Diesel Exhaust and Wood Smoke for Air Pollution Exposure

(WADE Trial)

Overseen By Parteek Johal

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: University of British Columbia

Disqualifiers: Pregnancy, Frequent WS or DE exposures

Compensation: Varies

Number of Visits: 4

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests how different types of air pollution, such as diesel exhaust and wood smoke, quickly affect health. Researchers aim to identify differences between these pollution types, which are common in Canada and may impact health differently. Participants will be exposed to either filtered air, wood smoke, diesel exhaust, or a mix of diesel and wood smoke to compare effects. The study seeks healthy, non-smoking adults aged 19-40 who are not regularly exposed to these pollutants. As an unphased trial, it offers a unique opportunity to contribute to understanding environmental health impacts.

Do I need to stop taking my current medications to join the trial?

The trial protocol does not specify whether you need to stop taking your current medications. However, since the study is for healthy individuals with no history of respiratory disease, it's likely that participants are not on regular medications for such conditions.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research shows that both diesel exhaust and wood smoke affect human health. Breathing in diesel exhaust links to issues like asthma, lung diseases, and even lung cancer with prolonged exposure. It can also worsen existing heart and lung conditions, posing a concern for those with chronic health issues.

Wood smoke irritates the lungs and causes inflammation, increasing the likelihood of lung infections. It can also impact the immune system and contribute to heart and lung diseases.

Studies examining controlled human exposure to these pollutants have identified specific health effects for each. Diesel exhaust tends to have stronger effects on the body, including changes in gene function. While these pollutants carry risks, researchers design studies to minimize harm and provide important insights into their health effects. Participants should be aware of these risks but also know that the studies aim to ensure safety. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about this trial because it explores how different types of air pollution, specifically diesel exhaust and wood smoke, affect human health. Unlike traditional studies that look at air pollution as a whole, this trial isolates specific pollutants to understand their individual impacts. By examining diesel exhaust, wood smoke, and a combination of both, researchers aim to pinpoint how each source contributes to health issues. This detailed approach could lead to more targeted strategies for reducing pollution-related health risks.

What evidence suggests that this trial's treatments could be effective in assessing the health impact of air pollution?

This trial will compare the effects of different air pollution exposures. Participants will be exposed to diesel exhaust, wood smoke, a combination of both, or filtered air as a control. Research has shown that both diesel exhaust and wood smoke can harm health. Breathing in diesel exhaust affects blood vessel and brain function, impacting heart and cognitive abilities. Similarly, wood smoke causes inflammation in the lungs and body, leading to respiratory and other health issues. When combined, these pollutants may have similar harmful effects, as both contain tiny particles that penetrate deep into the lungs. Overall, both types of air pollution are linked to higher risks of illness and death, highlighting the need to understand their specific health impacts. ^{2 3 6 7 8}

Who Is on the Research Team?

Chris Carlsten, MD

Principal Investigator

University of British Columbia

Are You a Good Fit for This Trial?

This trial is for individuals with or without rhinitis (including hay fever) who are generally healthy. It aims to understand how different types of air pollution affect health.

Inclusion Criteria

I am between 19 and 40 years old.

I am healthy and have never had a lung disease.

Lifetime non-smoker and non-vaper

Exclusion Criteria

I am often exposed to smoke or diesel exhaust at home or work.

Pregnant, planning to become pregnant, or breastfeeding during the study period (confirmed through pregnancy tests at each visit if applicable)

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Exposure

Participants are exposed to filtered air, wood smoke, diesel exhaust, and a combination of diesel exhaust and wood smoke, each for 2 hours with a 4-week washout period between exposures.

16 weeks

4 visits (in-person)

Follow-up

Participants are monitored for changes in biomarkers and lung function after each exposure.

5 months

What Are the Treatments Tested in This Trial?

Interventions

• Diesel Exhaust and Wood Smoke (DEWS)
• Diesel Exhaust (DE)
• Filtered Air (FA)
• Wood Smoke (WS)

Trial Overview The study compares the health effects of breathing in diesel exhaust and wood smoke versus filtered air. Participants will be exposed to these conditions in a controlled environment to assess acute health changes.

How Is the Trial Designed?

Group I: Wood Smoke (WS) Active Control 1 Intervention

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).

Group II: Diesel Exhaust (DE) Active Control 1 Intervention

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).

Group III: Diesel Exhaust and Wood Smoke (DEWS) Active Control 1 Intervention

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).

Group IV: Filtered Air (FA) Placebo Group 1 Intervention

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

Who Is Running the Clinical Trial?

University of British Columbia

Lead Sponsor

Trials

1,506

Recruited

2,528,000+

Citations

1. particleandfibretoxicology.biomedcentral.com particleandfibretoxicology.biomedcentral.com/articles/10.1186/s12989-022-00450-5

Controlled human exposure to diesel exhaust: results ... Diesel exhaust exposure impairs vasomotor function. Exposure to air pollution has been consistently associated with cardiovascular morbidity and ...

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9840312/

Brief diesel exhaust exposure acutely impairs functional brain ... Brief diesel exhaust exposure acutely impairs functional brain connectivity in humans: a randomized controlled crossover study · Abstract.

3. healtheffects.org healtheffects.org/air-pollution/diesel-exhaust

Diesel Exhaust A study documenting the substantial improvements that can result from using emissions control technologies, including diesel particulate filters and selective ...

4. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0160412017315878

Diesel exhaust exposure, its multi-system effects, and the ... The new standards are estimated to reduce PM emissions by 110,000 tons each year and toxic air pollutants such as benzene by 17,000 tons in the U.S. annually ( ...

5. ww2.arb.ca.gov ww2.arb.ca.gov/resources/overview-diesel-exhaust-and-health

Overview: Diesel Exhaust & Health | California Air Resources ... Based on 2012 estimates of statewide exposure, DPM is estimated to increase statewide cancer risk by 520 cancers per million residents exposed over a lifetime.

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC8039848/

A systematic review of the health effects associated with ... The results from this systematic review demonstrate that exposure to different components in diesel exhaust can have distinct and independent health effects.

7. epa.gov epa.gov/dera/learn-about-impacts-diesel-exhaust-and-diesel-emissions-reduction-act

Learn About Impacts of Diesel Exhaust and the ... Human Health - Exposure to diesel exhaust can lead to serious health conditions like asthma and respiratory illnesses and can worsen existing ...

8. cancer.org cancer.org/cancer/risk-prevention/chemicals/diesel-exhaust-and-cancer.html

Diesel Exhaust and Cancer Risk Several studies have found that long-term, heavy exposure to diesel exhaust can cause lung cancer in lab animals such as rats.