An experimental investigation of tobacco smoke pollution in cars

Nicotine Tob Res. 2009 Jun;11(6):627-34. doi: 10.1093/ntr/ntp019. Epub 2009 Apr 7.


Introduction: Tobacco smoke pollution (TSP) has been identified as a serious public health threat. Although the number of jurisdictions that prohibit smoking in public places has increased rapidly, just a few successful attempts have been made to pass similar laws prohibiting smoking in cars, where the cabin space may contribute to concentrated exposure. In particular, TSP constitutes a potentially serious health hazard to children because of prolonged exposure and their small size.

Methods: The present study investigated the levels of TSP in 18 cars via the measurement of fine respirable particles (<2.5 microns in diameter or PM(2.5)) under a variety of in vivo conditions. Car owners smoked a single cigarette in their cars in each of five controlled air-sampling conditions. Each condition varied on movement of the car, presence of air conditioning, open windows, and combinations of these airflow influences.

Results: Smoking just a single cigarette in a car generated extremely high average levels of PM(2.5): more than 3,800 microg/m3 in the condition with the least airflow (motionless car, windows closed). In moderate ventilation conditions (air conditioning or having the smoking driver hold the cigarette next to a half-open window), the average levels of PM(2.5) were reduced but still at significantly high levels (air conditioning = 844 microg/m3; holding cigarette next to a half-open window = 223 microg/m3).

Discussion: This study demonstrates that TSP in cars reaches unhealthy levels, even under realistic ventilation conditions, lending support to efforts occurring across a growing number of jurisdictions to educate people and prohibit smoking in cars in the presence of children.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Air Movements
  • Air Pollutants / analysis*
  • Air Pollution, Indoor / analysis*
  • Automobiles*
  • Canada
  • Child
  • Child Welfare
  • Environmental Monitoring / methods
  • Humans
  • Inhalation Exposure / analysis*
  • Inhalation Exposure / prevention & control
  • Risk Assessment
  • Tobacco Smoke Pollution / analysis*
  • Tobacco Smoke Pollution / prevention & control
  • Ventilation / methods


  • Air Pollutants
  • Tobacco Smoke Pollution