Air quality impacts of a scheduled 36-h closure of a major highway

Quiros, David; Zhang, Qunfang; Choi, Won-Sik; He, Meilu; Paulson, Suzanne E.; Winer, Arthur M.; Wang, Rui; Zhu, Yifang

doi:10.1016/j.atmosenv.2012.10.020

Cited by 29 publications

(23 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In Choi et al (2012), we also reported reduced peak UFP concentrations near freeways compared to the peak values observed in 2008 and 2005 by Hu et al (2009) and Zhu et al (2006), respectively. In addition, Quiros et al (2013) reported a value of PNEF (3.7 × 10 13 particles km −1 vehicle −1 ) similar to our estimate. Between 2001 and 2010, many characteristics of the vehicle fleet have changed, such as improvement of engine emissions control technology, fleet turnover to newer cleaner vehicles, recent shifts to smaller engines (Snyder, 2011), and more stringent regulations for truck engines and fuel composition by the California Air Resources Board (CARB, 2004(CARB, , 2008 as discussed in Quiros et al (2013).…”

Section: Estimate Of Particle Number Emission Factorsupporting

confidence: 90%

Factors controlling pollutant plume length downwind of major roadways in nocturnal surface inversions

2014

View full text Add to dashboard Cite

A fitting method using a semi-empirical Gaussian dispersion model solution was successfully applied to obtain both dispersion coefficients and a particle number emission factor (PNEF) directly from ultrafine particle (UFP; particles smaller than < 0.1 µm in diameter) concentration profiles observed downwind of major roadways in California's South Coast Air Basin (SoCAB). The effective Briggs' formulation for the vertical dispersion parameter σ z was adopted in this study due to its better performance in describing the observed profiles compared to other formulations examined. The two dispersion coefficients in Briggs' formulation, α and β, ranged from 0.02 to 0.07 and from −0.5 × 10 −3 to 2.8 × 10 −3 , respectively, for the four freeway transects studied and are significantly different for freeways passing over vs. under the street on which measurements of the freeway plume were made. These ranges are wider than literature values for α and β under stable conditions. The dispersion coefficients derived from observations showed strong correlations with both surface meteorology (wind speed/direction, temperature, and air stability) and differences in concentrations between the background and plume peak. The relationships were applied to predict freeway plume transport using a multivariate regression, and produced excellent agreement with observed UFP concentration profiles. The mean PNEF for a mixed vehicle fleet on the four freeways was estimated as 7.5 × 10 13 particles km −1 vehicle −1 , which is about 15 % of the value estimated in 2001 for the I-405 freeway, implying significant reductions in UFP emissions over the past decade in the SoCAB.Published by Copernicus Publications on behalf of the European Geosciences Union.

show abstract

Section: Estimate Of Particle Number Emission Factorsupporting

confidence: 90%

Factors controlling pollutant plume length downwind of major roadways in nocturnal surface inversions

2014

View full text Add to dashboard Cite

show abstract

“…Our preferred estimate (Column (2) of Table 9) implies that average NO 2 concentrations at the two downwind monitors are 2.1 times higher than ambient levels. 14 This 2.1-times figure is also consistent with the results from Quiros et al (2013) and our reduced-form estimates imply that a 15.5 percentage point increase in downwind frequency raises mortality rates by 3.6 to 6.8 percent. The "IV" estimate thus suggests an elasticity of mortality rates (among 75+ year olds) with respect to near-roadway pollution in the range of 0.10 to 0.18.…”

Section: A! "First-stage" Estimatessupporting

confidence: 75%

As the Wind Blows: The Effects of Long-Term Exposure to Air Pollution on Mortality

Anderson

2015

View full text Add to dashboard Cite

There is strong evidence that short-run fluctuations in air pollution negatively impact infant health and contemporaneous adult health, but there is less evidence on the causal link between long-term exposure to air pollution and increased adult mortality. This project estimates the impact of long-term exposure to air pollution on mortality by leveraging quasi-random variation in pollution levels generated by wind patterns near major highways. We combine geocoded data on the residence of every decedent in Los Angeles over three years, high-frequency wind data, and Census Short Form data. Using these data, we estimate the effect of downwind exposure to highway-generated pollutants on the age-specific mortality rate by using bearing to the nearest major highway as an instrument for pollution exposure. We find that doubling the percentage of time spent downwind of a highway increases mortality among individuals 75 and older by 3.6 to 6.8 percent. These estimates are robust and economically significant.

show abstract

“…Traffic (through both exhaust and non-exhaust inputs) is a major contributor to PNCs near roads (Padró-Martínez et al, 2012;Quiros et al, 2013). There are complex relationships between vehicle inputs to PNC at the roadsides, and how these concentrations are transformed by factors including the street geometry and the meteorology (Kumar et al, 2008a).…”

mentioning

confidence: 99%

Linking particle number concentration (PNC), meteorology and traffic variables in a UK street canyon

Price

Arthur²,

Bérubé

et al. 2014

Atmospheric Research

View full text Add to dashboard Cite

show abstract

Air quality impacts of a scheduled 36-h closure of a major highway

Cited by 29 publications

References 41 publications

Factors controlling pollutant plume length downwind of major roadways in nocturnal surface inversions

Factors controlling pollutant plume length downwind of major roadways in nocturnal surface inversions

As the Wind Blows: The Effects of Long-Term Exposure to Air Pollution on Mortality

Linking particle number concentration (PNC), meteorology and traffic variables in a UK street canyon

Contact Info

Product

Resources

About