Particulate Concentration in Automobile Passenger Compartments

Ptak, T. J.; Fallon, Stephen L.

doi:10.1080/02726359408906658

Cited by 18 publications

(7 citation statements)

References 3 publications

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“…Even higher concentrations have been measured for individuals riding motorcycles or bicycles in or near traffic (77,78). Measurements of PM and formaldehyde are also elevated in these microenvironments compared with indoor or ambient outdoor levels (76,79,80).…”

Section: In-vehicle Air Concentrationsmentioning

confidence: 99%

Assessing exposure to air toxics relative to asthma.

Weisel

2002

Environ Health Perspect

100

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Asthma is a respiratory disease whose prevalence has been increasing since the mid 1970s and that affects more than 14.6 million residents of the United States. Environmental triggers of asthma include air pollutants that are respiratory irritants. Air toxics emitted into the ambient air are listed in the 1990 Clean Air Act Amendments as hazardous air pollutants (HAPs) if they can adversely affect human health, including the respiratory tract. HAPs include particulate and gaseous-phase pollutants, individual organic compounds and metals, and mixtures. Associations between asthma exacerbation and both particles and indoor volatile organic compounds (VOCs), often referred to as indoor air quality, have been reported. Studies conducted in the United States, Canada, and Europe over the past two decades have shown that most people living in the developed countries spend the majority of their time indoors and that the air concentrations of many air toxics or HAPs are higher indoors than in the ambient air in urban, suburban, and rural settings. Elevated indoor air concentrations result from emissions of air toxics from consumer products, household furnishings, and personal activities. The Relationship of Indoor, Outdoor and Personal Air (RIOPA) study was designed to oversample homes in close proximity to ambient sources, excluding residences where smokers lived, to determine the contribution of ambient emissions to air toxics exposure. The ratios of indoor to outdoor air concentrations of some VOCs in homes measured during RIOPA were much greater than one, and for most other VOCs that had indoor-to-outdoor ratios close to unity in the majority of homes, elevated ratios were found in the paired samples with the highest concentration. Thus, although ambient emissions contribute to exposure of some air toxics indoors as well as outdoors, this was not true for all of the air toxics and especially for the higher end of exposures to most volatile organic air toxics examined. It is therefore critical, when evaluating potential effects of air toxics on asthma or other adverse health end points, to determine where the exposure occurs and the source contributions for each air toxic and target population separately and not to rely solely on ambient air concentration measurements.

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Section: In-vehicle Air Concentrationsmentioning

confidence: 99%

Assessing exposure to air toxics relative to asthma.

Weisel

2002

Environ Health Perspect

100

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“…Roadways and sidewalks have been shown to exhibit the highest outdoor concentrations for many air pollutants and elevated concentrations of elemental carbon and polycyclic aromatic hydrocarbons (PAH) have been recorded in tunnels and on heavily traveled roadways (Benner et al, 1989;Venkataraman et al, 1994;Kirchstetter and Harley, 1999). In-vehicle concentrations have been shown to be higher than those measured at fixed site monitors and in some cases higher than those measured along roadways (Shikiya et al, 1989;Ptak and Fallon, 1994;Lawryk and Weisel, 1995;Rodes et al, 1998;Alm et al, 1999). However, although a number of studies have investigated exposure to air pollutants inside vehicles, the majority of these focused on passenger cars and pollutants predominantly emitted by them (carbon monoxide and volatile organic compounds), and few focused on dieselrelated pollutants such as particulate matter (PM), particlebound PAH (PB-PAH) or black carbon.…”

Section: Introductionmentioning

confidence: 99%

Characterizing the range of children's air pollutant exposure during school bus commutes

Sabin

Behrentz

Winer

et al. 2004

J Expo Sci Environ Epidemiol

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Real-time and integrated measurements of gaseous and particulate pollutants were conducted inside five conventional diesel school buses, a diesel bus with a particulate trap, and a bus powered by compressed natural gas (CNG) to determine the range of children's exposures during school bus commutes and conditions leading to high exposures. Measurements were made during 24 morning and afternoon commutes on two Los Angeles Unified School District bus routes from South to West Los Angeles, with seven additional runs on a rural/suburban route, and three runs to test the effect of window position. For these commutes, the mean concentrations of diesel vehicle-related pollutants ranged from 0.9 to 19 mg/m 3 for black carbon, 23 to 400 ng/m 3 for particle-bound polycyclic aromatic hydrocarbon (PB-PAH), and 64 to 220 mg/m 3 for NO 2 . Concentrations of benzene and formaldehyde ranged from 0.1 to 11 mg/m 3 and 0.3 to 5 mg/m 3 , respectively. The highest real-time concentrations of black carbon, PB-PAH and NO 2 inside the buses were 52 mg/m 3 , 2000 ng/m 3 , and 370 mg/m 3 , respectively. These pollutants were significantly higher inside conventional diesel buses compared to the CNG bus, although formaldehyde concentrations were higher inside the CNG bus. Mean black carbon, PB-PAH, benzene and formaldehyde concentrations were higher when the windows were closed, compared with partially open, in part, due to intrusion of the bus's own exhaust into the bus cabin, as demonstrated through the use of a tracer gas added to each bus's exhaust. These same pollutants tended to be higher on urban routes compared to the rural/suburban route, and substantially higher inside the bus cabins compared to ambient measurements. Mean concentrations of pollutants with substantial secondary formation, such as PM 2.5 , showed smaller differences between open and closed window conditions and between bus routes. Type of bus, traffic congestion levels, and encounters with other diesel vehicles contributed to high exposure variability between runs.

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“…al., 2017;Kumar and Goel, 2016). Ptak and Fallon (1994) found that air filters remove 40-70% of coarse particles. The percentage of coarse particles could be higher in buses compared to the cars (Kumar et al, 2018).…”

Section: 1mentioning

confidence: 99%