NCT06749093

Brief 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. 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.

Trial Health

63
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Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
48

participants targeted

Target at P25-P50 for not_applicable

Timeline
45mo left

Started Jul 2025

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress19%
Jul 2025Dec 2029

First Submitted

Initial submission to the registry

October 23, 2024

Completed
2 months until next milestone

First Posted

Study publicly available on registry

December 27, 2024

Completed
6 months until next milestone

Study Start

First participant enrolled

July 1, 2025

Completed
1.5 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 31, 2026

Expected
3 years until next milestone

Study Completion

Last participant's last visit for all outcomes

December 31, 2029

Last Updated

December 27, 2024

Status Verified

December 1, 2024

Enrollment Period

1.5 years

First QC Date

October 23, 2024

Last Update Submit

December 17, 2024

Conditions

Keywords

Air PollutionWood SmokeDiesel Exhaust

Outcome Measures

Primary Outcomes (6)

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

    Differentially count lung cells.

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

  • 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.

    Through study completion, anticipated ~5 months.

  • 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.

    Through study completion, anticipated ~5 months.

  • 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.

    Through study completion, anticipated ~5 months.

  • 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).

    Through study completion, anticipated ~5 months.

  • 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.

    Through study completion, anticipated ~5 months.

Secondary Outcomes (5)

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

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

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

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

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

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

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

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

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

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

Study Arms (4)

Filtered Air (FA)

PLACEBO COMPARATOR

Participants will be exposed to 2 hours of high-efficiency particulate air (HEPA) filtered air (FA).

Other: Filtered Air (FA)

Wood Smoke (WS)

ACTIVE COMPARATOR

Participants 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).

Other: Wood Smoke (WS)

Diesel Exhaust (DE)

ACTIVE COMPARATOR

Participants 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).

Other: Diesel Exhaust (DE)

Diesel Exhaust and Wood Smoke (DEWS)

ACTIVE COMPARATOR

Participants 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).

Other: Diesel Exhaust and Wood Smoke (DEWS)

Interventions

Exposure to HEPA filtered air, as a control

Filtered Air (FA)

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

Wood Smoke (WS)

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

Also known as: Traffic-Related Air Pollution
Diesel Exhaust (DE)

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

Also known as: Air Pollution
Diesel Exhaust and Wood Smoke (DEWS)

Eligibility Criteria

Age19 Years - 40 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

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

You may not qualify if:

  • 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).

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University of British Columbia

Vancouver, British Columbia, V5Z 1M9, Canada

Location

MeSH Terms

Conditions

Rhinitis, Allergic

Interventions

Vehicle EmissionsAir Pollution

Condition Hierarchy (Ancestors)

RhinitisNose DiseasesRespiratory Tract DiseasesRespiratory HypersensitivityOtorhinolaryngologic DiseasesHypersensitivity, ImmediateHypersensitivityImmune System Diseases

Intervention Hierarchy (Ancestors)

Complex MixturesEnvironmental PollutionPublic HealthEnvironment and Public Health

Study Officials

  • Chris Carlsten, MD

    University of British Columbia

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Parteek Johal

CONTACT

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
TRIPLE
Who Masked
PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
Purpose
BASIC SCIENCE
Intervention Model
CROSSOVER
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Professor

Study Record Dates

First Submitted

October 23, 2024

First Posted

December 27, 2024

Study Start

July 1, 2025

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

December 31, 2029

Last Updated

December 27, 2024

Record last verified: 2024-12

Data Sharing

IPD Sharing
Will share

Participant data that underlie the results reported in accepted articles for publications, after deidentification (text, tables, figures, and appendices).

Time Frame
Immediately following publication. No end date.
Access Criteria
Researchers who provide a methodologically sound proposal to the PI to complement the approved study aims.

Locations