Investigating the real-world emission characteristics of light-duty gasoline vehicles and their relationship to local socioeconomic conditions in three communities in Los Angeles, California
| Autor: | A. Vijayan, Seong Suk Park, Jorn D. Herner, Steve Mara |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Engineering
010504 meteorology & atmospheric sciences Fine particulate 010501 environmental sciences Management Monitoring Policy and Law Atmospheric sciences 01 natural sciences Ultrafine particle Gasoline Waste Management and Disposal Socioeconomic status NOx Vehicle Emissions 0105 earth and related environmental sciences Pollutant Air Pollutants business.industry Light duty Environmental engineering Los Angeles Motor Vehicles Socioeconomic Factors Particulate Matter business Vehicular Emissions Environmental Monitoring |
| Zdroj: | Journal of the Air & Waste Management Association. 66:1031-1044 |
| ISSN: | 2162-2906 1096-2247 |
| Popis: | This paper discusses results from a vehicular emissions research study of over 350 vehicles conducted in three communities in Los Angeles, CA, in 2010 using vehicle chase measurements. The study explores the real-world emission behavior of light-duty gasoline vehicles, characterizes real-world super-emitters in the different regions, and investigates the relationship of on-road vehicle emissions with the socioeconomic status (SES) of the region. The study found that in comparison to a 2007 earlier study in a neighboring community, vehicle emissions for all measured pollutants had experienced a significant reduction over the years, with oxides of nitrogen (NOX) and black carbon (BC) emissions showing the largest reductions. Mean emission factors of the sampled vehicles in low-SES communities were roughly 2-3 times higher for NOX, BC, carbon monoxide, and ultrafine particles, and 4-11 times greater for fine particulate matter (PM2.5) than for vehicles in the high-SES neighborhood. Further analysis indicated that the emission factors of vehicles within a technology group were also higher in low-SES communities compared to similar vehicles in the high-SES community, suggesting that vehicle age alone did not explain the higher vehicular emission in low-SES communities. Evaluation of the emission factor distribution found that emissions from 12% of the sampled vehicles were greater than five times the mean from all of the sampled fleet, and these vehicles were consequently categorized as "real-world super-emitters." Low-SES communities had approximately twice as many super-emitters for most of the pollutants as compared to the high-SES community. Vehicle emissions calculated using model-year-specific average fuel consumption assumptions suggested that approximately 5% of the sampled vehicles accounted for nearly half of the total CO, PM2.5, and UFP emissions, and 15% of the vehicles were responsible for more than half of the total NOX and BC emissions from the vehicles sampled during the study.This study evaluated the real-world emission behavior and super-emitter distribution of light-duty gasoline vehicles in California, and investigated the relationship of on-road vehicle emissions with local socioeconomic conditions. The study observed a significant reduction in vehicle emissions for all measured pollutants when compared to an earlier study in Wilmington, CA, and found a higher prevalence of high-emitting vehicles in low-socioeconomic-status communities. As overall fleet emissions decrease from stringent vehicle emission regulations, a small fraction of the fleet may contribute to a disproportionate share of the overall on-road vehicle emissions. Therefore, this work will have important implications for improving air quality and public health, especially in low-SES communities. |
| Databáze: | OpenAIRE |
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