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1.
Environ Monit Assess ; 191(11): 641, 2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31586255

RESUMO

The aim of this study was to determine concentrations of antimony and barium in air quality samples and assess the potential suitability of these metals as tracer elements for non-exhaust traffic emissions sources. Air quality filters sampled at monitoring sites around the UK for the purposes of the UK Heavy Metals Monitoring Network were subjected to microwave digestion in hydrogen peroxide and nitric acid, then analysed by ICP-MS for a suite of metals including antimony and barium. The average antimony concentration found across all the network sites was 1.84 ng m-3; the average barium concentration was 6.33 ng m-3. The range of antimony concentrations observed was 0.13-8.02 ng m-3; barium concentrations ranged from levels below the detection limit of 0.18 to 39.9 ng m-3. There are no legislative limits for antimony and barium in ambient air, but the maximum concentrations found are well below the Workplace Exposure Limits specified by the UK Health and Safety Executive. The highest concentrations were found at roadside sites situated to monitor traffic environments, supporting the suitability of antimony and barium to be considered tracer elements for traffic emissions sources. Strong correlations were observed between antimony, barium and copper, indicating they share a common traffic-related source. Based on the strong correlation with copper at urban and traffic locations, indicative annual UK atmospheric emission estimates for antimony and barium in brake and tyre wear were calculated as 6 and 19 tonnes respectively.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Antimônio/análise , Bário/análise , Monitoramento Ambiental/métodos , Emissões de Veículos/análise , Reino Unido
2.
Chemosphere ; 220: 993-1002, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31543100

RESUMO

Biodiesel or renewable diesel fuels are alternative fuels produced from vegetable oil and animal tallow that are being considered to help reduce the use of petroleum-based fuels and emissions of air pollutants including greenhouse gases. Here, we analyzed the gene expression of inflammatory marker responses and the cytochrome P450 1A1 (CYP1A1) enzyme after exposure to diesel and biodiesel emission samples generated from an in-use heavy-duty diesel vehicle. Particulate emission samples from petroleum-based California Air Resource Board (CARB)-certified ultralow sulfur diesel (CARB ULSD), biodiesel, and renewable hydro-treated diesel all induced inflammatory markers such as cyclooxygenase-2 (COX)-2 and interleukin (IL)-8 in human U937-derived macrophages and the expression of the xenobiotic metabolizing enzyme CYP1A1. Furthermore, the results indicate that the particle emissions from CARB ULSD and the alternative diesel fuel blends activate the aryl hydrocarbon receptor (AhR) and induce CYP1A1 in a dose- and AhR-dependent manner which was supported by the AhR luciferase reporter assay and gel shift analysis. Based on a per mile emissions with the model year 2000 heavy duty vehicle tested, the effects of the alternative diesel fuel blends emissions on the expression on inflammatory markers like IL-8 and COX-2 tend to be lower than emission samples derived from CARB ULSD fuel. The results will help to assess the potential benefits and toxicity from biofuel use as alternative fuels in modern technology diesel engines.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Biocombustíveis/toxicidade , Citocromo P-450 CYP1A1/metabolismo , Gasolina/toxicidade , Mediadores da Inflamação/metabolismo , Macrófagos/patologia , Receptores de Hidrocarboneto Arílico/fisiologia , Emissões de Veículos/toxicidade , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Animais , Biocombustíveis/análise , Gasolina/análise , Humanos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Emissões de Veículos/análise
3.
Environ Pollut ; 252(Pt B): 1863-1871, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31369942

RESUMO

Alternative transportation fuels (ATFs) can reduce air pollution. However, the influence of conventional fuels-diesel and gasoline, and particularly ATFs on photochemical air pollution is not well-characterized, limiting assessments of ATFs and air quality. This is mainly due to frequent use of lumped chemical mechanisms by related atmospheric modeling. Here we hypothesized that applying a chemical mechanism that is specifically developed according to both emission fractions and photochemical ozone creation potential of volatile organic compounds (VOCs) is key to gaining reliable insights into the impact of transportation fuels on photochemistry. We used a heterogeneous chemical mechanism with 927 reactions and relatively detailed emission inventories to specifically meet the requirements for reliable simulation of the effect of exhaust emissions from vehicles fueled by selected model fuels-diesel, gasoline, and mixtures of 15% gasoline with 85% ethanol (E85) or 85% methanol (M85)-on photochemistry. These dispersion-box model simulations revealed a strong influence of atmospheric background balance between VOCs and nitrogen oxides (NOX = [NO] + [NO2]) on the impact of exhaust emissions on photochemistry, with higher tendency toward ozone (O3) formation or destruction for more VOC-limited or NOX-limited conditions, respectively. Accordingly, higher [NOX]/[VOC] exhaust emission, such as from diesel and M85, resulted in lower O3, not only locally but also downwind of the emission. This offers a new perspective and measure for transportation fuel assessment. Rapid conversion of O3 to hydroxyl and hydroperoxyl radicals downwind of the exhaust emission indicates the importance of simulating the impact of road transportation on photochemistry at high spatial and temporal resolution. Peroxyacetyl nitrate formation was more sensitive to VOC emission under VOC-limited conditions than to NOX emission under NOX-limited conditions. Secondary formaldehyde dominated over primary emitted formaldehyde several minutes after emission. These findings should be verified using a 3D modeling study under varying meteorological conditions.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Gasolina/análise , Óxidos de Nitrogênio/análise , Ozônio/análise , Emissões de Veículos/análise , Radical Hidroxila/análise , Modelos Teóricos , Fotoquímica , Transportes , Compostos Orgânicos Voláteis/análise
4.
Sci Total Environ ; 687: 720-731, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31412475

RESUMO

A computational system consisting of an urban mobility simulator, validated fluid dynamics and an integral exposure model, is proposed to obtain cyclist and pedestrian exposure to PMx and NOx. Pedestrian activities in the urban anthroposphere include walking and running. The computational experiments take place in a computer-generated urban canyon, subject to emissions from diesel and gasoline Euro 5 and Euro 6 vehicular technologies, in continuous and stop-and-go traffic scenarios, and three wind directions at two speeds. The exposure time in the computational domain of slow and fast pedestrians were obtained. Slow pedestrians had exposure times around 17% more than fast pedestrians due to their higher sidewalk residence time. Runners and cyclists decreased their exposures by 57% and 73% respectively compared with walkers. Two traffic scenarios are implemented: one due the presence of a hump and another without a hump. The presence of the hump, increased exposure and fuel consumption by 60% per heavy duty vehicle, about 44-48% per light duty vehicle and about 54-71% per passenger car. Vehicular technology had a large influence on exposure: Heavy duty-Euro 6 vehicle decreased 86% the exposure to PM2.5 and 66% to NOX with respect to Euro 5. The proposed computational system provides information on how wind velocity influenced the inhomogeneous pollutant distribution in the street-canyon, causing exposure to be dependent on pedestrian route location. Microscale sidewalk areas in the order of meters containing higher concentrations were thus located. The cleanest routes in the urban canyon were identified. When the wind intensity doubled from 2 to 4 m s-1, exposure concentration decreased around 45%. The proposed system provides a computational platform to study urban atmospheric fluids, scenarios such as pedestrian routes, vehicular technologies, traffic velocities, meteorological conditions and urban morphology affecting pollution exposure.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/estatística & dados numéricos , Exposição Ambiental/estatística & dados numéricos , Emissões de Veículos/análise , Exposição Ambiental/análise , Humanos , Hidrodinâmica , Pedestres
5.
Ecotoxicol Environ Saf ; 183: 109552, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31442804

RESUMO

To study source-specific carcinogenicity and mutagenicity of polycyclic aromatic hydrocarbons (PAHs) under diverse anthropogenic activities, PM2.5-bound PAHs were detected in Beijing in four periods. PAHs in Asia-Pacific Economic Cooperation meeting (APEC) was much lower than that in after-APEC period. The highest PAHs concentration was in heating period (303 ng/m3). Sources were quantified by Positive Matrix Factorization (PMF). In heating period, due to high emissions, weak diffusion, low degradation and evaporation, high contributions of all sources were observed, and both absolute and relative contributions of coal combustion increased. Changed contributions in during-APEC and after-APEC periods implied effectiveness of reinforced emission control, especially for coal combustion and vehicles. Furthermore, variations of sources-specific carcinogenicity and mutagenicity were investigated. In non-heating period, contributions of gasoline exhaust (38.4% TEQ: Toxic Equivalent Quantity, 33.7% MEQ: Mutagenic Equivalent Quantity) and diesel exhaust (53.8% TEQ, 57.9% MEQ) dominated both carcinogenic and mutagenic risks. Coal combustion sharply increased in heating period, attributing 27.5% TEQ and 21.7% MEQ. In during-APEC period, all contributions to carcinogenicity and mutagenicity were lower than those in after-APEC period, but "others" linked with regional transport contributed increased fractions (above 20%). Sources-specific carcinogenicity and mutagenicity under diverse anthropogenic activities, especially for APEC meeting with reinforced control, gave a new insight into assessment of control measures based on health risks.


Assuntos
Poluentes Atmosféricos/análise , Carcinógenos/análise , Monitoramento Ambiental/métodos , Mutagênicos/análise , Material Particulado/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Atmosféricos/toxicidade , Pequim , Carcinógenos/toxicidade , China , Carvão Mineral/análise , Carvão Mineral/toxicidade , Calefação , Atividades Humanas , Mutagênicos/toxicidade , Tamanho da Partícula , Material Particulado/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Emissões de Veículos/análise , Emissões de Veículos/toxicidade
6.
Environ Pollut ; 254(Pt B): 113046, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31454587

RESUMO

Parent polycyclic aromatic hydrocarbons (PPAHs) in the ambient air of the coastal cities near the Bohai and Yellow Seas were measured over a full year. The range and geometric average of total PPAH29 (29 species) were 5.16-1.22 × 103 and 118 ng/m3, respectively, with 77 ±â€¯14% in a gaseous phase. The 16 priority components accounted for 90 ±â€¯4% of the total mass concentration. The incremental life cancer risk (ILCR) via inhalation exposure to the PPAHs (3.17 × 10-4) was underestimated by 80%, as only the priority PPAHs were considered. The air concentrations of PPAHs in the Bohai Sea area were generally higher (p < 0.01) than those in the Yellow Sea area. A significant increase (p < 0.01) in the levels of PPAHs and large fractions of high molecular weight (HMW) components were observed in winter. Absorption by particulate organic carbon dominated in gas-particle partitioning of the PPAHs, and the seasonal variations in gas-particle partitioning of the low and moderate molecular weight compounds were more noticeable relative to the HMW species. In summer, significantly higher concentrations of PPAHs were found in the daytime than during nighttime, while the opposite case occurred in winter (p < 0.05). The positive matrix factorization (PMF) results indicated greater contributions of coal and biomass combustion to the PPAH emissions in the coastal cities of the Bohai Sea area compared with the Yellow Sea area. The burning of coal and biomass served as the main source of PPAHs in winter, while traffic exhaust was the dominant source in other seasons. The potential source contribution function (PSCF) revealed the important impacts of the external inputs on the local PPAHs via air mass transport. The contributions of the resolved emission sources to the ILCR were clearly different from those of the mass concentrations, indicating the necessity for source-oriented risk assessments.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Hidrocarbonetos Policíclicos Aromáticos/análise , China , Cidades , Carvão Mineral/análise , Poeira , Exposição por Inalação , Oceanos e Mares , Material Particulado/análise , Medição de Risco , Estações do Ano , Emissões de Veículos/análise
7.
An Acad Bras Cienc ; 91(3): e20180334, 2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31411254

RESUMO

The aim of this study is to discuss the concentration distribution, composition and possible sources of trace metals and 13 PAHs in topsoils of the University campus, in the city of São Paulo, the largest city of South America. Mineralogy and granulometry of topsoils (0-10 cm) samples, were determined and As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Sb, V, Zn, Hg, Pt, Pd and PAHs concentrations were quantified in the bulk fraction. The average clay content of soils was 221±61.8 g kg-1 and total carbon was low (mean of 25 g kg-1). Concentrations of metals were generally lower than the reference value established by the São Paulo State Environmental Agency and other studies in the São Paulo urban area, except for Cd, Ni, Pb, Cr and Zn. The mean concentration of the sum of 13 PAHs was 0.33 mg kg-1 and fluorene, indeno(1,2,3-cd)pyrene, anthracene, pyrene and benzo(ghi)perylene were the most abundant compounds. PAHs and trace metals variability were constrained in PMF analysis and showed an association with exhaust and non-exhaust vehicular emissions. The results also pointed out a spatial pattern in the campus area related to traffic conditions and intensity and terrain slope.


Assuntos
Metais Pesados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Solo/química , Oligoelementos/análise , Universidades , Brasil , Cidades , Monitoramento Ambiental , Humanos , Metais Pesados/química , Hidrocarbonetos Policíclicos Aromáticos/química , Medição de Risco , Análise Espacial , Oligoelementos/química , Poluição Relacionada com o Tráfego/análise , Emissões de Veículos/análise
8.
Bull Environ Contam Toxicol ; 103(4): 604-609, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31410499

RESUMO

This paper assesses the impact of vehicle emissions on energy stores in assimilation organs of five plant species on plots at different distances from the highway. On more remote plots (500 m away from the road) with lower level of pollutants there was a significant increase in the amount of energy in leaves of Negundo aceroides, Quercus rubra and Anthriscus sylvestris. The increase of energy in Quercus cerris was negligible and in the case of Fraxinus excelsior was even recorded a decrease in energy store. The tightness of the relationships between energy accumulated in plant leaves and the distance from the highway was as follows: N. aceroides > Q. cerris > Q. rubra > A. sylvestris. The most suitable for energy biomonitoring appear N. aceroides and A. sylvestris, which in the period of full highway operation bound significantly less energy than before its construction. Q. cerris have demonstrated greater ability to accumulate energy on Cambisols, F. excelsior on Fluvisols.


Assuntos
Monitoramento Ambiental , Veículos Automotores , Plantas , Emissões de Veículos/análise , Folhas de Planta/metabolismo , Quercus/fisiologia
9.
Environ Sci Pollut Res Int ; 26(26): 26617-26627, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31292869

RESUMO

A comparative experiment was conducted based on a non-road diesel engine to investigate the effects of two after-treatment devices on the engine's emission characteristics as well as their power and fuel consumption performances. The first after-treatment device is a combination of a diesel oxidation catalyst (DOC) and a catalytic diesel particulate filter (CDPF). The second device is a single CDPF-coated improved noble metal catalyst. Results showed that the two after-treatment devices had almost no effect on the power and fuel consumption performance. The gaseous and particulate emissions of the engine depended on the operation conditions including the speed and load. However, the dual DOC+CDPF system and the single CDPF reduced more than 81% of the carbon monoxide (CO) and 73% of the hydrocarbon (HC) emissions. Notably, the reduction efficiency by the single CDPF was higher than that of the DOC+CDPF system. In terms of the particulate emissions, both after-treatment devices achieved more than 96% reduction of the particle number (PN) and up to 88% reduction of the particulate mass (PM). Similarly, the single CDPF outperformed the dual DOC+CDPF system in reducing particle emissions. Although no changes occurred in the bimodal particle size distribution of the engine after the installation of the two after-treatment devices, they performed differently in reducing particles with different sizes. The particles reduction efficiency of the DOC+CDPF system was higher than that of the single CDPF for the particles smaller than 14.3 nm, and this trend converted for particles larger than 14.3 nm. Improving the noble metal catalyst load in the CDPF ensured a performance that rivaled the DOC+CDPF system. Apart from the NOx emissions, the installation of a single CDPF with an improved noble metal catalyst load can make the non-road diesel engine meet the limits of the China IV emission regulations.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/prevenção & controle , Gasolina , Emissões de Veículos/análise , Monóxido de Carbono/análise , Catálise , China , Hidrocarbonetos/análise , Oxirredução , Emissões de Veículos/prevenção & controle
10.
Environ Sci Pollut Res Int ; 26(26): 26646-26663, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31292872

RESUMO

Organic carbon (OC) and elemental carbon (EC) were measured in 24 h fine particulate matter (PM2.5) samples collected from May 2015 to April 2016 at urban and rural sites in Nanchong, a rapidly urbanized but low-level industrialized city in the Sichuan Basin, China. The annual average PM2.5, OC, and EC concentrations at urban sites were 45.6-55.7, 8.5-11.5, and 2.8-3.4 µg m-3, respectively, which were similar to the corresponding values (48.3, 10.6, and 3.3 µg m-3) at the rural site. The PM2.5 concentrations displayed strong monthly variations, with the highest (78.8-105.0 µg m-3) in January or February. Likewise, daily OC and EC concentrations exhibited high values in October (only for OC) and December 2015 to February 2016. Correlation, positive matrix factorization, and concentration weighted trajectory analyses were combined to investigate the sources of carbonaceous aerosol. The results indicated that OC and EC were mainly from biomass burning (60.7% and 45.8%) and coal combustion (30.2% and 25.7%), followed by vehicle emissions and road dust. The enhanced emissions from residential coal and biofuel uses in winter and straw combustion in October contributed to higher concentrations of OC and EC during these months. The contributions of biomass burning to OC and EC were significantly higher at the rural site (69.2% and 51.8%) than urban sites (56.3-58.6% and 37.8-41.5%). In addition to local emissions, the high concentrations of OC and EC at Nanchong were also influenced by regional transport in the basin.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Material Particulado/análise , Urbanização , Biomassa , Carbono/análise , China , Cidades , Carvão Mineral/análise , Poeira/análise , Monitoramento Ambiental/métodos , Desenvolvimento Industrial , Estações do Ano , Emissões de Veículos/análise
11.
Environ Sci Pollut Res Int ; 26(26): 26577-26592, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31292877

RESUMO

Mobile sources are considered to be one of the most important sources of air pollution among which are motor vehicles, recognized as the major contributor of air pollutants in urban areas. To determine the emissions for CO, SO2, and NO2 from motor vehicles as part of the attempt to realize the extent of traffic air pollution, measurements were carried out in two heavily traversed traffic tunnels in Tehran metropolitan area. The concentrations of pollutants and metrological and traffic data were collected through intensive measurements from September 27 to October 17, 2016. Resalat Tunnel fleet was composed of about 10% diesel-fueled vehicles and 90% non-diesel-fueled vehicles while throughout the entire duration of our campaign, only non-diesel-fueled vehicles traversed Niayesh Tunnel. Under an average traffic speed of 43 km h-1, emission factors from Resalat Tunnel campaign were measured to be (6.59 ± 2.69)E+3, (1.42 ± 0.84)E+2, and 6.80 ± 4.99 mg km-1 for CO, SO2, and NO2, respectively. These values were respectively 11% higher, 22% lower, and 40% higher than those from Niayesh Tunnel measurements which were recorded at a traffic speed of 30 km h-1. Current results indicate that the vehicular emissions in certain countries, especially the developing ones and in this case, Iran, are quite different from those measured in developed countries and that the high emission levels of SO2 in Iran are associated with the high sulfur content of the gasoline.


Assuntos
Poluentes Atmosféricos/análise , Dióxido de Carbono/análise , Monitoramento Ambiental , Dióxido de Nitrogênio/análise , Dióxido de Enxofre/análise , Emissões de Veículos , Monitoramento Ambiental/métodos , Gasolina , Humanos , Irã (Geográfico) , Veículos Automotores , Emissões de Veículos/análise
12.
Chemosphere ; 235: 726-733, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31279123

RESUMO

As yet, the effect of biodiesels on the emissions of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from heavy-duty diesel engines (HDDEs) has only been studied using limited fuel blend ratios. To clarify the influence of using higher fractions of biodiesel on the emissions of toxic organic pollutants from diesel engines, in this research, the emissions of PM, PAHs, and persistent organic pollutants (POPs) from EURO IV and EURO III HDDEs fueled by low to high waste cooking oil (WCO)-based biodiesel-petrodiesel fuel blends were studied, including D100 (0% biodiesel), B20 (20%), B40 (40%), B60 (60%), B80 (80%), and B100 (100%). The engines were tested according to the US FTP-75 test procedure. The results for the EURO IV diesel engine showed that the PM and toxic organic pollutant emissions were reduced with increases in the blending ratio up until the B60 scenario when compared to the D100 scenario. This is because biodiesel has higher oxygen content and no or lower aromatic content than petrodiesel. Nevertheless, during the B80 and B100 scenarios, the PM and toxic organic pollutant emissions increased due to the high viscosity property of biodiesel, which negatively affected the combustion process. The biodiesel effect on the emissions from EURO III engine was more pronounced because of its lower combustion efficiency, and therefore the improvement in combustion using biodiesel resulted in greater PCDD/F reductions.


Assuntos
Poluentes Atmosféricos/análise , Biocombustíveis/análise , Emissões de Veículos/análise , Culinária , Dibenzofuranos , Poluentes Ambientais , Gasolina/análise , Dibenzodioxinas Policloradas/análise , Hidrocarbonetos Policíclicos Aromáticos/análise
13.
Environ Pollut ; 252(Pt B): 1819-1827, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31299511

RESUMO

Twenty-six polycyclic aromatic hydrocarbons (PAHs) and four synthetic musk compounds (SMCs) accumulated by Masson pine needles from different areas of Shanghai were investigated in the present study. Concentrations of Σ26PAHs (sum of 26 PAHs) ranged from 234 × 10-3 to 5370 × 10-3 mg kg-1. Levels of Σ26PAHs in different sampling areas followed the order: urban areas (Puxi and Pudong) > suburbs > Chongming. Total concentrations of 16 USEPA priority PAHs ranged from 225 × 10-3 to 5180 × 10-3 mg kg-1, ranking at a relatively high level compared to other regions around the world. Factor analysis and multi-linear regression model has identified six sources of PAHs with relative contributions of 15.1% for F1 (vehicle emissions), 47.8% for F2 (natural gas and biomass combustion), 7.8% for F3 (oil), 10.6% for F4 (coal combustion), 15.7% for F5 ("anthracene" source) and 3.0% for F6 (coke tar). Total concentrations of 4 SMCs varied between 0.071 × 10-3 and 2.72 × 10-3 mg kg-1 in pine needles from Shanghai. SMCs with the highest detected frequency were Galaxolide and musk xylene, followed by musk ketone and Tonalide. The highest level of SMCs was found near industrial park and daily chemical plant. The results obtained from this study may have important reference value for local government in the control of atmospheric organic pollution.


Assuntos
Monitoramento Ambiental/métodos , Poluição Ambiental/análise , Ácidos Graxos Monoinsaturados/análise , Pinus/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluição do Ar/análise , China , Carvão Mineral/análise , Coque/análise , Poluição Relacionada com o Tráfego/análise , Emissões de Veículos/análise
14.
Environ Sci Pollut Res Int ; 26(24): 25190-25207, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31256401

RESUMO

This paper involves discovering effective and better reaction of the diesel engine at various velocities by having ideal values in a short period. Therefore, gene expression programming is used for modeling and presenting governing expression for the related factors. The effective parameters consist of engine speed, intake air temperature, rate of air over fuel, fuel mass, NOx emission, mechanical efficiency, and immediate infusion diesel engine used as a part of demonstrating. Gene expression programming and its values exactly predict output results and present precise formula. Moreover, the sensitivity analysis was performed to recognize the effectiveness of the factors for reducing NOx and increasing mechanical efficiency. In the sensitivity analysis, the methods such as partial correlation coefficient, standard regression coefficient, and the Sobol'-Jansen and distributed evaluation of local sensitivity analysis are all used. The obtained results show that air/fuel rate is more influential factor in both NOx emission and mechanical efficiency. Moreover, the difference between results of standard regression or partial correlation coefficients and Sobol'-Jansen or distributed evaluation methods is in nonlinearity effect or interactions among the factors.


Assuntos
Gasolina , Modelos Químicos , Óxidos de Nitrogênio/análise , Emissões de Veículos/análise , Automóveis , Temperatura Ambiente
15.
Environ Pollut ; 253: 259-267, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31319242

RESUMO

Seasonal and diurnal variations of carbonyl compounds were investigated in the ambient air of a mountainous city in China, from September 2014 to July 2015. The most abundant carbonyl compounds are formaldehyde, acetaldehyde and acetone, propionaldehyde and methacryladehyde (MACR), which were all measured in most samples. The average concentrations of formaldehyde, acetaldehyde, acetone, propionaldehyde and MACR in the atmosphere in Changsha were broken down into each season: 6.57, 3.29, 3.66, 0.67 and 0.54 µg/m3 respectively during Spring, 14.09, 8.28, 9.02, 1.28 and 0.6 µg/m3, respectively during Summer, 9.24, 5.48, 8.62, 0.73 and 0.62 µg/m3, respectively during Autumn, and 5.88, 4.84, 7.84, 0.87 and 0.26 µg/m3 respectively during Winter. And majority of the species had higher concentration during noon, showing photochemical oxidation and human activities played an important role in diurnal variation. The highest average C1/C2 (formaldehyde/acetaldehyde) ratio was observed in summer (2.10) compared to those (1.33-2.03) in other seasons, implying the photochemical activities had a positive effect on increasing the ratio of C1/C2. In this study, the monthly concentration of formaldehyde produced from isoprene accounts for 4.8%-39.1% of formaldehyde in ambient air. Strong correlation among some carbonyl compounds means that they came from the same sources. Photochemical reaction was the main source of carbonyl compounds in summer and vehicular exhaust (gasoline and diesel engines) in winter. Changsha is not a completely urbanized city and it is rich in vegetation of broadleaf evergreen shrubs. Both atmospheric photochemical reactions and anthropogenic sources, including vehicular exhaust and industrial processes, dominate the levels of carbonyls. The ILTCR and HQ values of formaldehyde and acetaldehyde are 1.23E-04 and 1.34E-05, 2.80E-01 and 1.86E-01, respectively.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Acetaldeído/análise , Acetona , Aldeídos , Atmosfera/química , China , Cidades , Formaldeído/análise , Humanos , Estações do Ano , Emissões de Veículos/análise
16.
Environ Pollut ; 253: 667-679, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31330358

RESUMO

Many cities fail to meet air quality standards, which results in increased risk for pulmonary disorders, including asthma. Human and experimental studies have shown that diesel exhaust (DE) particles are associated with worsening of allergic asthma. Biodiesel (BD), a cleaner fuel from renewable sources, was introduced in the eighties. Because of the reduction in particulate matter (PM) emissions, BD was expected to cause fewer adverse pulmonary effects. However, only limited data on the effect of BD emissions in asthma are available. OBJECTIVE: Determine whether BD exhaust exposure in allergic sensitized mice leads to different effects on inflammatory and functional responses compared to DE exposure. METHODS: Balb/C mice were orotracheally sensitized with House Dust Mite (HDM) or a saline solution with 3 weekly instillations. From day 9 until day 17 after sensitization, they were exposed daily to filtered air (FA), DE and BD exhaust (concentration: 600 µg/m3 PM2.5). Lung function, bronchoalveolar lavage fluid (BALF) cell counts, cytokine levels (IL-2, IL-4, IL-5, IL-17, TNF-α, TSLP) in the BALF, peribronchiolar eosinophils and parenchymal macrophages were measured. RESULTS: HDM-sensitized animals presented increased lung elastance (p = 0.046), IgG1 serum levels (p = 0.029), peribronchiolar eosinophils (p = 0.028), BALF levels of total cells (p = 0.020), eosinophils (p = 0.028), IL-5 levels (p = 0.002) and TSLP levels (p = 0.046) in BALF. DE exposure alone increased lung elastance (p = 0.000) and BALF IL-4 levels (p = 0.045), whereas BD exposure alone increased BALF TSLP levels (p = 0.004). BD exposure did not influence any parameters after HDM challenge, while DE exposed animals presented increased BALF levels of total cells (p = 0.019), lymphocytes (p = 0.000), neutrophils (p = 0.040), macrophages (p = 0.034), BALF IL-4 levels (p = 0.028), and macrophagic inflammation in the lung tissue (p = 0.037), as well as decreased IgG1 (p = 0.046) and IgG2 (p = 0.043) levels when compared to the HDM group. CONCLUSION: The results indicate more adverse pulmonary effects of DE compared to BD exposure in allergic sensitized animals.


Assuntos
Biocombustíveis/toxicidade , Emissões de Veículos/toxicidade , Alérgenos , Animais , Asma/induzido quimicamente , Biocombustíveis/análise , Líquido da Lavagem Broncoalveolar , Citocinas , Modelos Animais de Doenças , Humanos , Inflamação/induzido quimicamente , Interleucina-17 , Pulmão/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Neutrófilos , Material Particulado/efeitos adversos , Testes de Toxicidade , Emissões de Veículos/análise
17.
Environ Pollut ; 253: 552-559, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31330347

RESUMO

This paper presents a traffic-related air emissions inventory of a developing megacity using a traffic assignment model that results in a detailed temporal and spatial emission representation, disaggregating emissions sources by vehicle type and hour of the day, for five criteria air pollutants.


Assuntos
Poluentes Atmosféricos , Modelos Teóricos , Emissões de Veículos , Poluentes Atmosféricos/análise , Colômbia , Monitoramento Ambiental/métodos , Emissões de Veículos/análise
18.
Environ Pollut ; 253: 731-740, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31336351

RESUMO

The government of China has announced an ambitious plan to expand the mandatory use of ethanol blended gasoline fuels by 2020. Given the dissimilarity in fuel properties between China and other countries with ethanol blending practices, it is necessary to assess the energy and environmental impacts of ethanol blending. In this study, we prepared two types of ethanol blended fuels (E10, with ethanol contents of approximately 10%) with lower contents of aromatics (ELA) and olefins (ELO), respectively, compared with the market China 5 gasoline. Nine in-use gasoline vehicles varying by manufacturer, engine technology, model year, and emission standard level were analyzed using a chassis dynamometer, which followed the Worldwide Harmonized Light Vehicles Test Cycle (WLTC). Two major positive effects from using E10 fuels could be observed in this study. First, tested turbocharged gasoline direct injection (GDI) vehicles could gain reductions in CO2 emission, fuel consumption and energy consumption by switching to the higher-octane-number ELO. This finding, along with the engine development trends in the automotive industry (e.g., downsizing and higher compression ratio), may have a synergistic effect to deliver greater energy efficiency in the future. Second, the two ethanol blended fuels could be more effective in reducing the particle mass (PM) and particle number (PN) emissions than the levels of using China 5 gasoline. Notably, the benefit of using ELO was more significant, with average emission reductions of 35% for the PM and of 44% for the PN. However, ELA and ELO possibly increased emissions of gaseous pollutants for certain vehicles in the study, but the intra-vehicle differences between the various fuel groups were not statistically significant (not significant, p > 0.05, t-test). We suggest that more measurements under various environmental conditions and comprehensive air quality simulations should be conducted to better understand the environmental impacts of ethanol blending in China.


Assuntos
Poluentes Atmosféricos/análise , Etanol , Gasolina/análise , Material Particulado/análise , Emissões de Veículos/análise , Poluição do Ar/análise , China , Poluentes Ambientais , Gases , Veículos Automotores
19.
Environ Monit Assess ; 191(7): 474, 2019 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-31256268

RESUMO

In this study, polybrominated diphenyl ethers (PBDEs) levels in soil were studied for a whole year in highly industrialized region of Turkey (Dilovasi) at 23 sampling sites. Σ8PBDE concentrations were between 0.15 and 286 µg kg-1 and the overall average concentration was 14.45 ± 25.07 µg kg-1 (average ± SD). BDE-209 was the most abundant compound. PBDEs concentrations decreased spatially as follows: industrial/urban > urban > suburban > rural. However, there was not any significant seasonal trend except for some industrial/urban sites. In the region, calm weather conditions prevailed during the sampling periods, enhancing the impact of the industrial emissions on nearby soil concentrations by atmospheric deposition without being diluted by winds. All congeners had significant but weak correlations with soil organic matter content indicating the impact of nearby sources rather than soil properties on soil PBDEs concentrations at the sampling sites. Positive matrix factorization method was also used for the apportionment of the PBDEs sources in Dilovasi soil. Industrial activities (i.e., iron-steel production, metallurgical processes, and recycling of plastics), traffic, and residential areas were found to be the primary sources of the measured PBDEs in the soil.


Assuntos
Éteres Difenil Halogenados/análise , Poluentes do Solo/análise , Emissões de Veículos/análise , Monitoramento Ambiental/métodos , Desenvolvimento Industrial , Indústrias , Solo/química , Turquia
20.
Environ Sci Process Impacts ; 21(8): 1323-1333, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31289797

RESUMO

Semi-volatile organic compounds (SVOCs) are widely used in materials employed in vehicle interiors, causing poor in-cabin air quality. The emission characteristics of SVOCs from vehicle cabin materials can be characterized by two key parameters: the gas-phase SVOC concentration adjacent to the material surface (y0) and the convective mass transfer coefficient across the material surface (hm). Accurate determination of y0 and hm is fundamental in investigating SVOC emission principles and health risks. Considering that the steady state SVOC concentration (y) in a ventilated chamber changes with the ventilation rate (Q), we developed a varied ventilation rate (VVR) method to simultaneously measure y0 and hm for typical vehicle cabin materials. Experimental results for di(2-ethylhexyl)phthalate (DEHP) emissions from test materials indicated that the VVR method has the merits of simple operation, short testing time, and high accuracy. We also examined the influence of temperature (T) on y0 and hm, and found that both y0 and hm increase with increasing temperature. A theoretical correlation between y0 and T was then derived, indicating that the logarithm of y0T is linearly related to 1/T. Analysis based on the data from this study and from the literature validates the effectiveness of the derived correlation. Moreover, preliminary exposure analysis was performed to assess the health risk of DEHP in a vehicular environment.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Dietilexilftalato/análise , Manufaturas/análise , Veículos Automotores/normas , Compostos Orgânicos Voláteis/análise , Temperatura Ambiente , Emissões de Veículos/análise , Ventilação
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