Conformity: Long-Term Prognoses for Selected Ozone Nonattainment Areas in California

1997 ◽  
Vol 1587 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Douglas Thompson ◽  
Michael Baker ◽  
Dennis Wade
Keyword(s):  
Vehicle Emissions ◽  
Motor Vehicle ◽  
Control Strategies ◽  
Planning Horizon ◽  
Oxides Of Nitrogen ◽  
Nitrogen Emissions ◽  
Control Programs ◽  
Motor Vehicle Emissions ◽  
Heavy Duty Vehicle ◽  
Ozone Precursor

The Clean Air Act requires that long-range transportation plans conform to emissions budgets established for nearer-term attainment years in state implementation plans (SIPs). This poses the question of whether travel growth in the intervening period may overwhelm the benefits of fleet turnover and adopted control strategies, with adverse implications for air quality and for conformity. Emissions trends are examined for three planning areas in California that are nonattainment for ozone. Forecasted emissions of ozone precursors for attainment years are compared with projected emissions for 2020. The latest model for estimation of on-road motor vehicle emissions in California is employed to estimate emissions, augmented by estimated effects of additional control strategies from the 1994 California ozone SIP. Alternative higher-growth travel forecasts for two areas, developed in consultation with regional transportation agency modeling staffs, are then applied to test the sensitivity of emissions to various travel growth scenarios. Ozone precursor emissions are found to remain within attainment year baseline levels for each growth scenario. Oxides of nitrogen emissions approach attainment year levels in one area, due to high projected growth in heavy-duty vehicle travel. Demonstrations of conformity to the ozone SIP for transportation planning horizon years are significantly aided by California’s adopted and planned fuels and motor vehicle emissions control programs.

scholarly journals Chemical characterization and source identification of PM<sub>2.5</sub> at multiple sites in the Beijing–Tianjin–Hebei region, China

2017 ◽  
Vol 17 (21) ◽  
pp. 12941-12962 ◽  
Author(s):  
Xiaojuan Huang ◽  
Zirui Liu ◽  
Jingyun Liu ◽  
Bo Hu ◽  
Tianxue Wen ◽  
...  
Keyword(s):  
Coal Combustion ◽  
Vehicle Emissions ◽  
Motor Vehicle ◽  
Control Strategies ◽  
Vehicle Exhaust ◽  
Motor Vehicle Emissions ◽  
Haze Pollution ◽  
Inorganic Aerosol ◽  
Urban Sites ◽  
Bth Region

Abstract. The simultaneous observation and analysis of atmospheric fine particles (PM2.5) on a regional scale is an important approach to develop control strategies for haze pollution. In this study, samples of filtered PM2.5 were collected simultaneously at three urban sites (Beijing, Tianjin, and Shijiazhuang) and at a regional background site (Xinglong) in the Beijing–Tianjin–Hebei (BTH) region from June 2014 to April 2015. The PM2.5 at the four sites was mainly comprised of organic matter, secondary inorganic ions, and mineral dust. Positive matrix factorization (PMF) demonstrated that, on an annual basis, secondary inorganic aerosol was the largest PM2.5 source in this region, accounting for 29.2–40.5 % of the PM2.5 mass at the urban sites; the second-largest PM2.5 source was motor vehicle exhaust, particularly in Beijing (24.9 %), whereas coal combustion was also a large source in Tianjin (12.4 %) and Shijiazhuang (15.5 %), with particular dominance in winter. Secondary inorganic aerosol plays a vital role in the haze process, with the exception of the spring haze in Shijiazhuang and Tianjin, for which the dust source was crucial. In addition to secondary transformations, local direct emissions (coal combustion and motor vehicle exhaust) significantly contribute to the winter haze at the urban sites. Moreover, with the aggravation of haze pollution, the OC ∕ EC mass ratio of PM2.5 decreased considerably and the nitrate-rich secondary aerosol increased during all four seasons in Beijing, both of which indicate that local motor vehicle emissions significantly contribute to the severe haze episodes in Beijing. To assess the impacts of regional transport on haze pollution, the PMF results were further processed with backward-trajectory cluster analysis, revealing that haze pollution usually occurred when air masses originating from polluted industrial regions in the south prevailed and is characterized by high PM2.5 loadings with considerable contributions from secondary aerosols. This study suggests that control strategies to mitigate haze pollution in the BTH region should focus on the reduction of gaseous precursor emissions from fossil fuel combustion (motor vehicle emissions in Beijing and coal combustion in Tianjin, Hebei, and nearby provinces).

scholarly journals Quantifying Air Pollutant Variations during COVID-19 Lockdown in a Capital City in Northwest China

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 788
Author(s):  
Rong Feng ◽  
Hongmei Xu ◽  
Zexuan Wang ◽  
Yunxuan Gu ◽  
Zhe Liu ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Rural Areas ◽  
Vehicle Emissions ◽  
Motor Vehicle ◽  
Northwest China ◽  
Air Pollutant ◽  
Capital City ◽  
Air Pollution Control ◽  
Motor Vehicle Emissions

In the context of the outbreak of coronavirus disease 2019 (COVID-19), strict lockdown policies were implemented to control nonessential human activities in Xi’an, northwest China, which greatly limited the spread of the pandemic and affected air quality. Compared with pre-lockdown, the air quality index and concentrations of PM2.5, PM10, SO2, and CO during the lockdown reduced, but the reductions were not very significant. NO2 levels exhibited the largest decrease (52%) during lockdown, owing to the remarkable decreased motor vehicle emissions. The highest K+ and lowest Ca2+ concentrations in PM2.5 samples could be attributed to the increase in household biomass fuel consumption in suburbs and rural areas around Xi’an and the decrease in human physical activities in Xi’an (e.g., human travel, vehicle emissions, construction activities), respectively, during the lockdown period. Secondary chemical reactions in the atmosphere increased in the lockdown period, as evidenced by the increased O3 level (increased by 160%) and OC/EC ratios in PM2.5 (increased by 26%), compared with pre-lockdown levels. The results, based on a natural experiment in this study, can be used as a reference for studying the formation and source of air pollution in Xi’an and provide evidence for establishing future long-term air pollution control policies.

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

Long-Term Trends in Motor Vehicle Emissions in U.S. Urban Areas

2013 ◽  
Vol 47 (17) ◽  
pp. 10022-10031 ◽  
Author(s):  
Brian C. McDonald ◽  
Drew R. Gentner ◽  
Allen H. Goldstein ◽  
Robert A. Harley
Keyword(s):  
Urban Areas ◽  
Vehicle Emissions ◽  
Motor Vehicle ◽  
Motor Vehicle Emissions ◽  
Long Term Trends

Emissions Reductions From Vehicle Retirement Programs

1997 ◽  
Vol 1587 (1) ◽  
pp. 121-127 ◽  
Author(s):  
Beth Deysher ◽  
Don Pickrell
Keyword(s):  
Vehicle Emissions ◽  
Motor Vehicle ◽  
Cost Effective ◽  
Control Measures ◽  
Emissions Reductions ◽  
Reduction Strategies ◽  
Alternative Measures ◽  
Reduce Emissions ◽  
Ozone Precursor ◽  
The Cost

Nonattainment areas taking advantage of EPA’s modified enforcement of the 1990 Clean Air Act mandates for unpopular emissions control measures will be required to identify alternative measures to reduce emissions, and several areas have indicated their intention to implement scrappage programs for older vehicles as a means of “replacing” the emissions reductions originally expected to result from these other measures. The potential reductions in fleetwide motor vehicle emissions from scrappage of all older light-duty vehicles in a typical urban area’s fleet are analyzed, and the sensitivity of those reductions to the timing of the program’s implementation and to alternative assumptions about more intensive use of vehicles remaining in the fleet are explored. The cost-effectiveness of such a program in reducing ozone precursor emissions is investigated and the reliability of estimates of the program’s effectiveness developed by using the MOBILE5a vehicle emissions model are evaluated. The likely emissions reductions from even so comprehensive a vehicle scrappage program cannot replace those anticipated to result from measures such as enhanced inspection and maintenance and sales of reformulated gasoline, but smaller-scale retirement programs may be a cost-effective element of a larger package of emissions reduction strategies.

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