scholarly journals Receptor Model Source Apportionment of Nonmethane Hydrocarbons in Mexico City

2002 ◽  
Vol 2 ◽  
pp. 844-860 ◽  
Author(s):  
V. Mugica ◽  
J. Watson ◽  
E. Vega ◽  
E. Reyes ◽  
M.E. Ruiz ◽  
...  
Keyword(s):  
Mexico City ◽  
Motor Vehicle ◽  
Ambient Air ◽  
Nonmethane Hydrocarbons ◽  
Receptor Model ◽  
Liquefied Petroleum Gas ◽  
Vehicle Exhaust ◽  
Source Profiles ◽  
Source Contributions ◽  
Initial Source

With the purpose of estimating the source contributions of nonmethane hydrocarbons (NMHC) to the atmosphere at three different sites in the Mexico City Metropolitan Area, 92 ambient air samples were measured from February 23 to March 22 of 1997. Light- and heavy-duty vehicular profiles were determined to differentiate the NMHC contribution of diesel and gasoline to the atmosphere. Food cooking source profiles were also determined for chemical mass balance receptor model application. Initial source contribution estimates were carried out to determine the adequate combination of source profiles and fitting species. Ambient samples of NMHC were apportioned to motor vehicle exhaust, gasoline vapor, handling and distribution of liquefied petroleum gas (LP gas), asphalt operations, painting operations, landfills, and food cooking. Both gasoline and diesel motor vehicle exhaust were the major NMHC contributors for all sites and times, with a percentage of up to 75%. The average motor vehicle exhaust contributions increased during the day. In contrast, LP gas contribution was higher during the morning than in the afternoon. Apportionment for the most abundant individual NMHC showed that the vehicular source is the major contributor to acetylene, ethylene, pentanes, n-hexane, toluene, and xylenes, while handling and distribution of LP gas was the major source contributor to propane and butanes. Comparison between CMB estimates of NMHC and the emission inventory showed a good agreement for vehicles, handling and distribution of LP gas, and painting operations; nevertheless, emissions from diesel exhaust and asphalt operations showed differences, and the results suggest that these emissions could be underestimated.

scholarly journals Measurements and receptor modeling of volatile organic compounds in Southeastern Mexico City, 2000–2007

2010 ◽  
Vol 10 (18) ◽  
pp. 9027-9037 ◽  
Author(s):  
H. Wöhrnschimmel ◽  
M. Magaña ◽  
W. A. Stahel ◽  
S. Blanco ◽  
S. Acuña ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Mexico City ◽  
Weekend Effect ◽  
Receptor Modeling ◽  
Liquefied Petroleum Gas ◽  
Linear Regression Models ◽  
Vehicle Exhaust ◽  
Source Contributions ◽  
Volatile Organic

Abstract. Ambient samples of volatile organic compounds (VOCs) were measured between 2000 and 2007 in Southeastern Mexico City, quantifying 13 species (ethane, propane, propylene, butane, acetylene, pentane, hexane, heptane, benzene, octane, toluene, nonane, o-xylene). These time series were analyzed for long-term trends, using linear regression models. A main finding was that the concentrations for several VOC species were decreasing during this period. A receptor model was applied to identify possible VOC sources, as well as temporal patterns in their respective contributions. Domestic use of liquefied petroleum gas (LPG) and vehicle exhaust are suggested to be the principal emission sources, contributing together between 70% and 80% to the total of quantified species. Both diurnal and seasonal patterns, as well as a weekend effect were recognized in the modelled source contributions. Furthermore, decreasing trends over time were found for LPG and hot soak (−7.8% and −12.7% per year, respectively, p < 0.01), whereas for vehicle exhaust no significant trend was found.

scholarly journals Non-methane hydrocarbons source apportionment at different sites in Mexico City during 2002–2003

2007 ◽  
Vol 7 (5) ◽  
pp. 13561-13596 ◽  
Author(s):  
E. Vega ◽  
G. Sanchez ◽  
L. Molina
Keyword(s):  
Mexico City ◽  
Rural Areas ◽  
Circulation Pattern ◽  
Receptor Model ◽  
Liquefied Petroleum Gas ◽  
Field Campaign ◽  
Weekly Cycle ◽  
Diesel Vehicles ◽  
Rural Environments ◽  
Gasoline Vehicles

Abstract. The atmospheric concentrations of a variety of non-methane hydrocarbons (NMHC) collected at different sites, representing urban and rural environments within Mexico City Metropolitan Area (MCMA) during 1997, 2002 and 2003 field campaigns, were compared and used as an input for the Chemical Mass Balance (CMB) receptor model to determine the source contribution of NMHC to the atmosphere. A common feature at all the locations was the dominance of alkenes (59%), aromatics (16%) and olefins (9%) in the average NMHC burden. At the urban sites the interquartile range of NMHC concentrations showed stabilization over this period with a slight increase in the concentrations of propane and butanes in the southwest site of the MCMA in 2003 due to the increased use of liquefied petroleum gas (LPG). The receptor model CMB version 8.0 was used to apportion the NMHC sources at six locations within the MCMA, representing the heavily industrialized, commercial, residential and rural areas. For the 2003 field campaign, the contribution of vehicular emissions dominated the NMHC concentrations (19.7%±7.1% for gasoline vehicles and 35.4%±17.5% for diesel vehicles) followed by the emissions of marketing and handling of LPG (29.9%±8.0%). The NMHC concentrations showed a weekly cycle with the highest levels towards the end of the week and lowest at weekend and beginning of the week, suggesting that both emissions and accumulations process play a key role in building up NMHC levels. The toluene to benzene ratio was used to determine photochemical ageing of the air samples during the 2003 field campaign. The database was divided into periods with similar wind circulation pattern; the results suggest that ageing process within the MCMA is generally suppressed by the amount of fresh emissions.

scholarly journals Effectiveness of replacing catalytic converters in LPG-fueled vehicles in Hong Kong

2015 ◽  
Vol 15 (24) ◽  
pp. 35939-35990 ◽  
Author(s):  
X. P. Lyu ◽  
H. Guo ◽  
I. J. Simpson ◽  
S. Meinardi ◽  
P. K. K. Louie ◽  
...  
Keyword(s):  
Hong Kong ◽  
Vehicle Emissions ◽  
Intervention Program ◽  
Control Strategies ◽  
Ambient Air ◽  
Receptor Modeling ◽  
Liquefied Petroleum Gas ◽  
Vehicle Exhaust ◽  
Reduction Percentage

Abstract. Many taxis and public buses are powered by liquefied petroleum gas (LPG) in Hong Kong. With more vehicles using LPG, they have become the major contributor to ambient volatile organic compounds (VOCs) in Hong Kong. An intervention program aimed to reduce the emissions of VOCs and nitrogen oxides (NOx) from LPG-fueled vehicles was implemented by the Hong Kong Government in September 2013. Long-term real-time measurements indicated that the program was remarkably effective in reducing LPG-related VOCs, NOx and nitric oxide (NO) in the atmosphere. Receptor modeling results further revealed that propane, propene, i-butane, n-butane and NO in LPG-fueled vehicle exhaust emissions decreased by 37.3 ± 0.4, 50.2 ± 0.3, 32.9 ± 0.4, 41.1 ± 0.4 and 75.9 ± 0.3 %, respectively, during the implementation of the program. In contrast, despite the reduction of VOCs and NOx, the O3 production following the program increased by 0.25 ± 0.04 ppbv h−1 (4.8 %). Moreover, the production rate of HOx decreased due to the reduction of VOCs, whereas NO reduction resulted in a more significant decrease of the HOx in destruction compared to the decrease in production, and an increase of hydroxyl (OH) and hydroperoxyl (HO2). Analysis of O3-VOCs-NOx sensitivity in ambient air indicated VOC-limited regimes in the O3 formation before and during the program. Moreover, a maximum reduction percentage of NOx (i.e., 29.4 %) and the lowest reduction ratio of VOCs / NOx (i.e., ~ 3 : 1) in LPG-fueled vehicle emissions were determined to give a zero O3 increment. The findings are of great help to future formulation and implementation of control strategies on vehicle emissions in Hong Kong.

Chemical source profiles for particulate motor vehicle exhaust under cold and high altitude operating conditions

1990 ◽  
Vol 93 ◽  
pp. 183-190 ◽  
Author(s):  
J.G. Watson ◽  
J.C. Chow ◽  
L.C. Pritchett ◽  
J.A. Houck ◽  
R.A. Ragazzi ◽  
...  
Keyword(s):  
High Altitude ◽  
Motor Vehicle ◽  
Operating Conditions ◽  
Vehicle Exhaust ◽  
Source Profiles

scholarly journals Cigarette smoke or motor vehicle exhaust exposure induces PD-L1 upregulation in lung epithelial cells in COPD model rats.

2021 ◽  
Author(s):  
Rui Chen ◽  
Defu Li ◽  
Lingling Wang ◽  
Jiahui Dong ◽  
Richeng Xiong ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Air Pollution ◽  
Epithelial Cells ◽  
Cigarette Smoke ◽  
Motor Vehicle ◽  
Ambient Air ◽  
Lung Epithelial Cells ◽  
Ambient Air Pollution ◽  
Vehicle Exhaust ◽  
Lung Epithelial

Abstract Cigarette smoking and ambient air pollution are common risk factors for COPD and lung cancer. However, the underlying mechanism between COPD prevalence and lung cancer is remained elusive. In this study, we established rat COPD model through exposure to cigarette smoke (CS) or motor vehicle exhaust (MVE). The model rats developed COPD-like phenotypes, manifested as lung functions decline, lung inflammation and airway remodeling. The Programmed death-ligand 1 (PD-L1), a factor contributing to immune escape of tumor cells, was overexpressed in lungs from COPD model rats. The inflammatory responses and PD-L1 upregulations were also observed in cultured human bronchial epithelial cells BEAS-2B upon treatment with cigarette smoke extract (CSE) or diesel related particulate matter 2.5 (PM2.5, SEM1650b). Furthermore, both CS/CSE and MVE/PM2.5 induced ERK1/2 activation, a kinase mediating PD-L1 upregulation in premalignant bronchial cells or NSCLC cells, in COPD rats’ lungs or in BEAS-2B cells. Activations of STAT1/3, which was reportedly associated with PD-L1 expression in lung tumors, were detected in lungs from CS- or MVE-induced COPD model rats. However, CSE preferred to activate STAT3 and PM2.5 inclined to activate STAT1 in BEAS-2B cells. Therefore, we proposed that cigarette smoke and ambient air pollution elevate the risk of lung cancer in COPD patients by increasing PD-L1 expression in lung epithelial cells, suggesting the effects of immunesuppressive microenvironment on promoting tumorigenesis in COPD patient’s lung.

scholarly journals Measurements and receptor modeling of volatile organic compounds in south-eastern Mexico City, 2000–2007

2010 ◽  
Vol 10 (2) ◽  
pp. 3319-3346 ◽  
Author(s):  
H. Wöhrnschimmel ◽  
M. Magaña ◽  
W. A. Stahel ◽  
S. Blanco ◽  
S. Acuña ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Mexico City ◽  
Weekend Effect ◽  
Receptor Modeling ◽  
Liquefied Petroleum Gas ◽  
Linear Regression Models ◽  
Vehicle Exhaust ◽  
South Eastern ◽  
Volatile Organic

Abstract. Ambient samples of volatile organic compounds (VOCs) were measured between 2000 and 2007 in south-eastern Mexico City, quantifying 13 species (ethane, propane, propylene, butane, acetylene, pentane, hexane, heptane, benzene, octane, toluene, nonane, o-xylene). These time series were analyzed for long-term trends, using linear regression models. A main finding was that the concentrations for several of the quantified VOC species were decreasing during this period. A receptor model was applied to identify possible VOC sources, as well as temporal patterns in their respective activities. Domestic use of liquefied petroleum gas and vehicle exhaust are suggested to be the principal emission sources, contributing together between 70% and 80% to total VOC. Both diurnal and seasonal patterns, as well as a weekend effect were recognized in the modelled source activities. Furthermore, vehicle exhaust emissions showed a decreasing trend over time, with a reduction of about 8% per year.

scholarly journals Effectiveness of replacing catalytic converters in LPG-fueled vehicles in Hong Kong

2016 ◽  
Vol 16 (10) ◽  
pp. 6609-6626 ◽  
Author(s):  
Xiaopu Lyu ◽  
Hai Guo ◽  
Isobel J. Simpson ◽  
Simone Meinardi ◽  
Peter K. K. Louie ◽  
...  
Keyword(s):  
Hong Kong ◽  
Intervention Program ◽  
Control Strategies ◽  
Ambient Air ◽  
Receptor Modeling ◽  
Positive Contribution ◽  
Liquefied Petroleum Gas ◽  
Vehicle Exhaust ◽  
Reduction Percentage

Abstract. Many taxis and public buses are powered by liquefied petroleum gas (LPG) in Hong Kong. With more vehicles using LPG, they have become the major contributor to ambient volatile organic compounds (VOCs) in Hong Kong. An intervention program which aimed to reduce the emissions of VOCs and nitrogen oxides (NOx) from LPG-fueled vehicles was implemented by the Hong Kong government in September 2013. Long-term real-time measurements indicated that the program was remarkably effective in reducing LPG-related VOCs, NOx and nitric oxide (NO) in the atmosphere. Receptor modeling results further revealed that propane, propene, i-butane, n-butane and NO in LPG-fueled vehicle exhaust emissions decreased by 40.8 ± 0.1, 45.7 ± 0.2, 35.7 ± 0.1, 47.8 ± 0.1 and 88.6 ± 0.7 %, respectively, during the implementation of the program. In contrast, despite the reduction of VOCs and NOx, O3 following the program increased by 0.40 ± 0.03 ppbv (∼  5.6 %). The LPG-fueled vehicle exhaust was generally destructive to OH and HO2. However, the destruction effect weakened for OH and it even turned to positive contribution to HO2 during the program. These changes led to the increases of OH, HO2 and HO2 ∕ OH ratio, which might explain the positive O3 increment. Analysis of O3–VOCs–NOx sensitivity in ambient air indicated VOC-limited regimes in the O3 formation before and during the program. Moreover, a maximum reduction percentage of NOx (i.e., 69 %) and the lowest reduction ratio of VOCs ∕ NOx (i.e., 1.1) in LPG-fueled vehicle exhaust were determined to give a zero O3 increment. The findings are of great help to future formulation and implementation of control strategies on vehicle emissions in Hong Kong, and could be extended to other regions in China and around the world.

Fuel-based motor vehicle emission inventory for the metropolitan area of Mexico city

2005 ◽  
Vol 39 (5) ◽  
pp. 931-940 ◽  
Author(s):  
I. Schifter ◽  
L. Díaz ◽  
V. Múgica ◽  
E. López-Salinas
Keyword(s):  
Mexico City ◽  
Metropolitan Area ◽  
Emission Inventory ◽  
Motor Vehicle ◽  
Vehicle Emission

Impact of sulfur-in-gasoline on motor vehicle emissions in the metropolitan area of Mexico City☆

Fuel ◽  
2003 ◽  
Vol 82 (13) ◽  
pp. 1605-1612 ◽  
Author(s):  
I Schifter ◽  
L Dı́az ◽  
M Vera ◽  
E Guzmán ◽  
E López-Salinas
Keyword(s):  
Mexico City ◽  
Metropolitan Area ◽  
Vehicle Emissions ◽  
Motor Vehicle ◽  
Motor Vehicle Emissions

On the spread of ultrafine particulate matter: A mathematical model for motor vehicle emissions and their effects as an asthma trigger

2021 ◽  
Author(s):  
Michelle N. Rosado-Pérez ◽  
Karen Ríos-Soto
Keyword(s):  
Mathematical Model ◽  
Ultrafine Particles ◽  
Motor Vehicle ◽  
Traveling Wave Solutions ◽  
Reaction Diffusion ◽  
Ambient Air ◽  
Air Pollutant ◽  
Pollutant Emissions ◽  
Motor Vehicles ◽  
Diffusion Type

Asthma is a respiratory disease that affects the lungs, with a prevalence of 339.4 million people worldwide [G. Marks, N. Pearce, D. Strachan, I. Asher and P. Ellwood, The Global Asthma Report 2018, globalasthmareport.org (2018)]. Many factors contribute to the high prevalence of asthma, but with the rise of the industrial age, air pollutants have become one of the main Ultrafine particles (UFPs), which are a type of air pollutant that can affect asthmatics the most. These UFPs originate primarily from the combustion of motor vehicles [P. Solomon, Ultrafine particles in ambient air. EM: Air and Waste Management Association’s Magazine for Environmental Managers (2012)] and although in certain places some regulations to control their emission have been implemented they might not be enough. In this work, a mathematical model of reaction–diffusion type is constructed to study how UFPs grow and disperse in the environment and in turn how they affect an asthmatic population. Part of our focus is on the existence of traveling wave solutions and their minimum asymptotic speed of pollutant propagation [Formula: see text]. Through the analysis of the model it was possible to identify the necessary threshold conditions to control the pollutant emissions and consequently reduce the asthma episodes in the population. Analytical and numerical results from this work prove how harmful the UFEs are for the asthmatic population and how they can exacerbate their asthma episodes.

Sign in / Sign up

Export Citation Format

Share Document