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1.
Environ Sci Technol ; 2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32208626

RESUMO

Landfill and incineration are the primary disposal practices for municipal solid waste (MSW) and have been considered as the critical reservoir of antibiotic resistance genes (ARGs). However, the possible transmission of ARGs from the municipal solid waste treatment system (MSWT system) to ambient air is still unclear. In this study, we collected inside and ambient air samples (PM10 and PM2.5) and potential source samples (leachate and solid waste) in the MSWT system. The results showed that the MSWT system contributed to the increased ambient airborne bacteria and associated ARGs. Forty-one antibiotic-resistant bacteria (ARB) harboring blaTEM-1 were isolated, and the full-length nucleotide sequences of the blaTEM-1 gene (harbored by identical bacillus) from air (downwind samples) were 100% identical with those in the leachate and solid waste, indicating that the MSWT system was the important source of disperse bacteria and associated ARGs in the ambient air. The daily intake (DI) burden level of ARGs via PM inhalation was comparable with that via ingestion of drinking water but lower than the DI level via ingestion of raw vegetables. The antibiotic-resistant opportunistic pathogen Bacillus cereus was isolated from air, with a relatively high DI level of Bacillus via inhalation (104-106 copies/day) in the MSWT system. This study highlights the key pathway of airborne ARGs to human exposure.

2.
Sci Total Environ ; 705: 135674, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-31785918

RESUMO

Human gut microbiota is an important reservoir of antibiotic resistance genes (ARGs). Although dysbacteriosis after the antibiotic course has been previously observed in the patient guts, a comprehensive comparison of gut resistomes, microbiota and antibiotic residues in healthy individuals and patients undergoing antibiotic administration is little. Using high-throughput qPCR, 16S rRNA gene amplicon sequencing and UPLC-MS/MS, we systematically examined the antibiotic resistome, gut microbiota, and antibiotic residues in fecal samples from both Chinese healthy individuals and patients receiving antibiotic therapy. Compared with healthy individuals, patients' guts harbored lower diverse gut resistome and microbiota, but higher concentrations of antibiotics and ARGs. Antibiotic concentration in human guts was positively correlated with ARG total abundance, but was negatively related to the diversity of both ARGs and bacterial communities, which demonstrated that antibiotic administration could shape the antibiotic resistomes and bacterial communities in the patient guts. Gene cfxA was evaluated as a potential biomarker to distinguish the patients receiving antibiotic therapy from the healthy individuals in China since its wide detection and significant enrichment in the guts of the patients. The detection of some veterinary antibiotics in human guts illustrated the potential transmission of antibiotic from the external environment to human via the food chain. The obtained results could help to better understand the influence of antibiotic therapy in shaping antibiotic reistomes and bacterial communities in Chinese individuals.

3.
Huan Jing Ke Xue ; 40(8): 3840-3848, 2019 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854795

RESUMO

To accurately evaluate the biotoxicity of PM2.5, PM2.5 samples from winter fog-haze days, winter normal days, and summer days in Changzhou were selected for evaluation based on the acute toxicity of luminescent bacteria and zebrafish embryos and the cytotoxicity of human lung adenocarcinoma cells in vitro (A549). The three atmospheric conditions and the physical and chemical indicators were also evaluated using correlation analysis. The PM2.5 samples showed either acute or developmental toxicity during all three periods. The toxicity unit (TU) of the luminescent bacteria for the winter fog-haze days, winter normal days, and summer days were 1.74 (toxic), 1.19 (toxic), and 0.92 (slightly toxic), respectively. The maximum TU of the zebrafish embryos was for winter normal days (TU=1.14, toxic) followed by winter fog-haze days (TU=0.79, slightly toxic), and summer days (TU=0, non-toxic). The highest TU of A549 was for winter fog-haze days (TU=0.61, toxic) followed by summer days (TU=0.38, toxic) and winter normal days (TU=0.31, toxic). With respect to developmental toxicity, with the exception of summer day samples, the PM2.5 samples from the other two periods had detrimental effects on the development of zebrafish embryos, mainly showing pericardial edema, a bent notochord, and tail deformity. The average toxicity (AvTx), toxic print (TxPr), and most sensitive test (MST) indices showed that the PM2.5 samples from winter fog-haze days and winter normal days exhibited toxicity, while samples from the summer days showed slight toxicity; PM2.5 samples from winter fog-haze days had the highest level of comprehensive toxicity. In addition, luminescent bacteria were the most sensitive to PM2.5 samples, followed by zebrafish embryos and A549. The results of chemical analysis and biological toxicity tests show that the pollutants contained in PM2.5 have a biological toxicity effect, which can provide a basis for the comprehensive assessment of PM2.5 biological toxicity and human health risks.


Assuntos
Poluentes Atmosféricos , Material Particulado , Bioensaio , China , Monitoramento Ambiental , Humanos , Estações do Ano
4.
Chemosphere ; 235: 1089-1096, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31561299

RESUMO

WWTPs may be one of the important ways for MPs to enter surface water. In the present study, the influent and effluent from eleven WWTPs in Changzhou were collected and analyzed. At the same time, the abundance, size, color, and shape of MPs in influent and effluent were investigated. The average abundance of MPs in the influent and effluent were 196.00 ±â€¯11.89 n/L and 9.04 ±â€¯1.12 n/L respectively, and the MPs removal efficiency of eleven WWTPs was almost over 90% in which it could be up to 97.15%. MPs were divided into four particle size based on abundance changes, and the size of MPs with the highest abundant was mainly concentrated at 0.1-0.5 mm. Among these MPs, fibers were the main shape in wastewater, followed by fragments, flakes, spheres and films. The colors of MPs in wastewater were various and 14 types of plastics were detected from wastewater using attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Moreover, Rayon and PET were the dominant polymer types in eleven WWTPs. The research results provided basic data for the research and supervision of MPs pollution in WWTPs.


Assuntos
Plásticos/análise , Instalações de Eliminação de Resíduos/normas , Águas Residuárias/química , Poluentes Químicos da Água/análise , Celulose/análise , Cor , Tamanho da Partícula , Plásticos/isolamento & purificação , Polietilenotereftalatos/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Eliminação de Resíduos Líquidos
5.
Huan Jing Ke Xue ; 40(2): 567-572, 2019 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-30628318

RESUMO

Concentrated poultry feeding operations are an important source of antibiotic resistance genes (ARGs). Little attention has been given to PM2.5 as a mechanism for exposing ARGs to humans. In this study, PM2.5 and fecal samples from inside the broiler feeding operation and PM2.5 samples from outside the broiler feeding operation were collected. All samples were subjected to the determination of class Ⅰ integrin (intI1), total bacterial gene (16S rDNA), and 19 ARGs of six types by quantitative real-time PCR (qPCR). The results indicated that, excluding blaGES-1 and blaSHV-1, the remaining 17 ARGs were detected in all six samples. Sulfonamide resistance genes, tetracycline resistance genes, macrolide resistance genes, and aminoglycoside resistance genes were abundant in the feces, reaching 1.04×109-3.27×1010 copies·g-1, while feces was an important source of antibiotic resistance genes in PM2.5 of the broiler feeding operation. There were high abundances of sulfonamide resistance genes and macrolide resistance genes in PM2.5 from inside the broiler feeding operation, reaching (8.9±1.9)×107 copies·m-3 and (5.6±3.1)×107 copies·m-3, respectively. The abundance of ARGs in the PM2.5 samples from inside the broiler feeding operation was significantly higher compared to the outside PM2.5 samples. There was a significant positive correlation between PM2.5 mass concentration and 16S rDNA, intI1, and ARGs abundance, indicating that PM2.5 was the reservoir and disseminator of airborne bacteria, ARGs, and intI1 in the broiler feeding operation. The abundance of intI1 was higher than ARGs among all samples, and the co-occurring relationship between intI1 and ARGs demonstrates the threat of multi-drug resistance, which is harmful to the surrounding air environment and the health of the breeder and poultry.


Assuntos
Galinhas , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Criação de Animais Domésticos , Animais , Antibacterianos , Fezes , Humanos , Material Particulado
6.
Huan Jing Ke Xue ; 39(3): 1151-1158, 2018 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-29965459

RESUMO

In order to investigate the characteristics of bacterioplankton in the spring in Zhushan Bay, Lake Taihu, the 16S rRNA gene of the bacterioplankton at four sampling sites in Zhushan Bay was sequenced by high-throughput sequencing using water samples collected from Yapugang, Shatanggang, Zhushanhunan, and Jiaoshan. The results showed that the coverage of the sequencing library was very high and could accurately represent the bacterioplankton community in the samples. The species richness of Jiaoshan was the highest, but the species evenness was lower. Cyanobacteria, Actinobacteria, Proteobacteria, and Bacteroidetes were the dominant phylum in Zhushan Bay. The average abundance of Cyanobacteria was as high as 64.73%, which indicated an outbreak of cyanobacteria bloom in the water. At the genus level, Anabaena, hgcI_clade, CL 500-29 _marine_group, Microcystis, Synechococcus, and Mycobacterium were predominant. The results of redundancy analysis (RDA) for the relationship between bacterioplankton and environmental factors showed that water temperature, chlorophyll a (Chl-a), ammonia nitrogen(NH4+-N), dissolved oxygen (DO), and phosphate (PO43--P)were the main environmental factors affecting the bacterioplankton community. Dissolved oxygen could significantly affect Microcystis; nutrient and water temperature also had an effect.


Assuntos
Bactérias/classificação , Lagos/microbiologia , Plâncton/classificação , Amônia/análise , Bactérias/crescimento & desenvolvimento , Baías , China , Clorofila A/análise , Monitoramento Ambiental , Oxigênio/análise , Fosfatos/análise , Plâncton/crescimento & desenvolvimento , RNA Ribossômico 16S/genética , Temperatura Ambiente
7.
Sci Total Environ ; 618: 1254-1267, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29089134

RESUMO

Massive partial sequencing of 16S rRNA genes has become the predominant tool used for studying microbial ecology. However, determining which hypervariable regions and primer sets should be used for screening microbial communities requires extensive investigation if controversial results are to be avoided. Here, the performances of different variable regions of the 16S rRNA gene on bacterial diversity studies were evaluated in silico with respect to the SILVA non-redundant reference database (SILVA SSU Ref 123NR), and subsequently verified using samples from Lake Taihu in China, a eutrophic lake. We found that the bacterial community composition results were strongly impacted by the different V regions. The results show that V1-V2 and V1-V3 regions were the most reliable regions in the full-length 16S rRNA sequences, while most V3 to V6 regions (including V3, V4, V3-V4, V5, V4-V5, V6, V3-V6, V4-V6, and V5-V6) were more closely aligned with the SILVA SSU Ref 123NR database. Overall, V4 was the most prominent V region for achieving good domain specificity, higher coverage and a broader spectrum in the Bacteria domain, as confirmed by the validation experiments. S-D-Bact-0564-a-S-15/S-D-Bact-0785-b-A-18 is, therefore, a promising primer set for surveying bacterial diversity in eutrophic lakes.


Assuntos
Bactérias/genética , Monitoramento Ambiental , Eutrofização , Lagos/microbiologia , Bactérias/classificação , China , Genes Bacterianos , Variação Genética , RNA Ribossômico 16S , Análise de Sequência de DNA
8.
Water Sci Technol ; 78(10): 2046-2054, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30629532

RESUMO

Wastewater discharged from wastewater treatment plants (WWTPs) is suspected to be a significant contributor of microplastics (MPs) to the environment, and fiber is the main shape of MPs in wastewater effluent. A typical textile industry WWTP with 30,000 tons of daily treatment capacity was sampled for microfibers at different stages of the treatment process to ascertain at what stage in the treatment process the microfibers are being removed. The average abundance of microfibers was 334.1 (±24.3) items/litre in influent, and it reduced to 16.3 (±1.2) items/litre in the final effluent with a decrease of 95.1%. Despite this large reduction we calculated that this textile industry WWTP was releasing 4.89 × 108 microfibers including microplastic fibers and non-microplastic fibers into the receiving water every day. This study showed that a modest amount of microplastics being released per litre of effluent could result in significant amounts of fibers entering the environment, despite the fact that efficient removal rates of microplastic fibers and non-microplastic fibers were achieved by this modern treatment plant when dealing with such a large volume of effluent. The fate of fibers is described during the textile industry wastewater treatment process.


Assuntos
Monitoramento Ambiental , Têxteis , Águas Residuárias/química , Poluentes Químicos da Água/análise , Plásticos , Indústria Têxtil , Eliminação de Resíduos Líquidos
9.
J Hazard Mater ; 339: 340-346, 2017 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-28668751

RESUMO

This work sets out to investigate biological responses of Eisenia fetida to Cd, based on the bioavailable rather than total concentration of Cd, in soils. E. fetida was cultured for 14d in three selected Chinese soils amended with 0.1-40mgkg-1 Cd. Potentially bioavailable concentrations of Cd were measured in soil solution, in extractions using CaCl2 and HAc solutions, and using the technique of diffusive gradients in thin-films (DGT). Antioxidant system responses in E. fetida to Cd were measured as biological endpoints. Biological responses were more highly correlated with Cd concentrations evaluated using bioavailable methods than with total concentrations. Cd concentration measured using DGT and CaCl2 extraction provided the narrowest ranges of lowest observed effect concentration (LOEC) values based on biological responses, indicating the potential use of these measurements in management of soil quality and setting soil remediation standards. The LOEC values obtained from 15 field soils contaminated by Cd were similar to those from the three Cd-amended soils and suggested that DGT in particular can be a good tool to predict stress responses of E. fetida to Cd in soils. The study shows the potential of combining biological response and DGT measurements in risk assessment.


Assuntos
Cádmio/farmacocinética , Cádmio/toxicidade , Oligoquetos/efeitos dos fármacos , Poluentes do Solo/farmacocinética , Poluentes do Solo/toxicidade , Animais , Disponibilidade Biológica , Glutationa Transferase/metabolismo , Malondialdeído/metabolismo , Metalotioneína/metabolismo , Oligoquetos/metabolismo , Superóxido Dismutase/metabolismo
10.
Environ Sci Pollut Res Int ; 24(7): 6715-6723, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28091988

RESUMO

To further treat the reclaimed municipal wastewater and rehabilitate the aquatic ecosystem of polluted urban rivers, an 18.5-km field-scale ecological restoration project was constructed along Jialu River, a polluted urban river which receives only reclaimed municipal wastewater from Zhengzhou City without natural upland water dilution. This study investigated the potential efficiency of water quality improvement, as well as genotoxicity and cytotoxicity reduction along the ecological restoration project of this polluted urban river. Results showed that the chemical oxygen demand (COD) and ammonia nitrogen (NH3-N) of the reclaimed municipal effluent were reduced by more than 45 and 70%, respectively, meeting the Chinese surface water environmental quality standard level IV, while the total phosphorus and metal concentrations had no significant reduction along the restoration project, and Pb concentrations in all river water samples exceeded permissible limit in drinking water set by WHO (2006) and China (GB5749-2006). The in vitro SOS/umu assay showed 4-nitroquinoline-1-oxide equivalent (4-NQO-EQ) values of reclaimed municipal wastewater of 0.69 ± 0.05 µg/L in April and 0.68 ± 0.06 µg/L in December, respectively, indicating the presence of genotoxic compounds. The results of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and hepatic cell apoptosis in zebrafish after a chorionic long-term (21 days) in vivo exposure also demonstrated that the reclaimed municipal wastewater caused significant DNA oxidative damage and cytotoxicity. After the ecological purification of 18.5-km field-scale restoration project, the genotoxicity assessed by in vitro assay was negligible, while the DNA oxidative damage and cytotoxicity in exposed fish were still significantly elevated. The mechanisms of DNA oxidative damage and cytotoxicity caused by the reclaimed municipal wastewater need further study.


Assuntos
Rios , Águas Residuárias/toxicidade , Poluentes Químicos da Água/toxicidade , Amônia/análise , Animais , Análise da Demanda Biológica de Oxigênio , China , Cidades , Dano ao DNA , Ecossistema , Recuperação e Remediação Ambiental , Peixes , Fígado/efeitos dos fármacos , Testes de Mutagenicidade , Salmonella typhimurium/genética , Águas Residuárias/análise , Poluentes Químicos da Água/análise , Purificação da Água , Qualidade da Água , Peixe-Zebra/genética
11.
Chemosphere ; 164: 611-617, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27635643

RESUMO

Microplastic is an emerging contaminant affecting freshwater and marine ecosystem across the globe. In the present study, the filter feeding tadpoles of Xenopus tropicalis were exposed to polystyrene microspheres (1 and 10 µm) for 48 h. Microspheres were observed in gills and digestive tract of tadpoles within 1 h after exposure as well as in feces 6 h after exposure. The accumulation of microspheres in the tadpoles were concentration dependent (Univariate ANOVA, p < 0.001), but no time dependent accumulation of microspheres was observed in tadpoles 48 h after exposure (Univariate ANOVA, p > 0.05). After the exposed tadpoles were transferred to clean water, the number of microspheres in the tadpoles decreased dramatically after 1 d and continued to decrease gradually afterwards. The absorbed polystyrene particles in unfed tadpoles was significantly higher than those in the fed tadpoles at 12 and 24 h after exposure. After transfer to clean water, the fed tadpoles showed a significant decrease in the amount of absorbed polystyrene particles, while the unfed tadpoles showed no significant change in the amount of absorbed polystyrene particles. Our results suggested that microspheres were likely to be ingested and egested relatively fast by tadpoles. Our results indicated that aquatic vertebrate organisms might ingest more microplastics if the abundance of microplastics continues to increase while the available food becomes less.


Assuntos
Monitoramento Ambiental/métodos , Larva/efeitos dos fármacos , Poliestirenos/farmacocinética , Poluentes Químicos da Água/farmacocinética , Animais , Organismos Aquáticos , Água Doce , Trato Gastrointestinal/química , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/metabolismo , Brânquias/química , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Larva/química , Larva/metabolismo , Microesferas , Modelos Teóricos , Plásticos , Poliestirenos/análise , Poluentes Químicos da Água/análise , Xenopus
12.
Environ Pollut ; 216: 711-719, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27381875

RESUMO

In comparison with marine environments, the occurrence of microplastics in freshwater environments is less understood. In the present study, we investigated microplastic pollution levels during 2015 in Taihu Lake, the third largest Chinese lake located in one of the most developed areas of China. The abundance of microplastics reached 0.01 × 10(6)-6.8 × 10(6) items/km(2) in plankton net samples, 3.4-25.8 items/L in surface water, 11.0-234.6 items/kg dw in sediments and 0.2-12.5 items/g ww in Asian clams (Corbicula fluminea). The average abundance of microplastics was the highest in plankton net samples from the southeast area of the lake and in the sediments from the northwest area of the lake. The northwest area of the lake was the most heavily contaminated area of the lake, as indicated by chlorophyll-α and total phosphorus. The microplastics were dominated by fiber, 100-1000 µm in size and cellophane in composition. To our best knowledge, the microplastic levels measured in plankton net samples collected from Taihu Lake were the highest found in freshwater lakes worldwide. The ratio of the microplastics in clams to each sediment sample ranged from 38 to 3810 and was negatively correlated to the microplastic level in sediments. In brief, our results strongly suggest that high levels of microplastics occurred not only in water but also in organisms in Taihu Lake.


Assuntos
Lagos/química , Plásticos/análise , Poluentes Químicos da Água/análise , Animais , Bivalves , China , Monitoramento Ambiental/métodos , Poluição Ambiental/análise , Sedimentos Geológicos/química , Fósforo/análise , Plâncton , Plásticos/química , Poluentes Químicos da Água/química
13.
J Appl Toxicol ; 36(5): 685-91, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26177576

RESUMO

The frog embryo teratogenesis assay-Xenopus (FETAX) is an established method to evaluate the developmental toxicity of chemicals. In FETAX, a 48 h continuous exposure is usually conducted when the X. tropicalis embryo is used as the test model. In the present study, we exposed X. tropicalis embryos to nine known teratogens for four separate 12-h periods. The embryos showed great variations in response to nine tested compounds during different exposure periods. Based on the value of the score of malformations, the most sensitive 12 h exposure periods of embryos were significantly distinguished for all the compounds with the exception of NiCl2 . The embryos were the most sensitive to retinols (e.g. all-trans-retinoic acid and 9-cis-retinoic acid) during 0-12 h and to metal compounds (e.g. triphenlytin and CdCl2) during a 24 to 36 h exposure period. In the further 3 h exposure experiment, the most sensitive period could only be determined for one of three tested compounds. Based on the present results, we proposed an assay to determine a 12 h sensitive window of embryos to chemical exposure using Xenopus tropicalis.


Assuntos
Embrião não Mamífero/efeitos dos fármacos , Testes de Toxicidade/métodos , Xenopus/embriologia , Alitretinoína , Animais , Cloreto de Cádmio/toxicidade , Níquel/toxicidade , Teratogênese , Teratogênios/toxicidade , Fatores de Tempo , Tretinoína/toxicidade
14.
Environ Health Perspect ; 124(2): 184-92, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26220256

RESUMO

BACKGROUND: Three decades of rapid economic development is causing severe and widespread PM2.5 (particulate matter ≤ 2.5 µm) pollution in China. However, research on the health impacts of PM2.5 exposure has been hindered by limited historical PM2.5 concentration data. OBJECTIVES: We estimated ambient PM2.5 concentrations from 2004 to 2013 in China at 0.1° resolution using the most recent satellite data and evaluated model performance with available ground observations. METHODS: We developed a two-stage spatial statistical model using the Moderate Resolution Imaging Spectroradiometer (MODIS) Collection 6 aerosol optical depth (AOD) and assimilated meteorology, land use data, and PM2.5 concentrations from China's recently established ground monitoring network. An inverse variance weighting (IVW) approach was developed to combine MODIS Dark Target and Deep Blue AOD to optimize data coverage. We evaluated model-predicted PM2.5 concentrations from 2004 to early 2014 using ground observations. RESULTS: The overall model cross-validation R(2) and relative prediction error were 0.79 and 35.6%, respectively. Validation beyond the model year (2013) indicated that it accurately predicted PM2.5 concentrations with little bias at the monthly (R(2) = 0.73, regression slope = 0.91) and seasonal (R(2) = 0.79, regression slope = 0.92) levels. Seasonal variations revealed that winter was the most polluted season and that summer was the cleanest season. Analysis of predicted PM2.5 levels showed a mean annual increase of 1.97 µg/m(3) between 2004 and 2007 and a decrease of 0.46 µg/m(3) between 2008 and 2013. CONCLUSIONS: Our satellite-driven model can provide reliable historical PM2.5 estimates in China at a resolution comparable to those used in epidemiologic studies on the health effects of long-term PM2.5 exposure in North America. This data source can potentially advance research on PM2.5 health effects in China.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/instrumentação , Material Particulado/análise , Astronave , China , Modelos Estatísticos , Tamanho da Partícula , Imagens de Satélites , Estações do Ano
15.
Environ Sci Process Impacts ; 15(10): 1904-12, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23999790

RESUMO

The plant uptake and phytotoxicity of decabromodiphenyl ether (BDE-209) in ryegrass (Lolium perenne L) seedlings were investigated. Results showed that ryegrass could take up BDE-209 from the contaminated soils and most of the BDE-209 in plants is located in roots, indicating that BDE-209 has low root-to-shoot translocation. Except for about 35% inhibition of root growth and about 30% decrease of the chlorophyll b and carotenoid contents of leaves, no visual toxicity symptoms were observed in seedlings grown even at a high concentration of 100 mg kg(-1). BDE-209 exposure significantly induced the generation of the superoxide radical (O2˙(-)) and malondialdehyde (MDA) in ryegrass leaves. With the increase of BDE-209 concentration, the activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and glutathione-S-transferase (GST) were significantly changed, and the ratio of reduced glutathione to oxidized glutathione (GSH/GSSG) was also significantly reduced. Results suggested that BDE-209 exposure could cause oxidative stress and damage, which may play an important role in the phytotoxicity of BDE-209 in ryegrass seedlings.


Assuntos
Éteres Difenil Halogenados/toxicidade , Lolium/efeitos dos fármacos , Lolium/crescimento & desenvolvimento , Poluentes do Solo/toxicidade , Antioxidantes/metabolismo , Biomassa , China , Éteres Difenil Halogenados/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Lolium/metabolismo , Malondialdeído/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Poluentes do Solo/metabolismo
16.
J Hazard Mater ; 192(3): 1795-803, 2011 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-21807460

RESUMO

The effectiveness of a two-stage reduction/subsequent oxidation (T-SRO) treatment of BDE-47, consisting of Fe-Ag reduction and Fenton-like oxidation, was investigated in this study. As an oxidation-resisting pollutant, BDE-47 (5 mg L(-1)) was difficult to be degraded by homogeneous Fe-Ag/H(2)O(2) system coupled with ultrasound (US) in 30 min. However, when this solution was firstly treated with Fe-Ag/US, the final debrominated product could be rapidly oxidized by the succeeding Fenton-like reactions, resulting in an efficient debromination of BDE-47 and a 100% mineralization of diphenyl ether (DPE). To scrutinize the degradation mechanism, several analytical techniques including HPLC, LC-MS/MS and GC/MS, were employed to monitor the major intermediates and final products. Moreover, luminescent bacteria test showed that the acute toxicity of the original solution (before reduction) was evidently lower than that of Fe-Ag/US reduction-treated solution; no toxicity was detected after Fenton-like oxidation. Evidence for the significance of a T-SRO treatment to decompose BDE-47 was presented.


Assuntos
Éteres Difenil Halogenados/análise , Oxigênio/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Água/química , Bactérias/genética , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida/métodos , Desenho de Equipamento , Cromatografia Gasosa-Espectrometria de Massas/métodos , Éteres Difenil Halogenados/química , Peróxido de Hidrogênio/química , Ferro/química , Cinética , Luminescência , Espectrometria de Massas/métodos , Éteres Fenílicos/química , Bifenil Polibromatos
17.
Ecotoxicology ; 18(6): 693-9, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19499334

RESUMO

Biochemical effects of tetrabromobisphenol A (TBBPA) on the earthworm Eisenia fetida, including superoxide dismutase, catalase, glutathione-S-transferase, reduced glutathione, oxidized glutathione, GSH/GSSG ratio and malondialdehyde (MDA) level, were measured to assess ecological toxicity of TBBPA. With OECD standard filter-paper contact test method, earthworms were exposed to TBBPA of a range of concentrations (0.00, 0.01, 0.05, 0.1, 0.5 and 1.0 mg L(-1)). According to the electron paramagnetic resonance spectrum, reactive oxygen species (ROS) generated in the earthworm was identified as the hydroxyl radical ((*)OH) which was significantly induced at all TBBPA concentrations. With the increasing of TBBPA concentration, the antioxidant enzymes, glutathione and MDA levels varied significantly. The results showed that TBBPA exerts its toxic effects on E. fetida by inducing the generation of ROS and resulting in oxidative damage. The results show that the (*)OH production leads to oxidative stress in the tissues of the earthworm E. fetida.


Assuntos
Poluentes Ambientais/toxicidade , Radical Hidroxila/metabolismo , Oligoquetos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Bifenil Polibromatos/toxicidade , Animais , Catalase/metabolismo , Relação Dose-Resposta a Droga , Glutationa/metabolismo , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Malondialdeído/metabolismo , Oligoquetos/enzimologia , Oligoquetos/metabolismo , Superóxido Dismutase/metabolismo , Testes de Toxicidade Aguda
18.
Ecotoxicol Environ Saf ; 71(3): 685-91, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18397810

RESUMO

Oxidative stress and defense response in leaves of tomato seedlings exposed to extraneous lead (Pb) at 0-500 mg kg(-1) soil for nearly 2 months were investigated. Superoxide radical (O(2)(-)) was quantified by electron paramagnetic resonance (EPR). Results showed that levels of O(2)(-), malondialdehyde (MDA), carbonyl group and superoxide dismutase (SOD) increased with the increase of bioavailable Pb. The O(2)(-) level was well correlated with MDA, carbonyl groups and SOD activities, suggesting that O(2)(-) might be responsible for them. Intensities in two bands of SOD isoenzymes increased along with added Pb in treatments against control, implying that multigenic expression in SOD enzymes were activated to counteract O(2)(-) stress. Heat shock protein 70 (HSP70) was induced sensitively by soil Pb, which was to alleviate oxidative damage (i.e. increased carbonyl groups). The overall results indicated that HSP70 and O(2)(-) were the most sensitive parameters and the combination of them might be potential biomarkers of soil Pb contamination in tomato seedlings.


Assuntos
Chumbo/toxicidade , Lycopersicon esculentum/efeitos dos fármacos , Plântula/efeitos dos fármacos , Poluentes do Solo/toxicidade , Biomarcadores/metabolismo , Relação Dose-Resposta a Droga , Proteínas de Choque Térmico HSP70/metabolismo , Chumbo/análise , Chumbo/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Lycopersicon esculentum/metabolismo , Malondialdeído/metabolismo , Estresse Oxidativo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Plântula/metabolismo , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/metabolismo , Superóxido Dismutase/metabolismo , Superóxidos/metabolismo
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