RESUMO
Understanding the distribution of halogenated organic compounds (HOCs) in marine sediments is essential for understanding the marine carbon and halogen cycling, and also important for assessing the ecosystem health. In this study, a method based on combustion-ion chromatography was developed for determination of the composition and abundance of HOCs in marine sediments. The method showed high accuracy, precision and reproducibility in determining the content of adsorbable organic halogens (AOX), including fluorine, chlorine and bromine (AOF, AOCl, AOBr) and the corresponding insoluble organic halogens (IOF, IOCl, IOBr, IOX), as well as total organic halogen contents (TOX). Application of the method in coastal and deep-sea sediments revealed high ratios of organic halogens in the organic carbon pool of marine sediments, suggesting that organic halogen compounds represent an important yet previously overlooked stock of carbon and energy in marine sediments. Both the TOX and the proportion of organohalogens in organic carbon (X:C ratio) showed an increasing trend from the coast to the deep-sea sediments, indicating an increased significance of HOCs in deep-sea environments. The developed method and the findings of this study lay the foundation for further studies on biogeochemical cycling of HOCs in the ocean.
Assuntos
Monitoramento Ambiental , Sedimentos Geológicos , Poluentes Químicos da Água , Sedimentos Geológicos/química , Sedimentos Geológicos/análise , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise , Halogênios/análise , Halogênios/química , Hidrocarbonetos Halogenados/análise , Cromatografia/métodosRESUMO
The distribution of polycyclic aromatic hydrocarbons (PAHs) and halogenated PAHs (HPAHs) in surface soils from the petroleum industrial area of the Yellow River Delta (YRD) in China were investigated. The total concentrations of 16 PAHs ranged from 19.6 to 1560 ng/g, while 22 HPAHs ranged from 2.44 to 14.9 ng/g. Moreover, a high degree of spatial distribution heterogeneity was observed for both PAHs and HPAHs, which is likely attributed to the distinct industrial activities in studied area. The combustion of biomass and petroleum were identified as primary sources of soil PAHs and HPAHs in the YRD. Furthermore, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[g,h,i]perylene exhibited high ecological risks (with risk quotients of 1.47, 1.44, and 1.02, respectively) in specific sites within the YRD. Considering the high toxicity of HPAHs and their potential joint environmental effects with PAHs, continuous attention should be directed towards the environmental risks associated with both PAHs and HPAHs.
Assuntos
Monitoramento Ambiental , Hidrocarbonetos Policíclicos Aromáticos , Rios , Poluentes do Solo , Solo , Hidrocarbonetos Policíclicos Aromáticos/análise , Medição de Risco , China , Poluentes do Solo/análise , Solo/química , Rios/química , Poluentes Químicos da Água/análise , Hidrocarbonetos Halogenados/análiseRESUMO
As important chemical raw materials and organic solvents, halogenated hydrocarbons not only play an important role in economic development, but are also the main source of environmental pollution. This study proposed an improved groundwater risk assessment model system, aimed at identifying and treating contaminants at leak sites. Groundwater ubiquity score (GUS) was used to evaluate the leachability of organic pollutants. The entropy-weighted water quality index (EWQI) method was used to assess the comprehensive quality of groundwater at the site. An improved groundwater health risk assessment model was constructed to analyze the health risks of groundwater. The sources of organic pollutants were identified based on the positive matrix factorization (PMF) model. Self-organizing mapping (SOM) and the K-means algorithm were integrated to classify and manage pollution source areas. The results showed that groundwater in the study area was strongly affected by human activities. The pollution source was located in a factory near S05. Different organic pollutants were highly leachable and had high potential to contaminate surrounding groundwater. 1,2-dichloropropane and 1,2,3-trichloropropane caused the largest range of contamination. The groundwater pollution index in the study area was high, and 72% of the monitoring points were non-drinkable. Both the carcinogenic and non-carcinogenic indexes of groundwater far exceeded the international standard limits and had a great impact on human health. 1,2,3-trichloropropane and 1,2-dichloropropane were major non-carcinogenic risk factors. The leakage of pollutants and pesticide solvents were the main causes of groundwater pollution. Cluster areas III and II were areas with significant pollution impacts and needed to be monitored intensively. Most areas were cluster I, with relatively low risk. This study can provide technical support for groundwater pollution risk assessment and management in similar industrial parks.
Assuntos
Água Subterrânea , Poluentes Químicos da Água , Água Subterrânea/química , Água Subterrânea/análise , Poluentes Químicos da Água/análise , Medição de Risco , Humanos , Monitoramento Ambiental/métodos , Hidrocarbonetos Halogenados/análise , Conservação dos Recursos Naturais , Qualidade da ÁguaRESUMO
For the past few years, short-lived unsaturated halocarbons have been marketed as environmentally friendly replacements for long-lived halogenated greenhouse gases and ozone-depleting substances. The phase-in of unsaturated halocarbons for various applications, such as refrigeration and foam blowing, can be tracked by their emergence and increase in the atmosphere. We present the first atmospheric measurements of the hydrofluoroolefin (HFO) HFO-1336mzz(Z) ((Z)-1,1,1,4,4,4-hexafluoro-2-butene, cis-CF3CHâCHCF3), a newly used unsaturated hydrofluorocarbon. HFO-1336mzz(Z) has been detected in >90% of all measurements since 2018 during multi-month campaigns at three Swiss and one Dutch location. Since 2019, it is found in â¼30% of all measurements that run continuously at the Swiss high-altitude Jungfraujoch station. During pollution events, mole fractions of up to â¼10 ppt were observed. Based on our measurements, Swiss and Dutch emissions were estimated at 2-7 Mg yr-1 (2019-2021) and 30 Mg yr-1 (2022), respectively. Modeled spatial emission distributions only partly conform to population density in both countries. Monitoring the presence of new unsaturated halocarbons in the atmosphere is crucial since long-term effects of their degradation products are still debated. Furthermore, the production of HFOs involves climate-active substances, which may leak to the atmosphereâin the case of HFO-1336mzz(Z), for example, the ozone-depleting CFC-113a (CF3CCl3).
Assuntos
Gases de Efeito Estufa , Hidrocarbonetos Halogenados , Ozônio , Hidrocarbonetos Halogenados/análise , Monitoramento Ambiental , AtmosferaRESUMO
Despite being regulated globally for almost three decades, halocarbon continues to play a vital role in climate change and ozone layer because of its long lifetime in the ambient air. In recent years, unexpected halocarbon emissions have been found in Asia, raising concerns about ozone recovery. As a number of studies focused on halocarbon variations and source profiles, there is an increasing need to identify halocarbon source origins. In this study, an eight-month regular air sampling was conducted at a coastal site in Hong Kong from November 2020 to June 2021, and seventeen halocarbon species were selected for extensive investigation after advanced sample analysis in our laboratory. The temporal variations of halocarbon mixing ratio enhancements were analyzed, and the spatial variations of source origins were investigated by wind sectors and backward trajectory statistics. Our results indicate lower enhancements beyond the background values for major regulated CFCs and CCl4 than later controlled HCFCs and HFCs, suggesting the greater progress of Montreal Protocol implementation for the former species. The notable high enhancement values of non-regulated halocarbons from the north direction indicate their widespread usage in China. The source apportionment analysis estimates the contributions from six emission sectors on measured halocarbons, including solvent usage (43.57 ± 4.08 %), refrigerant residues (17.05 ± 5.71 %), cleaning agent/chemical production (13.18 ± 4.76 %), refrigerant replacements (13.06 ± 2.13 %), solvent residues (8.65 ± 3.28 %), and foaming agent (4.49 ± 1.08 %). Trajectories statistical analysis suggests that industrial solvent was mainly contributed by eastern China (i.e., Shandong and YRD), cleaning agent/chemical production was spread over southeast China (i.e., YRD and Fujian), and refrigeration replacements were dominant in Hong Kong surrounding regions. This work provides insight into the progress made in implementing the Montreal Protocol in Hong Kong and the surrounding region and the importance of continuous emission control.
Assuntos
Poluentes Atmosféricos , Hidrocarbonetos Halogenados , Hidrocarbonetos Halogenados/análise , Hong Kong , Poluentes Atmosféricos/análise , China , Solventes/análise , Monitoramento Ambiental/métodos , Emissões de Veículos/análiseRESUMO
Volatile organic compound (VOCs) emissions from poultry and livestock facilities affect the surrounding environmental quality and human health. However, VOCs emissions from broiler houses have been less characterized, and studies of related dominant odorants, carcinogenic risk, and ozone formation potential are still lacking. To fill this research gap, VOCs pollutants emitted from a broiler house were investigated in this study. The VOCs emission characteristics of the broiler house during three different periods of broiler growth (early, middle, and later) were analyzed using gas chromatography-mass spectrometry. The results showed that 77 types of VOCs were detected, including 16 types of halogenated hydrocarbons, 21 types of alkanes, 5 types of olefins, 12 types of aromatic hydrocarbons, 15 types of oxygenated volatile organic compounds (OVOCs), and 8 types of sulfides. During the entire 42-day growth period, the concentrations of halogenated hydrocarbons, alkanes, olefin, aromatic hydrocarbons, and OVOCs in the broiler house showed few changes. However, with the growth of broilers, the intake of sulfur-containing amino acids and the fecal emission coefficient increased, resulting in the gradual conversion of the VOCs to sulfide. Therefore, emissions of sulfur-containing VOCs increased in the early and middle growth periods. Moreover, the increase in ventilation in the house during the later growth period resulted in a decrease in the sulfur-containing VOCs concentrations. The dominant odorants in the broiler house were naphthalene, ethyl acetate, acetaldehyde, carbon disulfide, dimethyl disulfide, methanethiol, methanethiol, and thiophene. Methanethiol had the highest odorous values, ranging from 2172.4 to 19090.9. Meanwhile, there were acceptable levels of carcinogenic risk in the early and middle growth periods, with a lifetime cancer risk (LCR) of 7.7×10-6 and 4.5×10-6, respectively. The average ozone formation potential (OFP) was (1458.9±787.4) µg·m-3. The results of this study can provide a scientific basis for the monitoring of malodorous substances and formulation of emission reduction strategies in broiler production.
Assuntos
Poluentes Atmosféricos , Dissulfeto de Carbono , Hidrocarbonetos Aromáticos , Hidrocarbonetos Halogenados , Ozônio , Compostos Orgânicos Voláteis , Acetaldeído/análise , Poluentes Atmosféricos/análise , Alcanos/análise , Alcenos/análise , Aminoácidos , Animais , Dissulfeto de Carbono/análise , Galinhas , China , Monitoramento Ambiental , Humanos , Hidrocarbonetos Aromáticos/análise , Hidrocarbonetos Halogenados/análise , Naftalenos , Ozônio/análise , Compostos de Sulfidrila , Enxofre/análise , Tiofenos/análise , Emissões de Veículos/análise , Compostos Orgânicos Voláteis/análiseRESUMO
The oceanic production and release of volatile halocarbons (VHCs) to the atmosphere play a vital role in regulating the global climate. In this study, seasonal and spatial variations in VHCs, including trichlorofluoromethane (CFC-11), methyl iodide (CH3I), dibromomethane (CH2Br2), and bromoform (CHBr3), and environmental parameters affecting their concentrations were characterized in the atmosphere and seawater of the Yangtze River Estuary and its adjacent marine area during two cruises from October 17 to October 26, 2019 and from May 12 to May 25, 2020. Significant seasonal variations were observed in the atmosphere and seawater because of seasonal differences in the prevalent monsoon, water mass (Yangtze River Diluted Water), and biogenic production. VHCs concentrations were positively correlated with Chl-a concentrations in the surface water during autumn. The average sea-to-air fluxes of CH3I, CH2Br2, and CHBr3 in autumn were 19.7, 4.0, and 7.6 nmol m-2 d-1, respectively, while those in spring were 6.3, 6.4, and -3.6 nmol m-2 d-1. In the ship-based incubation experiments, ocean acidification and dust deposition had no significant effects on VHCs concentrations. The concentrations of CH2Br2 and CHBr3 were significantly positively correlated with phytoplankton biomass under lower pH condition (M3: pH 7.9). This result indicated that CH2Br2 and CHBr3 concentrations were mainly related to the biological release.
Assuntos
Estuários , Hidrocarbonetos Halogenados , China , Monitoramento Ambiental , Hidrocarbonetos Halogenados/análise , Concentração de Íons de Hidrogênio , Rios/química , Estações do Ano , Água do Mar/química , ÁguaRESUMO
During chlorination of seawater, the presence of bromide and ammonia alters the speciation of the oxidant and lead to the formation of chlorinated and brominated amines. This can affect the effectiveness of the disinfection treatment and the formation of disinfection by-products released to the environment. In this study, a Membrane Introduction Mass Spectrometry (MIMS) analytical method was developed to differentiate brominated trihalamines (i.e. tribromamine NBr3, dibromochloramine NBr2Cl and bromodichloramine NBrCl2) in synthetic and natural chlorinated seawater. A mass-to-charge ratio of m/z = 253 corresponding to the parent ion was used for the quantification of NBr3 in absence of organic matter and the signal of the fragment at m/z = 177 was chosen in presence of high concentration of organic matter. Limits of detection were 0.23 µM (49 µg Cl2/L) and 0.18 µM (38 µg Cl2/L) for m/z 253 and m/z 177, respectively. Both NBr2Cl and NBrCl2 were monitored in chlorinated seawaters with their respective parent ion at m/z = 207 and m/z = 163 but were not quantified. MIMS results also showed that reaction of brominated trihalamines with natural organic matter (NOM) was a minor pathway for 1-2 mg C/L compared to their auto-decomposition in natural or synthetic seawater. Overall, MIMS was able to unambiguously differentiate and monitor brominated trihalamines for the first time in chlorinated seawater, which was not possible by using UV measurement, titration and colorimetric methods.
Assuntos
Desinfetantes , Hidrocarbonetos Halogenados , Poluentes Químicos da Água , Purificação da Água , Aminas , Desinfecção/métodos , Halogenação , Hidrocarbonetos Halogenados/análise , Espectrometria de Massas , Água do Mar , Poluentes Químicos da Água/análise , Purificação da Água/métodosRESUMO
Volatile halogenated hydrocarbons (VHCs) attracted many attentions due to its toxicity and persistence in the environment. In this research, a novel in situ ecological restoration reactor was applied to the degradation of VHCs in polluted river water. The optimized working condition adaptation of the in situ restoration technique was evaluated through orthogonal tests. The experiments showed that when the water depth was 0.4 m, the HRT was 5 days, and the current velocity was 1 m/s, the optimal removal efficiency of VHCs in the reactor was achieved. And the removal rates of CHCl3, CCl4, C2HCl3, and C2Cl4 reached 70.27%, 70.59%, 67.74%, and 81.82%, respectively. The results showed that both HRT and water depth were significantly related to the removal efficiency of reactor. The physiological state of the plants was analyzed by fitting rapid light curve (RLC) model, which showed that the accumulation of VHCs inhibited the photosynthetic performance of plants. Moreover, the microbial community structures of fillers were tested by high-throughput sequencing, and the findings supported that the microbial community made a great response to adapt to the changes in environment of the reactor. The relative abundance of Rhodocyclaceae increased slightly, which hinted that it had good adaptability to VHCs in polluted river water. The research results confirmed that in situ ecological restoration reactor was a potential approach for removal VHCs in polluted river water.
Assuntos
Hidrocarbonetos Halogenados , Microbiota , Fluorescência , Hidrocarbonetos Halogenados/análise , Rios , ÁguaRESUMO
CVD 103-HgR live, attenuated oral cholera vaccine strain is indicated for single dose immunization against Vibrio cholerae, the causative agent for cholera. The vaccine packets containing buffer powder and lyophilized CVD 103-HgR are reconstituted in water and consumed. Studies were performed to explore the viability of CVD 103-HgR in drinking waters from common sources. CVD 103-HgR vaccine was reconstituted in bottled and tap waters from the United States and Europe, and viability was measured via colony forming units assay. Chemical analysis of select water samples was used to identify chemicals that have a negative effect on CVD 103-HgR viability. CVD 103-HgR titers were stable in all bottled waters tested, including purified bottled water, bottled spring water, and sparkling waters. However, tap water from certain cities in the US and Europe affected viability and are not compatible with vaccine. Water chemistry revealed that these tap waters contained copper, likely leached from copper plumbing. These studies give high confidence in the stability of CVD 103-HgR reconstituted in a variety of bottled waters. Waters containing copper, including tap water, should not be used to reconstitute CVD 103-HgR strain oral vaccine due to the common use of copper plumbing.
Assuntos
Vacinas contra Cólera , Água Potável/microbiologia , Vibrio cholerae/fisiologia , Carga Bacteriana , Cloro/análise , Cobre/análise , Água Potável/química , Europa (Continente) , Fluoretos/análise , Hidrocarbonetos Halogenados/análise , Engenharia Sanitária , Trialometanos/análise , Estados Unidos , Vacinas Atenuadas , Vibrio cholerae/efeitos dos fármacos , Vibrio cholerae/isolamento & purificação , Purificação da ÁguaRESUMO
Due to the characteristics of ozone-depleting and high global warming potential, chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) have been restricted by the Montreal Protocol and its amendments over the world. Considering that China is one of the main contributors to the emission of halocarbons, a long-term atmospheric observation on major substances including CFC-11 (CCl3F), CFC-12 (CCl2F2), HCFC-22 (CHClF2), HCFC-141b (CH3CCl2F), HCFC-142b (CH3CClF2) and HFC-134a (CH2FCF3) was conducted in five cities (Beijing, Hangzhou, Guangzhou, Lanzhou and Chengdu) of China during 2009-2019. The atmospheric concentrations of CFC-11, CFC-12, HCFC-141b and HCFC-142b all showed declining trends on the whole while those of HCFC-22 and HFC-134a were opposite. A paired sample t-test showed that the ambient mixing ratios of HCFC-22 and HFC-134a in cities were 41.9% and 25.7% higher on average than those in suburban areas, respectively, while the other substances did not show significant regional differences. The annual emissions of halocarbons were calculated using an interspecies correlation method and the results were generally consistent with the published estimates. Discrepancies between bottom-up inventories and the estimates in this study for CFCs emissions were found. Among the most consumed ozone depleting substances (ODSs) in China, CFCs accounted for 75.1% of the ozone depletion potential (ODP)-weighted emissions while HCFCs contributed a larger proportion (58.6%) of CO2-equivalent emissions in 2019. China's emissions of HCFC-141b and HCFC-142b contributed the most to the global emission (17.8%-48.0%). The elimination of HCFCs in China will have a crucial impact on the HCFCs phase-out in the world.
Assuntos
Hidrocarbonetos Halogenados , Pequim , China , Clorofluorcarbonetos/análise , Aquecimento Global , Hidrocarbonetos Halogenados/análiseRESUMO
The high-concentration wastewater produced in the industrial reverse osmosis (RO) process contains a large amount of refractory organic matters, which will have serious impacts on the natural environment and human health. Among them, contaminants can be transformed by humus-reducing bacteria based on humus. In this study, O3- assisted UV-Fenton method was applied as pretreatment. Biological activated carbon (BAC) technology in which humus-reducing bacteria were the dominant bacteria, enhanced by electron donor and Fe3+, was used to dispose of RO concentrate (ROC). The results showed that water treatment process combining oxidation with biological filtration had a positive effect on the removal of stubborn contaminants in ROC. The system was strengthened by adding electron donor and Fe3+, and the chemical oxygen demand (COD) removal efficiency was up to 80.1%. However, when the removal efficiency of UV254 absorbing pollutants reached optimal value (87.3%), that means only Fe3+ was added.
Assuntos
Carvão Vegetal/análise , Compostos Férricos/química , Substâncias Húmicas , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Análise da Demanda Biológica de Oxigênio , Filtração/métodos , Substâncias Húmicas/análise , Substâncias Húmicas/microbiologia , Hidrocarbonetos Halogenados/análise , Peróxido de Hidrogênio/química , Ferro/química , Osmose , Oxirredução , Ozônio/química , Raios Ultravioleta , Águas Residuárias/análise , Águas Residuárias/microbiologiaRESUMO
Halogenated natural products (HNPs) and persistent organic pollutants (POPs) were quantified in South African sardines (Sardinops sagax) from one site in the South Atlantic Ocean and one in the Indian Ocean. At both sites, HNPs [2,3,3',4,4',5,5'-heptachloro-1'-methyl-1,2'-bipyrrole (Q1), mixed halogenated compound 1 (MHC-1), 2,4,6-tribromoanisole (2,4,6-TBA), 2'-MeO-BDE 68 (BC-2), and 6-MeO-BDE 47 (BC-3)] were 1 order of magnitude higher concentrated than anthropogenic POPs [mainly polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT), â¼3 ng/g lipids]. MHC-1 and Q1 were the major HNPs in the samples from both sites, contributing with up to 49 and 52 ng/g lipids, respectively. The same 1,1-dichloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDE)/PCB ratio suggested that the major POPs were evenly distributed at both sites. Different ratios of Q1/MHC-1 in the samples from the Indian (â¼2:1) and South Atlantic (â¼1:1) Oceans indicated that the occurrence of HNPs in seafood is difficult to predict and should be investigated more in detail. The PCB levels in sardines were found to pose no risk to human consumers, whereas HNPs could not be evaluated because of the lack of toxicological data.
Assuntos
Peixes/metabolismo , Contaminação de Alimentos/análise , Hidrocarbonetos Halogenados/análise , Alimentos Marinhos/análise , Poluentes Químicos da Água/análise , Animais , Oceano Atlântico , Hidrocarbonetos Halogenados/metabolismo , Oceano Índico , Poluentes Químicos da Água/metabolismoRESUMO
Since many household products used by individuals contain flame retardants (FRs), there is more chance that these chemicals may be present in the various exhibit of the indoor environment. Despite being one of the fastest-growing economies worldwide, the contamination level, sources, products, and pathways of FRs in India, is either not known or limited. This inspired us to investigate the level, profile, spatial distribution, and sources of different classes of FRs in the indoor air. For this purpose, 15 brominated, 2 chlorinated, and 8 organophosphate FRs (OPFRs) were investigated in indoor air samples from urban and suburban sites of an Indian state of Bihar. Additionally, inhalation health risk exposure to children and the adult was estimated to predict the risk of these chemicals. Overall, ∑8OPFRs (median 351 pg/m3) was the most prominent in air, followed by novel brominated FR (∑6NBFRs) (median 278 pg/m3), polybrominated diphenyl ether (∑9PBDE) (median 5.05 pg/m3), and dechlorane plus (∑2DPs) (median 2.52 pg/m3), and accounted for 55%, 44%, 0.8% and 0.4% of ∑FRs, respectively. Generally, ∑9PBDEs (median 6.29 pg/m3) and ∑8OPFRs (median 355 pg/m3) were measured high at sub-urban sites, while urban sites had the highest level of ∑2DPs (median 2.81 pg/m3) and ∑6NBFRs (median 740 pg/m3). BDE-209 was most abundant among ∑9PBDEs, while syn-DP dominated in ∑2DPs. Likewise, DBDPE was most prevalent in ∑6NBFRs, while TMPP topped among ∑8OPFRs. The principal component analysis revealed contribution from household items, food packaging and paints, hydraulic fluid, a gasoline additive, and de-bromination of BDE-209 as the primary sources of FRs. The estimated daily inhalation exposure (DIE) indicated a relatively high risk to children than the adult. The DIE of individual FR was several folds lower than their corresponding oral reference dose (RfDs), suggesting minimal risk. However, exposure risk, especially to children, may still need attention because other routes of intake may always be significant in the case of Bihar.
Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Retardadores de Chama/análise , Hidrocarbonetos Halogenados/análise , Exposição por Inalação/análise , Organofosfatos/análise , Humanos , Hidrocarbonetos Halogenados/química , Índia , Organofosfatos/química , Análise de Componente Principal , Medição de RiscoRESUMO
BACKGROUND: The aim of this study was to characterize solid particulate aerosol derived from a cutlery microenterprise and to investigate substances associated with activities performed within the work environment. OBJECTIVE: Suspended particulate matter (SPM) was collected at different locations in the cutlery workshop and near machines used by workers, using passive sampling devices fitted with polytetrafluoroethylene filters, onto which total particulate material was deposited. The substances present in the SPM were analyzed using gas chromatography-mass spectrometry (GC-MS). RESULTS: Identification of the substances was performed using the National Institute of Standards (NIST) library and automated mass spectral deconvolution and identification system. (AMDIS) software, considering at least 70% probability. The concentration of total dust, obtained using a gravimetric method, was approximately 1âmg.m-3. CONCLUSION: The toxic substances found in the SPM included halogenated hydrocarbons (containing chlorine, fluorine, and iodine) and aromatic hydrocarbons. The toxic substances included naphthalene, which is classified as carcinogenic.
Assuntos
Hidrocarbonetos Aromáticos/análise , Hidrocarbonetos Halogenados/análise , Material Particulado/análise , Poluentes Ocupacionais do Ar/análise , Brasil , Cromatografia Gasosa-Espectrometria de Massas , Utensílios Domésticos , Naftalenos/análise , Empresa de Pequeno PorteRESUMO
BACKGROUND: The effect of oxygen on markers of oxidative stress has not been totally elucidated because previous studies have yielded conflicting results. METHODS: A method for the collection and gas chromatography-mass spectrometry of the halogenated volatile organic compounds in human alveolar breath is described. A transportable apparatus sampled specifically alveolar breath; the volatile organic compounds were captured in a thermal desorption tube, Carbotrap 200®. The sample was thermally desorbed from the trap in an automated gas chromatography with mass spectrometry detection and peak fragmentation. Compounds were identified by reference to a computer-based library of mass spectra. RESULTS: Trichlorotrifluoroethane, tetrafluoroethane, dichlorodifluoromethane were identified in alveolar breath of healthy volunteers after mental exercise-induced oxidative stress. The effects of halogenated alkanes were investigated on electron transport chain activity. These agents impaired the NADH oxidation suggesting an inhibition of the complex I (NADH: ubiquinone oxidoreductase) of the electron transport chain. These inhibitory effects are suspected likely to fight against oxidative stress deleterious reactions. CONCLUSION: Chemical inhibition of the oxidative burst in human body trough these halogenated inhibitors is a new concept of significant practical, medical, biological and scientific interest.
Assuntos
Testes Respiratórios/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Hidrocarbonetos Halogenados/análise , Estresse Oxidativo , Alvéolos Pulmonares/metabolismo , Pensamento , Compostos Orgânicos Voláteis/análise , Alcanos/análise , Testes Respiratórios/instrumentação , Complexo I de Transporte de Elétrons/metabolismo , Cromatografia Gasosa-Espectrometria de Massas/instrumentação , Humanos , Mitocôndrias/metabolismo , Células U937RESUMO
Post-operative isoflurane has been observed to be present in the end-tidal breath of patients who have undergone major surgery, for several weeks after the surgical procedures. A major new non-controlled, non-randomized, and open-label approved study will recruit patients undergoing various surgeries under different inhalation anaesthetics, with two key objectives, namely (1) to record the washout characteristics following surgery, and (2) to investigate the influence of a patient's health and the duration and type of surgery on elimination. In preparation for this breath study using proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS), it is important to identify first the analytical product ions that need to be monitored and under what operating conditions. In this first paper of this new research programme, we present extensive PTR-TOF-MS studies of three major anaesthetics used worldwide, desflurane (CF3CHFOCHF2), sevoflurane ((CF3)2CHOCH2F), and isoflurane (CF3CHClOCHF2) and a fourth one, which is used less extensively, enflurane (CHF2OCF2CHFCl), but is of interest because it is an isomer of isoflurane. Product ions are identified as a function of reduced electric field (E/N) over the range of approximately 80 Td to 210 Td, and the effects of operating the drift tube under 'normal' or 'humid' conditions on the intensities of the product ions are presented. To aid in the analyses, density functional theory (DFT) calculations of the proton affinities and the gas-phase basicities of the anaesthetics have been determined. Calculated energies for the ion-molecule reaction pathways leading to key product ions, identified as ideal for monitoring the inhalation anaesthetics in breath with a high sensitivity and selectivity, are also presented.
Assuntos
Anestésicos Inalatórios/análise , Testes Respiratórios/métodos , Hidrocarbonetos Halogenados/análise , Espectrometria de Massas/métodos , Prótons , Compostos Orgânicos Voláteis/análise , Teoria da Densidade Funcional , Desflurano/análise , Eletricidade , Feminino , Humanos , Íons , Isoflurano/análise , Masculino , Sevoflurano/análise , Processamento de Sinais Assistido por ComputadorRESUMO
The reduction of halocarbons by NADH models and NADH under ambient conditions is reported as a new type of reactivity pointing towards a hitherto unknown disruptive pathway for NADH/NADPH-dependent processes. The reaction was studied with the omnipresent pesticide DDT, the inhalation anesthetic halothane, and several simple halocarbons. The halide-hydride exchange represents a biochemical equivalent for the reduction of halocarbons by traditional synthetic reagents like silanes (R3Si-H) and stannanes (R3Sn-H). High precision thermochemical calculations (CBS-QB3) reveal the carbon-hydrogen bond dissociation energy of NADH (70.8â¯kcal·mol-1) to be lower than that of stannane (SnH4: 78.1â¯kcal·mol-1), approaching that of the elusive plumbane (PbH4: 68.9â¯kcal·mol-1). The ready synthetic accessibility of NADH models, their low carbon-hydrogen bond dissociation energy, and their dehalogenation activity in the presence of air and moisture recommend these compounds as substitutes for the air-sensitive or toxic metal hydrides currently employed in synthesis.
Assuntos
DDT/metabolismo , Poluentes Ambientais/metabolismo , Recuperação e Remediação Ambiental/métodos , Halotano/metabolismo , Hidrocarbonetos Halogenados/análise , Hidrocarbonetos Halogenados/metabolismo , NAD/metabolismo , Carbono/química , Hidrogênio/química , Ligação de Hidrogênio , Indicadores e Reagentes , Silanos/química , Compostos de Estanho/químicaRESUMO
In the past few years, polyhalogenated carbazoles (PHCZs) have been of increasing concern because their structure is similar to that of legacy POPs. In the present study, an analytical method, including intensive cleanup and fractionation procedures in combination with instrumental parameters, was developed to determine ultratrace polyhalogenated carbazoles (PHCZs) in soil and sediment. The eluting sorbents, volume and packing of the column were optimized. Our results showed that 5â¯g of florisil and 4â¯g of silica gel under 150â¯mL of hexane/DCMâ¯=â¯3:1 presented good performance in terms of recovery and repeatability. GC-HRMS, GC-MS/MS (EI-MRM) and GC-MS (EI-SIM) were applied to compare the performance of PHCZ analysis. For sensitivity, EI-MRM presents method detection limits comparable to those of GC-HRMS and much lower than those of EI-SIM. Regarding selectivity, GC-HRMS performed better than the other two techniques since GC-HRMS can reduce interference from perfluorokerosene (PFK) and DDX (DDT, DDE, and DDD) due to its high resolution. GC-HRMS was then further optimized by shortening the run time and modifying the SIM ion. The final method was successfully applied to determine PHCZs in soil and sediment, and the target compounds had almost 100% detection frequency in the samples. The ubiquitous presence of PHCZ in soil and sediment calls for a further investigation of its source, distribution and degradation in the environment.
Assuntos
Carbazóis/análise , Recuperação e Remediação Ambiental/métodos , Sedimentos Geológicos/química , Hidrocarbonetos Halogenados/análise , Poluentes do Solo/análise , Solo/química , Cromatografia Gasosa-Espectrometria de Massas , Hexanos/química , Limite de Detecção , Silicatos de Magnésio/química , Dióxido de Silício/química , Espectrometria de Massas em TandemRESUMO
The exposure to several compounds such as polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), organophosphorus pesticides (OPs), polycyclic aromatic hydrocarbon (PAHs), perfluoroalkyl substances (PFASs) and polybrominated diphenyl ethers (PBDEs) is a public health issue. The European Union (EU) recommended that its member states monitor the presence of emerging contaminants, like PBDEs and PFASs, in food and in the environment to obtain an accurate estimation of exposure. The tissues of wild animals exposed to these compounds can represent a suitable indicator of environmental pollution. The aim of this work is to evaluate: (i) the occurrence of PCBs, PBDEs, PFASs, PAHs, OCPs and OPs in four game animals' meat (chamois, red deer, wild boar and roe deer); (ii) interspecies differences and (iii) human exposure. Muscle samples from seventy-nine animals were collected during the hunting season in a Northern Italy mountain area at altitudes ranging from 300 to 2500 meters above sea level. The analyses were performed with gas chromatography-mass spectrometry (GC-MS/MS) and ultra-performance liquid chromatography - tandem mass spectrometry (UHPLC-MS/MS). No PBDEs were found in the samples. OCPs, OPs and PCBs were detected in almost all samples at different concentration ranges, showing higher frequency in ungulate species than in wild boar. PFAs were found only in wild boar. Anthracene and benzopyrene, among PAHs, were found only in chamois, at low concentrations. The lack of an accurate pattern of exposure as well as variable consumption by hunters does not allow accurate risk characterisation. However, a low risk for consumers can be indicated due to the frequent detection of contaminants only at trace levels, the scarce prevalence of high concentrations of some contaminants and the low consumption of game animal meat. In conclusion, the organisation of a control plan on residues in game animals would be advisable.