The influence of passenger activities on exposure to particles inside buses

Song, Wenbin; Ashmore, M.R.; Terry, Andrew

doi:10.1016/j.atmosenv.2009.05.004

Cited by 25 publications

(16 citation statements)

References 20 publications

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“…Particle counts inside of buses were 5.07 Â 10 6 , compared to 9.72 Â 10 7 in this study. However, the lower cutoff particle size for these results is 0.75 mm, whereas in this study it is 0.3 mm, thus the lower counts reported in the bus study is not surprising [34]. The second study in Thailand (Chiang Mai), measured inside classrooms in the size range 0.3-5.0 mm, presents comparable particle counts to this study with average concentrations of 1.8 Â 10 8 [35]; however, increased variance is reported for the larger particles compared to the smaller particle, whereas in this study the variables remained constant for all particle sizes.…”

Section: Concentrations Of Contaminantscontrasting

confidence: 70%

Endotoxin and Particle Concentrations in Subsidized Households with Asthmatic Children in Philadelphia: A Pilot Study

Leavey

Perez

Burstyn

2011

Indoor and Built Environment

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This study seeks to identify the home and behavior characteristics that may affect indoor exposures to endotoxin and particles in subsidized housing of asthmatic children in Philadelphia, PA. Sixty seven endotoxin samples were collected from children's usual sleeping surfaces, and 97 airborne indoor particle measurements were made. The geometric mean (GM) endotoxin concentration was 1933 EUm À2 ; the total particle count (!0.3 mm) was 9.72 Â 10 7 (ptm À3 ). Between-home variability of endotoxin measurements (geometric standard deviation, GSD, 6.3) was greater than that of particle counts (GSD 2.2-3.2). Endotoxin concentrations were negatively associated with the presence of upholstered furniture and stuffed toys, evidence of mold and increased ventilation in the home. The smoking status of the household was a significant determinant of concentrations of particles smaller than 2.0 mm. None of these determinants explained more than 11% of exposure variability. Endotoxin and particle concentrations were not correlated. Direct measurement of contaminants of interest remains the best option for indoor air quality investigations in the households surveyed.

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Section: Concentrations Of Contaminantscontrasting

confidence: 70%

Endotoxin and Particle Concentrations in Subsidized Households with Asthmatic Children in Philadelphia: A Pilot Study

Leavey

Perez

Burstyn

2011

Indoor and Built Environment

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“…The contrast agrees with the self-pollution of up to 30% reported for U.S. school buses ( Adar et al 2008 ; Behrentz et al 2004 ). The smaller difference in PM 10 exposure between diesel and electric buses can be explained by passengers causing resuspension of PM 10 in both types of buses ( Song et al 2009 ). Differences between buses with and without retrofitted particulate filters were small and not significant, but the number of measurements may not have been sufficient to detect differences.…”

Section: Discussionmentioning

confidence: 99%

Commuters’ Exposure to Particulate Matter Air Pollution Is Affected by Mode of Transport, Fuel Type, and Route

Zuurbier

Hoek

Oldenwening

et al. 2010

Environ Health Perspect

298

160

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BackgroundCommuters are exposed to high concentrations of air pollutants, but little quantitative information is currently available on differences in exposure between different modes of transport, routes, and fuel types.ObjectivesThe aim of our study was to assess differences in commuters’ exposure to traffic-related air pollution related to transport mode, route, and fuel type.MethodsWe measured particle number counts (PNCs) and concentrations of PM2.5 (particulate matter ≤ 2.5 μm in aerodynamic diameter), PM10, and soot between June 2007 and June 2008 on 47 weekdays, from 0800 to 1000 hours, in diesel and electric buses, gasoline- and diesel-fueled cars, and along two bicycle routes with different traffic intensities in Arnhem, the Netherlands. In addition, each-day measurements were taken at an urban background location.ResultsWe found that median PNC exposures were highest in diesel buses (38,500 particles/cm3) and for cyclists along the high-traffic intensity route (46,600 particles/cm3) and lowest in electric buses (29,200 particles/cm3). Median PM10 exposure was highest from diesel buses (47 μg/m3) and lowest along the high- and low-traffic bicycle routes (39 and 37 μg/m3). The median soot exposure was highest in gasoline-fueled cars (9.0 × 10−5/m), diesel cars (7.9 × 10−5/m), and diesel buses (7.4 × 10−5/m) and lowest along the low-traffic bicycle route (4.9 × 10−5/m). Because the minute ventilation (volume of air per minute) of cyclists, which we estimated from measured heart rates, was twice the minute ventilation of car and bus passengers, we calculated that the inhaled air pollution doses were highest for cyclists. With the exception of PM10, we found that inhaled air pollution doses were lowest for electric bus passengers.ConclusionsCommuters’ rush hour exposures were significantly influenced by mode of transport, route, and fuel type.

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“…For the Ningbo bus incident all model parameters are known except for the air exchange rate. We estimate λ a = 1.25/h for a moving bus with closed windows, based on studies of pollutants in British transit buses (90). We thus infer C q = 90 q/m 3 , a value that lies in the range of intermediate speaking, as might be expected on board a bus filled to capacity.…”

Section: Application To Covid-19mentioning

confidence: 99%

Beyond Six Feet: A Guideline to Limit Indoor Airborne Transmission of COVID-19

Bazant

Bush

2020

Preprint

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The revival of the global economy is being predicated on the Six-Foot Rule, a guideline that offers little protection from pathogen-bearing droplets sufficiently small to be continuously mixed through an indoor space. The importance of indoor, airborne transmission of COVID-19 is now widely recognized; nevertheless, no quantitative measures have been proposed to protect against it. In this article, we build upon models of airborne disease transmission in order to derive a safety guideline that would impose a precise upper bound on the cumulative exposure time, the product of the number of occupants and their time in an enclosed space. We demonstrate the manner in which this bound depends on the ventilation rate and dimensions of the room; the breathing rate, respiratory activity and face-mask use of its occupants; and the infectiousness of the respiratory aerosols, a disease-specific parameter that we estimate from available data. Case studies are presented, implications for contact tracing considered, and appropriate caveats enumerated.

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The influence of passenger activities on exposure to particles inside buses

Cited by 25 publications

References 20 publications

Endotoxin and Particle Concentrations in Subsidized Households with Asthmatic Children in Philadelphia: A Pilot Study

Endotoxin and Particle Concentrations in Subsidized Households with Asthmatic Children in Philadelphia: A Pilot Study

Commuters’ Exposure to Particulate Matter Air Pollution Is Affected by Mode of Transport, Fuel Type, and Route

Beyond Six Feet: A Guideline to Limit Indoor Airborne Transmission of COVID-19

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