Commuter Air Pollution Intervention Study (CAPI)

Reducing Commuter Air Pollutant Exposure by Cabin Air Filtration

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?

Study Overview

• Status: Completed
• Conditions: Cognitive Function; Cardiopulmonary Function; Lung Inflammation; Air Pollution Exposure; Saliva Stress Hormones
• Intervention / Treatment: Other: Placebo; Device: Cabin Air Filtration

• Study Type: Interventional
• Enrollment (Actual): 48
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Quebec
    • Montreal, Quebec, Canada
      • Guy-Favreau Complex

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / 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

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Variation in cardiopulmonary function	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.	5 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in neuropsychological Function	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.	5 hours
Changes in endothelial function	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.	5 hours
Changes in levels of Hypothalamic-Pituitary-Adrenal (HPA) Axis	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.	5 hours
Fraction of Exhaled Nitric Oxyde	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.	5 hours

Collaborators and Investigators

• Sponsor: Health Canada
• Investigators: Principal Investigator: Gary Mallach, Health Canada

Study record dates

Study Major Dates

• Study Start: October 1, 2014
• Primary Completion (Actual): November 1, 2014
• Study Completion (Actual): November 1, 2014

Study Registration Dates

• First Submitted: October 9, 2014
• First Submitted That Met QC Criteria: October 27, 2014
• First Posted (Estimate): October 28, 2014

Study Record Updates

• Last Update Posted (Estimate): March 2, 2015
• Last Update Submitted That Met QC Criteria: February 26, 2015
• Last Verified: February 1, 2015

More Information

Terms related to this study

• Keywords: Particulate Matter; Cabin Air Filtration; Commuter Exposure; Traffic Related Air Pollution
• Additional Relevant MeSH Terms: Pathologic Processes; Infections; Respiratory Tract Infections; Respiratory Tract Diseases; Lung Diseases; Inflammation; Pneumonia
• Other Study ID Numbers: REB 2014-0006