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

Abstract

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...

Controlled experiments measuring personal exposure to PM2.5in close proximity to cigarette smoking

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“…To compare the indoor results with similar outdoor experiments, two types of outdoor experiments were performed in the vicinity of Home #1 in Redwood City, CA: (i) sitting at an outdoor table (patio, restaurant, and picnic table) or a park bench; and (ii) sitting at a bus stop on a busy highway. The eight experiments at a bus stop on a busy highway are discussed in a separate paper (Ott et al., ), because in those experiments, two sources were compared (cigarettes and motor vehicle emissions) and we also measured ultrafine particle concentrations and traffic volume simultaneously with the PM 2.5 concentrations.…”

“…EPA's Total Exposure Assessment Methodology (Hartwell et al, 1992;€ Ozkaynak et al, 1996) studies, assessing the exposures of large populations, showed that the concentrations of volatile organics and of particulate matter (PM) measured using a personal monitoring device are often significantly higher than stationary measurements collected simultaneously indoors or outdoors. Rodes et al (1991) theorized that there were at least three causes of this 'personal cloud': (i) a proximity effect (due to time spent close to sources; Furtaw et al, 1996); (ii) for PM, a resuspension effect (due to particles resuspended from surfaces or from clothing; Ferro et al, 2004); and (iii) for indoor environments, a compartmental effect (due to higher pollutant levels in the room containing the source, for example, Ferro et al, 2009).…”

Particulate matters from diesel heavy duty trucks exhaust versus cigarettes emissions: a new educational antismoking instrument

“…Our findings enforce the results of a recent study, where researchers depicted the exposure levels to fine and ultrafine particles (UFP) by a bus stop, in close proximity of a smoker. PM 2.5 and UFP concentrations were 16–35 and 6.2 times higher than the background concentrations due to cars and trucks on an adjacent arterial highway [ 14 ].…”

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“…Acevedo-Bolton et al (2013) reported in a study of indoor measurements that a nonsmoker sitting within 1 m of a burning cigarette was exposed to over 160 mg/m 3 during the smoking period. In outdoor environments, a strong "proximity effect" of the smoker was observed at bus stops (Ott et al, 2014). The mean PM 2.5 personal exposures of nonsmokers at distances 0.5, 1.0, and 1.5 m from the smoker were 59, 40, and 28 mg/m 3 , respectively, compared with a background level of 1.7 mg/m 3 .…”