COVID-19 is an emerging, rapidly evolving situation.
Get the latest public health information from CDC:

Get the latest research information from NIH: Menu

Commuter Air Pollution Intervention Study (CAPI)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02277002
Recruitment Status : Completed
First Posted : October 28, 2014
Last Update Posted : March 2, 2015
Information provided by (Responsible Party):
Gary Mallach, Health Canada

Brief Summary:

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?

Condition or disease Intervention/treatment Phase
Cognitive Function Cardiopulmonary Function Saliva Stress Hormones Air Pollution Exposure Lung Inflammation Device: Cabin Air Filtration Other: Placebo Not Applicable

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 48 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double (Participant, Care Provider)
Primary Purpose: Prevention
Official Title: Reducing Commuter Air Pollutant Exposure by Cabin Air Filtration
Study Start Date : October 2014
Actual Primary Completion Date : November 2014
Actual Study Completion Date : November 2014

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Air Pollution

Arm Intervention/treatment
Placebo Comparator: Placebo
Participants are exposed to unfiltered cabin air
Other: Placebo
No Cabin Air Filtration

Active Comparator: Cabin Air Filter
Participants are exposed to filtered cabin air
Device: Cabin Air Filtration

Primary Outcome Measures :
  1. Variation in cardiopulmonary function [ Time Frame: 5 hours ]
    Heart Rate Variability (HRV) will be measured from continuous ambulatory electrocardiogram (ECG) recordings collected during the study protocol. ECG will be worn for the duration of the study day period (approximately 5 hours), including a period prior to exposure and following exposure.

Secondary Outcome Measures :
  1. Changes in neuropsychological Function [ Time Frame: 5 hours ]
    Assessment of neuropsychological function can be achieved using a battery of mood and cognitive tests. The study will use a battery of tests that are comercially available through CANTAB, the mini-mental state exam designed by University of Cambridge. Battery will be administered before and after exposure.

  2. Changes in endothelial function [ Time Frame: 5 hours ]
    Endothelial function will be assessed using the non-invasive, FDA approved Endo-Pat2000 instrument. Test administration involves continuous measurement of blood flow and vascular tone in the fingertips of both index fingers, before, during and after an occlusion of blood flow to the non-dominant hand. Blood flow is occluded using a standard blood pressure cuff positioned on the upper arm. Measures will be carried out before and after exposure.

  3. Changes in levels of Hypothalamic-Pituitary-Adrenal (HPA) Axis [ Time Frame: 5 hours ]
    In the present study, salivary cortisol will be assessed as a non-invasive measure of HPA axis activation. Saliva sample collection will be done with Salivette swabs twice before exposure, once during exposure and twice following exposure.

  4. Fraction of Exhaled Nitric Oxyde [ Time Frame: 5 hours ]
    Lung inflammation will be assessed as the fraction of nitric oxide (NO) exhaled in the participants' breath using a portable, FDA approved, fractional exhaled nitric oxide (FENO) measurement device, the NIOX Mino. Measures will be carried out before and after exposure.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02277002

Layout table for location information
Canada, Quebec
Guy-Favreau Complex
Montreal, Quebec, Canada
Sponsors and Collaborators
Health Canada
Layout table for investigator information
Principal Investigator: Gary Mallach Health Canada
Layout table for additonal information
Responsible Party: Gary Mallach, Air Health Effects Researcher, Health Canada Identifier: NCT02277002    
Other Study ID Numbers: REB 2014-0006
First Posted: October 28, 2014    Key Record Dates
Last Update Posted: March 2, 2015
Last Verified: February 2015
Keywords provided by Gary Mallach, Health Canada:
Cabin Air Filtration
Particulate Matter
Commuter Exposure
Traffic Related Air Pollution
Additional relevant MeSH terms:
Layout table for MeSH terms
Pathologic Processes
Lung Diseases
Respiratory Tract Diseases
Respiratory Tract Infections