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1.
Sci Total Environ ; 741: 140465, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32887012

RESUMO

BACKGROUND: Long-term exposure to air pollution is linked with increased risk of adverse health outcomes, but the evidence for the association between nitrogen dioxide (NO2) and mortality is weak because of the inadequate adjustment of potential confounders and limited spatial resolution of the exposure assessment. Moreover, there are concerns about the independent effects of NO2. Therefore, we examined the association between NO2 long-term exposure and all-cause and cause-specific mortality. METHODS: We included participants who were enrolled in health checkups in Okayama City, Japan, in 2006 or 2007 and were followed until 2016. We used a land-use regression model to estimate the average NO2 concentrations from 2006 to 2007 and allocated them to the participants. We estimated hazard ratios (HRs) for a 10-µg/m3 increase in NO2 levels for all-cause or cause-specific mortality using Cox proportional hazard models. RESULTS: After excluding the participants who were assigned with outlier exposures, a total of 73,970 participants were included in the analyses. NO2 exposure was associated with increased risk of mortality and the HRs and their confidence intervals were 1.06 (95% CI: 1.02, 1.11) for all-cause, 1.02 (0.96, 1.09) for cardiopulmonary, and 1.36 (1.14, 1.63) for lung cancer mortality. However, the elevated risks became equivocal after the adjustment for fine particulate matter except lung cancer. CONCLUSION: Long-term exposure to NO2 was associated with increased risk of all-cause, cardiopulmonary, and lung cancer mortality. The elevated risk for lung cancer was still observable even after adjustment for fine particulate matter.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar , Causas de Morte , Poluentes Atmosféricos/toxicidade , Exposição Ambiental/análise , Humanos , Japão , Dióxido de Nitrogênio/análise , Material Particulado/análise
2.
Environ Monit Assess ; 192(10): 624, 2020 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-32895739

RESUMO

Particulate matter (PM) concentrations are affected by anthropogenic emissions and sand transport jointly; however, the relative contributions from those two aspects are usually unknown. In our work, statistical analysis and back trajectories model were used to identify the dominant source in such area, by taking Yumen City as an example. We come to the conclusion that local emissions dominate the concentration of airborne pollutants, while sand transport plays a significant role on PM concentration. The conclusions were supported by the following results. (1) PM monthly mean concentrations at the two air quality stations, which are 70 km far away from each other, have the similar levels and variation trend; furthermore, a regression analysis of PM2.5 and PM10 daily concentrations between both stations indicated a significant correlation, suggesting that PM at both locations was influenced by the same emission sources; (2) statistical analysis results revealed that PM concentration has a positive correlation with wind speed, indicating the wind-blown dust and sand contribute mainly on PM concentration; (3) back-trajectory clustering analysis indicates that long-distance transport particulates from dust sources and their pathways had a significant impact on local PM concentrations.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Poluentes Ambientais , China , Cidades , Monitoramento Ambiental , Material Particulado/análise
3.
Environ Monit Assess ; 192(10): 627, 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32901375

RESUMO

Numerous health studies have linked the exposure to particulate matter with adverse health effects, while there is an increasing scientific interest in the particle metrics of surface area (SA) and lung-deposited SA (LDSA) concentration. In the present study, two integrated SA estimation methods, both based on widely used instrumentation, were applied at an urban traffic environment in Athens for a 6-month period. The first estimation method used the size distribution by number to estimate SA (average SA1 669.3 ± 229.0 µm2 cm-3), while the second method used a simple inversion scheme that incorporates number and mass concentrations (average SA2 1627.9 ± 562.8 µm2 cm-3). In pairwise comparisons, SA2 levels were found two times greater than the corresponding SA1, but exhibited a strong correlation (r = 0.73). SA1 and SA2 concentrations correlated well with the traffic-related pollutants NOx (r = 0.64 and 0.78) and equivalent black carbon (r = 0.53 and 0.51). The diurnal variation of SA1 concentrations by size range indicated traffic as a major controlling factor. Estimated LDSA (53.9 µm2 cm-3 on average) concentrations were also clearly affected by anthropogenic emissions with more pronounced associations in the 0.01-0.4 µm range (r = 0.66 with NOx and r = 0.65 with equivalent black carbon). Validating estimated LDSA through simultaneous measurements with a reference instrument revealed that the estimation method underestimates LDSA by a factor between 2 and 3, exhibiting, however, a high correlation (r = 0.79). Overall, the performance of estimation methods appear satisfactory and indicate that a trustworthy assessment of the temporal variability of SA and LDSA concentration metrics can be provided in real time, on the basis of relatively lower-cost instrumentation, especially in view of recent advances in particle sensing technologies.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Grécia , Material Particulado/análise , Emissões de Veículos/análise
4.
Environ Monit Assess ; 192(10): 634, 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32909141

RESUMO

Volatile organic compounds, VOCs, are air pollutants widely produced by biogenic and anthropogenic sources. This work quantitatively studied the presence of these gases in the internal and external environments of schools, comparing one in an urban area (La Salle School, Canoas, RS) and another in a rural area (Santa Cassia Farm School, Nova Santa Rita, RS). The aim of this study was to compare if this environmental differences (location) influence their gases concentration. Monitoring campaigns were conducted for 6 months, occurring every 2 weeks in both schools during class hours, 1 day indoors and 1 day outdoors. The results showed higher concentrations of total volatile organic compounds in the urban school external environment compared with the same rural school environment and, in the comparison between environments, the internal environments of the two schools obtained higher VOC concentrations than the external ones, except in November and December at the urban school.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Compostos Orgânicos Voláteis/análise , Brasil , Monitoramento Ambiental , Humanos
5.
Sci Total Environ ; 741: 140515, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32887014

RESUMO

An ecologic analysis was conducted to explore the correlation between air pollution, and COVID-19 cases and fatality rates in London. The analysis demonstrated a strong correlation (R2 > 0.7) between increment in air pollution and an increase in the risk of COVID-19 transmission within London boroughs. Particularly, strong correlations (R2 > 0.72) between the risk of COVID-19 fatality and nitrogen dioxide and particulate matter pollution concentrations were found. Although this study assumed the same level of air pollution across a particular London borough, it demonstrates the possibility to employ air pollution as an indicator to rapidly identify the city's vulnerable regions. Such an approach can inform the decisions to suspend or reduce the operation of different public transport modes within a city. The methodology and learnings from the study can thus aid in public transport's response to COVID-19 outbreak by adopting different levels of human-mobility reduction strategies based on the vulnerability of a given region.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Infecções por Coronavirus , Pandemias , Pneumonia Viral , Betacoronavirus , Cidades , Humanos , Londres , Dióxido de Nitrogênio/análise , Material Particulado/análise
6.
Sci Total Environ ; 738: 140313, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-32806346

RESUMO

OBJECTIVE: We aimed to establish a representative exposure response function between PM2.5 and lung cancer to evaluate the impact on lung cancer burden and the benefits gained in association with the environmental policy change in Beijing, China. METHODS: Based on population-based cancer registration data during 2001-2016, using a spatiotemporal Poisson regression model, long-term concentrations of PM2.5 were linked to sex-age adjusted incidence rates of total lung cancer and its pathological subtypes. We calculated the health and monetary benefits associated with air quality improvement using the cost of illness method. RESULTS: In the constructed regression model, a 10 µg/m3 increment of PM2.5 was associated with increases of 6.0% (95% confidence interval [95% CI]: 4.3%, 7.7%), 14.8% (10.3%, 19.4%), and 6.5% (3.3%, 9.8%) in the incidence of total lung cancer, squamous cell carcinoma, and adenocarcinoma, respectively. The estimated associations indicate that long-term exposure to PM2.5 contributed 1947 to 3059 incident cases of lung cancer per year among the residents in Beijing during the study period. Clean air actions saved 4978 (95% CI: 2711, 7417) lung cancer cases, which brought a savings of 218 (118, 324) million RMB (~31 [17, 46] million US dollars) in direct inpatient medical expenditures. If air quality had met national standards of long-term PM2.5 (35 µg/m3) in 2014-2016, 10,003 (95% CI: 9325, 10,650) lung cancer cases could have been prevented and direct inpatient medical expenditures of 438 (409, 466) million RMB (~63 [58, 67] million US dollars) could have been saved. CONCLUSIONS: This study enriches epidemiological study, confirming the association between exposure to PM2.5 and lung cancer or its subtypes, and provides novel evidence for the notable reduction in lung cancer burden and medical expenditure savings that were achieved through air quality improvements in Beijing from 2014 to 2016.


Assuntos
Poluentes Atmosféricos/análise , Neoplasias Pulmonares , Pequim , China , Exposição Ambiental , Humanos , Material Particulado/análise , Melhoria de Qualidade
7.
Environ Pollut ; 265(Pt A): 114675, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32806393

RESUMO

Urban afforestation can mitigate the effects of air pollution by acting as a sink for atmospheric emissions, but these emissions (e.g., combustion gases from diesel engines) can be a precursor of structural and physiological changes in higher plant species, which could compromise the success of afforestation projects. In this study, Guabiroba (Campomanesia xanthocarpa O. Berg.) plants were exposed in greenhouses to combustion gases emitted by a diesel engine over 120 days, with daily intermittent gas exposure. Every 30 days, leaf injury (chlorosis and necrosis), plant biomass and physiological/biochemical parameters (proteins, chlorophyll and peroxidase enzyme activity) were evaluated. The data obtained were used to construct a hierarchy of the sensitivity (and inversely, of the resistance or tolerance) of this higher plant species to the diesel oil combustion gases: peroxidase > biomass ≈ chlorophyll > protein > leaf injury. Variations in these parameters could be used for the early diagnosis of plant stress or as a marker for stress tolerance in trees. In the first case, a sensitive species could be used for the phytomonitoring of air quality and in the second case the lack of significant variations in these parameters would indicator tolerance of the plant species to air pollution. The results showed that Guabiroba, a plant native to the Atlantic forest, is sensitive to air pollution and could therefore be used for air quality monitoring, since all parameters analyzed were affected by the polluted air.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar , Monitoramento Ambiental , Gasolina , Emissões de Veículos/análise
8.
Environ Pollut ; 265(Pt A): 115058, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32806396

RESUMO

Due to the increase of the human population and the rapid industrial growth in the past few decades, air quality monitoring is essential to assess the pollutant levels of an area. However, monitoring air quality in a high-density area like Sunway City, Selangor, Malaysia is challenging due to the limitation of the local monitoring network. To establish a comprehensive data for air pollution in Sunway City, a mobile monitoring campaign was employed around the city area with a duration of approximately 6 months, from September 2018 to March 2019. Measurements of air pollutants such as carbon dioxide (CO2) and nitrogen dioxide (NO2) were performed by using mobile air pollution sensors facilitated with a GPS device. In order to acquire a more in-depth understanding on traffic-related air pollution, the measurement period was divided into two different time blocks, which were morning hours (8 a.m.-12 p.m.) and afternoon hours (3 p.m.-7 p.m.). The data set was analysed by splitting Sunway City into different zones and routes to differentiate the conditions of each region. Meteorological variables such as ambient temperature, relative humidity, and wind speed were studied in line with the pollutant concentrations. The air quality in Sunway City was then compared with various air quality standards such as Malaysian Air Quality Standards and World Health Organisation (WHO) guidelines to understand the risk of exposure to air pollution by the residence in Sunway City.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Cidades , Monitoramento Ambiental , Humanos , Malásia
9.
Environ Pollut ; 265(Pt A): 115062, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32806405

RESUMO

Measuring ammonia (NH3) is important for understanding the role of NH3 in secondary aerosol formation and the atmospheric deposition of reactive N. In this study, NH3 was measured in an urban area, a background region, and a tunnel in Beijing. The average NH3 concentrations between September 2017 and August 2018 were 24.8 ± 14.8 ppb and 11.6 ± 10.3 ppb in the urban area and background region, respectively. Higher NH3 concentrations at both the urban and background sites, relative to some earlier measurements indicated a likely increase in the NH3 concentrations in these regions. The urban NH3 level in Beijing was much higher than that typically observed at urban and industrial sites in other domestic and foreign cities, suggesting that the Beijing urban area was affected by greater NH3 emissions than other regions. Based on the relationship among NH3, wind direction, and wind speed, the urban area was affected by both local emissions and air transported from North China Plain (NCP). Potential source contribution function analyses suggested that regional transport from the NCP could greatly affect local concentrations of NH3 in both urban and background areas in spring and autumn; however, in addition to the NCP, urban emissions could also affect NH3 levels in the background region in summer and winter. The average NH3 concentration at the Fenshuiling Tunnel was 8.5 ± 7.7 ppb from December 2017 to February 2018. The NH3:CO emission ratio measured in the tunnel test was 0.022 ± 0.038 ppb/ppb, which was lower than values in the USA and South Korea. The contribution of traffic to NH3 in Beijing did not agree well with the available emission inventories, suggesting that vehicular emissions were underestimated and further evaluation is necessary.


Assuntos
Poluentes Atmosféricos/análise , Amônia/análise , Pequim , China , Cidades , Monitoramento Ambiental , República da Coreia
10.
Science ; 369(6503): 575-578, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32732425

RESUMO

Air pollution at any given time is unequally distributed across locations. Average concentrations of fine particulate matter smaller than 2.5 micrometers in diameter (PM2.5) have fallen over time. However, we do not know how the spatial distribution of PM2.5 has evolved. Here, we provide early evidence. We combine 36 years of PM2.5 concentrations measured over ~8.6 million grid cells with geographic, economic, and demographic data from ~65,000 U.S. census tracts. We show that differences in PM2.5 between more and less polluted areas declined substantially between 1981 and 2016. However, the most polluted census tracts in 1981 remained the most polluted in 2016. The least polluted census tracts in 1981 remained the least polluted in 2016. The most exposed subpopulations in 1981 remained the most exposed in 2016. Overall, absolute disparities have fallen, but relative disparities persist.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Exposição Ambiental , Material Particulado/análise , Humanos , Estados Unidos
11.
J Environ Radioact ; 222: 106341, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32778530

RESUMO

Micro-SWIFT SPRAY (MSS) is a 3D Lagrangian particle dispersion model that maintains a good balance between accuracy and computational cost. However, its capabilities for air dispersion modeling in the presence of both complex topography and high building densities have not been investigated for nuclear emergency response. In this study, MSS is systematically evaluated against two wind tunnel experiments that simulate a typical Chinese nuclear power plant with the above two features. The MSS predictions are compared with both 2D horizontal and vertical measurements. Sensitivity studies are performed with respect to the particle number, the lower bound of the turbulence intensity, and the horizontal and vertical grid size. The results demonstrate that ground-level predictions of both wind and radionuclide concentrations are in satisfactory agreement with the measurements under optimized parameter values. The vertical predictions exhibit site-dependent accuracy, but generally consistent tendencies. The default lower bound of the turbulence intensity in MSS may be insufficient for reproducing the correct plume width observed in the wind tunnel experiments. An increased lower bound is suggested to solve this problem. In addition, artificially high concentrations may arise near steep slopes if large horizontal/vertical grid sizes are used. Suitable parameters for preventing this problem are also provided.


Assuntos
Poluentes Atmosféricos , Monitoramento de Radiação , Modelos Teóricos , Centrais Nucleares , Radioisótopos
12.
Nat Commun ; 11(1): 4229, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32843631

RESUMO

Scarlet fever has resurged in China starting in 2011, and the environment is one of the potential reasons. Nationwide data on 655,039 scarlet fever cases and six air pollutants were retrieved. Exposure risks were evaluated by multivariate distributed lag nonlinear models and a meta-regression model. We show that the average incidence in 2011-2018 was twice that in 2004-2010 [RR = 2.30 (4.40 vs. 1.91), 95% CI: 2.29-2.31; p < 0.001] and generally lower in the summer and winter holiday (p = 0.005). A low to moderate correlation was seen between scarlet fever and monthly NO2 (r = 0.21) and O3 (r = 0.11). A 10 µg/m3 increase of NO2 and O3 was significantly associated with scarlet fever, with a cumulative RR of 1.06 (95% CI: 1.02-1.10) and 1.04 (95% CI: 1.01-1.07), respectively, at a lag of 0 to 15 months. In conclusion, long-term exposure to ambient NO2 and O3 may be associated with an increased risk of scarlet fever incidence, but direct causality is not established.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Exposição Ambiental/análise , Escarlatina/diagnóstico , Poluição do Ar/efeitos adversos , China/epidemiologia , Exposição Ambiental/efeitos adversos , Geografia , Humanos , Incidência , Dióxido de Nitrogênio/análise , Dinâmica não Linear , Ozônio/análise , Material Particulado/análise , Fatores de Risco , Escarlatina/epidemiologia , Escarlatina/etiologia , Estações do Ano , Análise Espaço-Temporal
13.
Environ Sci Pollut Res Int ; 27(29): 36013-36026, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32816182

RESUMO

In the present work, wind tunnel experiments and numerical simulations were carried out to evaluate the physical behaviour of the fluid flow of a stockpile in the presence of an isolated cubic building. Comparing the obtained experimental results with those for the isolated stockpile configuration and observing the differences in the erosion patterns and emission estimates was possible to conclude that (i) the emissions considerably increase due to the presence of the building; (ii) the higher the free stream velocity, due to the presence of the obstacle, the more efficient the dynamics of the pavement process; and (iii) the increase of the gap between the building and the pile does not generate expressive changes in the emitted mass measurements. These findings play an important role since it is possible to obtain an optimal industrial open yard configuration where fewer particles are emitted to the atmosphere.


Assuntos
Poluentes Atmosféricos/análise , Modelos Teóricos , Atmosfera , Monitoramento Ambiental
14.
Mar Pollut Bull ; 159: 111522, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32771665

RESUMO

Airborne microplastics and microfibers are released from daily materials, contaminating both indoor and outdoor air. Sampling in Aveiro, Portugal, revealed concentrations of 6 fibers m-3, with more synthetic fibers found in outdoor than indoor (8.5% vs. 4.1%, n = 6), with variations in fiber characteristics between sampling periods. Suspected microplastics (<10 µm) also followed this trend (12 vs. 5 particles m-3). Synthetic fibers presented peculiar characteristics, with larger median sizes of 513 µm and 90% of lighter colors. Nonetheless, numerous fibers and suspected microplastics were found in field blanks, possibly from sampling contamination, reducing the reliability of results. Few previous works have reported field blanks so far, raising concerns about the quality of their results as well. Thus, quality assurance measures should be more strictly applied when working with airborne fibers and microplastics, while more research should focus on the factors involved in the variation of concentrations and characteristics of airborne fibers.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Monitoramento Ambiental , Microplásticos , Plásticos/análise , Portugal , Reprodutibilidade dos Testes
15.
Rev Saude Publica ; 54: 84, 2020.
Artigo em Português, Inglês | MEDLINE | ID: mdl-32844984

RESUMO

OBJECTIVE To analyze the impact of two interventions (implementation and suspension of mandatory vehicle inspection) on morbidity and mortality due to conditions related to air pollution, from 2008 to 2017. METHODS Interrupted time series (ARIMA models), using data available in public repositories. RESULTS A total of 229,337 children of up to 5 years old were hospitalized due to respiratory diseases, and 1,053 died (average monthly mortality ratio for this population: 1.12/100,000). Exact 137,876 individuals over 40 years old were hospitalized for an acute myocardial infarction, and 19,492 died (3.7/100,000). A total of 11,010 individuals over 40 years old were hospitalized with malignant neoplasms of the respiratory system; 2,898 died (0.5/100,000). A total of 20,807 individuals over 60 years old were hospitalized with chronic obstructive pulmonary diseases; 2,627 died (1.5/100,000). As for strokes, 69,180 individuals were hospitalized, and 10,866 died (2.1/100,000). We found no significant regression coefficient for the implementation or suspension of the program regarding hospitalizations and deaths. 38,207 children of up to 14 years old were hospitalized with asthma, and 25 of them died (0.007/100,000). The coefficients show a monthly increase of 0.05 deaths/100,000 people (p = 0.01) in the post-inspection period. We found no correlation between the measured concentrations of the pollutants PM2.5 and CO - in a monitoring station, in the central region of the municipality - and the implementation or suspension of the inspection. CONCLUSIONS No evidence confirms that the program had a measurable beneficial impact on morbidity and mortality due to respiratory and circulatory diseases.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Saúde Pública , Poluição Relacionada com o Tráfego/prevenção & controle , Emissões de Veículos , Adolescente , Adulto , Brasil , Criança , Pré-Escolar , Cidades , Monitoramento Ambiental , Humanos , Pessoa de Meia-Idade
16.
Waste Manag ; 116: 66-78, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32784123

RESUMO

To mitigate the greenhouse gas effect, accurate and precise landfill gas prediction models are required for more precise prediction of the amount and recovery time of methane gas from landfills. When the study associates to greenhouse gas emissions problems, time series prediction models are of considerable interests, in which significant past records of gas data are required. This study is the first to specially impute the missing methane (CH4) data for applying in time series artificial neural network (ANN) model in an attempt to predict daily CH4 generation rate from a landfill in Regina, SK, Canada. Pre-processing was conducted on data to evaluate independent and significant meteorological input variables and provide suitable dataset for developing CH4 generation models. A two-stage time series model proposed in this study was performed by missing data imputation at the first stage, followed by a neural network auto-regressive model with exogenous inputs (NARX) at the second stage. The model with 3 layers, 5 climatic variables and 9 neurons in the hidden layer was the optimal structure. This model shows the high performance in CH4 prediction with the average index of agreement of 0.92 and the average mean absolute percentage error (MAPE) of 3.03% during the testing stage. Missing data imputation coupled with NARX method decreased the mean squared error (MSE) of the model by 84% (compared to Multilayer Perceptrons neural network model) in the testing period representing the effectiveness of missing data estimation coupling with time series ANN models in daily CH4 generation prediction.


Assuntos
Poluentes Atmosféricos/análise , Canadá , Metano/análise , Redes Neurais de Computação , Instalações de Eliminação de Resíduos
17.
Sci Total Environ ; 739: 139755, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32758934

RESUMO

Biomass burning (BB) emissions significantly deteriorate air quality in many regions worldwide, impact human health and perturbing Earth's radiation budget and climate. South America is one of largest contributors to BB emissions globally. After Amazonia, BB emissions from open and agricultural fires of Northern South America (NSA) are the most significant. Recent evidence shows a strong correlation between fire counts in NSA and Brown Carbon in some Colombian cities, suggesting a substantial seasonal contribution of regional BB sources to air pollution levels in the densely populated areas of NSA. In this work we use the atmospheric regional chemical transport model WRF-Chem to assess the contribution of open BB events to pollutant concentration and to estimate potential health impacts associated with wildfire events in NSA. Three nested domains are used to simulate atmospheric composition in the Northern part of South America and the Caribbean. Simulations included biogenic and anthropogenic emissions from a global emission inventory merged with local emissions for the city of Bogotá. Two modelling scenarios were considered, a base case without BB emissions (NO_FIRE) and a sensitivity scenario with BB emissions. Simulations were carried out for periods of strong BB activity in NSA. In the NO_FIRE scenario, aerosol concentrations are unrealistically low. When BB emissions are is included background PM2.5 concentrations increase 80%. The increment in aerosol concentrations is mainly driven by Secondary Organic Aerosols. In the case of Bogotá, the most densely populated city in the domain, monthly mean increase in PM2.5 is 3.3 µg m-3 and 4.3 ppb for O3. Modeled meteorological and air pollution fields are in better agreement with observations when high spatial resolution (3 × 3 km) is used in the simulations. The total estimated short-term all-cause mortality associated to BB during February in the region is 171 cases, 88 PM2.5-related and 83 O3-related mortality.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Aerossóis/análise , Biomassa , Brasil , Região do Caribe , Cidades , Monitoramento Ambiental , Humanos , América do Norte , Material Particulado/análise
18.
J Environ Sci (China) ; 96: 138-150, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32819688

RESUMO

Speciated characterization of Volatile Organic Compounds (VOCs), including oxygenated VOCs (OVOCs), from construction machinery and river ships in China is currently lacking. In this regard, we conducted field measurement on speciated VOC (including OVOC) emissions from six construction machinery and five river ships in the Pearl River Delta (PRD) region to identify VOC emission characteristics. We noticed that OVOC emissions from construction machinery and ships accounted for more than 50% of the total VOC emissions, followed by alkenes, aromatics and alkanes. Formaldehyde and acetaldehyde were the most emission species, accounting for 61.8%-83.2% of OVOCs. For construction machinery, the fuel-based emission factors of roller, grader and pile driver were 3.12, 3.12 and 7.36 g/kg, respectively. With the rigorous restraint by the national emission standards, VOC emissions of construction machinery had decreased considerably, especially during stage Ⅲ. Ozone formation potential was also significantly reduced due to the significant decrease in emissions of OVOCs and alkenes with higher reactivity. For river ships, the fuel-based emission factors of cargo ships and speedboat were 1.46 and 0.44 g/kg, respectively. VOC emissions from construction machinery and river ships in Guangdong Province in 2017 were 8851.0 and 4361.0 ton, respectively. This study filled the knowledge gaps of reactive gas emissions from different kinds of non-road mobile sources over the PRD, and more importantly, highlighted the necessity in adding OVOC measurement to give a complete and accurate depiction of reactive gas emissions from non-road mobile sources.


Assuntos
Poluentes Atmosféricos/análise , Ozônio/análise , Compostos Orgânicos Voláteis/análise , China , Monitoramento Ambiental , Rios , Navios , Emissões de Veículos/análise
19.
J Environ Sci (China) ; 96: 72-84, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32819701

RESUMO

In this study, the black carbon (BC) measurements in the atmosphere of Nanjing, China were continuously conducted from 2015 to 2018 using a Model AE-33 aethalometer. By combining dataset of PM2.5, PM10, CO, NO2, SO2, O3 and meteorological parameters, the temporal variations and the source apportionment of BC were given in this study. The results showed that the PM2.5 mass concentrations decreased in Nanjing, with an average annual rate of variation of 6.50 µg/(m3⋅year). Differently, the annual average concentrations of BC increased with an average annual variation rate of 214.71 ng/(m3⋅year). The seasonal variations showed the pattern of BC mass concentrations in winter > autumn > spring > summer. The diurnal variations of BC mass concentrations showed a double-peak in all four seasons. The first peak occurred at approximately 7:00 in spring, summer and autumn and around 8:00 in winter. The second peak took place after 18:00. The average AAE (absorption Ångström exponent) was 1.26 with a maximum of 1.35 during wintertime and the lowest (1.12) during summertime. In addition, the AAE was smaller in the daytime than that at night, with a minimum occurring between 13:00 and 14:00. BC and visibility show a good power-function relationship at different humidity levels. The average values of the visibility thresholds of the BC mass concentrations in spring, summer, autumn and winter were 1.326, 5.522, 1.340 and 0.708 µg/m3, respectively. The greater the relative humidity, the smaller the visibility threshold for the BC mass concentrations was.


Assuntos
Poluentes Atmosféricos/análise , Rios , Carbono/análise , China , Monitoramento Ambiental , Material Particulado , Estações do Ano
20.
Environ Monit Assess ; 192(9): 591, 2020 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-32820457

RESUMO

Identifying an ozone pollution zone during the pollution processes is significant for ozone pollution management and environmental health risk assessment. However, few studies have focused on ozone pollution zone identification during pollution processes. A spatial-temporal clustering framework for identifying pollution zones during ozone pollution processes was initially proposed in this study, and an ozone pollution process in China in May 2017 was selected as a case. The results showed that the framework can help selecting one more accurate method to identify the pollution zone according to the pollution characteristics of air pollution process. In addition, different ozone pollution zone identification methods work well in different scenarios: The self-organizing map (SOM) method was suitable for identifying the zone with the duration of pollution between 24 and 48 h, the image fusion based on wavelet transform (IFbWT) method for the zone with the duration of pollution over 48 h and the Apriori method for the zone with obvious boundaries between high-value and low-value ozone concentrations. The proposed procedure can also be applied to identify the pollution zone of the pollution process of other pollutants.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Ozônio/análise , China , Monitoramento Ambiental
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