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

Обзор

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.

Подробное описание

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.

Вмешательства

• Другое Filtered Air (FA)
  Exposure to HEPA filtered air, as a control
• Другое Wood Smoke (WS)
  Wood smoke (WS) standardized to 300µg/m³ of particulate matter with a diameter of 2.5 micrometers or less (PM2.5).
• Другое Diesel Exhaust (DE)
  Diesel exhaust (DE) standardized to 300µg/m³ of particulate matter with a diameter of 2.5 micrometers or less (PM2.5).
• Другое Diesel Exhaust and Wood Smoke (DEWS)
  Combined diesel exhaust and wood smoke standardized to 300µg/m³ of particulate matter with a diameter of 2.5 micrometers or less (PM2.5).

Первичные конечные точки

• Woodsmoke (WS) and/or diesel exhaust (DE) exposure effects on inflammatory cells in the lungs. [Срок оценки: 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. [Срок оценки: Through study completion, anticipated ~5 months.]
• Within-individual change in lung protein biomarkers of inflammation following exposure to woodsmoke and/or diesel exhaust. [Срок оценки: Through study completion, anticipated ~5 months.]
• Within-individual change in circulating transcriptomic biomarkers of inflammation following exposure to woodsmoke and/or diesel exhaust. [Срок оценки: Through study completion, anticipated ~5 months.]
• Within-individual change in circulating protein biomarkers of inflammation following exposure to woodsmoke and/or diesel exhaust. [Срок оценки: Through study completion, anticipated ~5 months.]
• Within-individual change in airway resistance following exposures to woodsmoke and/or diesel exhaust. [Срок оценки: Through study completion, anticipated ~5 months.]

Вторичные конечные точки (5)

• Woodsmoke (WS) and/or diesel exhaust (DE) exposure effects on inflammatory cells in the nose. [Срок оценки: 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. [Срок оценки: 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. [Срок оценки: Comparison of the different arms (over the span of ~5 months).]
• Woodsmoke (WS) and/or diesel exhaust (DE) exposure effects on lung function. [Срок оценки: Comparison of the different arms (over the span of ~5 months).]
• Woodsmoke (WS) and/or diesel exhaust (DE) exposure effects on nasal resistance. [Срок оценки: Comparison of the different arms (over the span of ~5 months).]

Критерии участия

Критерии включения

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

Критерии исключения

• 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).

Критерии приведены из реестра в оригинале (на английском). Окончательную оценку соответствия проводит исследовательский центр.

Здоровые добровольцы: Да

Дизайн исследования

Распределение

Рандомизированное

Модель

Перекрёстный дизайн

Маскирование

Тройное слепое

Основная цель

Фундаментальное исследование

Центры проведения

Канада · 1 центр

• University of British Columbia — Vancouver

Идентификаторы

NCT: NCT06749093 · H24-00776

Первоисточники (государственные реестры)

• ClinicalTrials.gov (NIH, США)

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