Measurements of ultrafine particles and other vehicular pollutants inside school buses in South Texas

Zhang, Qunfang; Zhu, Yifang

doi:10.1016/j.atmosenv.2009.09.044

Cited by 69 publications

(51 citation statements)

References 34 publications

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“…Similar UFP concentrations near roadways and in traffic have been reported in other studies (Hagler et al, 2009;Zhang and Zhu, 2010). To reduce emissions from aging diesel trucks and buses in the state, the California Air Resources Board has approved a Truck and Bus rule that began its phase-in on January 1, 2012.…”

Section: Uncertainties and Implicationsmentioning

confidence: 59%

“…In contrast with these relatively low PM 2.5 background concentrations, the mean exposure of the closest nonsmoker (0.5 m) during the two smoking periods at Bus Stop E ranged from 37 to 96 mg/m 3 . These results are based on the SidePak PM 2.5 monitor calibration factors for secondhand smoke described earlier, and although we do not have a custom calibration factor for the aerosol emitted by traffic sources, the calibration factor of 0.42 that Zhang and Zhu (2010) reported for school buses was not very different from the calibration factors we used. The experiments by Jiang et al (2011) compared the SidePak monitors with gravimetric measurements of other combustion sources: large and small incense sticks (CF ¼ 0.33-0.35), wood chips (CF ¼ 0.77), and toasting bread (CF ¼ 0.79).…”

Section: Resultsmentioning

confidence: 99%

“…Using individual gravimetric-based calibration factors for secondhand smoke for each monitor, as in the present study, would reduce the measurement error further. As discussed in Methods, the calibration factor for traffic emissions is less well established than for tobacco smoke, and the calibration factor for the TSI DustTrak reported by Zhang and Zhu (2010) for PM 2.5 in school buses (0.42) was closer to the mean of the calibration factors for our seven SidePak monitors (0.28) than to the SidePak factory default value of 1.0. Even using the factory default calibration factor, however, the mean sidewalk background PM 2.5 concentrations in our study all were <10 mg/m 3 .…”

Section: Uncertainties and Implicationsmentioning

confidence: 94%

“…A published SidePak calibration factor for highway emissions was not directly available, so we used the same secondhand smoke calibration factors for each monitor during both the smoking and nonsmoking periods. Zhang and Zhu (2010) reported a calibration factor of CF ¼ 0.42 for concentrations measured inside a school bus using a TSI DustTrak monitor, which is similar in design to the TSI SidePak monitor, and Chung et al (2001) reported CF ¼ 0.33 for the DustTrak in ambient air. We found that applying the much higher factory default calibration factor of CF ¼ 1.0 still gave relatively low mean background PM 2.5 concentrations measured on the sidewalks in our study, <10 mg/m 3 , and applying the calibration factor of Zhang and Zhu (2010) gave mean sidewalk concentrations <4 mg/m 3 .…”

Section: Instruments and Measurementsmentioning

confidence: 99%

“…Zhang and Zhu (2010) reported a calibration factor of CF ¼ 0.42 for concentrations measured inside a school bus using a TSI DustTrak monitor, which is similar in design to the TSI SidePak monitor, and Chung et al (2001) reported CF ¼ 0.33 for the DustTrak in ambient air. We found that applying the much higher factory default calibration factor of CF ¼ 1.0 still gave relatively low mean background PM 2.5 concentrations measured on the sidewalks in our study, <10 mg/m 3 , and applying the calibration factor of Zhang and Zhu (2010) gave mean sidewalk concentrations <4 mg/m 3 . Each participant, including the smoker, wore a SidePak continuous PM 2.5 monitor to measure personal exposure, with the monitor's sampling intake probe located within 0.2 m of the person's breathing zone.…”

Section: Instruments and Measurementsmentioning

confidence: 99%

See 4 more Smart Citations

Outdoor fine and ultrafine particle measurements at six bus stops with smoking on two California arterial highways—Results of a pilot study

Ott

Acevedo-Bolton

Cheng

et al. 2013

Journal of the Air & Waste Management Association

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As indoor smoking bans have become widely adopted, some U.S. communities are considering restricting smoking outdoors, creating a need for measurements of air pollution near smokers outdoors. Personal exposure experiments were conducted with four to five participants at six sidewalk bus stops located 1.5-3.3 m from the curb of two heavily traveled California arterial highways with 3300-5100 vehicles per hour. At each bus stop, a smoker in the group smoked a cigarette. Gravimetrically calibrated continuous monitors were used to measure fine particle concentrations (aerodynamic diameter 2.5 µm; PM 2.5 ) in the breathing zones (within 0.2 m from the nose and mouth) of each participant. At each bus stop, ultrafine particles (UFP), wind speed, temperature, relative humidity, and traffic counts were also measured. For 13 cigarette experiments, the mean PM 2.5 personal exposure of the nonsmoker seated 0.5 m from the smoker during a 5-min cigarette ranged from 15 to 153 µg/m 3 . Of four persons seated on the bench, the smoker received the highest PM 2.5 breathing-zone exposure of 192 µg/m 3 . There was a strong proximity effect: nonsmokers at distances 0.5, 1.0, and 1.5 m from the smoker received mean PM 2.5 personal exposures of 59, 40, and 28 µg/m 3 , respectively, compared with a background level of 1.7 µg/m 3 . Like the PM 2.5 concentrations, UFP concentrations measured 0.5 m from the smoker increased abruptly when a cigarette started and decreased when the cigarette ended, averaging 44,500 particles/cm 3 compared with the background level of 7200 particles/cm 3 . During nonsmoking periods, the UFP background concentrations showed occasional peaks due to traffic, whereas PM 2.5 background concentrations were extremely low. The results indicate that a single cigarette smoked outdoors at a bus stop can cause PM 2.5 and UFP concentrations near the smoker that are 16-35 and 6.2 times, respectively, higher than the background concentrations due to cars and trucks on an adjacent arterial highway.Implications: Rules banning smoking indoors have been widely adopted in the United States and in many countries. Some communities are considering smoking bans that would apply to outdoor locations. Although many measurements are available of pollutant concentrations from secondhand smoke at indoor locations, few measurements are available of exposure to secondhand smoke outdoors. This study provides new data on exposure to fine and ultrafine particles from secondhand smoke near a smoker outdoors. The levels are compared with the exposure measured next to a highway. The findings are important for policies that might be developed for reducing exposure to secondhand smoke outdoors. IntroductionWith widespread adoption of indoor smoking bans, there has been considerable interest by local communities in restricting smoking outdoors. However, few data exist on air pollutant concentrations near a smoker outdoors to support these policies, and there are no published data comparing secondhand smoke exposure at sidewalk bus stops with the l...

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Section: Uncertainties and Implicationsmentioning

confidence: 59%

Section: Resultsmentioning

confidence: 99%

Section: Uncertainties and Implicationsmentioning

confidence: 94%

Section: Instruments and Measurementsmentioning

confidence: 99%

Section: Instruments and Measurementsmentioning

confidence: 99%

See 3 more Smart Citations

Outdoor fine and ultrafine particle measurements at six bus stops with smoking on two California arterial highways—Results of a pilot study

Ott

Acevedo-Bolton

Cheng

et al. 2013

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

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Particulate Matter (PM) and Fibers

Fromme

2023

Indoor Air Quality

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Air quality and passenger comfort in an air-conditioned bus micro-environment

Zhu

Wang

et al. 2018

Environ Monit Assess

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In this study, passenger comfort and the air pollution status of the micro-environmental conditions in an air-conditioned bus were investigated through questionnaires, field measurements, and a numerical simulation. As a subjective analysis, passengers' perceptions of indoor environmental quality and comfort levels were determined from questionnaires. As an objective analysis, a numerical simulation was conducted using a discrete phase model to determine the diffusion and distribution of pollutants, including particulate matter with a diameter < 10 μm (PM), which were verified by experimental results. The results revealed poor air quality and dissatisfactory thermal comfort conditions in Jinan's air-conditioned bus system. To solve these problems, three scenarios (schemes A, B, C) were designed to alter the ventilation parameters. According to the results of an improved simulation of these scenarios, reducing or adding air outputs would shorten the time taken to reach steady-state conditions and weaken the airflow or lower the temperature in the cabin. The airflow pathway was closely related to the layout of the air conditioning. Scheme B lowered the temperature by 0.4 K and reduced the airflow by 0.01 m/s, while scheme C reduced the volume concentration of PM to 150 μg/m. Changing the air supply angle could further improve the airflow and reduce the concentration of PM. With regard to the perception of airflow and thermal comfort, the scheme with an airflow provided by a 60° nozzle was considered better, and the concentration of PM was reduced to 130 μg/m.

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Measurements of ultrafine particles and other vehicular pollutants inside school buses in South Texas

Cited by 69 publications

References 34 publications

Outdoor fine and ultrafine particle measurements at six bus stops with smoking on two California arterial highways—Results of a pilot study

Outdoor fine and ultrafine particle measurements at six bus stops with smoking on two California arterial highways—Results of a pilot study

Particulate Matter (PM) and Fibers

Air quality and passenger comfort in an air-conditioned bus micro-environment

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