Population Density, Particulate Emission Characterization, and Impact on the Particulate Inventory of Smoking Vehicles in the South Coast Air Quality Management District

Abstract

The impact of high-particulate-emission vehicles on the total light-duty vehicle particulate emission inventory in the South Coast Air Quality Management District (SCAQMD) has been estimated by an analysis of the SCAQMD's CUT-SMOG database, a field survey of smoking vehicles, and particulate emissions testing of representative smoking vehicles. The field study, carried out at 61 sites throughout the SCAQMD, showed that 1.11%-1.75% of the vehicles in the light-duty fleet emit visible smoke. This fleet of smoking vehicles is composed mainly of older vehicles, 8 to 18 years of age. Particulate emission testing of 23 smoking vehicles gave an average Federal Test Procedure (FTP) weighted emission rate of 399 mg/mi with a range of 64-2,323 mg/mi, while the average IM240 emission rate was 346 mg/mi, with a range from 13-1,807 mg/mi. The contribution of light-duty smoking vehicles to the IMPLICATIONS Understanding the population density and emission characteristics of high-emitting vehicles has been found to be an important element in improving mobile source emissions inventories. For gaseous emissions, much progress has been made in this area through the use of remote sensing and follow-up dynamometer studies. To date, no attempt has been reported to define the population of highparticulate-emission vehicles, their characteristics, and emission rates. This paper reports results on the population and characteristics of high-particulate-emission lightduty vehicles as determined by a field study to identify visibly smoking vehicles in the South Coast Air Quality Management District. Particulate emission rates for a representative fleet of these vehicles were determined, and estimates were made of the contribution of these vehicles to the particulate emission inventory in the district. This updating and improvement of the particulate emissions inventory for the district will allow improved air quality management.particulate emissions inventory in the SCAQMD is estimated to be 0.51-0.81 tons per day.

Light-Duty Motor Vehicle Exhaust Particulate Matter Measurement in the Denver, Colorado, Area

“…This is much lower than found in a more extensive roadside survey conducted in the South Coast Air Quality Management District. 7 Part of the difference may be that the City of Denver requires that light-duty gasoline smoking vehicles be repaired or removed from use. However, it should be kept in mind that this survey was limited in scope, and by its nature is subjective.…”

“…Durbin et al 7 measured particle size distributions from smoking gasoline and diesel vehicles. They Table 5.…”

“…In contrast, Durbin et al 7 studied smoking vehicles in the South Coast Air Quality Management District. The study, an intensive visual survey of on-road vehicles, concluded that between 1.1 and 1.8% of the light-duty fleet emits some visible smoke, and that these are composed mainly of both gasoline and diesel vehicles that are 8-18 years old.…”

Air contaminant exposures during the operation of lawn and garden equipment

“…The optical Sidepak method has a minimum size detection cutpoint of approximately 0.1 mm in aerodynamic diameter. Studies on gasoline-powered mobile source emissions indicate that a significant portion of mass emissions occur in the sub 0.1 mm size range (Cadle et al, 1999;Durbin et al, 1999;Kleeman et al, 2000); thus, the optical method would measure lower concentrations with a similar emission source containing a significant mass fraction of sub 0.1 mm particles. Another factor that may have contributed to differences in concentration values is the composition of the measured aerosol.…”

Methods of Characterizing the Distribution of Exhaust Emissions from Light-Duty, Gasoline-Powered Motor Vehicles in the U.S. Fleet

“…14 Durbin noted that light-duty gasoline vehicles with visible smoke emitted from the tailpipe constituted only 1.1-1.7% of the lightduty fleet in the South Coast Air Quality Management District in California, yet these vehicles contributed approximately 20% of the total PM emissions from the light-duty fleet. 15 Because of the varying PM emissions estimates for gasoline-powered motor vehicles, whether from source apportionment studies or emission inventory projections, and the potentially significant contributions of this emission source to ambient PM concentrations, the Kansas City Light-Duty Vehicle Emission Study (KCLDVS) was initiated. The study provided a representative sample of light-duty gasoline-powered motor vehicles to estimate the distribution of PM emissions in the U.S. light-duty fleet.…”