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1.
Environ Pollut ; 313: 120167, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36115492

RESUMO

Biodegradable plastic mulch film (BDM) is an environmentally friendly alternative to conventional polyethylene mulch, and has been growingly used in agriculture. However, practical degradation performance of BDM, especially the widely used type of blended polylactic acid (PLA)/polybutylene adipate (PBAT) in different ratios, and microbial alteration in soil environments, remain largely unrevealed. In this study, four types of BDM blended with 40-80% PLA and 20-60% PBAT were comparatively investigated through microcosm soil incubation experiments for 105 days, and combined with conditions of different soil moisture or pH. Microbiome within film-surrounding soil were assayed using 16 S rRNA high-throughput sequencing. Results showed a trend of increasing degradation efficiency with the increase of PLA proportion, and 70% PLA and 30% PBAT group presented the highest weight loss rate, i.e., 60.16 ± 5.86%. In addition, degradation and aging of PLA/PBAT varied among different soil moisture and pH values. A moderate moisture, i.e., 60% and a neutral pH7.0 caused significantly high degradation efficiency compared to other moisture or pH conditions. Moreover, bacterial abundance and community structure in the surrounding soil were related to soil moisture and pH. PLA/PBAT incubation treatment induced a remarkable increase in abundance of degradation-related species Pseudomonas and Sphingomonas. Bacterial richness and diversity in soil correspondingly respond to ratio-different PLA/PBAT's degradation under moisture/pH-different conditions through a redundancy analysis. Altogether, these findings indicate that practical degradation of PLA/PBAT film is closely related to soil environments and bacterial community. It is significant for the application of biodegradable plastics in agriculture on the perspective of soil sustainability.


Assuntos
Plásticos Biodegradáveis , Solo , Adipatos , Polienos , Poliésteres/química , Polietileno
2.
Biosensors (Basel) ; 12(6)2022 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-35735535

RESUMO

Bisphenol A (BPA) has emerged as a contaminant of concern because long-term exposure may affect the human endocrine system. Herein, a novel aptamer sensor based on magnetic separation and surface-enhanced Raman scattering (SERS) is proposed for the extremely sensitive and specific detection of trace BPA. Moreover, the capture unit was prepared by immobilizing thiolated (SH)-BPA aptamer complementary DNA on AuNP-coated magnetic halloysite nanotubes (MNTs@AuNPs), and SH-BPA aptamer-modified Au@4-MBA@Ag core-shell SERS nanotags acted as signal units. By the complementary pairing of the BPA aptamer and the corresponding DNA, MNTs@AuNPs and Au@4-MBA@AgCS were linked together through hybridization-ligation, which acted as the SERS substrate. In the absence of BPA, the constructed aptamer sensor generated electromagnetic enhancement and plasmon coupling to improve the sensitivity of SERS substrates. Owing to the high affinity between BPA and the aptamer, the aptamer probe bound to BPA was separated from the capture unit by an externally-induced magnetic field. Thus, the Raman intensity of the MNTs@AuNP-Ag@AuCS core-satellite assemblies was negatively correlated with the BPA concentration. High sensitivity measurements of BPA might be performed by determining the decline in SERS signal strength together with concentration variations. The proposed aptasensor is a promising biosensing platform for BPA detection.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Nanopartículas Metálicas , Nanotubos , Compostos Benzidrílicos , Argila , Ouro , Humanos , Limite de Detecção , Fenômenos Magnéticos , Oligonucleotídeos , Fenóis , Análise Espectral Raman
3.
Sci Total Environ ; 828: 154387, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35276177

RESUMO

There are increasing concerns regarding the ecological risks of plastics to the natural environment, especially the potential effects of plastic leachates on organisms, which contain various toxic components. However, appropriate methods to assess the overall environmental risks of plastics are limited. In this study, five different plastic products (three conventional and two biodegradable plastics) were immersed in simulated freshwater, and their toxicity was assessed using a battery of bioassays. We evaluated the effects of plastic leachates effects on organisms from four trophic levels of species (nematodes, Caenorhabditis elegans; algae, Scenedesmus obliquus; daphnids, Daphnia magna; and fish, Danio rerio) by measuring their acute and chronic toxicity. Our results indicated that all plastic leachates exhibited poor acute and chronic toxicity to the organisms. The acute toxicity of conventional plastic leachates with EC20 values <1.6 g plastic/L was higher than that of the biodegradable polydioxanone (PPDO) leachate (EC20: 16.2-796.1 g plastic/L); however, the toxicity of PPDO-octane (EC20: 0.04-1.9 g plastic/L) was similar to that of polyethylene or polystyrene (excluding toxicity in D. magna). Similarly, the leachates of the three conventional plastics and PPDO-octane had obvious inhibitory effects on the growth of C. elegans at exposure concentrations higher than 0.01 g plastic/L; however, the toxicity of the PPDO leachates was at least an order of magnitude lower. Therefore, the environmental related concentration of the plastic leachates did not have significant toxic effects. Considering that a single bioassay does not provide comprehensive information on biological implications, this study provided a new integrated and efficient method for the environmental risk assessment (ERA) of plastic leachates. Moreover, the toxicity sensitivity of different organisms varied following exposure to different plastics, thus demonstrating that multiple organisms from different trophic levels should be included in the ERA for plastics.


Assuntos
Plásticos , Poluentes Químicos da Água , Animais , Bioensaio , Caenorhabditis elegans , Daphnia , Octanos/farmacologia , Plásticos/toxicidade , Poluentes Químicos da Água/análise , Peixe-Zebra
4.
Sci Total Environ ; 802: 149838, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34454156

RESUMO

Microplastics (MPs) have been widely detected in aquatic environments, and become emerging contaminants of growing concern. It is urgently needed to explore how to effectively remove MPs from water. This study first established an alternative method of removing MPs by magnetic nano-Fe3O4. Results showed that 1.3 g·L-1 nano-Fe3O4 and 150 min treatments caused optimal magnetization of MPs via surface absorption. Then, magnetized MPs in water can be conveniently removed by suction of the magnet. The average removal rate of four common types of MPs including polyethylene, polypropylene, polystyrene and polyethylene terephthalate in size of approximately 200-900 µm was 86.87 ± 6.92%, 85.05 ± 4.70%, 86.11 ± 6.21%, and 62.83 ± 8.34%, respectively. The removal rate varied among polymer- and size-different MPs, and was positively related to the density of nano-Fe3O4 absorbed on MP surfaces. In addition, the removal rate of MPs in artificial seawater was relatively high in comparison to pure water. Furthermore, the established approach was effectively applied to remove MPs in environmental water bodies including river water, domestic sewage, and natural seawater, with the removal rate of higher than 80%. Altogether, this study provided a novel and simple removal approach to remove MPs in water, which has a certain application prospect.


Assuntos
Microplásticos , Poluentes Químicos da Água , Monitoramento Ambiental , Fenômenos Magnéticos , Plásticos , Água , Poluentes Químicos da Água/análise
5.
J Hazard Mater ; 424(Pt A): 127283, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-34564045

RESUMO

Microplastics (MPs) pollution is increasingly appreciated as a significant environmental issue, however, the large-scale pattern of MPs in farmland soils and its associated environmental impacts are unknown. This study investigated a national-scale distribution of micro(meso)plastics (MMPs) in the soil of 30 farmlands across China. The abundance of MMPs in soils was 25.56-2067.78 items kg-1, with a mean of 358.37 items kg-1, i.e. 6.79 mg kg-1 or 0.0007% after mass conversion. MPs accounted for 93.1% of MMPs, the abundance varied greatly among different regions, high in arid or semi-arid north but relatively low in mild southwest regions. Major MPs included polypropylene, polyethylene, and polyester, tending to decrease in abundance from surface to deeper soil layers. Further, meta-analysis revealed that MPs exposure influenced bulk density, soil enzymes including fluorescein diacetate hydrolase (FDAse) and urease, and crop biomass, and minimum effective concentrations (MEC) were in the range of 0.0040-10%. We found that actual abundance in the national-scale soils was lower than MEC, but partly overlapped or close, which implies various degrees of environmental impacts. These findings disclose the national-scale pollution pattern of MPs in farmlands and its latent risks to soil environments and crop growth.


Assuntos
Plásticos , Solo , China , Monitoramento Ambiental , Fazendas
6.
Environ Pollut ; 292(Pt B): 118465, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34748889

RESUMO

Indoor airborne microplastics fibers (MPFs) are emerging contaminants of growing concern. Nowadays, air conditioners (ACs) are widely used in indoor environments. However, little is known about their impact on the distribution of indoor MPFs. In this study, we first disclosed the prevalence of MPF contamination in filters for indoor split ACs used in living rooms, dormitories, and offices. The average density of microfibers was 1.47-21.4 × 102 items/cm2, and a total 27.7-35.0% of fibers were MPFs. Of these fibers, the majority were polyester (45.3%), rayon (27.8%), and cellophane (20.1%). We further tracked the long-term accumulation of MPFs on AC filters in three types of rooms, and demonstrated that dormitories showed relatively heavy accumulation especially after running for 35-42 days. Furthermore, we found that simulative AC filters which had been lined with PET MPFs could effectively release those MPFs into indoor air, propelling them away from the ACs at varying distances. Statistical analysis showed that the estimated daily intake of MPFs (5-5000 µm length) from AC filters would increase gradually with their usage, with the intake volume reaching up to 11.2 ± 2.2-44.0 ± 8.9 items/kg-BW/day by the 70th day, although this number varied among people of different ages. Altogether, these findings suggest that AC filters can act as both a sink and a source of microplastics fibers. Therefore, AC filters should be evaluated not only for their substantial impact on the distribution of indoor airborne MPFs, but also for their role in the prevalence of the related health risks.


Assuntos
Filtros de Ar , Poluição do Ar em Ambientes Fechados , Poluição do Ar em Ambientes Fechados/análise , Monitoramento Ambiental , Humanos , Microplásticos , Plásticos
7.
Sci Total Environ ; 815: 152507, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-34968597

RESUMO

Agricultural soil is a sink of microplastics (MPs) in the environment. MPs in topsoil can be transferred deeply or into surrounding water by rainfall. However, little is known about rainfall-induced migration pattern of different MPs in agricultural soil. In this study, soil leaching experiments of 21 d were performed on Nile red-stained size-different polyethylene terephthalate (PET) particles, and shape-different polyethylene (PE) MPs under simulated or natural rainfall. Results showed that simulated rainfall of 5-25 mm/d caused intensity-dependent migration of MPs in horizontal and vertical directions. Maximum migration depth of MP particles arrived up to 4-7 cm. Rise of soil slopes could significantly increase horizontal mobility of MPs. Comparatively, natural rainfall of similar intensity caused relatively high mobility of MPs. Moreover, under both simulative and natural rainfall, mobility of MPs presented size/shape-different characteristics. Comparatively, small-size MPs (especially <1 mm) showed relatively high mobility in horizontal or vertical direction, and had high-frequency presence in runoff water. Of four MPs' shapes, fiber and film had relatively high mobility in comparison to particles. These results indicate that rainfall can cause size/shape-dependent migration of MPs in agricultural soil. It suggests size/shape-different environment fate of MPs, and provides a reference for MP control.


Assuntos
Microplásticos , Poluentes do Solo , Agricultura , Plásticos , Solo , Poluentes do Solo/análise
8.
Mikrochim Acta ; 188(8): 281, 2021 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-34331147

RESUMO

The design and fabrication of a surface-enhanced Raman scattering (SERS) aptasensor for simultaneous detection of zearalenone (ZEN) and ochratoxin A (OTA) in wheat and corn samples is described. The capture and reporter probes were SH-cDNA-modified gold nanorods and SH-Apt-modified Au@Ag core-shell nanoparticles, respectively. After recognizing OTA and ZEN aptamers and complementary strands (SH-cDNA), the reporter probe generated a strong SERS signal. The preferred binding of OTA and ZEN aptamers to OTA and ZEN, respectively, caused reporter probes to release the capture probes, resulting in a linear decrease in SERS intensity. The detection of OTA showed good linearity with an R2 value of 0.986, which could be maintained across a wide concentration range (0.01 to 100 ng/mL), with the limit of detection of 0.018 ng/mL. For detection of ZEN, good linearity with an R2 value of 0.987 could be maintained across a wide concentration range (0.05 to 500 ng/mL), with 0.054 ng/mL as the limit of detection. Good accuracy (relative standard deviation < 4.2%) during mycotoxin determination as well as excellent quantitative recoveries (96.0-110.7%) during the analysis of spiked real samples was achieved. The proposed SERS aptasensor exhibited excellent performance in the detection of OTA and ZEN in real food samples. Hence, by simply changing the aptamer, this new model can be applied to the detection of multiple mycotoxins in the food industry.


Assuntos
Técnicas Biossensoriais/métodos , Nanopartículas Metálicas/química , Micotoxinas/análise , Nanotubos/química , Ocratoxinas/análise , Zearalenona/análise , Aptâmeros de Nucleotídeos/química , Grão Comestível/química , Contaminação de Alimentos/análise , Ouro/química , Ácidos Nucleicos Imobilizados/química , Limite de Detecção , Micotoxinas/química , Ocratoxinas/química , Reprodutibilidade dos Testes , Prata/química , Análise Espectral Raman , Triticum/química , Zea mays/química , Zearalenona/química
9.
J Hazard Mater ; 409: 124640, 2021 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-33246814

RESUMO

Microplastics (MPs) are widely found in complex solid matrices such as soil, sediments and sludge. The separation procedure is crucial for effective analysis of MPs, but existing methods varied among studies. Here, we systematically summarize and compare separation methods including density, oil, electrostatic, magnetic, and solvent extraction separation. Density separation is the most commonly used approach, but time-consuming and discharging hazardous materials dependent on extraction solutions. In contrast, oil, electrostatic, magnetic separation and solvent extraction separation are emerging approaches with advantages of low-cost, quick, or environmentally-friendly, but with high request of instruments. Despite variation among these approaches, the separation efficiency is closely related to characteristics of MPs including polymer types, sizes and shapes. The treatment of digestion and fluorescence staining can facilitate the detection of MPs. This analysis suggests that further optimization and improvement of existing approaches can facilitate the development of new separation technology for assaying MPs in complex environmental matrices.

10.
Sci Total Environ ; 746: 141289, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32745868

RESUMO

Despite increasing evidence of widespread plastic pollution in soil, it remains largely unknown about the fate of plastic influenced by soil animals. In this study, ingestion and biodegradation capability of expanded polystyrene (PS) foam was investigated in a globally distributed soil invertebrate, Achatina fulica. After 4-week exposure, 18.5 ± 2.9 mg polystyrene was ingested per snail, and egested microplastics (1.343 ± 0.625 mm) in feces with significant mass loss of mean 30.7%. Gel permeation chromatography analysis indicated a significant increase in weight-average molecular weight (Mw) and number-average molecular weight (Mn) of feces-residual PS, indicating limited extent depolymerization. Fourier transform infrared spectroscopy and proton nuclear magnetic resonance confirmed the formation of functional groups of oxidized intermediates. Suppression of gut microbes with oxytetracycline did not affect the depolymerization, indicating the independence of gut microbes. High-throughput sequencing analysis revealed significant shifts in the gut microbiome after ingestion of PS, with an increase of family Enterobacteriaceae, Sphingobacteriaceae, and Aeromonadaceae, suggesting that gut microorganisms were associated with PS biodegradation. These findings suggest that plastic litter can be disintegrated into microplastics and partially biodegraded by A. fulica, which highlights the significance of soil animals for the fate of plastic and its biodegradation in soil environments.


Assuntos
Plásticos , Poliestirenos , Animais , Biodegradação Ambiental , Caramujos , Solo
11.
J Hazard Mater ; 399: 123092, 2020 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-32531675

RESUMO

Microplastics (MPs) are persistent contaminants in aquatic environments. Microalgae, as the main phytoplankton and primary producers, usually co-exist with MPs. Despite previous studies that have proved the interaction of MPs and microalgae, it is largely unknown whether MPs can be uptake into cells of microalgae. In this study, both marine P. helgolandica var. tsingtaoensis and freshwater microalgae S. quadricauda were respectively exposed to 10 mg/L polystyrene microbeads with five diameter sizes: 1.0, 2.0, 3.0, 4.0, and 5.0 µm. Confocal laser scanning and 3D image analysis showed that mean 24.0 % or 11.3 % cells of P. helgolandica var. tsingtaoensis contained 1.0 µm or 2.0 µm MPs after 72 h exposure. While mean 43.3 % or 15.3 % of S. quadricauda individuals engulfed 1.0 µm or 2.0 µm MPs within cells. But, none of 3.0-5.0 µm MPs were observed within algal cells. These results demonstrate the size-dependent cellular internalization of MPs in microalgae. Exposure to 1.0-2.0 µm PS MPs caused a significant reduction in the density of microalgae and influenced photosynthesis, which suggests cellular internalization of MPs can influence algal fertility and growth. This discovery first confirms cellular internalization of MPs in phytoplankton, of significance for the fate and eco-toxicity of MPs in the aquatic ecosystem.


Assuntos
Microalgas , Poluentes Químicos da Água , Ecossistema , Humanos , Microplásticos , Plásticos/toxicidade , Poliestirenos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
12.
Sci Total Environ ; 709: 136214, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-31905592

RESUMO

Microplastics (MPs) pollution is an emerging environmental and health concern. MPs have been extensively observed in the aquatic environment, yet rarely investigated in the terrestrial ecosystem, especially in relation to health risks. To evaluate potential MPs pollution in land-dwelling animal medicine materials, we collected 20 types of small animal-based medicinal materials and 10 types of available fresh terrestrial animals from eight different regions in China. MPs were found in all medicinal materials with an average incidence rate of 94.67%. The abundance of MPs was in the range of 1.80 ± 0.38 to 7.80 ± 0.83 items/individual or 1.59 ± 0.33 to 43.56 ± 9.22 items/g (dry weight), with polymer distribution by polyethylene terephthalate (40.45%), rayon (30.64%), polyethylene (10.11%), nylon (7.35%), polypropylene (5.93%), and polyvinyl chloride (5.52%). The majority of MPs were microfibers (84.68%), with 15.32% of fragments. Moreover, MPs were directly observed in the intestine, detected in all ten types of fresh medicinal animals with the abundance of 0.83 ± 0.35 to 3.42 ± 0.46 items/individual. Furthermore, significant positive correlations (R: 0.32-0.99, p < 0.05) of MPs characteristics were found between medicinal materials and fresh animals, including shape, size, color, and polymer distribution of MPs. The results support that MPs in the medicinal materials were likely derived from living animals. This study demonstrates the prevalence of MPs in animal-based, traditional medicinal materials, and also suggests widespread MPs pollution in terrestrial environments and latent health risks.


Assuntos
Poluentes Químicos da Água , Animais , China , Ecossistema , Monitoramento Ambiental , Microplásticos , Prevalência
13.
Sci Total Environ ; 691: 341-347, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31323579

RESUMO

Microplastics (MP) have been recently found in soil environments. These MP might have adverse effects at high concentrations and thus efficient extraction and analysis of MP from soil is needed. Here we propose a new method of NaBr solution circulation for extracting soil MP. A device for the circular extraction of soil MP was developed. This device included a separation, vacuum filtration, and solution recovery system. It was then utilized to test separation efficiency of soil MP with three economic and environmentally friendly extraction reagents: NaCl, CaCl2 and NaBr solutions. The separation was tested with ten different types of polymers, three different size classes and three different shapes of MP. Extraction with NaBr showed the highest recovery rates ranging from 85% to 100%. After extraction the samples were treated with H2O2 and analyzed by micro-Fourier transform infrared spectroscopy. The developed method was assessed for its potential influence on MP and no significant changes in the integrity of multiple MP were found. Finally, the established method was used to analyze MP in four types of soil: farmland, yellow-brown, paddy and floodplain soil from the suburb of Shanghai. Results showed that the mean abundance of MP was 136.6-256.7 item kg-1. Various MP including PP (40%), PE (35.5%), Acrylic (15.6%), PET (6.7%) and PA (2.2%) were found. With this paper, we provide an alternative method through NaBr solution circulation for the extraction of soil MP.

14.
Environ Pollut ; 250: 447-455, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31026691

RESUMO

Recent studies have demonstrated the occurrence of microplastic fibers (MFs) in soil environments. To determine whether MFs are harmful for soil biota, we evaluated toxic effects on terrestrial snails (Achatina fulica) after 28 d exposure to polyethylene terephthalate MFs at concentrations of 0.01-0.71 g kg-1 (dry soil weight). Digestion kinetics experiments on 24 snails showed that MFs can be ingested and excreted within 48 h. We found the appearance of cracks and deterioration on the surface of MFs after depuration by the digestive system. Prolonged exposure to 40 snails showed that 0.14-0.71 g kg-1 MFs caused an average reduction of 24.7-34.9% food intake and 46.6-69.7% excretion. 0.71 g kg-1 MFs induced significant villi damage in the gastrointestinal walls of 40% snails, but did not influence the histology of the liver and kidney. Moreover, 0.71 g kg-1 MFs exposure reduced glutathione peroxidase (59.3 ±â€¯13.8%) and total antioxidant capacity (36.7 ±â€¯8.5%), but elevated malondialdehyde level (58.0 ±â€¯6.4%) in the liver, which indicates oxidative stress is involved in the toxic mechanism. Our results suggest that MFs have adverse impacts on the fitness of soil organisms, and highlight the ecological risks of microplastic pollution in terrestrial ecosystems.


Assuntos
Polietilenotereftalatos/metabolismo , Caramujos/fisiologia , Poluentes do Solo/metabolismo , Animais , Biota , Ecossistema , Poluição Ambiental , Glutationa , Malondialdeído/metabolismo , Estresse Oxidativo , Peroxidases , Plásticos , Polietilenotereftalatos/toxicidade , Solo/química , Poluentes do Solo/toxicidade
15.
Sci Total Environ ; 652: 1209-1218, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30586807

RESUMO

Microplastics are emerging contaminants of increasing concern. Despite the occurrence of microplastics in farmland soils, the knowledge on microplastics in rice-fish co-culture ecosystems is limited. In this study, we investigated the distribution of microplastics in three rice-fish culture stations in Shanghai. During non-rice and rice-planting periods, microplastics in water, soils and aquatic animals (eel, loach and crayfish) were systematically assayed using methods of NaCl density extraction, H2O2 digestion and micro-fourier transform infrared spectroscopy. Results showed that average microplastic abundances were 0.4 ±â€¯0.1 items L-1, 10.3 ±â€¯2.2 items kg-1, 1.7 ±â€¯0.5 items individual-1 in water, soils and aquatic animal samples, respectively. We found an increasing trend in microplastic abundances in water, soil and animal samples from non-rice period to rice-planting period. Almost all of microplastics were found in digestive tracts of animals. Major microplastics were small (<1 mm) polyethylene and polypropylene fibers, with color of white and translucent. Size, shape, color and polymer type distributions of microplastics were similarly found in environmental and animal samples. Moreover, microplastic abundances in aquatic animals correlated to abundance in farmland soils. This study, for the first time, reveals the occurrence and characteristics of microplastic pollution in rice-fish culture ecosystem which suggests the potential ecological risks of microplastics in the agroecosystem.


Assuntos
Agricultura/métodos , Peixes/crescimento & desenvolvimento , Oryza/crescimento & desenvolvimento , Plásticos/análise , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Animais , China , Sistema Digestório/química , Pesqueiros , Oryza/química
16.
Exp Neurol ; 309: 67-78, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30076829

RESUMO

Mitochondrial dysfunction is considered as a critical mechanism in the pathogenesis of Parkinson's disease (PD). Increasing evidence supports the notion of mitochondria-associated membranes (MAMs) in mitochondrial dysfunction; yet little is known about the role of MAMs-related proteins in the pathogenesis of PD. Herein we exposed the nematode Caenorhabditis elegans to 0.5-10.0 µM rotenone (RO) or 0.2-1.6 mM paraquat (PQ) for 3 days. Our results showed that both RO and PQ induced similar Parkinsonism including motor deficits and dopaminergic degeneration. RO/PQ caused mitochondrial damages characterized by the increase of vacuole areas and autophagy vesicles, but the decrease of mitochondrial cristae. RO/PQ-impacted mitochondrial function was also demonstrated by the decrease of ATP level and mitochondrial membrane potential. Additionally, the attachment or surrounding of endoplasmic reticulum to the damaged mitochondria indicates ultrastructural alterations in MAMs. Using fluorescently labeled transgenic nematodes, we further found that the expression of tomm-7 and genes of Complex I, II and III was reduced, whereas the expression of pink-1 was increased in the exposed animals. To determine MAMs in toxicity toward PD, we investigated the mutants of hop-1 and pink-1, encoding presenilin and PTEN-induced putative kinase 1 (PINK1) in mitochondria-associated membranes, respectively. Results demonstrated that the mutation of both hop-1 and pink-1 reduced the vulnerability of lethal, behavioral, and mitochondrial toxicity induced by RO/PQ. These findings suggest that presenilin and PINK1 play important roles in the RO/PQ-induced neurotoxicity through the mechanisms involved in mitochondria-associated membranes.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Proteínas de Membrana/metabolismo , Doenças Mitocondriais/etiologia , Mutação/genética , Transtornos Parkinsonianos , Proteínas Serina-Treonina Quinases/genética , Trifosfato de Adenosina/metabolismo , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans , Modelos Animais de Doenças , Proteínas da Membrana Plasmática de Transporte de Dopamina/genética , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Potencial da Membrana Mitocondrial/genética , Proteínas de Membrana/genética , Microscopia Eletrônica de Transmissão , Mitocôndrias/patologia , Mitocôndrias/ultraestrutura , Doenças Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Movimento/efeitos dos fármacos , Movimento/fisiologia , Paraquat/toxicidade , Transtornos Parkinsonianos/induzido quimicamente , Transtornos Parkinsonianos/complicações , Transtornos Parkinsonianos/patologia , Rotenona/análogos & derivados , Rotenona/toxicidade
17.
Environ Pollut ; 242(Pt A): 855-862, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30036839

RESUMO

Microplastics are emerging pollutants which have been extensively detected in water environments. However, little is known about microplastic pollution in soil environments. In this study, we investigated microplastics and mesoplastics in farmland soils from twenty vegetable fields around the suburbs of Shanghai. In each site, three duplicate soil samples were collected from shallow (0-3 cm) and deep soils (3-6 cm), respectively. Microplastics (sizes of 20 µm - 5 mm) and mesoplastics (5 mm - 2 cm) were detected using methods of density extraction, 30% H2O2 digestion and micro-fourier transform infrared spectroscopy. The abundance of microplastics was 78.00 ±â€¯12.91 and 62.50 ±â€¯12.97 items kg-1 in shallow and deep soils, respectively. While, mesoplastics were found with abundance of 6.75 ±â€¯1.51 and 3.25 ±â€¯1.04 items kg-1 in shallow and deep soils. Among these micro(meso)plastics, 48.79% and 59.81% were in size of <1 mm in shallow and deep soils. The main morphotypes of microplastics included fiber, fragment and film, mostly in color of black or transparent. Moreover, we found that topsoil contained higher concentrations and larger sizes of micro(meso)plastics than deep soil. In addition, the vast majority of micro(meso)plastics were polypropylene (50.51%) and polyethylene (43.43%). This study reveals occurrence and characteristics of microplastic pollution in typical farmland soils. It provides important data for subsequent research on microplatics in the terrestrial ecosystem.


Assuntos
Monitoramento Ambiental , Fazendas , Plásticos/análise , Poluentes do Solo/análise , Solo/química , China , Ecossistema , Poluição Ambiental/estatística & dados numéricos , Peróxido de Hidrogênio , Polietileno , Polipropilenos , Espectroscopia de Infravermelho com Transformada de Fourier
18.
Ecotoxicol Environ Saf ; 153: 8-15, 2018 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-29407742

RESUMO

The decline in amphibian populations is a critical threat to global biodiversity, and pesticide pollution is considered as one of the major factors. Although effects of single pesticides on amphibians have been documented, toxicological interactions prevailing in mixtures of pesticides have not been well elucidated. Strobilurin and succinate dehydrogenase inhibitor (SDHI) fungicides are new types of commonly used pesticides. In this study, effects of three strobilurins (pyraclostrobin, trifloxystrobin and azoxystrobin), two SDHIs (isopyrazam and bixafen), and their mixtures on X. tropicalis embryos were fully investigated. Results showed that exposure to individual fungicides induced lethal and teratogenetic effects; and malformed embryos displayed similar phenotypes including microcephaly, hypopigmentation, somite segmentation and narrow fin. Exposure to two strobilurins or two SDHIs at equitoxic concentrations caused additive or synergetic effects at environmentally relevant concentrations. TU for mixtures of isopyrazam and bixafen was 0.53 and 0.30 for lethal and teratogenic toxicity, respectively. Finally, binary mixtures of strobilurins and SDHIs also exhibited additive or synergetic effects on amphibian embryos. Overall, these results reveal that the mixtures of multiple fungicides caused a higher incidence of lethality and teratogenicity of amphibian embryos, compared to a single fungicide at the corresponding doses. Our findings provide important data about the ecotoxicology of agricultural fungicides on non-target organisms, which is useful for guiding management practices for pesticides.


Assuntos
Embrião não Mamífero/efeitos dos fármacos , Inibidores Enzimáticos/toxicidade , Fungicidas Industriais/toxicidade , Estrobilurinas/toxicidade , Succinato Desidrogenase/antagonistas & inibidores , Teratógenos/toxicidade , Animais , Sinergismo Farmacológico , Ecotoxicologia , Embrião não Mamífero/anormalidades , Xenopus
19.
Sci Total Environ ; 619-620: 1-8, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29136530

RESUMO

Microplastics have been frequently detected in aquatic environments, and there are increasing concerns about potential effects on biota. In this study, zebrafish Danio rerio and nematode Caenorhabditis elegans were used as model organisms for microplastic exposure in freshwater pelagic (i.e. water column) and benthic (i.e. sediment) environments. We investigated the toxic effects of five common types of microplastics: polyamides (PA), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC) and polystyrene (PS) particles. Results showed no or low lethality in D. rerio after exposure for 10d at 0.001-10.0mgL-1 microplastics. The PA, PE, PP and/or PVC microplastics with ~70µm size caused intestinal damage including cracking of villi and splitting of enterocytes. Exposure to 5.0mgm-2 microplastics for 2d significantly inhibited survival rates, body length and reproduction of C. elegans. Moreover, exposure to microplastics reduced calcium levels but increased expression of the glutathione S-transferase 4 enzyme in the intestine, which indicates intestinal damage and oxidative stress are major effects of microplastic exposure. Among 0.1, 1.0 and 5.0µm sizes of fluorescently labeled PS, 1.0µm particles caused the highest lethality, the maximum accumulation, the lowest Ca2+ level in the intestine and the highest expression of glutathione S-transferase 4 in nematodes. Taken together, these findings suggest that intestinal damage is a key effect of microplastics; and that the toxicity of microplastics is closely dependent on their size, rather than their composition.


Assuntos
Caenorhabditis elegans , Intestinos/lesões , Plásticos/efeitos adversos , Poluentes Químicos da Água/efeitos adversos , Peixe-Zebra , Animais , Cálcio , Monitoramento Ambiental , Glutationa Transferase , Estresse Oxidativo
20.
Chemosphere ; 181: 55-62, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28426941

RESUMO

Rare earth elements (REEs) are widely used in industry, agriculture, medicine and daily life in recent years. However, environmental and health risks of REEs are still poorly understood. In this study, neurotoxicity of trichloride neodymium, praseodymium and scandium were evaluated using nematode Caenorhabditis elegans as the assay system. Median lethal concentrations (48 h) were 99.9, 157.2 and 106.4 mg/L for NdCl3, PrCl3 and ScCl3, respectively. Sublethal dose (10-30 mg/L) of these trichloride salts significantly inhibited body length of nematodes. Three REEs resulted in significant declines in locomotor frequency of body bending, head thrashing and pharyngeal pumping. In addition, mean speed and wavelength of crawling movement were significantly reduced after chronic exposure. Using transgenic nematodes, we found NdCl3, PrCl3 and ScCl3 resulted in loss of dendrite and soma of neurons, and induced down-expression of dat-1::GFP and unc-47::GFP. It indicates that REEs can lead to damage of dopaminergic and GABAergic neurons. Our data suggest that exposure to REEs may cause neurotoxicity of inducing behavioral deficits and neural damage. These findings provide useful information for understanding health risk of REE materials.


Assuntos
Caenorhabditis elegans/efeitos dos fármacos , Metais Terras Raras/toxicidade , Agricultura , Animais , Tamanho Corporal/efeitos dos fármacos , Neurônios Dopaminérgicos/efeitos dos fármacos , Meio Ambiente , Neurônios GABAérgicos/efeitos dos fármacos , Movimento/efeitos dos fármacos , Neodímio/toxicidade , Praseodímio/toxicidade , Escândio/toxicidade
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