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1.
Environ Pollut ; 253: 1030-1037, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31434180

RESUMO

OBJECTIVES: Evaluate the relationship between arthritis diagnosis in those over 50 and exposure to extreme air pollution in utero or infancy (<1 year of age). METHODS: Compare rates of arthritis diagnosis between groups that experienced differential air pollution exposure in early-life due to quasi-random variation in birth location and date relative to the 1952 Great Smog in London. We use regression-estimated difference-in-differences analyses based on English Longitudinal Study of Aging (ELSA) data. RESULTS: In the 2816 respondent sample, aged 51-62, the arthritis diagnosis rate is 22.8%, with 16.4% reporting osteoarthritis and 4.6% reporting rheumatoid arthritis. We estimate that exposure to the Great Smog in infancy increases the arthritis diagnosis rate by 23.4 percentage points (95% CI: 1.97 to 44.8). Decomposing these results by type of arthritis reveals that the rheumatoid arthritis diagnosis rate increases due to infant exposure are larger and more significant than those for osteoarthritis: 14.9 percentage points (95% CI: 0.495 to 29.4) versus 9.5 percentage points (95% CI: -11.9 to 30.8). In utero exposure is not associated with significant increases in arthritis diagnosis rates. CONCLUSIONS: Our results are the first to link early-life air pollution exposure to later-life arthritis diagnoses, and suggest a particularly strong link for RA. These findings are consistent with those of shorter-term, correlational studies, and indicate that health effects of air pollution exposure can span decades and extend beyond cardiopulmonary systems.


Assuntos
Poluição do Ar/estatística & dados numéricos , Artrite/epidemiologia , Exposição Ambiental/estatística & dados numéricos , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Feminino , Humanos , Lactente , Londres/epidemiologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Material Particulado/análise , Análise de Regressão , Smog/análise
3.
Environ Pollut ; 252(Pt A): 897-906, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31212251

RESUMO

Atmospheric aerosols have been found to influence the development of planetary boundary layer (PBL) and hence to aggravate haze pollution in megacities. PBL height (PBLH) determines the vertical extent to which the most pollutant effectively disperses and is a key argument in pollution study. In this study, we quantitatively evaluate aerosol radiation effect on PBL, as well as assessment of surface cooling effect and atmosphere heating effect. All the data are measured at a site of Beijing from 2014 to 2017, of which PBLH is retrieved from micro pulse lidar and aerosol optical depth (AOD) from sunphotometer. Case study shows qualitatively that relative high aerosol load reduces PBLH, and in turn causes a high surface PM2.5 concentration. We preliminarily reveal the influential mechanism of aerosol on PBL. The influence of aerosol on the radiation flux of PBL is analyzed, with the correlation coefficient (R) of 0.938 between AOD and radiative forcing of BOA (RFBOA) and R = 0.43 between RFBOA and PBLH. Also, AOD is found to negatively correlate with PBLH (R = -0.41). With the increase of AOD, the cooling effect of surface is enhanced, and further impede the development of PBL. Due to aerosol-induced reduction of PBLH, near surface PM2.5 concentration surges and presents an exponential growth following AOD. Then, it is speculated and testified that the relationship between SSA (single scatting albedo) and PBLH would be determined by the location of absorbing aerosol within PBL. The upper PBL absorbing aerosol may decrease PBLH, while the lower absorbing aerosol appear to enhance PBLH. The study probably can provide effective observational evidence for understanding the effect of aerosol on PBL and be a reference of air pollution mitigation in Beijing and its surrounding areas.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Monitoramento Ambiental/métodos , Smog/análise , Atmosfera/química , Pequim
5.
Cent Eur J Public Health ; 27(4): 305-311, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31951690

RESUMO

OBJECTIVES: To our knowledge this is the first study measuring personal exposure to carcinogenic polycyclic aromatic hydrocarbons (cPAHs) bound to airborne particulate matter ≤ 2.5 µm (PM2.5) in periods of high air pollution (smog episode) in which citizen were tracked. METHODS: Measurements were performed in industrial regions of the Czech Republic: Ostrava, Karviná, Havírov. The city of Prague served as a control. Personal monitoring was conducted by active personal monitors for 48 hours. Non-smoking city policemen from Prague, Karviná and Havírov, office workers from Ostrava city and volunteers from Ostrava-Radvanice and Bartovice participated in the study (N = 214). RESULTS: The average personal exposure to benzo[a]pyrene (B[a]P) was highest in Ostrava (17.2 ng/m3), followed by Karviná, Havírov, Radvanice and Bartovice, and Prague (14.2, 12.0, 9.3, and 2.8 ng/m3, respectively). We tested for association between the personal exposure to cPAHs and various health-related factors extracted from the questionnaires, including lifestyle factors and day-to-day activities. CONCLUSIONS: Exposure to outdoor cPAHs, environmental tobacco smoke (ETS), commuting, and time spent indoors (in restaurants, workplace or home) were found to be the main determinants of the personal exposure. Daily cPAHs measurements in highly polluted areas are needed for evaluating the personal exposure and to avoid its underestimation resulting from stationary monitoring.


Assuntos
Poluição do Ar/análise , Exposição Ambiental/estatística & dados numéricos , Hidrocarbonetos Policíclicos Aromáticos/análise , Smog/análise , Cidades , República Tcheca , Monitoramento Ambiental , Humanos
7.
Environ Pollut ; 242(Pt B): 1308-1318, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30121485

RESUMO

Analysis of observed PM2.5 in Beijing since 2009 reveals that winter haze over North China Plain (NCP) peaked in 2012 and 2013 and there was an improvement in air quality until 2016. The variation of wintertime PM2.5 from 2009 to 2016 is influenced by both emission changes and meteorology conditions, and we quantified the relative contributions from these two aspects. Sensitivity simulation by GEOS-Chem suggested that emission reductions over NCP in 2013-2017 caused 10% decrease of regional mean PM2.5 concentration in 2016 winter compared to 2012 winter level. We removed emission influence on PM2.5 to get PM2.5 that influenced by meteorology (met-influenced PM2.5). For met-influenced PM2.5, compared to original-observed PM2.5(the US Embassy data), percentage of clean days (daily PM2.5 ≤ 75 µg m-3) decreases while that of polluted (75 µg m-3 < daily PM2.5 ≤150 µg m-3) and heavily polluted (150 µg m-3 < daily PM2.5 ≤ 250 µg m-3) days increases. However, proportion of extremely polluted (daily PM2.5 > 250 µg m-3) days stays unchanged, even if emission reduction is doubled, indicating that the extremely polluted situation over NCP is dominated by meteorological conditions, and emission control from 2013 to 2017 has little effects on the extremely polluted days. We developed an effective haze day index (HDI) to represent the weather conditions conducive to haze days. HDI is constructed based on the normalized near surface meridional wind (V850), temperature difference (δT) between near surface (850 hPa) and upper atmosphere (250 hPa), and the relative humidity at 1000 hPa (RH1000). HDI is skillful to detect 72% of the severe haze days (daily PM2.5 > 150 µg m-3). On average, the anomalously high V850 is the main cause of severe haze, while in 2012 winter, RH1000 favorable for secondary aerosols' formation is the largest contributor to haze.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Material Particulado/análise , Smog/análise , Atmosfera/análise , Pequim , China , Monitoramento Ambiental , Estações do Ano , Tempo (Meteorologia) , Vento
8.
J Air Waste Manag Assoc ; 68(7): 643-655, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29432064

RESUMO

Observations of smog over the Los Angeles Basin (LAB) links high oxidant mixing ratios with poor visibility, sometimes <5 km. By the 1970s, investigators recognized that most of the aerosol affecting visibility was from gaseous oxidation products, sulfate, nitrate, and organic carbon. This led to the 1972-1973 Aerosol Characterization Experiment (ACHEX), which included observations at the ground and from aircraft. Part of ACHEX was the measurement of smog by blimp in a Lagrangian-like format. The experiment on September 6, 1973, demonstrated that a blimp could travel with the wind across the LAB, observing ozone (O3) and precursors, and particles of different size ranges. These included condensation nuclei (CN) concentrations dominated by particles of ≤ 0.1 µm diameter and light scattering coefficient (bsc) representing mainly particles of 0.1-2.0 µm diameter. The results indicated a pollutant variation similar to that measured at a fixed site. Ozone was produced in an air mass, reaching a maximum of ~400 ppb in the presence of nitrogen oxides (NOx) and nonmethane hydrocarbons (NMHCs), then declined. Although the photochemistry was developing, bsc grew with O3 mixing ratio to a quasi-steady state at ~9-10 × 10-4 m-1, decreasing in value much later with decease in O3. The light scattering coefficient was found to be positively associated with the O3 mixing ratio, whereas CN concentrations were negatively proportional to O3 mixing ratio. The blimp experiment was supported with aircraft vertical profiles and ground-level observations from a mobile laboratory. The blimp flight obtained combined gas and particle changes aloft that could not be obtained by ground or fixed-wing aircraft measurements alone. The experiment was partially successful in achieving a true Lagrangian characterization of smog chemistry in a constrained or defined "open" air mass. IMPLICATIONS: The Los Angeles experiment demonstrated the use of a blimp as a platform for measurement of air pollution traveling with an air mass across an urban area. The method added unique data showing the relationship between photochemical smog chemistry and aerosol dynamics in smog. The method offers an alternative to reliance on smog chamber and modeling observations to designing air quality management strategies for reactive pollutants.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Aeronaves , Monitoramento Ambiental/métodos , Ozônio/análise , Smog/análise , Monitoramento Ambiental/história , História do Século XX , Los Angeles , Vento
11.
J Air Waste Manag Assoc ; 67(2): 219-230, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27629231

RESUMO

Smog has become a public environmental crisis in most areas of China, and in response, research efforts have mainly focused on the chemical properties of smog and its impact on human health. However, in-depth research on the public's perception of smog has not yet been conducted. A survey of residents living around eight state-controlled atmospheric environmental monitoring sites in Ningbo City was conducted using stratified sampling. The data was statistically analyzed to investigate people's views and behavioral tendencies in smog weather, the influence of different media reports on public outlook, and public opinions on the local atmosphere and pollution management in different areas. The results showed that people's perception of smog differs greatly from actual conditions, indicating that the public opinion tends to deviate when faced with a public crisis. Mainstream media (TV, newspaper, etc.), accounting for 67% of all media sources, are the main source for dissemination of smog information. The main sources of pollution, in order of decreasing contribution, according to residents of Ningbo City are as follows: motor vehicle exhaust, industrial coal combustion, large-scale construction, biomass burning, and kitchen fumes. IMPLICATIONS: Since 2011, most areas of China have been affected by frequent smog. Most research on smog has been concentrated on its causes, alert systems, and prevention measures, whereas in-depth research on the public perception of smog has not yet been conducted. When a risky environmental event such as smog occurs, consequences may be more serious than the event itself will cause if people take irrational measures because of lacking relevant knowledge. Therefore, investigating people's attitude and response to smog is both theoretically and practically significant.


Assuntos
Poluição do Ar/análise , Opinião Pública , Smog/análise , Adulto , Idoso , Poluição do Ar/prevenção & controle , Atitude , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Smog/prevenção & controle , Fatores Socioeconômicos , Inquéritos e Questionários , Adulto Jovem
12.
Artigo em Inglês | MEDLINE | ID: mdl-27669272

RESUMO

Recent studies in PM2.5 sources show that anthropogenic emissions are the main contributors to haze pollution. Due to their essential roles in establishing policies for improving air quality, socioeconomic drivers of PM2.5 levels have attracted increasing attention. Unlike previous studies focusing on the annual PM2.5 concentration (Cyear), this paper focuses on the accumulation phase of PM2.5 during the pollution episode (PMAE) in the Yangtze River Delta in China. This paper mainly explores the spatial variations of PMAE and its links to the socioeconomic factors using a geographical detector and simple linear regression. The results indicated that PM2.5 was more likely to accumulate in more developed cities, such as Nanjing and Shanghai. Compared with Cyear, PMAE was more sensitive to socioeconomic impacts. Among the twelve indicators chosen for this study, population density was an especially critical factor that could affect the accumulation of PM2.5 dramatically and accounted for the regional difference. A 1% increase in population density could cause a 0.167% rise in the maximal increment and a 0.214% rise in the daily increase rate of PM2.5. Additionally, industry, energy consumption, and vehicles were also significantly associated with PM2.5 accumulation. These conclusions could serve to remediate the severe PM2.5 pollution in China.


Assuntos
Poluentes Atmosféricos/provisão & distribução , Poluição do Ar/estatística & dados numéricos , Monitoramento Ambiental , Resíduos Industriais/estatística & dados numéricos , Material Particulado/provisão & distribução , Rios/química , Emissões de Veículos/análise , Poluentes Atmosféricos/efeitos adversos , Poluentes Atmosféricos/análise , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , China , Cidades , Humanos , Resíduos Industriais/efeitos adversos , Resíduos Industriais/análise , Centrais Elétricas , Smog/efeitos adversos , Smog/análise , Urbanização , Compostos Orgânicos Voláteis/efeitos adversos , Compostos Orgânicos Voláteis/provisão & distribução
14.
Environ Pollut ; 218: 86-94, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27552041

RESUMO

Urban air quality in China has been declining substantially in recent years due to severe haze episodes. The reduction of sulfur dioxide (SO2) and nitrogen oxide (NOx) emissions since 2013 does not yet appear to yield substantial benefits for haze mitigation. As the reductions of those key precursors to secondary aerosol formation appears not to sufficient, other crucial factors need to be considered for the design of effective air pollution control strategies. Here we argue that ammonia (NH3) plays a - so far - underestimated role in the formation of secondary inorganic aerosols, a main component of urban fine particulate matter (PM2.5) concentrations in China. By analyzing in situ concentration data observed in major cities alongside gridded emission data obtained from remote sensing and inventories, we find that emissions of NH3 have a more robust association with the spatiotemporal variation of PM2.5 levels than emissions of SO2 and NOx. As a consequence, we argue that urban PM2.5 pollution in China in many locations is substantially affected by NH3 emissions. We highlight that more efforts should be directed to the reduction of NH3 emissions that help mitigate PM2.5 pollution more efficiently than other PM2.5 precursors. Such efforts will yield substantial co-benefits by improving nitrogen use efficiency in farming systems. As a consequence, such integrated strategies would not only improve urban air quality, but also contribute to China's food-security goals, prevent further biodiversity loss, reduce greenhouse gas emissions and lead to economic savings.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Amônia/análise , Cidades , Monitoramento Ambiental/métodos , Smog/análise , Compostos Orgânicos Voláteis/análise , Aerossóis/análise , Poluentes Atmosféricos/química , Amônia/química , China , Poluição Ambiental , Humanos , Óxidos de Nitrogênio/análise , Ozônio , Tamanho da Partícula , Material Particulado/análise , Dióxido de Enxofre/análise , Compostos Orgânicos Voláteis/química
15.
J Environ Sci (China) ; 40: 92-104, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26969549

RESUMO

Molecular speciation of atmospheric organic matter was investigated during a short summer field campaign performed in a citrus fruit field in northern Corsica (June 2011). Aimed at assessing the performance on the field of newly developed analytical protocols, this work focuses on the molecular composition of both gas and particulate phases and provides an insight into partitioning behavior of the semi-volatile oxygenated fraction. Limonene ozonolysis tracers were specifically searched for, according to gas chromatography-mass spectrometry (GC-MS) data previously recorded for smog chamber experiments. A screening of other oxygenated species present in the field atmosphere was also performed. About sixty polar molecules were positively or tentatively identified in gas and/or particle phases. These molecules comprise a wide range of branched and linear, mono and di-carbonyls (C3-C7), mono and di-carboxylic acids (C3-C18), and compounds bearing up to three functionalities. Among these compounds, some can be specifically attributed to limonene oxidation and others can be related to α- or ß-pinene oxidation. This provides an original snapshot of the organic matter composition at a Mediterranean site in summer. Furthermore, for compounds identified and quantified in both gaseous and particulate phases, an experimental gas/particle partitioning coefficient was determined. Several volatile products, which are not expected in the particulate phase assuming thermodynamic equilibrium, were nonetheless present in significant concentrations. Hypotheses are proposed to explain these observations, such as the possible aerosol viscosity that could hinder the theoretical equilibrium to be rapidly reached.


Assuntos
Aerossóis/análise , Aerossóis/química , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/química , Monoterpenos Bicíclicos , Compostos Bicíclicos com Pontes/análise , Cicloexenos/análise , Monitoramento Ambiental/métodos , França , Cromatografia Gasosa-Espectrometria de Massas , Gases/análise , Gases/química , Limoneno , Região do Mediterrâneo , Monoterpenos/análise , Oxirredução , Smog/análise , Terpenos/análise , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química , Tempo (Meteorologia)
16.
Environ Sci Pollut Res Int ; 23(7): 6845-60, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26667647

RESUMO

Extreme haze episodes repeatedly shrouded Beijing during the winter of 2012-2013, causing major environmental and health problems. To better understand these extreme events, particle number size distribution (PNSD) and particle chemical composition (PCC) data collected in an intensive winter campaign in an urban site of Beijing were used to investigate the sources of ambient fine particles. Positive matrix factorization (PMF) analysis resolved a total of eight factors: two traffic factors, combustion factors, secondary aerosol, two accumulation mode aerosol factors, road dust, and long-range transported (LRT) dust. Traffic emissions (54%) and combustion aerosol (27%) were found to be the most important sources for particle number concentration, whereas combustion aerosol (33%) and accumulation mode aerosol (37%) dominated particle volume concentrations. Chemical compositions and sources of fine particles changed dynamically in the haze episodes. An enhanced role of secondary inorganic species was observed in the formation of haze pollution. Regional transport played an important role for high particles, contribution of which was on average up to 24-49% during the haze episodes. Secondary aerosols from urban background presented the largest contributions (45%) for the rapid increase of fine particles in the severest haze episode. In addition, the invasion of LRT dust aerosols further elevated the fine particles during the extreme haze episode. Our results showed a clear impact of regional transport on the local air pollution, suggesting the importance of regional-scale emission control measures in the local air quality management of Beijing.


Assuntos
Poluentes Atmosféricos/análise , Poeira/análise , Smog/análise , Aerossóis/análise , Poluição do Ar/estatística & dados numéricos , Pequim , Monitoramento Ambiental , Análise Fatorial , Tamanho da Partícula , Estações do Ano , Emissões de Veículos/análise , Tempo (Meteorologia)
17.
Int Immunopharmacol ; 26(1): 125-32, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25754765

RESUMO

OBJECTIVE: The present study aimed to investigate the combined effects of puerarin with edaravone on inhalation lung injury induced by black gunpowder smog. MATERIALS AND METHODS: Male Wistar rats were divided into five groups (control group, edaravone group, puerarin group, edaravone combined with puerarin group and inhalation group). The severity of pulmonary injuries was evaluated after inducing acute lung injury. Arterial blood gas, inflammatory cytokines, biochemical, parameters, cell counting, W/D weight ratio and histopathology were analyzed. Results in lung tissues, either edaravone or puerarin treatment alone showed significant protective effects against neutrophil infiltration and tissue injury, as demonstrated by myeloperoxidase activity and histopathological analysis (all p<0.05). In addition, combined treatment with both edaravone and puerarin demonstrated additive protective effects on smog-induced lung injury, compared with single treatment. CONCLUSIONS: Combination of edaravone and puerarin shows promise as a new treatment option for acute lung injury/acute respiratory distress syndrome patients.


Assuntos
Antipirina/análogos & derivados , Exposição por Inalação/efeitos adversos , Isoflavonas/uso terapêutico , Lesão Pulmonar/prevenção & controle , Pulmão/efeitos dos fármacos , Smog/efeitos adversos , Animais , Antipirina/administração & dosagem , Antipirina/uso terapêutico , Líquido da Lavagem Broncoalveolar/química , Líquido da Lavagem Broncoalveolar/citologia , Modelos Animais de Doenças , Quimioterapia Combinada , Edaravone , Isoflavonas/administração & dosagem , Pulmão/imunologia , Pulmão/patologia , Lesão Pulmonar/induzido quimicamente , Lesão Pulmonar/imunologia , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos Wistar , Smog/análise
18.
Environ Sci Pollut Res Int ; 22(2): 1043-53, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25106521

RESUMO

In January 2013, several serious haze pollution events happened in North China. Cimel sunphotometer measurements at an urban site of Beijing (Chinese Academy of Meteorological Sciences-CAMS) from 1 to 30 January 2013 were used to investigate the detailed variation of aerosol optical properties. It was found that Angstrom exponents were mostly larger than 0.80 when aerosol optical depth values are higher than 0.60 at the urban region of Beijing during January 2013. The aerosol optical depth (AOD) at the urban region of Beijing can remain steady at approximately 0.40 before haze happening and then increased sharply to more than 1.50 at 500 nm with the onset of haze, which suggests that the fine-mode AOD is a factor of 20 of the coarse-mode AOD during a serious haze pollution event. The single scattering albedo was approximately 0.90 ± 0.03 at 440, 675, 870 and 1,020 nm during the haze pollution period. The single scattering albedo at 440 nm as a function of the fine-mode fraction was relatively consistent, but it was highly variable at 675, 870 and 1,020 nm. Except on January 12 and 18, all the fine-mode particle volumes were larger than those of coarse particles, which suggests that fine particles from anthropogenic activities made up most of the haze. Aerosol type classification analysis showed that the dominant aerosol types can be classified as both "mixed" and "urban/industrial (U/I) and biomass burning (BB)" categories during the heavy haze period of Beijing in January of 2013. The mixed category occurrence was about 31 %, while the U/I and BB was about 69 %.


Assuntos
Poluentes Atmosféricos/química , Smog/análise , China , Tamanho da Partícula , Fotometria
19.
J Environ Sci (China) ; 26(9): 1894-902, 2014 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-25193840

RESUMO

The aerosol number concentration and size distribution as well as size-resolved particle chemical composition were measured during haze and photochemical smog episodes in Shanghai in 2009. The number of haze days accounted for 43%, of which 30% was severe (visibility<2km) and moderate (2km≤visibility<3km) haze, mainly distributed in winter and spring. The mean particle number concentration was about 17,000/cm(3) in haze, more than 2 times that in clean days. The greatest increase of particle number concentration was in 0.5-1µm and 1-10µm size fractions during haze events, about 17.78 times and 8.78 times those of clean days. The largest increase of particle number concentration was within 50-100nm and 100-200nm fractions during photochemical smog episodes, about 5.89 times and 4.29 times those of clean days. The particle volume concentration and surface concentration in haze, photochemical smog and clean days were 102, 49, 15µm(3)/cm(3) and 949, 649, 206µm(2)/cm(3), respectively. As haze events got more severe, the number concentration of particles smaller than 50nm decreased, but the particles of 50-200nm and 0.5-1µm increased. The diurnal variation of particle number concentration showed a bimodal pattern in haze days. All soluble ions were increased during haze events, of which NH4(+), SO4(2-) and NO3(-) increased greatly, followed by Na(+), K(+), Ca(2+) and Cl(-). These ions were very different in size-resolved particles during haze and photochemical smog episodes.


Assuntos
Smog/análise , Aerossóis/análise , China , Cidades , Ozônio/análise , Tamanho da Partícula
20.
Proc Natl Acad Sci U S A ; 111(29): 10473-8, 2014 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-25002466

RESUMO

Secondary organic aerosol (SOA) formed from the atmospheric oxidation of nonmethane organic gases (NMOG) is a major contributor to atmospheric aerosol mass. Emissions and smog chamber experiments were performed to investigate SOA formation from gasoline vehicles, diesel vehicles, and biomass burning. About 10-20% of NMOG emissions from these major combustion sources are not routinely speciated and therefore are currently misclassified in emission inventories and chemical transport models. The smog chamber data demonstrate that this misclassification biases model predictions of SOA production low because the unspeciated NMOG produce more SOA per unit mass than the speciated NMOG. We present new source-specific SOA yield parameterizations for these unspeciated emissions. These parameterizations and associated source profiles are designed for implementation in chemical transport models. Box model calculations using these new parameterizations predict that NMOG emissions from the top six combustion sources form 0.7 Tg y(-1) of first-generation SOA in the United States, almost 90% of which is from biomass burning and gasoline vehicles. About 85% of this SOA comes from unspeciated NMOG, demonstrating that chemical transport models need improved treatment of combustion emissions to accurately predict ambient SOA concentrations.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Compostos Orgânicos/análise , Atmosfera/química , Metano/análise , Smog/análise , Estados Unidos , Emissões de Veículos/análise
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