Measuring Secondhand Smoke Exposure in Vehicles

Dave Bohac, P.E., Zheng Zhou — Nov 2014

Project Update
The field portion of this project is complete and dissemination of findings in in full swing. The project team will present results at several upcoming conferences and is also working with project partner Association for Nonsmokers — Minnesota (ANSR) to create materials for tobacco control advocates, public health communities, and policymakers.
Full Project Update

Project Summary

The 2011 Minnesota Youth Tobacco and Asthma Survey found that 25.8 percent of middle school students and 37.3 percent of high school students had ridden in a car with someone who was smoking cigarettes in the preceding week. Secondhand smoke is especially dangerous for children because they are still developing physically and biologically. The levels of Secondhand smokein vehicles can be extremely high due to the enclosed area and can be 17 times higher than in Minnesota smoking bars (Bohac et al. 2012; Ott et al. 2008).  

CEE experts have been national leaders in secondhand smoke research since 2001. CEE has conducted extensive studies on secondhand smoke in bars and restaurants, multifamily buildings, and outdoor venues. Research results have supported the implementation of smoke-free legislation, such as the 2007 “Freedom to Breathe” amendments banning smoking in indoor public places. These studies have also provided guidance for voluntary action such as the adoption of smoke-free policy in hundreds of MN multi-family housing establishments. 

This is the first time ClearWay Minnesota has funded research on secondhand smoke exposure in vehicles. The purpose of the current study is to gather more information for the public and decision-makers. It will further the field of secondhand smoke research by providing necessary information for modeling passenger exposure to smoke in vehicles.  In addition, the study expands on previous research by exploring a wider range of variables that can affect exposure, including window positioning, ventilation settings, speed, smoking behavior, and type of vehicle. Lastly, the study includes monitoring in both summer and winter seasons, whereas previous research is limited to milder climates. It is important to consider that during frigid Minnesota winters drivers are more likely to use settings that increase passenger exposure to secondhand smoke (e.g. windows closed and vents on in recirculation mode).   

The study will involve a total of 132 research trials conducted from July 2014 to January 2015. In each trial, a participant will drive a vehicle and smoke while the air inside and outside is monitored.  Measurements will be taken in multiple locations within the vehicle. In addition, the ventilation, or air exchange rate, will be measured to better understand how secondhand smoke dissipates from the air (i.e. is flushed out by ventilation or absorbed onto the surfaces of the vehicle).

CEE will publish articles for scholarly journals and present the findings at conferences. The Association for Nonsmokers-Minnesota will assist with dissemination to the public.  

*This project is funded with support from Clearway Minnesota. And with co-funding by CEE in support of its nonprofit mission.

Related journal articles:

D.L. Bohac, M.J. Hewett, K.I. Kapphahn, J. Novacheck, D.T. Grimsrud, M.G. Apte, M.G., and L.A. Gundel. 2012. Secondhand Smoke Exposure in the Nonsmoking Section - How Much Protection? Nicotine & Tobacco Research.

D.L. Bohac, M.J. Hewett, K.I. Kapphahn, D. T. Grimsrud 2012.  Ventilation rate investigations in Minnesota bars and restaurants.  ASHRAE Transactions 118(1).

M.J. Hewett, M.J., Bohac, D.L., Kapphahn, K.I., Grimsrud, D.T., Apte, M.G., and Gundel, L.A. 2011. Secondhand Smoke Concentrations in Repeated Visits to a Probability Sample of Bars and Restaurants.  Proceedings of the 12th International Conference on Indoor Air Quality and Climate – Indoor Air 2011, Austin, TX.  International Society of Indoor Air Quality and Climate.

R. Lui, Bohac, D.L., Gundel, L.A., Hewett, M.J., Apte, M.G., and Hammond, S.K. 2011. An Assessment of Risk from Exposure to Secondhand Smoke in Minnesota Bars and Restaurants.  Proceedings of the 12th International Conference on Indoor Air Quality and Climate – Indoor Air 2011, Austin, TX.  International Society of Indoor Air Quality and Climate.

D.L. Bohac, M. J. Hewett, K.I. Kapphahn, D.T. Grimsrud, M.G. Apte, L.A. Gundel 2010.  Change in indoor particle levels after a smoking ban in Minnesota bars and restaurants.

Photo courtesy of Tobacco Free Kids

Project Info


ClearWay Minnesota

Association for Nonsmokers-Minnesota

CEE contact
Dave Bohac, P.E.