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1.
Chemosphere ; 241: 125100, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31629240

RESUMO

The most existing studies on the toxicity of antimony (Sb) were performed in limited types of soil and after short aging time. Effects of soil properties and long aging time on chronic toxicity of Sb(III) and Sb(V) to model organism Folsomia candida were studied in the laboratory studies. The results showed that after the Sb(V)-treated soils were aged for 365 d, the Sb exhibited no toxicity to survival and reproduction even at the nominal highest concentration of 12,800 mg kg-1 in ten types of soils with distinct differences in soil properties. In the Sb(III)-treated ten soils aged only for 30 d, the concentrations causing 50% mortality (LC50) and concentrations inhibiting 50% reproduction (EC50) were 1288-3219 mg kg-1 and 683-1829 mg kg-1, respectively. The LC50 were higher than the highest test concentration and the EC50 significantly increased by 2.24-6.16 fold after the Sb(III)-treated soils were aged for 150 d, and soil pH was the most important single factor explaining the variance in aging effects. After the aging time was 365 d, similar with Sb(V)-treated soils, no toxicity were observed in the most Sb(III)-treated soils, indicating the increasing aging effects with aging time. Regression analysis indicated that the OM and pH were the most important single factor predicting Sb toxicity to reproduction in Sb(III)-treated soils aged for 30 and 150 d, respectively.


Assuntos
Antimônio/toxicidade , Artrópodes/efeitos dos fármacos , Poluentes do Solo/toxicidade , Solo/química , Animais , Concentração de Íons de Hidrogênio , Dose Letal Mediana , Modelos Animais , Reprodução/efeitos dos fármacos , Poluentes do Solo/farmacologia , Fatores de Tempo
2.
Chemosphere ; 240: 124791, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31546189

RESUMO

Produced water (PW) is a mixture of formation water and injected water from oil and gas reservoirs, which contain a complex composition of dissolved and particulate organic and inorganic chemicals. High quantities of PW are extracted with the oil, which can be discharged into the environment, re-injected into the wells or treated for reuse. The present study aimed to evaluate the soil ecotoxicity under an irrigation system using treated PW (water-oil separation, sand filter, activated charcoal filter, reverse osmosis) for sunflower production, predicting conditions for PW reuse in the semi-arid region of Brazil. The experiment was conducted in a greenhouse using natural soil in vessels. Water from public water supply was used as control. Soil samples from two production cycles of sunflowers were assessed using ecotoxicity tests with soil invertebrate's species representing macro and mesofaunal groups: Eisenia andrei (earthworms), Folsomia candida (collembolans) and Enchytraeus crypticus (enchytraeids). Leachates samples were evaluated with aquatic ecotoxicity tests to assess the soil retention function. Results showed impact of irrigation with PW in all treatments except reverse osmosis. Significant negative correlations were found among reproduction of soil invertebrates, high Na+ concentrations and electrical conductivity. The effects of other contaminants not analyses should not be discarded. It is important to highlight that salinity is not usually included in target values of soil quality. This study reinforces the importance of ecotoxicity tests in predictive and retrospective risk assessment, joining effects of contaminant mixtures or even that contaminants not considered in chemical scope of analysis or legislation.


Assuntos
Irrigação Agrícola , Organismos Aquáticos , Poluentes do Solo/toxicidade , Eliminação de Resíduos Líquidos , Animais , Artrópodes/efeitos dos fármacos , Brasil , Monitoramento Ambiental , Campos de Petróleo e Gás , Oligoquetos/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Estudos Retrospectivos , Solo/química , Poluentes do Solo/análise , Água/análise
3.
Pestic Biochem Physiol ; 161: 33-46, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31685194

RESUMO

Chitin is a structural component of the arthropod cuticular exoskeleton and the peritrophic matrix of the gut, which play crucial roles in growth and development. In the past few decades, our understanding of the composition, biosynthesis, assembly, degradation, and regulation of chitinous structures has increased. Many chemicals have been developed that target chitin biosynthesis (benzoyphenyl ureas, etoxazole), chitin degradation (allosamidin, psammaplin), and chitin regulation (benzoyl hydrazines), thus resulting in molting deformities and lethality. In addition, proteins that disrupt chitin structures, such as lectins, proteases, and chitinases have been utilized to halt feeding and induce mortality. Chitin-degrading enzymes, such as chitinases are also useful for improving the efficacy of bio-insecticides. Transgenic plants, baculoviruses, fungi, and bacteria have been engineered to express chitinases from a variety of organisms for control of arthropod pests. In addition, RNA interference targeting genes involved in chitin pathways and structures are now being investigated for the development of environmentally friendly pest management strategies. This review describes the chemicals and proteins used to target chitin structures and enzymes for arthropod pest management, as well as pest management strategies based upon these compounds, such as plant-incorporated-protectants and recombinant entomopathogens. Recent advances in RNA interference-based pest management, and how this technology can be used to target chitin pathways and structures are also discussed.


Assuntos
Artrópodes/metabolismo , Quitina/metabolismo , Animais , Artrópodes/efeitos dos fármacos , Quitina/química , Quitinases/metabolismo , Inseticidas/farmacologia , Controle de Pragas/métodos , Interferência de RNA
4.
Environ Pollut ; 254(Pt B): 113105, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31476675

RESUMO

Soil organisms are exposed to natural and anthropogenic stressors, such as xenobiotics. However, to simplify and make laboratory experiments easily reproducible, natural stressors are often excluded from ecotoxicological studies and risk assessment. This might underestimate the effect of chemicals, since synergistic interactions between chemicals and natural stressors might occur, creating a more severe impact than expected. Several studies have addressed simultaneous exposure to natural and chemical stressors, but very little is known of about the persistence of these interactions during recovery. Here, we examined if recovery after chemical stress exposure was important for the ability of springtails (Folsomia candida) to tolerate subsequent drought- and heat stress. Nonylphenol (NP) and phenanthrene (PHE) was tested and their isolated toxicity resulted in LC50 values of 206 mg NP kg-1 dry soil and 109 mg PHE kg-1 dry soil in a 7-day test. Elimination of NP and PHE was rapid and only trace amounts remained in springtail tissues after 3-7 days of recovery. Isolated studies of drought and heat shock on Folsomia candida resulted in a lethal effect for 50% of the animals (LRH50) at a relative humidity (RH) of 97.9%, and 190 min at 34 °C was shown to be lethal for 50% of the test species (LT50). The results showed, as expected, significant synergistic interactions between the effects of the chemicals and the effects of drought and heat stress. The negative effects of NP and PHE on the drought tolerance disappeared within 7 days post exposure. Springtails exposed to PHE also recovered their heat tolerance within 7 days post exposure, while NP exposed animals had not fully recovered their heat tolerance 14 days after exposure. Overall, a recovery period post chemical exposure was found to be very important for springtails in order to cope with natural stressors like heat and drought.


Assuntos
Artrópodes/efeitos dos fármacos , Resposta ao Choque Térmico , Fenantrenos/toxicidade , Fenóis/toxicidade , Poluentes do Solo/toxicidade , Animais , Artrópodes/fisiologia , Secas , Solo
5.
Chemosphere ; 237: 124359, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31394455

RESUMO

The effect of zinc oxide nanoparticles (ZnO NPs) and zinc sulfide nanoparticles (ZnS NPs) on the toxicity of sewage sludges in sewage sludge-amended soils was investigated with respect to plant- (Lepidium sativum) and soil- (Folsomia candida) species. The toxicity of porewater obtained from the tested soils towards Vibrio fischeri (Microtox®) was also investigated. Two sewage sludges (SSL1 and SSL2) with different organic matter content were amended with nanoparticles. Depending on the type of biotest and the type of sewage sludge, different effects of ZnO or ZnS NPs on the toxicity of sewage sludge-amended soil were observed. In general, ZnO and ZnS NPs stimulated root growth for SSL1 or reduced the harmful impact of SSL2 on the root growth of L. sativum roots. Greater stimulation or inhibition of root growth was observed for the ZnO than ZnS NPs. The unfavorable effect of ZnO/ZnS NPs on F. candida mortality and reproduction was observed at a concentration of ZnO/ZnS in sewage sludge ≥250 mg/kg. Generally, there were no significant differences between ZnO and ZnS NPs toxicity towards F. candida. Aging for 45 days of sewage sludge-amended soil containing NPs affected ZnO and ZnS NPs toxicity to all tested organisms. In the most cases, the toxicity decreased after 45 days of aging for plant (L. sativum) and invertebrates (F. candida). The toxicity of porewater to V. fischeri from sewage sludge-amended soil contains ZnO NPs did not change, while in the case of ZnS NPs, the toxicity increased after 45 days of aging.


Assuntos
Bactérias/efeitos dos fármacos , Invertebrados/efeitos dos fármacos , Nanopartículas/química , Plantas/efeitos dos fármacos , Solo/química , Aliivibrio fischeri/efeitos dos fármacos , Animais , Artrópodes/efeitos dos fármacos , Lepidium sativum/efeitos dos fármacos , Esgotos , Poluentes do Solo/análise , Sulfetos/farmacologia , Compostos de Zinco/farmacologia , Óxido de Zinco/farmacologia
6.
Nat Commun ; 10(1): 3579, 2019 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-31395863

RESUMO

It is thought that fungi protect themselves from predation by the production of compounds that are toxic to soil-dwelling animals. Here, we show that a nontoxic pigment, the bis-naphthopyrone aurofusarin, protects Fusarium fungi from a wide range of animal predators. We find that springtails (primitive hexapods), woodlice (crustaceans), and mealworms (insects) prefer feeding on fungi with disrupted aurofusarin synthesis, and mealworms and springtails are repelled by wheat flour amended with the fungal bis-naphthopyrones aurofusarin, viomellein, or xanthomegnin. Predation stimulates aurofusarin synthesis in several Fusarium species and viomellein synthesis in Aspergillus ochraceus. Aurofusarin displays low toxicity in mealworms, springtails, isopods, Drosophila, and insect cells, contradicting the common view that fungal defence metabolites are toxic. Our results indicate that bis-naphthopyrones are defence compounds that protect filamentous ascomycetes from predators through a mechanism that does not involve toxicity.


Assuntos
Artrópodes/efeitos dos fármacos , Aspergillus ochraceus/fisiologia , Fusarium/fisiologia , Naftoquinonas/farmacologia , Pigmentos Biológicos/farmacologia , Adaptação Fisiológica , Animais , Artrópodes/fisiologia , Preferências Alimentares/efeitos dos fármacos , Naftoquinonas/metabolismo , Pigmentos Biológicos/metabolismo , Comportamento Predatório/efeitos dos fármacos
7.
Rev Environ Health ; 34(3): 303-307, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31444967

RESUMO

The aim of this research was to assess the effect of soil contamination with titanium (Ti) and iron (Fe) at military sites in Ukraine using the avoidance and reproduction tests with Folsomia candida (springtail). The soil used for the tests was sampled in 2017 from Dolyna, Ivano-Frankivsk region, Ukraine from two plots, namely a contaminated and a control site. The sample site is a former military site previously used for tank training. At the control site mainly the concentrations of Ti and Fe were exceeded. The control soil was free from contamination. The avoidance test and reproduction test were conducted with the use of springtail species F. candida. The following nine levels of contamination with heavy metals were established: 1%, 1.5%, 5%, 10%, 15%, 25%, 50%, 75% and 100%. The duration of the avoidance test was 7 days, and that of the reproduction test was 28 days. Overall, the results show that the avoidance and reproduction tests with collembolans have the potential to be used as screening tools in an ecological risk assessment of heavy metals. In the avoidance test, the concentrations from 1.5 to 100% significantly decreased the number of F. candida in the contamination site in comparison to the control site. At the same time, avoidance was not observed in the first concentration (1%). According to the reproduction test, the negative effect on the number of F. candida juveniles was observed beginning at the 10% dose. The half maximal effective concentration (EC50) for the avoidance test was 50.12%, while that for the reproduction test was 22.39%. The contamination with heavy metals at the military areas indicated the short- and long-term toxicity risk on the springtail F. candida.


Assuntos
Artrópodes/efeitos dos fármacos , Ferro/toxicidade , Poluentes do Solo/toxicidade , Titânio/toxicidade , Testes de Toxicidade , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Militares , Reprodução/efeitos dos fármacos , Medição de Risco
8.
Ecotoxicol Environ Saf ; 183: 109538, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31401331

RESUMO

It is well established that arsenic (As) pollution has a severe threat to food security and soil non-target organisms, however, its influences on soil fauna gut microbiota are poorly understood. The gut microbiota of soil fauna play an important role in host health and nutrient cycling. Here, we used dietary exposure to investigate the effects of As on the mortality and gut microbiota of two model soil collembolans (Folsomia candida and Onychiurus yodai) and determine the accumulation of As in collembolan body tissues. The results showed that, although As exposure did not induce the mortality of the two species, dose dependence of As accumulation was indeed detected in their body tissues. Oral As exposure (500 µg g-1 yeast) significantly altered the community structure (P < 0.05) of F. candida gut microbiota and reduced its diversity (by more than 20%; P < 0.05) compared to the control; however, no significant effects were observed in O. yodai gut microbiota. The two collembolan species possess significantly different gut microbiota (P < 0.05), which may partly explain the differences of the two collembolan gut microbiota response to As exposure. We further found that the genera Ochrobactrum, Geobacter and Staphylococcus were sensitive to As exposure in F. candida (P < 0.05), but these bacteria were low abundance and not altered in O. yodai. Moreover, the relative abundance of these bacteria was significantly correlated with As bioaccumulation in F. candida body tissues (P < 0.05, R2 > 0.6). Higher As bioaccumulation factor was also found in O. yodai body tissues compared to the F. candida. These results indicate that collembolan gut microbiota present a species-specific response to As and may be a more sensitive indicator than the mortality of collembolan.


Assuntos
Arseniatos/toxicidade , Artrópodes/efeitos dos fármacos , Microbioma Gastrointestinal/efeitos dos fármacos , Poluentes do Solo/toxicidade , Solo/química , Animais , Artrópodes/microbiologia , DNA Bacteriano/genética , Microbioma Gastrointestinal/genética , Análise de Componente Principal , Especificidade da Espécie
9.
Environ Pollut ; 254(Pt B): 113071, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31454566

RESUMO

Climatic stressors and chemicals should not be treated as isolated problems since they often occur simultaneously, and their combined effects must be evaluated including their possible interactive effects. In the present study we subjected springtails (Folsomia candida) to combined exposure to phenanthrene and dynamic heat cycles in a full factorial experiment. In a microcosm experiment, we studied the population growth of springtails subjected to a range of sub-lethal concentrations of phenanthrene. During the 28-day experiment we further subjected microcosms to varying numbers of repeated dynamic heat cycles (0-5 cycles) simulating repeated heat waves. We found a synergistic interaction between the effects of phenanthrene and the number of heat waves on both body mass of adults and juvenile production of F. candida showing that the negative effects of phenanthrene were intensified when animals were heat stressed, and/or vice versa. This interaction was not related to internal concentrations of phenanthrene in adult springtails, nor was it due to altered degradation of phenanthrene in soil. We argue that both phenanthrene (by its partitioning into membrane bilayers) and heat have detrimental effects on the physical conditions of cellular membranes in a dose-dependent manner, which, under extreme circumstances, can increase membrane fluidity to a level which is sub-optimal for normal membrane functioning. We discuss the possibility that the synergistic interactions subsequently reduce life-history parameters such as growth and reproduction.


Assuntos
Artrópodes/fisiologia , Resposta ao Choque Térmico , Fenantrenos/toxicidade , Poluentes do Solo/toxicidade , Animais , Artrópodes/efeitos dos fármacos , Temperatura Alta , Fenantrenos/metabolismo , Reprodução/efeitos dos fármacos , Solo , Poluentes do Solo/metabolismo
10.
Environ Sci Pollut Res Int ; 26(27): 27816-27822, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31342354

RESUMO

The bioavailability of metals can be influenced not only by soil properties but also by other species living at polluted sites. However, in laboratory experiments, usually only one test species is used to estimate bioavailability. In this study, a two-species approach was applied to assess the impact of the earthworm Lumbricus rubellus on the bioavailability of cadmium and lead to the springtail Folsomia candida using natural soils from a gradient of metal pollution. Earthworms were kept in half of the soil replicates for 4 weeks. Subsequently, the uptake and elimination kinetics of cadmium and lead in F. candida exposed for 21 days to the soils was determined. Earthworm activity affected soil properties but did not significantly affect metal uptake rate constants in springtails. The slightly higher uptake due to the presence of earthworms, which was consistent in all tested soils and for both metals, suggests that further research is needed on the role of species interactions in affecting metal bioavailability in soil.


Assuntos
Ampicilina/análogos & derivados , Cádmio/farmacologia , Chumbo/farmacologia , Oligoquetos/efeitos dos fármacos , Ampicilina/química , Animais , Artrópodes/química , Artrópodes/efeitos dos fármacos , Disponibilidade Biológica , Cádmio/química , Poluição Ambiental , Cinética , Chumbo/química , Solo
11.
Environ Sci Pollut Res Int ; 26(25): 26184-26192, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31280445

RESUMO

In the standard ISO soil toxicity test using Collembola, adult survival and juvenile production are the only endpoints that can be attainable. The information on egg production and egg hatching cannot be investigated in the ISO test. To overcome this limitation, in this study, the effects of teflubenzuron on life history parameters of Yuukianura szeptyckii (Collembola) were investigated with a compressed soil test. Teflubenzuron is an insect growth regulator and has a negative effect on egg production, and egg hatching process of arthropods. LC50 decreased with increases in exposure period from 6.97 mg/kg in the third week to 3.60 mg/kg in the fourth week. The EC50 for egg and juvenile production was 0.57 mg/kg and 0.26 mg/kg, respectively. The hatching rate decreased significantly from 46 to 7% as the concentration increased from 0.25 to 1.00 mg/kg, respectively, and the molting frequency was significantly affected only at > 4 mg/kg. The toxic contribution rate (TCR) was defined as the ratio of juvenile production at an exposure concentration compared with the control, and a simple life history model was developed for TCR estimations. At the lower concentrations (< 0.3 mg/kg), the hatching rate reduction was a main contributor to the total toxicity, but the adult mortality and egg production reduction were the main contributors at the higher concentrations (> 2.0 mg/kg). The contribution of egg production reduction remained relatively constant. Since collembolan populations in the soil can be composed of various developmental stages, the differences in the sensitivity to chemicals depending on the developmental stages should be included in the assessment of the toxic impact on soil ecosystems.


Assuntos
Benzamidas/toxicidade , Reprodução/efeitos dos fármacos , Poluentes do Solo/toxicidade , Animais , Artrópodes/efeitos dos fármacos , Benzamidas/química , Ecossistema , Dose Letal Mediana , Solo , Testes de Toxicidade
12.
Environ Pollut ; 249: 1081-1090, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31146314

RESUMO

In the present study, a screening level site-specific ecological risk assessment (ERA) was conducted on 10 abandoned metal mines in Korea to determine the ecological risk and prioritize the mines requiring further investigation. A cost-saving approach was adopted by combining both the chemical (ChemLoE) and the ecotoxicological (EcotoxLoE) lines of evidence for the evaluation of integrated risk (IR), rather than applying the full spectrum of Triad, including ecological LoE. The risk values for ChemLoE were derived by calculating the toxic pressure based on the total and 0.01 M CaCl2 extractable metal(loid) concentrations. The risk values for EcotoxLoE were based on the mortality and reproduction of the collembolan species Paronychiurus kimi in the mine soils. A response surface model with a central composite design (CCD) was constructed to standardize the effects of soil physicochemical properties (i.e., organic matter content, clay content, and soil pH) on the reproduction of P. kimi. The predicted number of offspring was used as a reference for the calculation of risk value for reproduction. The ChemLoE and EcotoxLoE values ranged from 0.34 to 1.00 and 0.12 to 0.49, respectively, in the surveyed mines. The contribution of the ChemLoE value to the IR was higher than that of the EcotoxLoE value for all mines. Overall, two of the 10 mines were classified as high-risk soils with high IR values (IR > 0.76), but large deviations were also observed between the LoEs in these mines, suggesting the need for further studies to confirm the potential risks. The future investigations of these mines should focus particularly on providing additional evidence to reduce the degree of uncertainty for risk assessment.


Assuntos
Artrópodes/efeitos dos fármacos , Monitoramento Ambiental/métodos , Metais/análise , Mineração , Poluentes do Solo/análise , Solo/química , Animais , Ecotoxicologia , Metais/toxicidade , Reprodução/efeitos dos fármacos , República da Coreia , Medição de Risco , Poluentes do Solo/toxicidade
13.
Environ Sci Pollut Res Int ; 26(18): 18230-18239, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31041701

RESUMO

Biochar as a carbon-rich highly porous substance has been proposed for use in agriculture and horticulture as a soil amendment. One of the main concerns of this application of biochar is its potential contamination with heavy metals (HMs) and polycyclic aromatic hydrocarbons. The aim of this research was to access the environmental risk of biochar used as a soil amendment on soil mesofauna (mites and springtails). We conducted both field and laboratory experiments with the use of wood-chip biochar from low-temperature (300 °C) flash pyrolysis. Biochar was free from polycyclic aromatic hydrocarbons (PAH), and the concentration of all tested toxic compounds was very low or even under the level of detection. Both the results of field and laboratory studies show no toxic effects on soil mesofauna. In the field studies, the biochar application of 50 t/ha in maize and oilseed rape crops significantly increased the mean number of mesofauna. This change probably resulted from improved soil chemical properties (in particular organic carbon content and cation exchange capacity) upon biochar addition. The results of the avoidance test with the use of springtail species Folsomia candida showed the possible short-term toxicity risk from a dose of 5%. The results of the reproduction test indicate the negative response of F. candida from the rate of 25% (higher than the field dose, which corresponds to 10% in laboratory tests). The reason for the short-term toxicity might be the considerable increase in soil pH after biochar addition. To our knowledge, this is the first study that has looked so widely into the effect of biochar on soil mesofauna. We encourage further studies into the risk assessment of biochar on soil organisms in both a controlled laboratory environment and in the open field.


Assuntos
Carvão Vegetal , Solo , Agricultura , Agroquímicos , Animais , Artrópodes/efeitos dos fármacos , Temperatura Baixa , Hidrocarbonetos Policíclicos Aromáticos/análise , Medição de Risco , Solo/química , Solo/parasitologia , Poluentes do Solo/análise , Temperatura Ambiente , Madeira/química
14.
Sci Total Environ ; 678: 457-465, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31077924

RESUMO

Safer by design (SBD) modifications of nanomaterials (NMs) have been pursued, aiming to maintain functionality and yet reduce hazard and support sustainable nanotechnology. The present case study involves copper oxide nanomaterials (CuO NMs) used in paint that have been surface modified by a SBD approach to particles coated with citrate (CIT-), ascorbate (ASC-), polyethylenimine (PEI+), and polyvinylpyrrolidone (PVP). We assessed the effect of the 4 different surface modified (CIT, ASC, PVP and PEI) NMs plus the pristine non-coated (PRI NM) and a Cu salt (CuCl2), using the soil multispecies test system (samples at 28-56-84 days). Further, the species were tested individually, and Cu was measured in the test media (soil and soil solution) and organisms. There was a potential relationship with zeta potential, and toxicity of CuO NMs was as follows: -PEI (+28 mV) caused the least impact, -ASC and -CIT (-17 mV, -18 mV) the most, while PVP and PRI (-8 mV, -9 mV) caused an intermediate response. Differences were not explained by the contribution of soluble Cu. Coating interfered with the release of Cu2+ and/or the activation of copper regulators and detoxification mechanisms in the organisms, i.e. time to reach some kind of stability in organisms' uptake was shorter for -ASC and longer for -PVP during prolonged time. Thus, one of the main findings is that NMs hazard assessment requires long term testing to understand predicted effects across materials. Further, the coverage using a multispecies approach offers increased relevance and a more ecosystem qualified response.


Assuntos
Artrópodes/efeitos dos fármacos , Cobre/toxicidade , Nanopartículas Metálicas/toxicidade , Oligoquetos/efeitos dos fármacos , Animais , Ácaros/efeitos dos fármacos , Pintura/análise , Testes de Toxicidade
15.
Ecotoxicol Environ Saf ; 180: 632-645, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31132559

RESUMO

Increasing concentrations of metals in soil have posed a serious threat to the soil environment. The control and evaluation of soil metal hazards demand the establishment of soil ecological criteria, which is mainly based on the obtainment of toxicity thresholds. As the most typical representative of soil-dwelling springtails, Folsomia candida performs numerous essential ecological functions in soil and has been extensively used to investigate metal toxicity effects and thresholds. This review outlined the current state of knowledge on the metal toxicity thresholds to Folsomia candida, including (1) toxicity thresholds of soil metals for the different endpoints, (2) the influence factors of metal toxicity thresholds including the test conditions, the chemical forms of metal, the soil physicochemical properties, aging time and leaching, (3) the bioavailable fractions predicting metal toxicity thresholds, (4) the internal threshold of metals. To conclude, several recommendations for future research are given to obtain the more reliable toxicity thresholds and further supplement the toxicity data of metals to Folsomia candida.


Assuntos
Artrópodes/efeitos dos fármacos , Biomarcadores Ambientais/efeitos dos fármacos , Metaloides/toxicidade , Metais/toxicidade , Poluentes do Solo/toxicidade , Animais , Artrópodes/fisiologia , Disponibilidade Biológica , Relação Dose-Resposta a Droga , Biomarcadores Ambientais/fisiologia , Metaloides/farmacocinética , Metais/farmacocinética , Solo/química , Poluentes do Solo/farmacocinética , Testes de Toxicidade
16.
Sci Total Environ ; 683: 210-215, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31132699

RESUMO

Heavy metal induced co-selection of antibiotic resistance genes (ARGs) has become an emerging environmental issue. The guts of soil fauna offer a unique habitat in the terrestrial ecosystem and harbor a variety of microorganisms. However, the effects of heavy metals on the gut-associated ARGs of soil fauna are poorly understood. In the present study, collembolans were cultivated with four types of heavy metals (Zn, Cu, Cd, and Cr) and one antibiotic (oxytetracycline), to investigate their impact on the gut-associated ARGs. High-throughput quantitative PCR and 16S rRNA gene amplicon sequencing were used to examine changes in the gut-associated ARGs and microbial composition caused by the metals and antibiotic. The results showed that heavy metals alone induced co-selection of ARGs in the collembolan gut, but the effects were weaker than selection by oxytetracycline. When Zn or Cu was present together with oxytetracycline, there was a strong synergistic effect between the compounds, which increased the selection of ARGs in the collembolan guts. Furthermore, redundancy analysis revealed that the gut microbiota and mobile genetic elements (MGEs) were significantly correlated with the ARG composition. These results extend our understanding on effects of heavy metals on the dispersal of ARGs in the soil food web.


Assuntos
Artrópodes/genética , Resistência Microbiana a Medicamentos/genética , Microbioma Gastrointestinal/genética , Metais Pesados/toxicidade , Seleção Genética/efeitos dos fármacos , Animais , Antibacterianos/farmacologia , Artrópodes/efeitos dos fármacos , Microbioma Gastrointestinal/efeitos dos fármacos , Oxitetraciclina/farmacologia
17.
Sci Total Environ ; 675: 90-97, 2019 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-31026647

RESUMO

Degradation rates of two widely used pesticides were assessed, and acute and chronic effects on a standard invertebrate species investigated. An herbicide (Montana®) and fungicide (Bravo500®) formulations were investigated and results were compared to the isolated active substances of each formulation (glyphosate and chlorothalonil, respectively). Tests were performed using the invertebrate Folsomia candida as test species and an agricultural natural soil. Degradation rate tests were determined under aerobic conditions at 20 ±â€¯2 °C, using an ecologically relevant concentration of 5 mg (a.i.) kg-1 of soil for both chemicals. Results demonstrated degradation half-lives (DT50) of 2.2 days for Montana® and 2.8 days when pure glyphosate was tested. Values of 1.1 and 2.9 days were registered for Bravo500® and its active substance chlorothalonil, respectively. There were no effects on survival for the tested concentrations of both forms of the herbicide (up to 17.3 mg kg-1). However, reproduction was affected, but only by the herbicide formulation, with an estimated EC50 value of 4.63 mg (a.i.) kg-1. Effects were most unlikely related to glyphosate. For chlorothalonil, both tested forms affected survival and reproduction. The estimated LC50 values were 117 mg (a.i.) kg-1 and 73.5 mg (a.i.) kg-1, and the EC50 41.3 mg (a.i.) kg-1 and 14.9 mg kg-1 for the formulation and the active ingredient, respectively. The effects of the active ingredient were significantly stronger, indicating the major influence of the active substance in the effects caused also by the formulation. Overall results demonstrate the importance of evaluating the effects of the formulated chemicals, as they are applied in the field, and not only their isolated active ingredients.


Assuntos
Praguicidas/análise , Poluentes do Solo/análise , Agricultura , Animais , Artrópodes/efeitos dos fármacos , Monitoramento Ambiental , Herbicidas , Praguicidas/toxicidade , Solo/química , Poluentes do Solo/toxicidade
18.
Sci Total Environ ; 668: 1183-1190, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-31018458

RESUMO

Soil antibiotic pollution has caused wide public concern, and the effects of antibiotics on the gut microbiota of soil non-target organisms are poorly understood. Here, we simulate natural exposure scenarios by exposing three species of soil collembolans (Sinella curviseta, Onychiurus yodai, Folsomia candida) to environmentally relevant concentrations of oxytetracycline (OTC) in the soil to explore the response of their gut and surrounding soil microbiota to OTC, including changes in the bacterial community composition and diversity and abundance of antibiotic resistance genes (ARGs). The different collembolan species harbored different gut microbiotas from the surrounding soil. OTC exposure significantly altered the gut microbiota of O. yodai but did not obviously affect that of S. curviseta or F. candida. (o) Entomoplasmatales and Acinetobacter were two main taxa found in O. yodai; the level of the former was significantly increased but that of the latter was reduced with OTC exposure. Moreover, OTC exposure affected the diversity and abundance of ARGs in the gut microbiota of the three collembolan species, with significantly enhanced ARG number and abundance in S. curviseta, especially for genes associated with tetracycline resistance. Our findings indicate that the effects of OTC on soil collembolans are species specific. This study contributes to our understanding of the effects of environmental pollutants on the gut microbiome and resistome of soil animals.


Assuntos
Artrópodes/efeitos dos fármacos , Microbioma Gastrointestinal/efeitos dos fármacos , Oxitetraciclina/toxicidade , Poluentes do Solo/toxicidade , Animais , Microbiologia do Solo , Especificidade da Espécie
19.
Sci Total Environ ; 673: 613-621, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-30999102

RESUMO

Fate, bioavailability and toxicity of silver nanoparticles (AgNP) are largely affected by soil properties. Here we focused on how these processes are connected in simulated soil pore water. OECD soil components (sand, kaolin clay, peat) were covered with NM-300K-, AgNO3- and NM-300K dispersant-contaminated water, and Folsomia candida were exposed on the water surface. After 14 days the majority of AgNP was in nano form in sand pore water where also silver uptake was highest. Multilayered cross sections from X-ray micrographs of Collembola exposed to AgNP showed that silver was located in animal areas of direct contact to the contaminated pore water and was ingested. In contrast, in simulated peat pore water only a small fraction of silver was bioavailable. AgNO3 was only bioavailable at the start of the test and not anymore at test end. AgNP and AgNO3 caused immobilization in sand and kaolin pore water while no toxicity was found with peat and OECD soil. A strong correlation (correlation coefficient = 0.901) existed between the concentration of nano silver and immobilization; for ionic silver this was not the case. The dispersant of AgNP was toxic on its own in sand and kaolin pore water. As there are analytical limitations of quantifying AgNP in complex matrices this test system enables a mechanistic view of exposure and uptake of AgNP (and other substances) by F. candida from soil pore water.


Assuntos
Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Poluentes do Solo/toxicidade , Animais , Artrópodes/efeitos dos fármacos , Nanopartículas Metálicas/química , Tamanho da Partícula , Prata/química , Solo/química , Poluentes do Solo/química , Testes de Toxicidade
20.
Environ Int ; 127: 522-530, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30981023

RESUMO

Under controlled laboratory conditions, toxicity data tend to be less variable than in more realistic in-field studies and responses may thus differ from those in the natural environment, creating uncertainty. The validation of data under environmental conditions is therefore a major asset in environmental risk assessment of chemicals. The present study aimed to validate the mode of action of a commercial fungicide formulation in the soil invertebrate F. candida, under more realistic exposure scenarios (in-field bioassay), by targeting specific molecular biomarkers retrieved from laboratory experiments. Organisms were exposed in soil cores under minimally controlled field conditions for 4 days to a chlorothalonil fungicide dosage causing 75% reduction of reproduction in a previous laboratory experiment (127 mg a.i. kg-1) and half this concentration (60 mg a.i. kg-1). After exposure, organisms were retrieved and RNA was extracted from each pool of organisms. According to previous laboratorial omics results with the same formulation, ten genes were selected for gene expression analysis by qRT-PCR, corresponding to key genes of affected biological pathways including glutathione metabolism, oxidation-reduction, body morphogenesis, and reproduction. Six of these genes presented a dose-response trend with higher up- or down-regulation with increasing pesticide concentrations. Highly significant correlations between their expression patterns in laboratory and in-field experiments were observed. This work shows that effects of toxicants can be clearly demonstrated in more realistic conditions using validated biomarkers. Our work outlines a set of genes that can be used to assess the early effects of pesticides in a realistic agricultural scenario.


Assuntos
Artrópodes/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Nitrilos/farmacologia , Animais , Artrópodes/química , Biomarcadores , Fungicidas Industriais/análise , Laboratórios , Nitrilos/análise , Praguicidas/análise , Reprodução/efeitos dos fármacos , Solo/química
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