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1.
Sci Total Environ ; 750: 142183, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33182173

RESUMO

To evaluate the transboundary pollution of organic aerosols from Northeast Asia, a highly time-resolved measurement of organic compounds was performed in March 2019 at Oki Island located in Japan, which is a remote site and less affected by local anthropogenic sources. PM2.5, water-soluble organic carbon (WSOC) concentrations, and WSOC fraction in PM2.5 showed high values on March 22-23 (high-WSOC period (HWSOC)) when the air mass passed through the area where many fire spots were detected in Northeast China. Biomass burning tracers showed higher concentration, especially levoglucosan exceeded 1 µg/m3 during the HWSOC than the low-WSOC period (LWSOC). Notably, high time-resolved measurements of biomass burning tracers and back trajectory analysis during HWSOC revealed a difference in the variation of lignin pyrolyzed compounds and anhydrous sugars on 22 and 23 March. The air mass passed to different areas in Northeast China in which fire spots were detected, such as the eastern area on the 22nd and the western area on the 23rd. Almost-organic compounds also showed high concentration and strong correlations with levoglucosan and sulfate during HWSOC. Moreover, low-carbon dicarboxylic acids (e.g., adipic acid) and secondary products from anthropogenic volatile organic compounds (e.g., 2,3-dihydroxy-4-oxopentanoic, phthalic, 5-nitrosalicylic acids), also showed a strong correlation with sulfate ions during the HWSOC and LWSOC, respectively. These higher concentrations and strong correlations with levoglucosan and sulfate during the HWSOC propose that their generation could be enhanced by biomass burning. The ratios of organics (e.g., levoglucosan/mannnosan, pinic/3-methylbutane-1,2,3-tricarboxylic acids) suggest that the high concentrations of PM2.5 and WSOC observed during the HWSOC were caused by aged organic aerosols that originated from the combustion of herbaceous plants transported from Northeast China. Our findings indicate that biomass combustion in Northeast China could significantly affect the chemical compositions and the characterization of organic aerosols in downwind regions of Northeast China.


Assuntos
Poluentes Atmosféricos , Material Particulado , Aerossóis/análise , Poluentes Atmosféricos/análise , Biomassa , Carbono/análise , China , Monitoramento Ambiental , Ilhas , Japão , Material Particulado/análise , Estações do Ano
2.
J Environ Sci (China) ; 99: 196-209, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33183697

RESUMO

The submicron particulate matter (PM1) and fine particulate matter (PM2.5) are very important due to their greater adverse impacts on the natural environment and human health. In this study, the daily PM1 and PM2.5 samples were collected during early summer 2018 at a sub-urban site in the urban-industrial port city of Tianjin, China. The collected samples were analyzed for the carbonaceous fractions, inorganic ions, elemental species, and specific marker sugar species. The chemical characterization of PM1 and PM2.5 was based on their concentrations, compositions, and characteristic ratios (PM1/PM2.5, AE/CE, NO3-/SO42-, OC/EC, SOC/OC, OM/TCA, K+/EC, levoglucosan/K+, V/Cu, and V/Ni). The average concentrations of PM1 and PM2.5 were 32.4 µg/m3 and 53.3 µg/m3, and PM1 constituted 63% of PM2.5 on average. The source apportionment of PM1 and PM2.5 by positive matrix factorization (PMF) model indicated the main sources of secondary aerosols (25% and 34%), biomass burning (17% and 20%), traffic emission (20% and 14%), and coal combustion (17% and 14%). The biomass burning factor involved agricultural fertilization and waste incineration. The biomass burning and primary biogenic contributions were determined by specific marker sugar species. The anthropogenic sources (combustion, secondary particle formation, etc) contributed significantly to PM1 and PM2.5, and the natural sources were more evident in PM2.5. This work significantly contributes to the chemical characterization and source apportionment of PM1 and PM2.5 in near-port cities influenced by the diverse sources.


Assuntos
Poluentes Atmosféricos , Aerossóis/análise , Poluentes Atmosféricos/análise , Biomassa , China , Cidades , Monitoramento Ambiental , Humanos , Material Particulado/análise , Estações do Ano , Emissões de Veículos/análise
3.
J Environ Sci (China) ; 99: 222-238, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33183700

RESUMO

PM10 samples were collected from an urban/industrial site nearby Athens, where uncontrolled burning activities occur. PAHs, monocarboxylic, dicarboxylic, hydroxycarboxylic and aromatic acids, tracers from BVOC oxidation, biomass burning tracers and bisphenol A were determined. PAH, monocarboxylic acids, biomass burning tracers and bisphenol A were increased during autumn/winter, while BSOA tracers, dicarboxylic- and hydroxycarboxylic acids during summer. Regarding aromatic acids, different sources and formation mechanisms were indicated as benzoic, phthalic and trimellitic acids were peaked during summer whereas p-toluic, isophthalic and terephthalic were more abundant during autumn/winter. The Benzo[a]pyrene-equivalent carcinogenic power, carcinogenic and mutagenic activities were calculated showing significant (p < 0.05) increases during the colder months. Palmitic, succinic and malic acids were the most abundant monocarboxylic, dicarboxylic and hydrocarboxylic acids during the entire sampling period. Isoprene oxidation was the most significant contributor to BSOA as the isoprene-SOA compounds were two times more abundant than the pinene-SOA (13.4 ± 12.3 and 6.1 ± 2.9 ng/m3, respectively). Ozone has significant impact on the formation of many studied compounds showing significant correlations with: isoprene-SOA (r = 0.77), hydrocarboxylic acids (r = 0.69), pinene-SOA (r = 0.63),dicarboxylic acids (r = 0.58), and the sum of phthalic, benzoic and trimellitic acids (r = 0.44). PCA demonstrated five factors that could explain sources including plastic enriched waste burning (30.8%), oxidation of unsaturated fatty acids (23.0%), vehicle missions and cooking (9.2%), biomass burning (7.7%) and oxidation of VOCs (5.8%). The results highlight the significant contribution of plastic waste uncontrolled burning to the overall air quality degradation.


Assuntos
Poluentes Atmosféricos , Material Particulado , Aerossóis/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Material Particulado/análise , Plásticos , Estações do Ano
4.
J Environ Sci (China) ; 99: 28-39, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33183707

RESUMO

This study finds out seasonal and monthly variations in Aerosol Optical Depth (AOD) over eastern and western routes of China Pakistan Economic Corridor (CPEC) and the relationship between AOD and meteorological parameters (i.e., temperature, rainfall and wind speed). The Moderate Resolution Imaging Spectroradiometer (MODIS) and Multi-angle Imaging Spectroradiometer (MISR) data was used from the terra satellite for the period of 2000-2016. This study aims to overtake the conventional view of the purpose of using the satellite datasets. This study takes on to the concept that validated satellite data sets rather should be used for the analysis instead of just validation specifically for our study region. Hence, after comparing MODIS AOD with MISR AOD, only MISR AOD dataset is used for further analysis. The results show a decreasing trend of AOD in summer season, a positive relationship between temperature and AOD during winter and spring seasons whereas a positive relationship between wind speed and AOD in winter and spring seasons over eastern and western routes. Periodic analysis of MODIS AOD and MISR AOD depicts May-Aug as the peak period of aerosol concentration over central Pakistan. The inter-annual analysis shows the aerosol trend remained higher during summer season however rainfall shows the washout effect. Eastern route has higher standard deviation and larger values for aerosol prevalence as compared to western route. The trajectory analysis using the HYSPLIT model suggests the bias of air mass trajectory caused deviation in the aerosol trend in the year 2014.


Assuntos
Poluentes Atmosféricos , Aerossóis/análise , Poluentes Atmosféricos/análise , China , Monitoramento Ambiental , Paquistão
5.
J Environ Sci (China) ; 99: 311-323, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33183710

RESUMO

Photochemical aging of volatile organic compounds (VOCs) in the atmosphere is an important source of secondary organic aerosol (SOA). To evaluate the formation potential of SOA at an urban site in Lyon (France), an outdoor experiment using a Potential Aerosol Mass (PAM) oxidation flow reactor (OFR) was conducted throughout entire days during January-February 2017. Diurnal variation of SOA formations and their correlation with OH radical exposure (OHexp), ambient pollutants (VOCs and particulate matters, PM), Relative Humidity (RH), and temperature were explored in this study. Ambient urban air was exposed to high concentration of OH radicals with OHexp in range of (0.2-1.2)×1012 molecule/(cm3•sec), corresponding to several days to weeks of equivalent atmospheric photochemical aging. The results informed that urban air at Lyon has high potency to contribute to SOA, and these SOA productions were favored from OH radical photochemical oxidation rather than via ozonolysis. Maximum SOA formation (36 µg/m3) was obtained at OHexp of about 7.4 × 1011molecule/(cm3•sec), equivalent to approximately 5 days of atmospheric oxidation. The correlation between SOA formation and ambient environment conditions (RH & temperature, VOCs and PM) was observed. It was the first time to estimate SOA formation potential from ambient air over a long period in urban environment of Lyon.


Assuntos
Poluentes Atmosféricos , Aerossóis/análise , Poluentes Atmosféricos/análise , França , Material Particulado , Fotoquímica
6.
Chemosphere ; 262: 127842, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32799146

RESUMO

New Particle Formation (NPF) refers to transformation of gaseous precursors in the atmosphere due to nucleation and subsequent growth process through physicochemical interaction. It has generated a lot of interest due to its profound impact on global and regional environment, climate and human health. We reviewed the studies on NPF in three city clusters of China: the North China Plain, the Yangtze River Delta and the Pearl River Delta obtained through experiment simulations (e.g., chamber simulation, flow-tube simulation, etc.), field observations, and numerical simulations. Due to its atmospheric background pollution and strong oxidation capacities resulting in high source rate of precursors, China's atmosphere possesses challenges different from those evaluated in previous studies on cleaning sites and other developing countries. Hence, NPF events can simultaneously exhibit high condensable sink, formation rate and growth rate. In addition, the high intensity of anthropogenic emissions in urban China has led to greater diversity of pollutant species involved in NPF nucleation and subsequent growth, compared to the dominant role of biogenic precursors at cleaning sites. Differences in geographical location and industrial structure also lead to significant distinctions in NPF characteristics of the three city clusters. Consequently, the lack of understanding of nucleation mechanism of complexly polluted background sites makes the global and regional climate models with submodels based on clean background have enormous uncertainty when applied to urban China. The establishment of a mature research ecosystem including field observations, laboratory simulations and numerical simulations is the key to the breakthrough of NPF research in China.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Aerossóis/análise , Atmosfera/química , China , Cidades , Clima , Ecossistema , Poluição Ambiental , Gases , Humanos , Tamanho da Partícula , Material Particulado/análise
7.
Sci Total Environ ; 753: 142238, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33207485

RESUMO

A top-down approach was employed to estimate the influence of lockdown measures implemented during the COVID-19 pandemic on NOx emissions and subsequent influence on surface PM2.5 and ozone in China. The nation-wide NOx emission reduction of 53.4% due to the lockdown in 2020 quarter one in China may represent the current upper limit of China's NOx emission control. During the Chinese New Year Holiday (P2), NOx emission intensity in China declined by 44.7% compared to the preceding 3 weeks (P1). NOx emission intensity increased by 20.3% during the 4 weeks after P2 (P3), despite the unchanged NO2 column. It recovered to 2019 level at the end of March (P4). The East China (22°N - 42°N, 102°E - 122°E) received greater influence from COVID-19. Overall NOx emission from East China for 2020 first quarter is 40.5% lower than 2019, and in P4 it is still 22.9% below the same period in 2019. The 40.5% decrease of NOx emission in 2020 first quarter in East China lead to 36.5% increase of surface O3 and 12.5% decrease of surface PM2.5. The elevated O3 promotes the secondary aerosol formation through heterogeneous pathways. We recommend that the complicated interaction between PM2.5 and O3 should be considered in the emission control strategy making process in the future.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Infecções por Coronavirus , Ozônio , Pandemias , Pneumonia Viral , Aerossóis/análise , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Betacoronavirus , China , Monitoramento Ambiental , Humanos , Óxidos de Nitrogênio/análise , Ozônio/análise , Material Particulado/análise
8.
Sci Total Environ ; 753: 141961, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-32889319

RESUMO

Nutrient stoichiometry and input of trace metals may profoundly affect the growth and community structure of phytoplankton. A bioassay experiment was designed to explore the key components in atmospheric deposition that affect marine phytoplankton growth by adding aerosols and analogues nutrients and Cu to the surface water of the coastal East China Sea (ECS). Our results showed that atmospheric deposition along with the input of phosphate could largely enhance the chlorophyll a (Chl a) concentrations in this eutrophic water. Phosphorus addition lifted the proportions of T. oceanica in Diatoms and B. brevisulcata in Dinoflagellates. T. oceanica replaced S. costatum and became the dominant diatom species after the Chl a peak, probably associated with the N/P ratio approaching to 16. Atmospheric aerosols containing affluent N and little P showed limited promotion to Chl a, and the positive effect was very likely due to the soluble Cu and other trace metals supplied by the aerosol. Moreover, soluble aerosol Cu was found to be conducive to the relative abundance of most dominant class Coscinodiscophyceae, and both soluble aerosol Fe and Cu seemed to be very important for increasing the proportion of S. costatum. Soluble metals could be the key components in aerosols controlling the phytoplankton composition in the eutrophic sea and such impact might exceed affluent P provided by other exogenous sources.


Assuntos
Diatomáceas , Fitoplâncton , Aerossóis/análise , China , Clorofila A
9.
Chemosphere ; 262: 127771, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32799139

RESUMO

The review initiates with current state of information on the atmospheric reaction mechanism of biogenic volatile organic compounds (BVOCs) and its fate in the atmosphere. The plants release BVOCs, i.e., isoprene, monoterpenes, and sesquiterpenes, which form secondary organic aerosols (SOA) upon oxidation. These oxidation reactions are primarily influenced by solar radiations along with other meteorological parameters viz.; temperature and relative humidity, therefore, the chemistry behind SOA formation is different during day than the night time. The review throws light upon the day and nighttime formation mechanism of SOA, recent advancements in the analytical techniques available for the measurements, and its impact on the environment. Studies have revealed that day time SOA formation is dominated by OH and O3, however, NOx initiated SOA production is dominated during night. The formation mechanism addresses that the gaseous products of VOCs are firstly formed and then partitioned over the pre-existing particles. New particle formation and biomass-derived aerosols are found to be responsible for enhanced SOA formation. 2-Dimensional gas chromatography-mass spectrometer (2D-GC/MS) is observed to be best for the analysis of organic aerosols. Radiative forcing (RF) SOA is observed to be a useful parameter to evaluate the environmental impacts of SOA and reviewed studies have shown mean RF in the ranges of -0.27 to +0.20 W m-2.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Atmosfera/química , Butadienos/análise , Hemiterpenos/análise , Monoterpenos/análise , Compostos Orgânicos Voláteis/análise , Aerossóis/química , Poluentes Atmosféricos/química , Butadienos/química , Hemiterpenos/química , Monoterpenos/química , Oxirredução , Temperatura , Compostos Orgânicos Voláteis/química
10.
Chemosphere ; 262: 127295, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32536422

RESUMO

Good air quality is documented as a significant factor of social justice. The human health hazards associated with air pollution are not distributed equally across cities; the most vulnerable people are more exposed to ambient air as they commute to work and wait for buses or trains at the stations. Aerosols play important roles in atmosphere quality and the climate; their oxidation at the nanoscale level may possibly increase the reactivity and toxicity of atmospheric particulates. Indoor school environments are characterized by high concentrations of different airborne particulate and gaseous pollutants. The documentation of nanoparticles (NPs), ultra-fine particles (UFPs), and micron-size particle species present in indoor primary schools are an important aspect in the recognition of their influence in respirational difficulties and decreased cognitive progress in children. This work utilizes the study of condensed water, sampled with portable dehumidifiers (PD), to describe NPs and UFPs in the vapor stage of enclosed zones. The acquired extracts were analyzed by advanced electron microscopy techniques. A total of 392 NPs and 251 UFPs were examined in a set of 22 samples acquired in moderately limited or inadequately ventilated indoor areas from several schools. Noting that NPs-related disorders happen at particular places of respirational structure, identification of site-specific NPs accumulation should be anticipated in direction to better verify the corresponding human health outcomes resulting from respirable NPs.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Nanopartículas/análise , Aerossóis/análise , Poluição do Ar/análise , Atmosfera , Criança , Cidades , Poeira , Monitoramento Ambiental/métodos , Gases , Humanos , Veículos Automotores , Tamanho da Partícula , Material Particulado/análise , Instituições Acadêmicas
11.
Water Sci Technol ; 82(8): 1547-1559, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33107849

RESUMO

An investigation on bioaerosol in a wastewater treatment plant (WWTP) located in Xi'an, China, was conducted to understand the characteristics of bioaerosol released from wastewater and sludge treatment facilities because the bioaerosols may pose a threat to human health. Using the Andersen impactor sampler collection and colony-counting method, bioaerosol concentrations and size distributions were detected. The risk quotient method was used to evaluate the health risks associated with inhalation of bioaerosol for WWTP staff, based on the average daily dose rates of exposure. The health risk in relation to Legionella pneumophila was quantitatively calculated using quantitative microbial risk assessment (QMRA), based on the assumption of the percentage. The maximum concentration of airborne bacteria (3,767 ± 280 colony forming units (CFU)/m3) and fungi (8,775 ± 406 CFU/m3) occurred from the aerated grit chamber and sludge thickening house, respectively, which all exceeded 500 CFU/m3 as the acceptable guideline proposed by the American Conference of Governmental Industrial Hygienists. The particle size of airborne bacteria was mainly distributed in the first three stages (>3.3 µm), while that of airborne fungi was from the second to the fourth stage (2.1-7.0 µm). The hazard index exposure to bioaerosol for adult males and females by inhalation were higher than 1. The proportion of L. pneumophila should be strictly controlled below 10-8, based on the QMRA approach.


Assuntos
Microbiologia do Ar , Águas Residuárias , Aerossóis/análise , China , Monitoramento Ambiental , Humanos , Medição de Risco
12.
Clin Microbiol Rev ; 34(1)2020 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-33115724

RESUMO

Since the beginning of the COVID-19 pandemic, there has been intense debate over SARS-CoV-2's mode of transmission and appropriate personal protective equipment for health care workers in low-risk settings. The objective of this review is to identify and appraise the available evidence (clinical trials and laboratory studies on masks and respirators, epidemiological studies, and air sampling studies), clarify key concepts and necessary conditions for airborne transmission, and shed light on knowledge gaps in the field. We find that, except for aerosol-generating procedures, the overall data in support of airborne transmission-taken in its traditional definition (long-distance and respirable aerosols)-are weak, based predominantly on indirect and experimental rather than clinical or epidemiological evidence. Consequently, we propose a revised and broader definition of "airborne," going beyond the current droplet and aerosol dichotomy and involving short-range inhalable particles, supported by data targeting the nose as the main viral receptor site. This new model better explains clinical observations, especially in the context of close and prolonged contacts between health care workers and patients, and reconciles seemingly contradictory data in the SARS-CoV-2 literature. The model also carries important implications for personal protective equipment and environmental controls, such as ventilation, in health care settings. However, further studies, especially clinical trials, are needed to complete the picture.


Assuntos
Aerossóis/análise , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/transmissão , Controle de Infecções/métodos , Pandemias/prevenção & controle , Material Particulado/análise , Equipamento de Proteção Individual/provisão & distribução , Pneumonia Viral/prevenção & controle , Pneumonia Viral/transmissão , Betacoronavirus , Infecção Hospitalar/prevenção & controle , Infecção Hospitalar/transmissão , Pessoal de Saúde/estatística & dados numéricos , Humanos , Modelos Biológicos , Ventilação
13.
Environ Sci Process Impacts ; 22(10): 2031-2057, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33084679

RESUMO

Hygroscopic particulate matter (PM) constituents promote uptake of aerosol water (AW), depending on relative humidity (RH), which can constrain qualities such as organic aerosol (OA) phase state and inorganic aerosol (IA) deliquescence and efflorescence. This work provides a first incorporation of AW predictions into residential indoor PM simulations. The indoor model, IMAGES, which simulates factored OA concentrations and thermodynamics using the 2D-volatility basis set, was expanded to predict speciated IA concentrations, AW with κ-Köhler theory of hygroscopic growth, and OA phase state with glass transition temperatures. Since RH is the largest driver of AW and varies with meteorology, simulations were conducted using a database of historical ambient weather and pollution records spanning the sixteen U.S. climate zones, facilitating assessment of seasonal and regional trends. Over this diverse simulation set, the residential indoor AW mass was ∼10 to 100 times smaller than dry PM mass. This relative AW amount indoors was about ∼10 times smaller than outdoors, since indoor-emitted aerosol is likely less hygroscopic. The indoor OA phase state was typically semisolid, suggesting kinetic limitations might inhibit thermodynamic OA partitioning equilibrium from being established indoors. Residences in hot and humid climates during the summertime may have liquid indoor OA, while amorphous solid indoor OA can exist in cold climates. Deliquescence and efflorescence of recirculated IA within HVAC systems during cooling or heating, respectively, was also modeled. Oftentimes, two IA populations with different histories existing as wet or dry aerosol were generated by HVAC operation depending on indoor and outdoor environmental conditions and the HVAC operating mode.


Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Aerossóis/análise , Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Monitoramento Ambiental , Umidade , Água
14.
Biosens Bioelectron ; 170: 112656, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33010706

RESUMO

Point-of-care risk assessment (PCRA) for airborne viruses requires a system that can enrich low-concentration airborne viruses dispersed in field environments into a small volume of liquid. In this study, airborne virus particles were collected to a degree above the limit of detection (LOD) for a real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). This study employed an electrostatic air sampler to capture aerosolized test viruses (human coronavirus 229E (HCoV-229E), influenza A virus subtype H1N1 (A/H1N1), and influenza A virus subtype H3N2 (A/H3N2)) in a continuously flowing liquid (aerosol-to-hydrosol (ATH) enrichment) and a concanavalin A (ConA)-coated magnetic particles (CMPs)-installed fluidic channel for simultaneous hydrosol-to-hydrosol (HTH) enrichment. The air sampler's ATH enrichment capacity (EC) was evaluated using the aerosol counting method. In contrast, the HTH EC for the ATH-collected sample was evaluated using transmission-electron-microscopy (TEM)-based image analysis and real-time qRT-PCR assay. For example, the ATH EC for HCoV-229E was up to 67,000, resulting in a viral concentration of 0.08 PFU/mL (in a liquid sample) for a viral epidemic scenario of 1.2 PFU/m3 (in air). The real-time qRT-PCR assay result for this liquid sample was "non-detectable" however, subsequent HTH enrichment for 10 min caused the "non-detectable" sample to become "detectable" (cycle threshold (CT) value of 33.8 ± 0.06).


Assuntos
Técnicas Biossensoriais/instrumentação , Coronavirus Humano 229E/isolamento & purificação , Infecções por Coronavirus/virologia , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Influenza Humana/virologia , Aerossóis/análise , Microbiologia do Ar , Técnicas Biossensoriais/economia , Coronavirus Humano 229E/genética , Monitoramento Ambiental/economia , Monitoramento Ambiental/instrumentação , Desenho de Equipamento , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H3N2/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/instrumentação , Fatores de Tempo
15.
J Breath Res ; 14(4): 047104, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33021211

RESUMO

Exhaled breath aerosols contain valuable metabolomic content due to gas exchange with blood at the alveolar capillary interface in the lung. Passive and selective filtering of these aerosols and droplets may reduce the amount of saliva contaminants and serve as an aid to enhance targeted metabolomic content when sampled in exhaled breath condensate (EBC). It is currently unknown if breath aerosol size distribution affects the types or abundances of metabolites sampled through EBC. This pilot study uses a previously described hand-held human breath sampler device with varying notch filter geometries to redirect the trajectory of breath aerosols based on size. Ten notch filter lengths were simulated with the device to calculate the effect of filter length on the breath aerosol size distribution and the proportion of aerosols which make their way through to an EBC collection tube. From three notch filter lengths, we investigate metabolite content of various aerosol fractions. We analyzed the non-volatile fraction of breath condensate with high performance liquid chromatography-mass spectrometry for broad metabolite coverage. We hypothesize that: (1) increasing the length of the notch filter in this device will prevent larger aerosols from reaching the collection tube thus altering the breath aerosol size distribution sampled in EBC; and (2) there is not a systematic large-scale difference in EBC metabolomic content that correlates with breath aerosol size. From simulation results, particles typically larger than 10 µm were filtered out. This indicates that a longer notch filter in this device prevents larger particles from reaching the collection tube thus altering the aerosol particle size distribution. Most compounds were commonly present in all three filter lengths tested, and we did not see strong statistical evidence of systematic metabolite differences between breath aerosol size distributions.


Assuntos
Aerossóis/análise , Testes Respiratórios/métodos , Expiração , Metabolômica , Tamanho da Partícula , Adulto , Simulação por Computador , Humanos , Masculino , Metaboloma , Projetos Piloto
16.
J Environ Sci (China) ; 98: 161-168, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33097148

RESUMO

Increasing attention has been paid to the air pollution more recently. Smog chamber has been proved as a necessary and effective tool to study atmospheric processes, including photochemical smog and haze formation. A novel smog chamber was designed to study the atmospheric photochemical reaction mechanism of typical volatile organic compounds (VOCs) as well as the aging of aerosols. The smog chamber system includes an enclosure equipped with black lights as the light source, two parallel reactors (2 m3 of each) with separate control of light source and temperature, with a series of coupled instruments for online monitoring of gas phase and particle phase reactants and products. Chamber characterization, including air source stability, effective light intensity, temperature stability, as well as gas phase and particle phase wall losses, were carried out before further research. The results showed that our smog chamber systems developed by other domestic and international groups. It was also observed that the wall loss of aromatic VOCs varied with different functional groups as well as the isomerism. The results of preliminary simulation experiment from styrene-NOx demonstrated that the chamber can be well utilized to simulate gas-particle conversion progresses in the atmosphere.


Assuntos
Poluição do Ar , Smog , Aerossóis/análise , Atmosfera/análise , Processos Fotoquímicos , Smog/análise
17.
J Breath Res ; 14(4): 042003, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33021206

RESUMO

Diagnosis of SARS-COV-2 infection (COVID-19) is currently based on detection of the viral RNA in nasopharyngeal swab samples by reverse transcription polymerase chain reaction (RT-PCR). However, sampling via nasopharyngeal swabs frequently provokes sneezing or coughing, which results in increased risk of the viral dissemination and environmental contamination. Furthermore, the sensitivity associated with the PCR tests s limited to 60%-70%, which is mainly attributable to technical deficiency in sampling. Given that the disease is transmitted via exhaled aerosol and droplets, and that the exhaled breath condensate (EBC) is the established modality for sampling exhaled aerosol, detection of the viral RNA in EBC is a promising approach for safe and efficient diagnosis of the disease. Subjects are those patients who are diagnosed with COVID-19 by positive nasopharyngeal swab PCR test and admitted to Saitama Medical Center, Japan. EBC samples will be collected using an R-tube® or R-tubeVent® device. Collected EBC samples will be introduced into a nucleic acid purifier. The purified nucleic acids will undergo amplification through RT-PCR for detection and quantification of SARS-COV-2 RNA. To date we have collected eight samples from seven subjects. Among them, two samples from two subjects tested positive for SARS-COV-2 RNA by the RT-PCR. Reflecting the second wave of COVID-19 prevalence in Japan, new admissions of COVID-19 patients to the Saitama Medical Center are increasing, and we are expecting to collect at least 50 EBC samples from 25 patients before the end of this year.


Assuntos
Testes Respiratórios/instrumentação , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Aerossóis/análise , Betacoronavirus , Técnicas de Laboratório Clínico , Tosse , Expiração , Humanos , Japão , Pandemias , RNA Viral/análise , Projetos de Pesquisa , Manejo de Espécimes , Carga Viral
18.
Huan Jing Ke Xue ; 41(11): 4803-4812, 2020 Nov 08.
Artigo em Chinês | MEDLINE | ID: mdl-33124224

RESUMO

In order to explore the pollution characteristics of the chemical components of atmospheric particulate matter in Nanjing Jiangbei New Area, size-resolved samples were collected from 2013 to 2014. The size distribution and seasonal variation of the chemical components of the particles were studied. The results showed that the total concentration of nine water-soluble ions in fine particles was higher in autumn and winter than in spring and summer, while the concentration of coarse particles was highest in winter. The ratio of NO3-/SO42- for the fine particles in winter was slightly higher than in the other three seasons, and lowest in the coarse particles. The trend of particle size distribution in spring, summer and autumn was consistent. The distribution of water-soluble ions was bimodal, and NO3- peaked at 0.65-1.1 µm in all four seasons. The peak radius of SO42- in the fine particles in summer and autumn was 0.43-0.65 µm, and the peak value in winter moved towards the coarser particles, while Na+ and Cl- mainly existed in the coarse particles. The charge equivalent of anion and anion indicated that the coarse and fine particles were alkaline and weakly alkaline, respectively. Organic carbon (OC) and elemental carbon (EC) mainly existed in the fine particles, with a bimodal distribution. The secondary organic carbon (SOC) in the fine particles in autumn and winter was significantly higher than in spring and summer. The ratio method further indicated that the carbonaceous component of the particulate matter in Nanjing Jiangbei New Area is mainly from the emissions of coal and biomass combustion, and vehicle exhaust.


Assuntos
Poluentes Atmosféricos , Aerossóis/análise , Poluentes Atmosféricos/análise , China , Carvão Mineral , Monitoramento Ambiental , Tamanho da Partícula , Material Particulado/análise , Estações do Ano
19.
Huan Jing Ke Xue ; 41(11): 4813-4824, 2020 Nov 08.
Artigo em Chinês | MEDLINE | ID: mdl-33124225

RESUMO

The aim of this study was to fully understand the pollution characteristics and sources of PM2.5 in Zhengzhou, and to investigate the differences in four seasons and between urban and suburban areas. At the Zhengzhou environmental monitoring center (urban areas) and Zhengzhou University (suburban areas), 1284 environmental PM2.5 samples were collected in the four seasons of 2018. The concentrations of nine kinds of inorganic water-soluble ions, organic carbon, elemental carbon and 27 kinds of elements, were measured by ion chromatography, carbon analyzer, and X-ray fluorescence spectrometry, respectively. Enrichment factors (EF), index of geoaccumulation (Igeo), potential ecological risk index (RI), chemical mass balance model (CMB), backward trajectory, and potential source contribution function were the methods used to study the chemical component characteristics and source differences of PM2.5 in different seasons in the urban and suburban areas of Zhengzhou. The results showed that the annual average PM2.5 concentration at the Zhengzhou environmental monitoring center and Zhengzhou University sites reached (59.7±24.0) µg·m-3 and (74.7±13.5) µg·m-3, respectively. The PM2.5 concentration at the suburban point was higher than at the urban point with the exception of winter, and the seasonal mean concentration decreased in the order of winter > autumn > spring > summer. Compared with the urban areas, the suburban areas were more affected by crustal substances in spring, and the concentrations of all components were higher in summer and autumn than the urban areas. Nevertheless, urban areas were more affected by coal burning sources and motor vehicle sources in winter. The component analysis results showed that the influences of soil dust and building dust were greater in the suburbs in spring than in the urban areas. In autumn, the suburbs were more affected by biomass sources than the urban areas, while the urban areas were more affected by building dust than were the suburbs. The concentrations of Cu, As, Zn, Pb, and Sb were strongly influenced by anthropogenic sources, and the enrichments of Zn, Cu, As, and Pb in urban areas were greater than in the suburbs. In addition, Zn, Cu, As, and Pb exhibited potential ecological risks. The outcomes of the CMB model showed that dust sources, secondary sulfate, secondary nitrate, and coal burning sources contributed significantly to PM2.5 concentrations in spring, summer, autumn and winter, respectively. The contributions of secondary pollution sources (secondary organic aerosol, secondary sulfate, and secondary nitrate) and motor vehicle sources to urban areas were higher than to suburban areas, and the influences of biomass sources in autumn and winter were significantly higher than in spring and summer and urban areas. The backward trajectory results indicated that the local PM2.5 concentration was affected by distant transmission from the northwest except in summer, was affected by neighboring provinces in the east in four seasons, and was affected by transmission from the south, with the exception of winter. Furthermore, the consequences of potential sources demonstrated that the local PM2.5 concentration was mainly affected by the potential areas in Henan province and its boundary with neighboring provinces.


Assuntos
Poluentes Atmosféricos , Material Particulado , Aerossóis/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Material Particulado/análise , Estações do Ano , Emissões de Veículos/análise
20.
Huan Jing Ke Xue ; 41(9): 3879-3888, 2020 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-33124266

RESUMO

High-resolution online monitoring data from January to February in 2020 was used to study the characterization of two heavy pollution episodes in Tianjin in 2020; the heavy pollution episode that lasted from January 16 to 18, 2020 (referred to as episode Ⅰ) and that from February 9 to 10, 2020 (referred to as episode Ⅱ) were analyzed. The results showed that two heavy pollution episodes were influenced by regional transportation in the early stage and local adverse meteorological conditions in the later stage. During these episodes, the average wind speed was low, the average relative humidity was close to 70%, and relative humidity approached the saturated, the boundary layer heights were below 300 m, and the horizontal and vertical diffusion conditions were poor. Compared to episode Ⅰ, the concentration of pollutants decreased during episode Ⅱ, especially for the concentration of NO2. During the episode Ⅱ, the concentrations of PM2.5 and CO were higher in the north of Tianjin. The chemical component concentrations and their mass ratios to PM2.5 changed significantly in both episodes; the concentrations of secondary inorganic ions (NO3-, SO42-, and NH4+), elemental carbon (EC) and Ca2+were higher in episode Ⅰ, the concentrations of organic carbon (OC) and Cl- slightly increased in episode Ⅱ; and the concentrations of K+were higher in episode Ⅱ. Compared to episode Ⅰ, because of the increase in the combustion sources and significant reductions in the number of vehicles, the mass ratios of SO42-, OC, and K+ to PM2.5 increased while the mass ratios of NO3- and EC to PM2.5 decreased in episode Ⅱ; the mass ratios of NH4+ and Cl- to PM2.5 were relatively higher due to the continuity of the industrial production processes; the mass ratios of Ca2+ to PM2.5 were lower in two heavy pollution episodes because construction activities were halted. Source apportionment of PM2.5 was performed using the positive matrix factorization (PMF) model. In episode Ⅰ, the major sources of PM2.5 in Tianjin were secondary sources, industrial and coal combustion, vehicle exhaust, crustal dust, fireworks and biomass burning, with contributions of 53.8%, 20.2%, 18.6%, 6.3%, and 1.1%, respectively. In episode Ⅱ, the same sources were identified in the PMF analysis with contributions of 48.3%, 28.2%, 8.7%, 2.6%, and 12.2%, respectively. Compared to episode Ⅰ, the contributions of industrial and coal combustion, fireworks and biomass burning increased, and the contributions of secondary sources, vehicle exhaust, and crustal dust decreased in episode Ⅱ; contributions of vehicle exhaust and crustal dust decreased by 53.2% and 58.7%, respectively.


Assuntos
Poluentes Atmosféricos , Material Particulado , Aerossóis/análise , Poluentes Atmosféricos/efeitos adversos , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Material Particulado/análise , Estações do Ano , Emissões de Veículos/análise
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