Backgrounder - Tobacco Smoke Concentrations in Cars Since the

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Backgrounder - Tobacco Smoke Concentrations in Cars Since the Powered By Docstoc
					Backgrounder - Tobacco Smoke Concentrations in Cars

    Since the release of the 2004 OMA paper, Exposure to Second-Hand Smoke: Are We
    Protecting Our Kids? significant research has been undertaken and there is now more
    compelling evidence to present about comparative concentrations of second-hand smoke
    (SHS) in vehicles.

    There have been numerous studies that have tested in-car SHS concentrations in virtually
    every conceivable smoking scenario – windows open, partially open, closed, one window
    partially open, vents on or off, heat, air conditioning, recirculation, the speed of the
    vehicle, the number of cigarettes, the smoker, etc. One study looked at 100 different air
    change rate measurements on four vehicles. 1

    These in-car smoking experiments have been compared with similar air quality tests in
    smoker’s homes, smoke-free homes, smoke-filled bars and ambient outdoor air. The
    findings are clear. Under all ventilation circumstances, even with windows open and the
    fan on high, SHS concentrations in a vehicle are greater than in any other micro-
    environment.

    Respirable particles in SHS – Key findings:

        •   In 2005, The State of California’s Air Resources Board (CARB) compared a large
            number of studies measuring SHS particle concentrations in different
            environments and found that in-car concentrations, with smoking and no
            ventilation were up to 60 times greater than in a smoke-free home, and up to 27
            times greater than in a smoker’s home.2

        •   The research shows that even under full ventilation, interior respirable particle
            concentrations were at least 13 times that of the outdoor concentration. With no
            ventilation, these particle concentrations reached levels as high as 300 times the
            outdoor particle concentration. 3

        •   Detailed SHS concentration studies conducted in a minivan showed that “the
            particle exposure for an average 5 hour automobile trip, with two cigarettes
            smoked per hour, would be 25 times higher than the same exposure scenario in a
            residence.” 4

1
  Wayne Ott, Neil Klepeis and Paul Switzer, “Air change rates of motor vehicles and in-vehicle pollutant
concentrations from secondhand smoke”. Journal of Exposure Science and Environmental Epidemiology, 18
July 2007; doi: 10.1038/sj.jes.7500601
2
  Proposed Identification of Environmental Tobacco Smoke as a Toxic Air Contaminant, California
Environmental Protection Agency: Air Resources Board, June 24, 2005.
3
  Ott, Klepeis, Switzer. 2007.
4
  Ibid.
OMA Tobacco Smoke Concentrations in Cars – Page 2



       •    Another comparison used field measurements to compare SHS particle concentrations
            in a vehicle, with those in a bar (when smoking was still allowed). In-vehicle
            concentrations were 20-times greater than inside the bar.5

Formaldehyde in SHS – Key Findings:

       •    The CARB also looked at Formaldehyde concentrations from cigarettes in vehicles. In
            the US, the recommended maximum occupational level for formaldehyde is 0.1 ppm.
            In-vehicle formaldehyde concentration tests found levels could reach 0.33 ppm after
            only one cigarette.6

Carbon Monoxide in SHS – Key findings:

       •    Studies have found that approximately 66 mg. of carbon monoxide (CO) are emitted
            per cigarette smoked. 7

       •    Testing CO concentrations in vehicles in which there was smoking found that
            concentrations could reach as high as 63.3 ppm with very limited circulation. 8 This is
            more that double Health Canada’s “Acceptable Short-Term Exposure Range for CO”
            which is a maximum one-hour average of 25 ppm.

       •    Carbon monoxide in the blood, represented by carboxyhemoglobin (COHb) levels,
            was measured for both the active and passive smoker in a vehicle and both increased
            significantly. The COHb level in the non-smoker (passively breathing the smoker’s
            SHS) rose from 2 ppm to 9.2 ppm after the passenger had smoked 3 cigarettes. 9




5
  Klepeis N.E., Nelson W.C., Ott W.R., Robinson J.P., Tsang A.M., Switzer P., Behar J.V., Hern S.C.,
Englemann W.H. (2001a). The National Human Activity Pattern Survey (NHAPS): A resource for assessing
exposure to environmental pollutants. J Expos Anal Environ Epidemiol. Vol. 11, pp. 231-252.
6
  Park J., Spengler J.D., Yoon D., Dumyahn T., Lee K., Özkaynak H. (1998). Measurement of air exchange rate
of stationary vehicles and estimation of in-vehicle exposure. J Expos Anal Environ Epidemiol. Vol. 8, pp. 65-78.
7
 Ott W, Langan L, Switzer P, A Time Series Model for Cigarette Smoking Activity Patterns: Model Validation
For Carbon Monoxide and Respirable Particles In A Chamber And An Automobile. Journal of Exposure
Analysis and Environmental Epidemiology, Vol. 2, Supl 2, pp. 175-200. 1992 ISSN: 1053-4245
8
    Ibid.
9
    Ibid.