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1.
Chem Biol Interact ; 318: 108978, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-32044341

RESUMO

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) accumulates in human body, probably influencing adipocyte differentiation and causing various toxic effects, including wasting syndrome. Recently, orientin, a phenolic compound abundant in natural health products, has been shown to have antioxidant properties. We investigated the protective effects of orientin against TCDD-induced adipocyte dysfunction and its underlying mechanisms. In this study, orientin suppressed TCDD-induced loss of lipid accumulation. Orientin inhibited TCDD-driven decreases in the levels of peroxisome proliferator-activated receptor γ and adiponectin. Orientin also reduced TCDD-induced prostaglandin E2, and cytosolic phospholipase A2α levels, and increased TCDD-inhibited peroxisome proliferator-activated receptor gamma coactivator 1-alpha levels in 3T3-L1 adipocytes. TCDD reduced the levels of insulin receptor substrate 1 and glucose transporter 4, and decreased insulin-stimulated glucose uptake activity; however, orientin diminished these TCDD-induced effects. These results suggest that orientin may have beneficial effects on the prevention of TCDD-induced wasting syndrome and type II diabetes mellitus accompanied by insulin resistance.


Assuntos
Adipócitos/efeitos dos fármacos , Adipogenia/efeitos dos fármacos , Flavonoides/farmacologia , Glucosídeos/farmacologia , Insulina/metabolismo , Dibenzodioxinas Policloradas/toxicidade , Transdução de Sinais/efeitos dos fármacos , Células 3T3-L1 , Animais , Dinoprostona , Regulação da Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Camundongos
2.
J Agric Food Chem ; 68(7): 2201-2213, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32023042

RESUMO

A feeding study was carried out to investigate the kinetics in cow milk of the 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), the 12 dioxin-like polychlorinated biphenyls (DL-PCBs), and the 6 non-dioxin-like PCBs (NDL-PCBs) regulated by the European (EU) legislation. A fortified ration (ΣPCDD/Fs and DL-PCBs: 24.68 ng TEQ/day/cow; ΣNDL-PCBs: 163.99 µg/day/cow) was given to the animals for 49 days, followed by 42 days on clean feed. EU maximum limit for TEQPCDD/F+DL-PCB was exceeded in milk after 1 week of exposure, while for ΣNDL-PCBs, after 5 weeks. Milk compliance was restored after 1 week on clean feed, but to return to the basal TEQPCDD/F+DL-PCB it took 42 days. At the end of the study, ΣNDL-PCBs had not yet reached the basal level. The carryover rate of ΣNDL-PCBs was 25.4%, while the carryover rate of TEQPCDD/F+DL-PCB was 36.9%. The latter was mainly affected by the 12 congeners contributing most to the toxic equivalent (TEQ) level, explaining the fast overcome of the maximum limit in milk.


Assuntos
Dibenzofuranos/análise , Contaminação de Alimentos/análise , Leite/química , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análise , Ração Animal/análise , Animais , Bovinos , Dioxinas/análise , Feminino
3.
Environ Sci Process Impacts ; 22(2): 239-255, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-31916559

RESUMO

A bibliometric analysis of published papers with the key words "positive matrix factorization" and "source apportionment" in 'Web of Science', reveals that more than 1000 papers are associated with this research and that approximately 50% of these were produced in Asia. As a receptor-based model, positive matrix factorization (PMF) has been widely used for source apportionment of various environmental pollutants, such as persistent organic pollutants (POPs), heavy metals, volatile organic compounds (VOCs) as well as inorganic cations and anions in the last decade. In this review, based on the papers mainly from 2008 to 2018 that focused on source apportionment of pollutants in different environmental media, we provide a comparison and summary of the source categories of typical environmental pollutants, with a special focus on polycyclic aromatic hydrocarbons (PAHs), apportioned using PMF. Based on the statistical average, coal combustion and vehicular emission, are shown to be the two most common sources of PAHs, and contribute much more to emissions than other sources, such as biomass burning, biogenic sources and waste incineration. Heavy metals were mainly from agricultural activities, industrial and vehicular emissions and mining activities. Quantitative source apportionment on pollutants such as VOCs and particulate matter were also apportioned, showing a prominent contribution from fossil-fuel combustion. We conclude that, aside from natural sources, abatement strategies should be focused on changes in energy structure and industrial activities, especially in China. Source apportionment of typical POPs including polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), halogenated flame retardants (HFRs) and perfluorinated compounds (PFCs) is less comprehensive and further study is required.


Assuntos
Poluentes Atmosféricos , Poluentes Ambientais , Dibenzodioxinas Policloradas , Hidrocarbonetos Policíclicos Aromáticos , Ásia , China , Dibenzofuranos , Monitoramento Ambiental
4.
Chemosphere ; 243: 125443, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31995890

RESUMO

Long-term sampling is essential for monitoring the air pollutants emitted from stack since it can monitor the pollutants emission continuously including the stages of start-up, shutdown and normal operation. However, commercial continuous sampling equipment such as AMESA faces the challenges of high weight and complicated sampling procedures. This study has developed a long-term and automatic sampling system (National Central University continuous stack sampling system, NCU-CS3), and compared the efficiency with manual sampling train (MST). The results indicate that relative standard deviation (RSD) of PCDD/Fs concentrations measured between NCU-CS3 and MST is <20%, demonstrating that the difference between NCU-CS3 and MST in measuring PCDD/Fs is insignificant. Besides, the effects of adsorbent temperature, adsorbent amount and type of adsorbent on breakthroughs of PAHs and unintentional-persistent organic pollutants (UPOPs) such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), chlorinated phenols (CPs), chlorinated benzenes (CBs) and polychlorinated naphthalenes (PCNs) are evaluated. The results indicate that the breakthrough of pollutants increases with increasing temperature of XAD-2 and decreases with increasing XAD-2 amount. Moreover, XAD-4 is used as alternative adsorbent to test the breakthrough and the results indicate that the breakthroughs of UPOPs of XAD-4 as adsorbent are lower than that with XAD-2 due to higher specific surface area of XAD-4. Furthermore, the residual of PCDD/Fs with NCU-CS3 as the sampling train is relatively low (1.5-3.8%), which meets the regulation of EN 1948-5 (10%).


Assuntos
Poluentes Atmosféricos/análise , Dibenzofuranos Policlorados/análise , Monitoramento Ambiental/métodos , Compostos Orgânicos/análise , Dibenzodioxinas Policloradas/análise , Benzofuranos/análise , Dibenzofuranos/análise , Poluentes Ambientais/análise , Estudos Longitudinais , Naftalenos/análise , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise
5.
Waste Manag ; 102: 114-121, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31671358

RESUMO

Emissions of dioxins and furans during the gasification of Automotive Shredder Residue (ASR) were investigated. The experimental work was carried out in a Dual Fluidized Bed (DFB) system, which consists of a 2-4-MWth gasifier that is fluidized with steam, and an interconnected fluidized bed combustor that is fluidized with air. Two different ASR fractions with higher and lower contents of plastic were tested. Measurements were carried out in the flue gas stream exiting the combustion side of the DFB, as well as in the raw gas stream exiting the gasifier side. A calcium (lime) coat was applied to the flue gas filter to ensure compliance with the emissions regulations regarding the retention of HCl and dioxins. The results showed lower emissions of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/PCDF) in the flue gas when the raw gas derived from the ASR gasification was combusted, as compared to the direct combustion of ASR. The level of polychlorinated compounds in the flue gas before the lime-coated filter was 0.11 ng/m3N dry gas (I-TEQ) when gasification was used as a pre-step, as compared to 0.27 ng/m3N dry gas (I-TEQ) when the ASR was directly combusted. The raw gas produced by gasification contained very low levels of PCDD/PCDF, whereby the toxicity per kg of ASR was 0.17 ng/kgASR, as compared to 3.44 ng/kgASR after passage through the combustion and cooling sections and 0.34 ng/kgASR at the outlet after the lime-coated filter. A higher content of plastic in the ASR led to an increase in the levels of dioxins and furans in the raw gas, with the highest yield seen for highly chlorinated compounds, while higher temperature in the gasifier is shown to be beneficial in reducing dioxin formation.


Assuntos
Dioxinas , Furanos , Dibenzodioxinas Policloradas , Dibenzofuranos Policlorados , Incineração , Vapor
6.
Chemosphere ; 239: 124614, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31505444

RESUMO

Studies are carried out in two wet scrubbing systems (WSSs) subordinated to two similar full-scale (30 t h-1) municipal solid waste (MSW) incinerators to explore the influence factors and mass balance of memory effect on polychlorinated-ρ-dibenzodioxins and dibenzofurans (PCDD/Fs) emissions. The results show that the memory effect on two WSSs notably increases the TEQ concentrations by 13.6 and 3 times, respectively, through increase in the total mass concentration and the proportions of low-chlorinated PCDD/Fs, directly resulting in the PCDD/F emissions of 1# MSW incinerator over the national standard. PCDD/F adsorption/desorption in WSSs is the reasonable acting mechanisms of memory effect. In addition, memory effect mainly influences gaseous PCDD/F emissions by elevating the percentage of PCDFs, while slightly affects PCDD/Fs in residuals. A mass balance of PCDD/Fs is established to further analyze the influence factors of memory effect on WSSs, indicating filling as the largest potential source discharging PCDD/Fs into outlet flue gas. The results pave the way for further industrial optimization of WSSs design, such as the filling materials with less adsorption capacity on PCDD/Fs and more reasonable operation.


Assuntos
Poluentes Atmosféricos/análise , Benzofuranos/análise , Dibenzofuranos Policlorados/análise , Incineração/métodos , Dibenzodioxinas Policloradas/análise , Resíduos Sólidos/análise , China , Monitoramento Ambiental/métodos , Gases
7.
Chemosphere ; 239: 124626, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31518918

RESUMO

Polybrominated dibenzo-p-dioxins (PBDDs) and mixed bromo/chloro dibenzo-p-dioxins (PXDDs) are persistent organic pollutants that can possess the same toxicity as their fully chlorinated analogs (PCDDs) and have been identified in the same matrices. Herein a general synthetic methodology is described to produce multiple congeners of PBDDs and PXDDs with varying degrees of halogenation and substitution patterns for use as analytical and/or internal standards, and for absorption, disposition, metabolism, and excretion (ADME) studies. The syntheses of PBDDs and PXDDs were accomplished by condensing a common precursor, 4,5-dibromo catechol, with variable precursors, i.e., polychlorinated 1-chloro-2-nitrobenzenes or polybrominated 1-fluoro-2-nitrobenzenes, to introduce a desired number of halogens and specific substitution patterns. Initial attempts to synthesize PBDDs and PXDDs were performed in potassium carbonate with DMSO at 145-150 °C. PXDDs syntheses resulted in formation of the desired products at >90% purity but attempts at higher brominated PBDDs syntheses resulted in dehalogenated by-products. To preclude by-product formation, additional syntheses for some PBDDs were conducted by refluxing the precursors in acetonitrile, which resulted in pure products at higher yield. Six PXDDs ranging from four to six halogens were synthesized (20-84% yield), of which three contained the halogen substitution pattern of 2,3,7,8. Five PBDDs ranging from four to six bromines were produced in 23-83% yield, three of which were toxic. Using the initial DMSO method, [14C]-1,3,7,8-tetrabromodibenzo-p-dioxin (0.26 µCi/µmol; 11% overall yield) was synthesized from commercially available [14C]-phenol to allow an ADME study to be conducted.


Assuntos
Dioxinas/síntese química , Retardadores de Chama/síntese química , Dibenzodioxinas Policloradas/síntese química , Bromo/química , Poluentes Ambientais/análise , Retardadores de Chama/análise
8.
Chemosphere ; 239: 124717, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31499315

RESUMO

Long-term atmospheric measurement of 17 total (gaseous and particulate) polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) has been made from 2007 to 2016 at five industrial and urban sites in Busan, South Korea, based on their persistence, bioaccumulation, and toxicity. In the present study, two pooled datasets covering a combination of 2 industry sites and 3 urban sites have been subjected to positive matrix factorization (PMF) to identify and quantify the major sources of PCDD/Fs. Additionally, PMF has been applied to the industrial urban dataset consisting of both polycyclic aromatic hydrocarbons (PAHs) and PCDD/Fs. The results show that the sum of PCDD/F mass (Σ17PCDD/Fs) at the industrial sites is determined by five major sources: non-ferrous metal production (33.7%), diesel vehicle emissions (30.2%), ferrous metal production (22.4%), other industrial emissions (11.1%), and traffic emissions (2.6%), while the PAH mass (Σ16PAHs) is predominantly associated with emissions from coal combustion, followed by traffic emissions. At the urban sites, the largest contribution to the Σ17PCDD/Fs was observed from transported emissions being emitted from metallurgical industry (75.5%), followed by diesel vehicle emissions (24.5%). The application of congener-specific toxicity to PCDD/F mass (Σ17fg I-TEQ Sm-3) indicates enhanced contributions from the ferrous metallurgical emission factor associated with penta- and hexa-chlorinated furans across the study sites.


Assuntos
Poluentes Atmosféricos/análise , Dibenzofuranos Policlorados/análise , Monitoramento Ambiental/métodos , Indústrias , Dibenzodioxinas Policloradas/análise , Carvão Mineral/efeitos adversos , República da Coreia , Urbanização , Emissões de Veículos
9.
Environ Sci Technol ; 54(2): 1033-1044, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31852180

RESUMO

The aryl hydrocarbon receptor (Ahr) is a ligand-activated transcription factor that mediates the toxicity of halogenated and polycyclic aromatic hydrocarbons in vertebrates. Atlantic cod (Gadus morhua) has recently emerged as a model organism in environmental toxicology studies, and increased knowledge of Ahr-mediated responses to xenobiotics is imperative. Genome mining and phylogenetic analyses revealed two Ahr-encoding genes in the Atlantic cod genome, gmahr1a and gmahr2a. In vitro binding assays showed that both gmAhr proteins bind to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), but stronger binding to gmAhr1a was observed. Transactivation studies with a reporter gene assay revealed that gmAhr1a is one order of magnitude more sensitive to TCDD than gmAhr2a, but the maximal responses of the receptors were similar. Other well-known Ahr agonists, such as ß-naphthoflavone (BNF), 3,3',4,4',5-pentachlorobiphenyl (PCB126), and 6-formylindolo[3,2-b]carbazole (FICZ), also activated the gmAhr proteins, but gmAhr1a was, in general, the more sensitive receptor and produced the highest efficacies. The induction of cyp1a in exposed precision-cut cod liver slices confirmed the activation of the Ahr signaling pathway ex vivo. In conclusion, the differences in transcriptional activation by gmAhr's with various agonists, the distinct binding properties with TCDD and BNF, and the distinct tissue-specific expression profiles indicate different functional specializations of the Atlantic cod Ahr's.


Assuntos
Gadus morhua , Dibenzodioxinas Policloradas , Hidrocarbonetos Policíclicos Aromáticos , Animais , Filogenia , Receptores de Hidrocarboneto Arílico
10.
Environ Sci Technol ; 54(2): 1111-1119, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31867966

RESUMO

Epidemiological studies have indicated the thyroid-disrupting effects of persistent organic pollutants (POPs). However, the association of low-exposure POPs with thyroid hormones (THs) remains unclear. Here, we aim to assess the association of low exposure of POPs, including polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), and polybrominated dibenzo-p-dioxins and furans, with THs [total L-thyroxine (TT4), total 3,3',5-triiodo-L-thyronine (TT3), and total 3,3',5'-triiodo-L-thyronine (TrT3)] measured in human breast milk. Ninety-nine breast milk samples were collected from the LUPE cohort (2015-2016, Bavaria, Germany). Fourteen PBDEs, 17 PCBs, and 5 PCDD/Fs had quantification rates of >80%. Nonmonotonic associations were observed. In adjusted single-pollutant models, (1) TT4 was inversely associated with BDE-99, -154, and -196; (2) TT3 was inversely associated with BDE-47, -99, -100, -197, -203, -207, and OCDD; and (3) TrT3 was inversely associated with BDE-47, -99, -183, and -203. Multipollutant analysis using principal component analysis and hierarchical clustering revealed inverse associations of PBDEs (BDE-28, -47, -99, -100, -154, -183, and -197) with TT4 and TrT3. These results indicate that POPs at low levels might be related to reduced THs. This study shows that human breast milk might be an appropriate specimen to evaluate the thyroid disruption of POPs.


Assuntos
Poluentes Ambientais , Bifenilos Policlorados , Dibenzodioxinas Policloradas , Animais , Dibenzofuranos , Feminino , Alemanha , Éteres Difenil Halogenados , Homeostase , Humanos , Leite Humano , Hormônios Tireóideos
11.
Ecotoxicol Environ Saf ; 188: 109895, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31706238

RESUMO

Seventeen soil samples collected in an industrial park located in Ningxia Province, Northwestern China were analyzed for polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs). The PCN, PCDD/F, and PCB concentration ranges were 183-3340, 7.00-215, and 45.1-355 pg/g, respectively. Positive matrix factorization showed that secondary ferrous metal smelters and cement kilns contributed more than 70% of the total PCN concentration. Historical use of Halowax 1051 also affected the PCN concentrations in soil. Principal component analysis indicated that the PCDD/F concentrations in soil in the study area were mainly affected by thermal processes in secondary ferrous metal smelters. CB-209 was an important contributor to total PCBs in the study area, and likely originated from the phthalocyanine-type pigments used in a local recycled paper mill. Samples S10, S1, S17, and S6 had high ∑TEQ (PCDD/Fs + PCNs + PCBs) concentrations, and the carcinogenic risks of PCDD/Fs, PCNs, and PCBs for workers from these samples were 0.487 × 10-6, 0.234 × 10-6, 0.230 × 10-6, and 0.210 × 10-6, respectively. According to our results, the health risks of PCDD/Fs, PCNs, and PCBs for workers in this area should be given more attention.


Assuntos
Monitoramento Ambiental/métodos , Hidrocarbonetos Clorados/análise , Indústrias , Naftalenos/análise , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análise , Poluentes do Solo/análise , China , Humanos , Medição de Risco , Solo/química
12.
Chemosphere ; 238: 124620, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31472354

RESUMO

Particulate toxic species, such as polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), polycyclic aromatic hydrocarbons (PAHs) and heavy metals may have significant health risks. This study investigated characteristics, sources and health risks of all three classes of toxic species in PM2.5 (particles with aerodynamic diameter ≤2.5 µm) samples collected at an industrial area in Changzhou, a big city in the Yangtze Delta region of China. Fourteen heavy metals altogether constituted 2.87% of PM2.5 mass, with Fe, Al and Zn as the major elements. Principal component analysis (PCA) suggested that heavy metals came from four sources: vehicles, industry, crustal dust, mixed coal combustion and industrial process. The daily average concentration of 18 PAHs was 235.29 ng/m3, accounting for 0.21% of PM2.5 mass. The dominant PAHs were high molecular weight ones, contributing 73.5% to the total PAHs. Diagnostic analyses indicated that sources of PAHs included vehicle/coal combustion and petroleum emissions, wherein diesel emission played a more important role than gasoline emission. PCA showed that the largest contributor of PAHs was vehicle exhaust mixed with coal combustion, followed by three industry-related sources. Total concentration of 17 PCDD/Fs varied between 3.14 and 37.07 pg/m3, with an average of 14.58 pg/m3. The 10 PCDFs accounted for 70.5% of total concentration of 17 PCDD/Fs. Health risk assessments showed that the carcinogenic risk of heavy metals was acceptable, while risks from PAHs and PCDD/Fs cannot be ignored. Back trajectory analysis indicated that local/regional transported air masses from northern China was the major source areas of the toxic species.


Assuntos
Exposição por Inalação/efeitos adversos , Metais Pesados/análise , Neoplasias/induzido quimicamente , Material Particulado/efeitos adversos , Dibenzodioxinas Policloradas/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Medição de Risco/métodos , Adulto , Poluentes Atmosféricos/análise , Carcinógenos/análise , Criança , China , Monitoramento Ambiental , Feminino , Humanos , Indústrias , Exposição por Inalação/análise , Masculino , Material Particulado/administração & dosagem , Dibenzodioxinas Policloradas/efeitos adversos , Hidrocarbonetos Policíclicos Aromáticos/efeitos adversos , Estações do Ano , Emissões de Veículos/análise
13.
Chemosphere ; 239: 124666, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31479911

RESUMO

The toxicity of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) is well known, and for this reason studying and monitoring these chemicals is fundamental. Activated carbon fibers (ACFs) are made of an adsorbent material widely used in the industrial field for the removal of micropollutants. The first step in this work was to perform a physico-chemical characterization of the adsorbent, focused on the analytical use of it. In particular, its specific surface area was defined around 2500 m2/g consisting in a homogeneous microporosity distribution and the characterization of ACF surface functional groups pointed out a balance between basic and acidic group. The validity of using the ACF as solid phase extraction and as passive sampler for PCDD/Fs and PCBs in water, has been evaluated by the percentage recovery (R %) of 13C12-labeled standards of PCDD/Fs and PCBs added in a known volume of water. The results were compared to the R% of Liquid-Liquid Extraction which showed a better reproducibility of the results and the proposed method satisfy completely the requirements of US EPA reference methods.


Assuntos
Carvão Vegetal/química , Dibenzofuranos Policlorados/análise , Monitoramento Ambiental/métodos , Recuperação e Remediação Ambiental/métodos , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análise , Benzofuranos/análise , Fibra de Carbono , Reprodutibilidade dos Testes , Extração em Fase Sólida , Água
14.
Chemosphere ; 239: 124685, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31521928

RESUMO

This review provides a summary of the levels and profiles of PCDD/Fs throughout China, as reported in peer reviewed literatures since 1997. The literature shows that PCDD/Fs are widespread in various environmental media including air, water, sediment, and soil. PCDD/Fs concentrations in air were relatively low in most regions, with only a few areas considered polluted. Many studies reported seasonal trends, with higher and lower concentrations in winter and summer, respectively. We analyzed the factors affecting the concentrations of dioxins in air and summarized the causes of seasonal changes. As hydrophobic organic compounds, PCDD/Fs readily accumulate in sediments. The distribution of dioxins in sediment in Bohai Sea area was mainly introduced and the factors affecting concentrations of dioxins were studied. The levels of dioxins in soil in different regions varied greatly, with higher levels in areas close to pollution sources. We examined the dioxins concentrations in soil in places where the levels were very low (including the Tibet Plateau and other remote areas), contaminated areas, and other areas. Apart from the contaminated areas, the dioxins concentrations in soil were low. The results of the relatively low number of studies that have investigated PCDD/Fs in water have reported no obvious pollution in some waters, apart from Dongting Lake. PCDD/Fs levels across China are similar to those worldwide. Point sources, mainly related to local geographic, economic, and historical factors, were the most common source of contamination. E-waste dismantling and chemical production has the greatest impact on PCDD/Fs in different media.


Assuntos
Dibenzofuranos Policlorados/análise , Monitoramento Ambiental/métodos , Poluição Ambiental/análise , Dibenzodioxinas Policloradas/análise , Poluentes Químicos da Água/análise , China , Sedimentos Geológicos/química , Lagos/química , Solo/química , Tibet
15.
Chemosphere ; 240: 124852, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31542585

RESUMO

This study presents four years ambient monitoring data of seventeen 2,3,7,8-chlorine substituted polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), twelve dioxin-like polychlorinated biphenyls (dl-PCBs) and sixteen polycyclic aromatic hydrocarbons (PAHs) designed by the US EPA at a background site in central Europe during 2011-2014. The concentrations expressed as toxic equivalents (TEQs) using the WHO2005-scheme for PCDD/Fs (0.2 fg m-3-61.1 fg m-3) were higher than for dl-PCBs (0.01 fg m-3-2.9 fg m-3), while the opposite was found in terms of mass concentrations. ΣPAHs ranged from 0.20 ng m-3 to 134 ng m-3. The mass concentration profile of PCDD/Fs, dl-PCBs and PAHs was similar throughout the four years. PCDD/Fs and PAHs concentrations were dominated by primary sources peaking in winter, while those of dl-PCBs were controlled by secondary sources characterized by a spring-summer peak. During 2011-2014, no significant decrease in the atmospheric levels of ΣPCDD/Fs was observed. On the other hand, the concentrations of Σdl-PCBs and ΣPAHs were decreasing, with halving times of 5.7 and 2.7 years, respectively. We estimated that 422 pg m-2 year-1-567 pg m-2 year-1 TEQ PCDD/Fs and 3.48 pg m-2 year-1-15.8 pg m-2 year-1 TEQ dl-PCBs were transferred from the air to the ground surfaces via dry particulate deposition during 2011-2014.


Assuntos
Poluentes Atmosféricos/análise , Dibenzofuranos Policlorados/análise , Dibenzodioxinas Policloradas/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , República Tcheca , Monitoramento Ambiental , Bifenilos Policlorados/análise , Estações do Ano
16.
Zhonghua Yu Fang Yi Xue Za Zhi ; 53(12): 1236-1241, 2019 Dec 06.
Artigo em Chinês | MEDLINE | ID: mdl-31795579

RESUMO

Objective: To investigate the content of persistent organic pollutants (POPs) in fish from Dongting Lake. Methods: Ten sample collection points were set in lakeside city Yueyang and Yuanjiang. In July (wet season) and November (dry season) of 2012, 13 common fish species were captured by convenience sampling in Dongting Lake. Two to three fish with similar weight were selected in each season for the same species of fish. After sample preparation and pretreatment, the contents of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), indicator polychlorinated biphenyls and polybrominated diphenyls ether (PBDEs) in the samples were determined by high resolution gas chromatographer-high resolution mass spectrometry. Toxicity Equivalents (TEQ) of PCDD/Fs and dl-PCBs were calculated according to the revised toxicity equivalent factor (TEF) of WHO in 2005. The contents of POPs were expressed by median and quavtile. The differences of POPs in fish in different periods were compared by Wilcoxon rank sum test. Results: The content of PCDD/Fs of fish in Dongting Lake in wet season was 12.397 (8.865, 24.964) pg/g, higher than that in the dry season 0.771 (0.490, 1.442) pg/g (P<0.001), and the toxicity equivalent quantity (TEQ) were 0.150 (0.066,0.528) and 0.143 (0.066, 0.235) pg-TEQ/g without statistically significant difference (P>0.05). For the fish in wet and dry season from Dongting Lake,Σdl-PCBs of fish were 66.475 (28.065, 77.794) and 24.205 (18.237, 90.777) pg/g, respectively, and the TEQ were 0.061 (0.046, 0.268) and 0.075 (0.054, 0.182) pg-TEQ/g; Σ indicative PCBs were 237.764 (153.896, 335.483) and 119.711 (52.171, 408.696) pg/g, respectively; Σ PBDEs were 106.513 (64.834, 164.860) and 86.837 (61.872, 177.108) pg/g, respectively. The highest content of PCDD/Fs was found in grass carp (198.360 pg/g) in wet season. The higher content of PCBs was found in long-necked fish (2 332.509 pg/g) and PBDEs was found in pelteobagrus fulvidraco (343.857 pg/g), respectively. Conclusion: A lower burden was found in fishes from Dongting Lake, and the content of POPs varied in different seasons and fishes.


Assuntos
Poluentes Ambientais , Peixes/metabolismo , Lagos/análise , Espectrometria de Massas/métodos , Dibenzodioxinas Policloradas/análise , Poluentes Químicos da Água/análise , Animais , Benzofuranos , China , Dibenzofuranos , Dibenzofuranos Policlorados , Lagos/química , Bifenilos Policlorados , Dibenzodioxinas Policloradas/efeitos adversos , Dibenzodioxinas Policloradas/metabolismo , Poluentes Químicos da Água/metabolismo
17.
Environ Pollut ; 255(Pt 3): 113357, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31671369

RESUMO

Gut microbiota is of critical importance to host health. Aryl hydrocarbon receptor (AhR) is found to be closely involved in the regulation of gut microbial dynamics. However, it is still not clear how AhR signaling shapes the gut microbiota. In the present study, adult zebrafish were acutely exposed to an AhR antagonist (CH223191), an AhR agonist (polychlorinated biphenyl 126; PCB126) or their combination for 7 d. Overall intestinal health and gut microbial community were temporally monitored (1 d, 3 d and 7 d) and inter-compared among different groups. The results showed that single exposure to PCB126 significantly disrupted the overall health of intestines (i.e., neural signaling, inflammation, epithelial barrier integrity, oxidative stress). However, CH223191 failed to inhibit but enhanced the physiological toxicities of PCB126, implying the involvement of extra mechanisms rather than AhR in the regulation of intestinal physiological activities. Dysbiosis of gut microbiota was also caused by PCB126 over time as a function of sex. It is intriguing that CH223191 successfully abolished the holistic effects of dioxin on gut microbiota, which inferred that growth of gut microbes was directly controlled by AhR activation without the involvement of host feedback modulation. When coming to detailed alterations at certain taxon, both antagonistic and synergistic interactions existed between CH223191 and dioxin, depending on fish sex, exposure duration and bacterial species. Correlation analysis found that gut inflammation was positively associated with pathogenic Legionella bacteria, but was negatively associated with epithelial barrier integrity, suggesting that integral intestinal epithelial barrier can prevent the influx of pathogenic bacteria to induce inflammatory response. Overall, this study has deciphered, for the first time, the direct regulative effects of AhR activity on gut microbiota. Future research is warranted to elucidate the specific mechanisms of AhR action on certain bacterial population.


Assuntos
Dioxinas/toxicidade , Microbioma Gastrointestinal/efeitos dos fármacos , Animais , Bactérias/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Disbiose , Intestinos , Microbiota , Bifenilos Policlorados , Dibenzodioxinas Policloradas , Receptores de Hidrocarboneto Arílico/metabolismo , Transdução de Sinais , Peixe-Zebra/metabolismo
18.
Environ Sci Technol ; 53(21): 12803-12811, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31566365

RESUMO

Field investigations have revealed the ability of the climbing perch Anabas testudineus to survive in highly contaminated water bodies. The aryl hydrocarbon receptor (AhR) pathway is vital in mediating the toxicity of aromatic hydrocarbon contaminants, and genotypic variation in the AhR can confer resistance to these contaminants. Thus, we characterized the AhR pathway in A. testudineus in order to understand the mechanism(s) underlying the resistance of this species to contaminants and to broaden current knowledge on teleost AhR. In A. testudineus, four AhRs, two AhR nuclear translocators (ARNTs), and one AhR repressor (AhRR) were found. Transient transfection assays revealed that AhR1a, AhR1b, and AhR2b were functional, whereas AhR2a was poorly activated by the potent agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Two ARNTs (partner of AhR) and one AhRR (repressor of AhR) all were functional with each of the active AhR. As a major form, the insensitivity of AhR2a might serve as a potential mechanism for A. testudineus' reduced sensitivity to severe contamination. We explored the key residues that may account for AhR2a's insensitivity in silico and then functionally validated them in vitro. Two sites (VCS322-324, M370) in its ligand-binding domain (LBD) were proved critical for its sensitivity to TCDD. This systematic exploration of the AhR pathway showed that most members have maintained their traditional functions as expected, whereas a nonfunctionalization event has occurred for AhR2a.


Assuntos
Dibenzodioxinas Policloradas , Receptores de Hidrocarboneto Arílico , Animais , Peixes
19.
Environ Pollut ; 255(Pt 2): 113310, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31600699

RESUMO

Ambient air contains a number of persistent organic pollutants (POPs), to which inhalation exposure has drawn worldwide concern. However, information regarding annual changes in the concentrations and health risks of POPs in the ambient air of São Paulo, Brazil, are limited. This study provides comprehensive information on annual changes in polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (DL-PCBs), and 10 groups of organochlorine pesticides (OCPs) in the ambient air of São Paulo between 2010 and 2015 based on the Global Monitoring Plan. The mass concentrations of the studied POPs (PCDD/Fs, DL-PCBs, and OCPs) showed declining trends from 2010 to 2015 (from 2.65 × 10-2 to 1.33 × 10-2 pg m-3, from 9.89 × 10-2 to 3.12 × 10-2 pg m-3, and from 0.313 to 0.100 ng m-3, respectively), which might be due to the decrease of non-intentional emissions. The carcinogenic risk (CR) and non-carcinogenic risk (Non-CR) of the studied POPs were 1.48 × 10-11 to 6.08 × 10-7 and 3.44 × 10-8 to 3.34 × 10-3, respectively, which are lower than the generally accepted threshold values (10-6/10-5 and 1 for CR and Non-CR, respectively), suggesting that the health risks posed by the studied POPs were acceptable. PCDD/Fs had the highest CR (6.08 × 10-8-4.81 × 10-7), whereas the 95th percentile CR of DL-PCBs and nine of the OCPs were lower than 10-7, suggesting that among the studied POPs, PCDD/Fs in the ambient air warrant special attention. The 95th percentile CRs of dichlorodiphenyltrichloroethane (2.30 × 10-8), dieldrin (1.30 × 10-8), hexachlorocyclohexanes (1.05 × 10-8), heptachlor (8.97 × 10-9), hexachlorobenzene (6.47 × 10-9), chlordane (5.89 × 10-9), heptachlor epoxide (1.42 × 10-9), aldrin (1.33 × 10-9), and mirex (2.71 × 10-10) in ambient air were relatively low, suggesting that their threats to human health were negligible. In general, PCDD/Fs, DL-PCBs, and OCPs in the ambient air of São Paulo did not pose serious threats to human health during 2010-2015.


Assuntos
Poluentes Atmosféricos/análise , Dibenzofuranos Policlorados/análise , Dioxinas/análise , Monitoramento Ambiental , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análise , Benzofuranos/análise , Brasil , Clordano , DDT , Dibenzofuranos/análise , Hexaclorobenzeno/análise , Hexaclorocicloexano , Humanos , Hidrocarbonetos Clorados/análise , Praguicidas/análise
20.
Ecotoxicol Environ Saf ; 184: 109615, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31518826

RESUMO

The mass concentrations, toxic equivalent quantity (TEQ) concentrations and congener profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the stack flue gas and ambient air of municipal solid waste incinerator (MSWI) were monitored in this study to evaluate the levels, emission characteristics, seasonal variation and emission sources of PCDD/Fs. Thirty-one ambient air samples were collected from four sites around MSWI during 2016-2017, and twelve stack flue gas samples were collected from one MSWI. Results showed that the PCDD/Fs concentrations of the stack flue gas ranged from 0.0077 to 0.021 ng I-TEQ/Nm3, with an average value of 0.016 ng I-TEQ/Nm3. The ambient air samples collected in 2016 and 2017 ranged from 0.017 to 0.27, and 0.035-0.27 pg I-TEQ/Nm3, with an average value of 0.078 and 0.10 pg I-TEQ/Nm3, respectively. The 2, 3, 4, 7, 8-PCDF always contributes most to toxicity both in stack flue gas and ambient air samples. PCDD/Fs in the ambient air of the study area showed significant seasonal differences, and the total concentration of PCDD/Fs was highest in winter, which was about 3.5-7.5 times that of summer. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to determine the correlation between MSWI emissions and PCDD/Fs in ambient air. It is worth mentioning that MSWI is not the main source of PCDD/Fs in ambient air.


Assuntos
Poluentes Atmosféricos/análise , Dibenzofuranos Policlorados/análise , Dibenzodioxinas Policloradas/análise , Eliminação de Resíduos/estatística & dados numéricos , Poluentes Atmosféricos/toxicidade , China , Dibenzofuranos Policlorados/toxicidade , Monitoramento Ambiental , Gases/análise , Gases/toxicidade , Incineração , Dibenzodioxinas Policloradas/toxicidade , Eliminação de Resíduos/métodos , Estações do Ano
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