Exposure to Particulate Matter in Vehicle Cabins of Private Cars

Vehicle cabin air filters are exposed to humid air more frequently than any other air filters during routine use. The filtration performance of several commercially-available cabin air filters was investigated, along with the humid exposure period, using laboratory-based measurements. The averaged filtration efficiency and pressure drop were measured at ~70% and 75 Pa, respectively. Significant increases in filtration efficiency (up to 15%) and pressure drop (up to 250 Pa) were observed as the humid exposure time increased. Filtration efficiency increased ~15% and pressure drop increased 250 Pa as 140 g water was absorbed, which represents ~60 minutes humid exposure at a relative humidity of 90%. The pressure drop increased significantly at the beginning of the humid exposure due to the greater water absorption capacity of dryer dust in the filter. The dust load had a significant effect on the changes in filtration efficiency and pressure drop. The filtration efficiency and pressure drop of the 12-month used filter increased 2 times faster than that of the new filter at the same exposure conditions. The filtration efficiency and pressure drop were explicitly expressed as functions of the water absorption mass in the filter. Two coefficients were empirically derived and successfully accounted for the effects of humid exposure on filtration efficiency and pressure drop.

Section: Introductionmentioning

confidence: 99%

Investigation of Air Humidity Affecting Filtration Efficiency and Pressure Drop of Vehicle Cabin Air Filters

Lin

et al. 2014

“…Clark et al (1984) also indicated that these compounds are added to fuels to increase the octane number and are emitted to the urban atmosphere as a component of automobile exhaust and by gasoline evaporation and spillage. Moreover, Geiss et al (2010) suggest that exposure to pollutants (VOCs and particles) inside car cabins is often very high, compared to other outdoor or indoor micro-environments.…”

Section: Introductionmentioning

confidence: 99%

Measurements and Correlations of MTBE and BETX in Traffic Tunnels

Hsieh

Wang

Yang

et al. 2011

In this study, the concentrations of five volatile organic compounds (VOCs), including BTEX and methyl tertiary-butyl ether (MTBE), were investigated in five different traffic tunnels (including Liangshan, Yueguangshan, Zoying, Guogang and Zhongliao tunnels) in southern Taiwan. Results showed that Guogang Tunnel was the most polluted with the highest average levels of both MTBE and BTEX while ethylbenzene had the lowest levels. The range of measured concentration of toluene in Liangshan, Yueguangshan, Zoying, Guogang and Zhongliao tunnels were from 5.6 to 6.2 (mean = 1.6), from 0.0 to 62.3 (mean = 17.6), from 2.7 to 26.7 (mean = 13.1), from 15.2 to 125.5 (mean = 57.5), and from 43.7 to 197.1 (mean = 115.8) μg/m 3 , respectively. In Guogang Tunnel, the average MTBE-BTEX ratios at two peak rush periods were (5.0:1, 5:3, 4:1, 0:1, 5:1.1) and (5.7:1, 3:3, 2:1, 0:1, 4:1.1). From morning till night, the ratios at different sampling periods in the five different tunnels suggest the existence of both different traffic flow and variations in traffic fleet type in different tunnels. T/B ratio ranged from 0 to 2.3, from 0 to 1.9, from 0.6 to 2.5, from 0.9 to 2.6 and from 0 to 10.5 in Liangshan, Yueguangshan, Zoying, Guogang and Zhongliao tunnels, respectively. We also observed a wide range of (m+p+o)-xylenes/ethylbenzene (ΣX/E) or m,p-X/E ratio in all five tunnels. The m,p-xylene/ethylbenzene ratio ranged from 2.2 to 5.7, from 1.4 to 3.3, from 2.0 to 7.7, from 1.4 to 1.5 and from 5.5 to 8.1 in Liangshan, Yueguangshan, Zoying, Guogang and Zhongliao Tunnels, respectively. Notably, those high ΣX/E ratios in all tunnels reflect a fresh air parcel in the tunnels due to the enclosed/half-enclosed environment. Nevertheless, it is important that the characteristics of X/E in different traffic tunnels are explored.

“…The information regarding the exposure of the commuter to particulate air pollution is potentially important but studies of journey time exposure to particulate matter are relatively rare. Most of these studies have focused on exposure to PM in motorized transport or to cyclists and were conducted in the developed world: UK (Bevan et al, 1991;Gee and Raper, 1999;Adams et al, 2001;Briggs et al, 2006;Gulliver and Briggs, 2007;Briggs et al, 2008;Nasir and Colbeck, 2009); Germany (Pramal and Schierl, 2000); China (Chan et al, 2002a); Hong Kong (Chan et al, 2002b;Kaminsky et al, 2009), Italy (Geiss et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Exposure to PM10, PM2.5, PM1 and Carbon Monoxide on Roads in Lahore, Pakistan

Colbeck

Nasir

Ahmad

et al. 2011

Particulate matter pollution is one of the major environmental concerns in Pakistan. Over the past 20 years there has been a considerable increase in the number of motor vehicles. The present study was conducted to assess journey time and roadside exposure to particulate matter and carbon monoxide along major roads of Lahore during November, 2007. Measurements of particulate mass and carbon monoxide were carried out continuously inside an air conditioned vehicle, while commuting, and outside the vehicle at 36 different locations in the city. Additionally, monitoring was undertaken at a background site throughout the period. The overall mean journey-time concentrations of PM 10 , PM 2.5 , PM 1 , PM 10-2.5 and CO were 103 μg/m , 397 μg/m 3 and 4 ppm, respectively. The highest levels were found at the sites with traffic congestion reflecting, not only, the large contribution of automobile exhaust but also the resuspension of road dust. The majority of public transport vehicles in Lahore are not air-conditioned and it is very likely that commuters are exposed to the similar high levels of pollution.