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Healthy IndividualsWADENCT06749093

Health Effects of Wood Smoke and Traffic-Related Air Pollution Exposures: a Necessary Comparison

A study testing Filtered Air (FA), Wood Smoke (WS) and Diesel Exhaust (DE) in people with Healthy Individuals and Allergic Rhinitis, run by University of British Columbia at 1 site in Canada.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
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Trial summary

Accumulating evidence demonstrates that breathing air pollutants leads to devastating increases in sickness and death worldwide over time. However, there is little data comparing the effects of different types of air pollution on health. Read more about this study

Who is it for?
Ages 19 to 40 yearsHealthy volunteers can take part
Conditions the study is for
Healthy Individuals, Allergic Rhinitis
What is being tested?
Filtered Air (FA), Wood Smoke (WS) and Diesel Exhaust (DE)
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
48 participants
Where
1 siteCanada
Study dates
1 Jul 2025to 31 Dec 2029
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 19 to 40 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Age 19-40
  • Healthy, with no history of respiratory disease
  • Lifetime non-smoker and non-vaper.

Who cannot join

  • Pregnant, planning to become pregnant, or breastfeeding during the study period (confirmed through pregnancy tests at each visit if applicable)
  • Frequent WS or DE exposures (e.g. home fireplace used for heating/cooking, or employment in transportation, mining, or as a firefighter).

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Parteek Johal contact

604-875-5132

Canada1 site
  • University of British Columbia

    Vancouver, British Columbia, V5Z 1M9

    Agnes Yuen, BSc, 604-875-4111 ext. 66455, agnes.yuen@ubc.ca

    PJ Johal, BSc, 604-875-5132, p.johal@ubc.ca

Other trials in Canada

About this study

Accumulating evidence demonstrates that breathing air pollutants leads to devastating increases in sickness and death worldwide over time. However, there is little data comparing the effects of different types of air pollution on health. In Canada, traffic-related air pollution and wood smoke (wildfires and wood burning for heating) are very common air pollutants. This study aims to safely complete a controlled human exposure study to test how these air pollution types acutely affect health.

Read the detailed description

Healthy adult participants (total 48; 24 of each biological sex assigned at birth) will breathe filtered air (control), wood smoke (WS), diesel exhaust (DE), and DE plus WS (DEWS) each for 2 hours, with 4 weeks between each exposure (washout). Before and after each exposure, participants will answer questions, perform breathing tests, and give blood samples. At 24 hours after each exposure, participants will undergo a bronchoscopy to collect samples from their lungs.

The study will look at what (if any) are the differences between breathing in fresh air (filtered air - FA) or polluted air containing either wood smoke (WS), diesel exhaust (DE) or diesel exhaust plus wood smoke (DEWS). The research team will use wood smoke generated from pine wood, since it is one of the most common types of wood found in Western Canadian forests where forest fires occur.

The investigators will evaluate multiple endpoints as detailed in the Outcome Measures section. For each applicable endpoint, the investigators will evaluate stratified analyses and effect modification by biological sex, participant age, gene score, and microbiomes.

Being tested
Filtered Air (FA), Wood Smoke (WS), Diesel Exhaust (DE), Diesel Exhaust and Wood Smoke (DEWS)
Keywords
Air Pollution, Wood Smoke, Diesel Exhaust
Medical subject headings
Rhinitis, Allergic

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Filtered Air (FA)Other

    Exposure to HEPA filtered air, as a control

  • Wood Smoke (WS)Other

    Wood smoke (WS) standardized to 300µg/m³ of particulate matter with a diameter of 2.5 micrometers or less (PM2.5).

  • Diesel Exhaust (DE)Other

    Also called Traffic-Related Air Pollution

    Diesel exhaust (DE) standardized to 300µg/m³ of particulate matter with a diameter of 2.5 micrometers or less (PM2.5).

  • Diesel Exhaust and Wood Smoke (DEWS)Other

    Also called Air Pollution

    Combined diesel exhaust and wood smoke standardized to 300µg/m³ of particulate matter with a diameter of 2.5 micrometers or less (PM2.5).

Study groups in NCT06749093
Study groupRoleWhat they receive
Filtered Air (FA)Placebo comparatorParticipants will be exposed to 2 hours of high-efficiency particulate air (HEPA) filtered air (FA).
Receives: Other: Filtered Air (FA)
Wood Smoke (WS)Active comparatorParticipants will be exposed to 2 hours of controlled wood smoke (WS) standardized to 300ug/m^3 of particulate matter with a diameter of 2.5 micrometers or less (PM2.5).
Receives: Other: Wood Smoke (WS)
Diesel Exhaust (DE)Active comparatorParticipants will be exposed to 2 hours of controlled diesel exhaust (DE) as a model of traffic-related air pollution (TRAP) standardized to 300ug/m^3 of particulate matter with a diameter of 2.5 micrometers or less (PM2.5).
Receives: Other: Diesel Exhaust (DE)
Diesel Exhaust and Wood Smoke (DEWS)Active comparatorParticipants will be exposed to 2 hours of combined controlled diesel exhaust (DE) and wood smoke (DEWS) standardized to 300ug/m^3 of particulate matter with a diameter of 2.5 micrometers or less (PM2.5).
Receives: Other: Diesel Exhaust and Wood Smoke (DEWS)

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Woodsmoke (WS) and/or diesel exhaust (DE) exposure effects on inflammatory cells in the lungs.

    Differentially count lung cells.

    Measured: Comparison of the different arms (over the span of ~5 months).

  2. Within-individual change in lung transcriptomic biomarkers of inflammation following exposure to woodsmoke and/or diesel exhaust.

    Within-individual change in lung biomarkers of inflammation (serum amyloid A (SAA), c-reactive protein (CRP), chemokine ligand 18 (CCL18), and fibrinogen) in RNA.

    Measured: Through study completion, anticipated ~5 months.

  3. Within-individual change in lung protein biomarkers of inflammation following exposure to woodsmoke and/or diesel exhaust.

    Within-individual change in lung biomarkers of inflammation (serum amyloid A (SAA), c-reactive protein (CRP), chemokine ligand 18 (CCL18), and fibrinogen) in protein.

    Measured: Through study completion, anticipated ~5 months.

  4. Within-individual change in circulating transcriptomic biomarkers of inflammation following exposure to woodsmoke and/or diesel exhaust.

    Within-individual change in circulating biomarkers of inflammation (CX3CL1, CCL23, CXCL8, SAA, MMP9, MMP12, APOB, APOM, SOD1, NQO1, HMOX1, CAT, CYP1B1, CYP1A2, NFE2L2 and AHRR) in RNA.

    Measured: Through study completion, anticipated ~5 months.

  5. Within-individual change in circulating protein biomarkers of inflammation following exposure to woodsmoke and/or diesel exhaust.

    Within-individual change in circulating protein biomarkers of inflammation (CX3CL1, CCL23, CXCL8, SAA, MMP9, MMP12, APOB, APOM, SOD1, NQO1, HMOX1, CAT, CYP1B1, CYP1A2, NFE2L2 and AHRR).

    Measured: Through study completion, anticipated ~5 months.

  6. Within-individual change in airway resistance following exposures to woodsmoke and/or diesel exhaust.

    Within-individual change in airway resistance, as measured by impulse oscillometry (resonant frequency (Fres) and peripheral airway resistance (R5-R20)) across exposures to woodsmoke and/or diesel exhaust relative to filtered air.

    Measured: Through study completion, anticipated ~5 months.

Secondary outcomes (5)
  1. Woodsmoke (WS) and/or diesel exhaust (DE) exposure effects on inflammatory cells in the nose.

    Differentially count nasal cells.

    Measured: Comparison of the different arms (over the span of ~5 months).

  2. Within-individual changes in exhaled nitric oxide following woodsmoke (WS) and/or diesel exhaust (DE) exposures.

    Measurement of fractional exhaled nitric oxide (FeNO) in parts per billion (ppb).

    Measured: Comparison of the different arms (over the span of ~5 months).

  3. Woodsmoke (WS) and/or diesel exhaust (DE) exposure effects on symptoms, stress and perceptions.

    Visual analog score (0-100) questionnaire will be completed, with a higher score indicating a worse outcome.

    Measured: Comparison of the different arms (over the span of ~5 months).

  4. Woodsmoke (WS) and/or diesel exhaust (DE) exposure effects on lung function.

    Lung function as evaluated by spirometry (e.g. FEV1).

    Measured: Comparison of the different arms (over the span of ~5 months).

  5. Woodsmoke (WS) and/or diesel exhaust (DE) exposure effects on nasal resistance.

    Measurement of peak nasal inspiratory flow (PNIF).

    Measured: Comparison of the different arms (over the span of ~5 months).

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted27 Dec 2024
  2. Study start1 Jul 2025 (estimated)
  3. Primary completion31 Dec 2026 (estimated)
  4. Study completion31 Dec 2029 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Randomised
Intervention model
Crossover
Masking
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
48 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06749093
Sponsor's protocol ID
H24-00776
Acronym
WADE
Status last verified
Dec 2024
First submitted
23 Oct 2024
Last updated
27 Dec 2024
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: Participant data that underlie the results reported in accepted articles for publications, after deidentification (text, tables, figures, and appendices).

Questions about this trial

What is this clinical trial studying?

A study testing Filtered Air (FA), Wood Smoke (WS) and Diesel Exhaust (DE) in people with Healthy Individuals and Allergic Rhinitis, run by University of British Columbia at 1 site in Canada.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: opening soon, as of the sponsor's last update on 27 Dec 2024. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Agnes Yuen (604-875-4111 ext. 66455, agnes.yuen@ubc.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Woodsmoke (WS) and/or diesel exhaust (DE) exposure effects on inflammatory cells in the lungs. (time frame: Comparison of the different arms (over the span of ~5 months).). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Dec 2024.

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