Traffic related air pollution is a well-recognised and much studied contributor to smog and is linked to a number of adverse health outcomes. Although traffic pollutants can travel long distances, exposure to the highest levels of the raw emissions can occur closest to the source; e.g. in a car in dense traffic conditions. Time spent in-vehicle may contribute up to half of commuters' daily exposure to certain air pollutants. Most new cars now have or allow for a cabin air filter, but it is not known how well cabin air filtration can reduce exposure to traffic-related air pollution.

This intervention study will measure commuters' exposure to air pollutants in rush hour traffic. It will evaluate the impact of this exposure on stress hormones in saliva, and short term cardiopulmonary health indicators such as blood pressure, heart rate variability and respiratory inflammation. It will also look at effects on cognition (mental processing and judgement) in this real world environment where any deficit could be important to safety. In addition, the study will examine whether cabin air filtration can reduce the exposure to traffic related air pollutants and result in improvements in short term cardiopulmonary and cognitive function. This research will contribute to our understanding of how this environment contributes to Canadians' overall air pollution exposure as well as the potential health impacts. It will also test a potentially valuable and economical means of reducing exposure to traffic related air pollution in a commuting environment. The study may also guide the future implementation of the use of cabin filters as an exposure reduction intervention.

Overall Project Objectives:

Can cabin air filtration effectively reduce exposure to traffic related air pollution? Does commuter exposure to air pollution affect short term stress, and cardiopulmonary and cognitive function? Can cabin air filtration mitigate the health effects of commuters' exposure to air pollution?

Inclusion Criteria:

• Healthy Individuals;
• non-smoking.

Exclusion Criteria:

• Smokers;
• living in a smoking household;
• currently experiencing seasonal allergies;
• suffering from heart rhythm problems or heart conditions;
• regularly taking corticosteroid medication;
• pregnant or breastfeeding;
• allergic to latex;
• sensitivity to adhesives