicity to earthworm. According to a three-step sequential extraction procedure, the bioavailable Sb ranged from 24.45% to 43.24% and 16.97% to 27.70% in fresh treatment and aged treatment, respectively, and the mortality of earthworm for 24 h decreased with the decrease of the content of mild acid-soluble antimony (which decreased averagely from 23.09% to 14.00%), which was more suited to assess Sb toxicity. This is the first report that confirms the toxicity of soil Sb to earthworm E. fetida as well as the considering of aging process and speciation.


Assuntos
Antimônio/toxicidade , Oligoquetos/fisiologia , Poluentes do Solo/toxicidade , Animais , Ecotoxicologia/métodos , Dose Letal Mediana , Solo , Poluentes do Solo/análise
5.
Chemosphere ; 262: 127735, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32777610

RESUMO

Despite the restriction of the use of neonicotinoids in the EU, including thiamethoxam and clothianidin, the debate over their risk on honey bees has not been fully settled. This study presents results of a three-year study working with 180 honey bee colonies in ten replicates. Colonies were sorted into three treatments (60 colonies per treatment) exposed to sunflower blooms grown from seeds treated with thiamethoxam, clothianidin and a non-treated control. Each colony was assessed at six moments: one before to exposition to sunflower, two during the exposition (short-time risk), two after exposition (medium-time risk) and one after wintering (long-time risk). The health and development of the colonies were assessed by monitoring adult bee population, brood development, status of the queen, food reserves and survival. No significant difference among treatments when raw data was considered. However, when evolution from initial status of the colony was evaluated, a significant difference was observed from the first week of exposure to sunflower blooms. In this period, the number of adult bees and the amount of brood were slightly lower in the bee hives exposed to neonicotinoids, although such differences disappeared in subsequent evaluations. The concentration of residues in samples of beebread and adult bees was at the level of ng·g-1. Magnitude of the effect of the treatment factor on the variability of colony health and development related parameters was low. The most important factor was the hive, followed by the replicate and year, and to a lesser extent the initial strength of the colonies.


Assuntos
Abelhas/efeitos dos fármacos , Guanidinas/toxicidade , Helianthus , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Sementes/efeitos dos fármacos , Tiametoxam/toxicidade , Tiazóis/toxicidade , Animais , Abelhas/fisiologia , Ecotoxicologia/métodos , Flores , Guanidinas/análise , Helianthus/efeitos dos fármacos , Inseticidas/análise , Neonicotinoides/análise , Resíduos de Praguicidas/análise , Polinização , Própole/análise , Sementes/química , Espanha , Tiametoxam/análise , Tiazóis/análise
6.
Chemosphere ; 262: 127716, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32799137

RESUMO

For the first time the occurrence of 25 organic micropollutants (OMPs) including; 11 personal care products (PCPs), six phthalate ester plasticizers (PEPs) and eight organophosphorus flame retardants (OPFRs) was investigated in 72 water samples obtained from five bays in the Uganda sector of Lake Victoria. In addition, an assessment of the potential ecotoxic risk of the target OMPs to aquatic organisms was conducted. Water samples were analyzed for the target OMPs using gas chromatography coupled with mass spectrometry (GC/MS). All the target PCPs were found in all the water samples with the exception of musk ketone and 2,6-di-tert-butylphenol. Triclosan (89-1400 ng L-1), benzophenone (36-1300 ng L-1), and 4-methylbenzylidine camphor (21-1500 ng L-1) were the most predominant PCPs. All the six plasticizers were found in all the water samples with dibutyl phthalate (350-16 000 ng L-1), and bis-(2-ethylhexyl) phthalate (210-23 000 ng L-1) detected at the highest concentrations. Five OPFRs out of the eight targeted were found in all the water samples. Tricresyl phosphate (25-8100 ng L-1), tris-(2-chloroethyl) phosphate (24-6500 ng L-1) and triphenyl phosphate (54-4300 ng L-1) were the most dominant OPFRs. The highest concentrations of OMPs were recorded in Murchison and Thurston Bays, presumably due to industrial wastewater effluents from the highly industrialized localities of the two Bays. Ecotoxicological risk assessment showed that PCPs (triclosan, musk ketone, and 4-MBC), plasticizers (dibutyl phthalate, bis-(2-ethylhexyl) adipate and bis-(2-ethylhexyl) phthalate) and OPFRs (tricresyl phosphate, triphenyl phosphate and tris-(2-chloroethyl) phosphate) pose a high ecotoxic risk to lives of aquatic organisms (risk quotients, RQ > 1).


Assuntos
Cosméticos/análise , Retardadores de Chama/análise , Lagos/análise , Compostos Organofosforados/análise , Plastificantes/análise , Poluentes Químicos da Água/análise , Animais , Cosméticos/toxicidade , Ecotoxicologia/métodos , Retardadores de Chama/toxicidade , Cromatografia Gasosa-Espectrometria de Massas/métodos , Compostos Organofosforados/toxicidade , Plastificantes/toxicidade , Medição de Risco , Análise Espaço-Temporal , Uganda , Águas Residuárias/química , Poluentes Químicos da Água/toxicidade
7.
Nanotoxicology ; 15(2): 145-166, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33320695

RESUMO

New registration requirements for nanomaterials under REACH consider the possibility to form 'sets of similar nanoforms' for a joined human health and environmental hazard, exposure and risk assessment. We developed a tool to create and justify sets of similar nanoforms and to ensure that each of the nanoforms is sufficiently similar to all other nanoforms. The decision logic is following the ECHA guidance in a transparent and evidence-based manner. For each two nanoforms the properties under consideration are compared and corresponding thresholds for maximal differences are proposed. In tier1, similarity is assessed based on intrinsic properties that mostly correspond to those required for nanoform identification under REACH: composition, impurities/additives, size, crystallinity, shape and surface treatment. Moreover, potential differences in the agglomeration/aggregation state resulting from different production processes are considered. If nanoforms were not sufficiently similar based on tier1 criteria, additional data from functional assays are required in tier2. In rare cases, additional short-term in vivo rodent data could be required in a third tier. Data required by tier 2 are triggered by the intrinsic properties in the first tier that did not match the similarity criteria. Most often this will be data on dissolution and surface reactivity followed by in vitro toxicity, dispersion stability, dustiness. Out of several nanoforms given by the user, the tool concludes which nanoforms could be justified to be in the same set and which nanoforms are outside. It defines the boundaries of sets of similar nanoforms and generates a justification for the REACH registration.


Assuntos
Ecotoxicologia/métodos , Exposição Ambiental/efeitos adversos , Nanoestruturas , Qualidade de Produtos para o Consumidor , Tomada de Decisões , Ecotoxicologia/legislação & jurisprudência , Exposição Ambiental/análise , União Europeia , Regulamentação Governamental , Humanos , Nanoestruturas/química , Nanoestruturas/classificação , Nanoestruturas/toxicidade , Tamanho da Partícula , Medição de Risco/métodos , Solubilidade , Propriedades de Superfície , Testes de Toxicidade
8.
Ecotoxicol Environ Saf ; 207: 111219, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32931966

RESUMO

Contamination by organic and inorganic compounds remains one of the most complex problems in both brackish and marine environments, causing potential implications for the reproductive success and survival of several broadcast spawners. Ficopomatus enigmaticus is a tubeworm polychaete that has previously been used as a model organism for ecotoxicological analysis, due to its sensitivity and ecological relevance. In the present study, the effects of five trace elements (zinc, copper, cadmium, arsenic and lead), one surfactant (sodium dodecyl sulfate, SDS) and one polycyclic aromatic hydrocarbon (benzo(a)pyrene, B(a)P) on the sperm quality of F. enigmaticus were investigated. Sperm suspensions were exposed in vitro to different concentrations of each selected contaminant under four salinity conditions (10, 20, 30, 35). Possible adverse effects on sperm function were assessed by measuring oxidative stress, membrane integrity, viability and DNA damage. Sperm quality impairments induced by organic contaminants were more evident than those induced by inorganic compounds. SDS exerted the largest effect on sperm. In addition, F. enigmaticus sperm showed high tolerance to salinity variation, supporting the wide use of this species as a promising model organism for ecotoxicological assays. Easy and rapid methods on polychaete spermatozoids were shown to be effective as integrated sperm quality parameters or as an alternative analysis for early assessment of marine and brackish water pollution.


Assuntos
Poliquetos/fisiologia , Espermatozoides/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Arsênico/farmacologia , Bioensaio , Cádmio/toxicidade , Ecotoxicologia/métodos , Masculino , Poliquetos/efeitos dos fármacos , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Salinidade , Oligoelementos/toxicidade
9.
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
10.
Ecotoxicol Environ Saf ; 205: 111187, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32853869

RESUMO

Ionic liquids have been becoming new 'green solvent' because of the low saturation vapor pressure, less volatilization and more recycling utilization. Since most ILs are soluble in water, it should be indispensable to evaluate the ecotoxicology effect of ILs on aquatic environment before using them widely. Based on the concept of norm index, a set of norm descriptors were proposed for anions, cations and ILs. The whole IL structure optimization method has been used to build a predictive norm index-based quantitative structure-toxicity relationship model for the toxicity of ILs on Vibrio fischeri. Statistical results indicated that norm descriptors were reliable and robust in expressing the relationship between structural information and toxicity of ILs. Meanwhile, a series of ILs without experimental values were predicted based on this stable QSTR model. The results indicated that for imidazole-based ILs, an increase in the length of substituent in the branch could enhance the toxicity of ILs on Vibrio fischeri, and the branch contains hydroxyl group, double bond or triple bonds might reduce the toxicity of ILs. Results obtained in this present work would be valuable for the molecular design and the toxicity evaluation toward aquatic organism of ILs.


Assuntos
Aliivibrio fischeri/efeitos dos fármacos , Imidazóis , Líquidos Iônicos , Modelos Teóricos , Solventes , Ânions/química , Cátions/química , Ecotoxicologia/métodos , Imidazóis/química , Imidazóis/toxicidade , Líquidos Iônicos/química , Líquidos Iônicos/toxicidade , Valor Preditivo dos Testes , Relação Quantitativa Estrutura-Atividade , Solventes/química , Solventes/toxicidade
11.
Ecotoxicol Environ Saf ; 203: 110941, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32678749

RESUMO

The increasing diversity and complexity of contaminants released in the environment continuously lead to new challenges when applying ecotoxicity assays. This paper comprises a review concerning exposure assessment and highlights important variables that should be taken into account when investigating aquatic media toxicity under both laboratory or field conditions. Thus, to reflect as much as possible what occurs in nature, ecotoxicity assays must carefully consider these variables in their experimental design. This includes contaminant properties, the selected bioindicators and biomarkers, the dose mode/regime, concentration vs. load, exposure to single vs. multiple contaminants and exposure of single vs. multiple species. Many of these, however, are not usually taken into account, leading to critical knowledge gaps in this area, discussed in detail herein.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Ecotoxicologia/métodos , Poluentes Químicos da Água/toxicidade , Animais , Ecotoxicologia/normas , Biomarcadores Ambientais/efeitos dos fármacos , Humanos , Medição de Risco , Especificidade da Espécie
12.
Ecotoxicol Environ Saf ; 203: 110981, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32678759

RESUMO

Heavy metal contamination in soil due to human activities is a global environmental problem. To find a washing solution that can significantly decontaminate heavy metals and minimize damage to soil quality, six washing solutions (H3PO4, K2CO3, CH3COOK, KH2PO4, HNO3 and KNO3) were used at different concentrations to treat contaminated soil collected from the field. Furthermore, changes in soil physicochemical properties and heavy metal speciation among prewashed, postwashed and neutralized samples were tested. Additionally, soil enzyme activities and soil microbial diversities in contaminated soil among the prewashed, postwashed and neutralized samples were also measured. Finally, a pot experiment was conducted with Mentha haplocalyx to test the efficiency of soil washing. The results revealed that the optimum washing solution was 1% HNO3 and that the removal rates of Cd and Pb were 75.7% and 60.6%, respectively, under treatment conditions of 35 °C, 90 min and a solid-liquid ratio of 1:10. The pH, total phosphorous, available potassium, soil enzyme activities and soil microbial diversity decreased significantly after washing. However, after the neutralization of washed soil with Ca(OH)2, the available phosphorous, total nitrogen and some microorganisms increased significantly compared with those of the soil before washing. After treatment with 1% HNO3, the chemical forms of Cd and Pb in soil mainly existed as F1 (exchangeable) fractions, but the main forms of the two metals changed to F5 (residual) and F3 (bound to Fe-Mn oxides) fractions after neutralization with Ca(OH)2. In addition, the plant height, root length, and fresh and dry weight of M. haplocalyx were not significantly affected by soil neutralization, while the Pb, Cu and As concentrations in the aboveground parts significantly decreased. Therefore, although soil washing could effectively remove Pb and Cd in soil, it also resulted in a significant decline in soil quality, but soil neutralization could effectively alleviate the negative effects during soil washing.


Assuntos
Ecotoxicologia/métodos , Metais Pesados/análise , Poluentes do Solo/análise , Solo/química
13.
J Environ Sci Health B ; 55(8): 749-755, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32558613

RESUMO

This study assessed the hematological, enzymatic and osmoregulatory responses of silver catfish (Rhamdia quelen) exposed to sublethal concentrations (1.125 and 3.750 µg/L) of a commercial thiamethoxam-containing insecticide used on rice crops. Groups of 6 fish per tank (in triplicate, n = 3, total 54 fish) were exposed for up to 96 h to different concentrations of the compound. After this period, fish were placed in clean water for 48 h. Two fish from each tank (6 per treatment) that had been exposed to the insecticide for 24 h were anesthetized with eugenol and blood was collected to evaluate hematological and biochemical parameters. Blood, liver and muscle were collected for determination of metabolic parameters, plasma cortisol, Cl-, Na+ and K+ levels and H+-ATPase and Na+/K+-ATPase activity in the gill. H+-ATPase activity was higher in fish exposed to 1.125 µg/L insecticide at 24 h compared to control (0.0 µg/L). Differences in cortisol levels were evidenced throughout the experimental period. These results indicated that exposure to the insecticide changed the hematological, biochemical and metabolic profile of the animals, suggesting concern about environmental safety. Therefore, we discourage the use of this pesticide in areas that come into contact with water bodies inhabited by fish.


Assuntos
Peixes-Gato/fisiologia , Inseticidas/toxicidade , Tiametoxam/toxicidade , Adenosina Trifosfatases/metabolismo , Animais , Peixes-Gato/sangue , Ecotoxicologia/métodos , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Hidrocortisona/sangue , Fígado/efeitos dos fármacos , Músculos/efeitos dos fármacos , Músculos/metabolismo , Potássio/metabolismo , Sódio/metabolismo , Testes de Toxicidade Aguda , Poluentes Químicos da Água/toxicidade
14.
Environ Geochem Health ; 42(11): 3703-3715, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32488800

RESUMO

The application of organophosphorus pesticides (OPPs) increased gradually because of the rise in global food demand that triggered the agriculture sector to increase the production, leading to OPP residues in the surface water. This study elucidated the presence of OPPs and estimated its ecological risk in the riverine ecosystem of the urbanised Linggi River, Negeri Sembilan, Malaysia. The OPP concentration in surface water was determined using solid-phase extraction method and high-performance liquid chromatography coupled with diode array detection. Further, the ecological risk was estimated by using the risk quotient (RQ) method. The three OPPs, i.e. chlorpyrifos, diazinon, and quinalphos were detected with mean concentrations of 0.0275 µg/L, 0.0328 µg/L, and 0.0362 µg/L, respectively. The OPPs were at high risk (in general and worst cases) under acute exposure. The estimated risk of diazinon was observed as medium for general (RQm = 0.5857) and high for worst cases (RQex = 4.4678). Notably, the estimated risk for chlorpyrifos was high for both general and worst cases (RQm = 1.9643 and RQex = 11.5643) towards the aquatic ecosystem of the Linggi River. Chronic risk of quinalphos remains unknown because of the absence of toxicity endpoints. This study presented clear knowledge regarding OPP contamination and possible risk for aquatic ecosystems. Hence, OPPs should be listed as one of the main priority contaminants in pesticide mitigation management in the future.


Assuntos
Compostos Organofosforados/análise , Praguicidas/análise , Poluentes Químicos da Água/análise , Animais , Clorpirifos/análise , Cromatografia Líquida de Alta Pressão/métodos , Diazinon/análise , Ecossistema , Ecotoxicologia/métodos , Exposição Ambiental/análise , Monitoramento Ambiental , Peixes , Invertebrados , Malásia , Compostos Organofosforados/toxicidade , Compostos Organotiofosforados/análise , Praguicidas/toxicidade , Rios/química , Extração em Fase Sólida/métodos , Urbanização , Poluentes Químicos da Água/toxicidade
15.
Chemosphere ; 258: 127340, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32563917

RESUMO

The group of synthetic chemicals known as poly and per-fluoroalkyl substances (PFAS) are currently of high concern to environmental regulators and the public due to their widespread occurrence, resistance to degradation and reported toxicity. However, little data exists on the effects of exposure to PFAS at environmentally relevant concentrations and this hampers the effective management of these compounds. This paper reviews current research on the occurrence and ecotoxicology of PFAS at environmentally relevant doses to assess their potential biological impacts. Hazard Quotient (HQ) analysis was undertaken as part of this assessment. Most PFAS detected in the environment were found to have a HQ risk value of <1 meaning their reported concentrations are below their predicted no effect concentration. This indicates many reported toxic effects of PFAS are, theoretically, unlikely to occur outside the laboratory. However, lack of information on new PFAS as well as their precursors and degradation products, coupled with lack of knowledge of their mixture toxicity means our understanding of the risks of PFAS is incomplete, especially in regard to sub-lethal and/or chronic effects. It is proposed that the development of molecular markers for PFAS exposure are needed to aid in the development of environmental PFAS regulations that are effective in fully protecting the environment.


Assuntos
Ecotoxicologia/métodos , Exposição Ambiental/normas , Fluorcarbonetos/farmacologia , Ácidos Alcanossulfônicos/toxicidade , Ecotoxicologia/normas , Fluorcarbonetos/análise , Humanos
16.
Chemosphere ; 250: 126416, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32380589

RESUMO

The flavonoid metal-insecticide magnesium-hesperidin complex (MgHP) has recently been considered as a novel insecticide to replace some persistent pesticides. However, it is important to evaluate its action on non-target species, mainly those living in an aquatic environment, as these ecosystems are the final receptors of most chemicals. Reactive oxygen species, antioxidant and oxidative stress biomarkers, genotoxicity as well as cell cycle was evaluated in the liver cell line from zebrafish (Danio rerio; ZF-L) exposed to 0, 0.1, 1, 10, 100 and 1000 ng mL-1 MgHP. MgHP affected cell stability by increasing reactive oxygen species (ROS) in both exposure times (24 and 96 h) at high concentrations. Catalase (CAT) activity decreased after 24 h exposure, and glutathione and metallothionein values increased, avoiding the lipid peroxidation. Genotoxicity increased as MgHP concentration increased, after 24 h exposure, exhibiting nuclear abnormalities; it was recovered after 96 h exposure, evidencing possible stimulation of DNA repair mechanisms. The alteration in the cell cycle (increasing in the Sub-G1 phase and decreasing in the S-phase) was associated with chromosomal instability. In conclusion, the responses of ROS and the antioxidant defense system depended on MgHP concentration and time exposure, while DNA exhibited some instability after 24 h exposure, which was recovered after 96 h.


Assuntos
Ciclo Celular/efeitos dos fármacos , Inseticidas/toxicidade , Fígado/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/metabolismo , Linhagem Celular , Dano ao DNA , Relação Dose-Resposta a Droga , Ecotoxicologia/métodos , Biomarcadores Ambientais/efeitos dos fármacos , Glutationa/metabolismo , Hesperidina/química , Hesperidina/toxicidade , Inseticidas/administração & dosagem , Inseticidas/química , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/citologia , Fígado/metabolismo , Magnésio/química , Testes de Mutagenicidade/métodos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Poluentes Químicos da Água/química , Peixe-Zebra
17.
J Environ Sci Health B ; 55(7): 646-654, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32432942

RESUMO

The aim of this work was to know the differential composition of the dissolved fraction of a glyphosate-based herbicide (GBH), commercialized as GLIFOPAC, when reaches different aquatic environments and its ecotoxicological effects on crustaceans species living in them. Daphnia magna, Tisbe longicornis, and Emerita analoga were exposed to glyphosate herbicide called GLIFOPAC (480 g L-1 of active ingredient or a.i.) at concentrations between 0.5 and 4.8 g a.i. L-1. Acute toxicity in D. magna (48 h-LC50), E. analoga (48 h-LC50), and T. longicornis (96 h-LC50) was studied. Chromatographic analysis of the GBH composition used and water (freshwater/sea water) polluted with GLIFOPAC were evaluated. Results reported acute toxicity (48-96 h-LC50) values for D. magna, E. analoga and T. longicornis of 27.4 mg L-1, 806.4 mg L-1, and 19.4 mg L-1, respectively. Chromatographic evaluation described around 45 substances of the GLIFOPAC composition, such as from the surfactant structures (aliphatic chain with esther/ether group), metabolites (AMPA), and other substances (glucofuranose, glucopyranoside, galactopyranose). This study evidenced differences in the GLIFOPAC composition in freshwater and marine water, which may differentiate the toxic response at the crustacean-level in each aquatic environment.


Assuntos
Crustáceos/efeitos dos fármacos , Daphnia/efeitos dos fármacos , Glicina/análogos & derivados , Herbicidas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Braquiúros/efeitos dos fármacos , Ecotoxicologia/métodos , Biomarcadores Ambientais/efeitos dos fármacos , Água Doce , Glicina/química , Glicina/toxicidade , Herbicidas/química , Dose Letal Mediana , Testes de Toxicidade Aguda , Poluentes Químicos da Água/química
18.
J Environ Sci Health B ; 55(5): 477-483, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32449480

RESUMO

Pyraoxystrobin is a novel strobilurin fungicide that is widely used on many crops. The high log Kow of pyraoxystrobin implies that it tends to accumulate in aquatic organisms. This study optimized the sorbents of QuEChERS (quick, easy, cheap, effective, rugged, and safe) using 13C-labelled pyraoxystrobin as the internal standard (IS). It has been established a QuEChERS-LC-MS/MS IS method to study the bioconcentration and elimination of pyraoxystrobin in zebrafish (Danio rerio). The results indicated that the method had satisfactory linearity between 0.234 and 15 µg L-1 (R2 = 0.9996). The limits of detection (LOD) and quantification (LOQ) for pyraoxystrobin were 0.01 and 0.03 µg L-1, respectively. The LOQs of the method for water and zebrafish were 0.05 µg L-1 and 0.01 mg/kg, respectively. The mean recovery of pyraoxystrobin in zebrafish and water at fortification levels of 0.01-0.3 mg kg-1 and 0.05-1.5 µg L-1 ranged from 98.31 to 105.61% and 101.87 to 108.48%, respectively, with a % RSD (relative standard deviation) of 0.94-3.57%. The bioconcentration has been evaluated. The bioconcentration factors for pyraoxystrobin in zebrafish were 1,792 and 3,505 after exposure to 0.5 µg L-1 for 168 h and 0.05 µg L-1 for 216 h, respectively. The half-life of pyraoxystrobin in zebrafish was 9.0-9.5 d.


Assuntos
Acrilatos/análise , Acrilatos/farmacocinética , Fracionamento Químico/métodos , Pirazóis/análise , Pirazóis/farmacocinética , Peixe-Zebra , Acrilatos/toxicidade , Animais , Bioacumulação , Cromatografia Líquida , Ecotoxicologia/métodos , Fungicidas Industriais/análise , Fungicidas Industriais/farmacocinética , Fungicidas Industriais/toxicidade , Meia-Vida , Limite de Detecção , Pirazóis/toxicidade , Sensibilidade e Especificidade , Espectrometria de Massas em Tandem/métodos , Testes de Toxicidade Aguda , Poluentes Químicos da Água/análise
19.
Ecotoxicol Environ Saf ; 199: 110669, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32450358

RESUMO

Ciliates are key components of aquatic ecosystems, significantly contributing to the decomposition of organic matter and energy transfer to higher trophic levels. They are considered good biological indicators of chemical pollution and relatively sensitive to heavy metal contamination. In this study, we performed a meta-analysis of the available toxicity data of heavy metals and ciliates to assess: (1) the sensitivity of freshwater ciliates to different heavy metals, (2) the relative sensitivity of ciliates in comparison to the standard test species used in ecotoxicological risk assessment, and (3) the difference in sensitivity across ciliate taxa. Our study shows that the tolerance of ciliates to heavy metals varies notably, which is partly influenced by differences in methodological conditions across studies. Ciliates are, in general, sensitive to Mercury > Cadmium > Copper > Zinc > Lead > Chromium. Also, this study shows that most ciliates are more tolerant to heavy metal pollution than the standard test species used in ecotoxicological risk assessments, i.e., Raphidocelis subcapitata, Daphnia magna, and Onchornyncus mykiss. Threshold concentrations derived from toxicity data for these species is expected to confer sufficient protection for the vast majority of ciliate species. Our data analysis also shows that the most commonly tested ciliate species, Paramecium caudatum and Tetrahymena thermophila, are not necessarily the most sensitive ones to heavy metal pollution. Finally, this study stresses the importance of developing standard toxicity test protocols for ciliates, which could lead to a better comprehension of the toxicological impact of heavy metals and other contaminants to ciliate species.


Assuntos
Cilióforos/efeitos dos fármacos , Ecotoxicologia/métodos , Água Doce/química , Metais Pesados/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Ecossistema , Metais Pesados/análise , Medição de Risco , Testes de Toxicidade , Poluentes Químicos da Água/análise
20.
J Environ Sci Health B ; 55(7): 669-676, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32396780

RESUMO

This study was designed to evaluate the acute toxicity of acetamiprid (neonicotinoid) and lambda-cyhalothrin (pyrethroid), individually and mixtures (Act-LCh mixture and Acer 35 EC®, 15 g/L of acetamiprid and 20 g/L of lambda-cyhalothrin) in African catfish juveniles (3.35 ± 0.75 g). The tests were conducted in the laboratory under semi-static conditions according to OECD Guideline 203. Mixture toxicity effects as a function of lethal concentrations were assessed using the additive index (AI) method. Acetamiprid with 96 h-LC50 = 265.7 ppm can be considered to be nontoxic for this species. However, lambda-cyhalothrin was highly toxic to C. gariepinus with 96 h-LC50 = 0.00083 ppm. Acer 35 EC® was less toxic (96 h-LC50 = 0.21 ppm) than the Act-LCh mixture (96 h-LC50 = 0.043 ppm). Marked changes indicating nervous system damage were also recorded. An antagonistic effect was shown for lethal concentrations leading to 5 to 15% mortality in 96 hours (96 h-LC5-15) while an additive effect was obtained for the 96 h-LC20-50. The results indicate that ecological risk assessment of these molecules in aquatic environments should consider their contamination levels. Moreover, particular attention to behavior changes related to their neurotoxicity is recommended for additional monitoring of the negative effects of these insecticides.


Assuntos
Peixes-Gato , Neonicotinoides/toxicidade , Nitrilos/toxicidade , Piretrinas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Comportamento Animal/efeitos dos fármacos , Ecotoxicologia/métodos , Inseticidas/toxicidade , Dose Letal Mediana , Mortalidade , Testes de Toxicidade Aguda
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