Efficacy of Respiratory Protection Against the Effects of Wood Smoke Exposure in Young Healthy Adults

Summary

Purpose: This study is designed to test whether the gaseous fraction of woodsmoke, volatile organic compounds, produce acute cardiac, respiratory, and systemic inflammatory health effects after controlled exposure to woodsmoke in health, young volunteers.

Participants: Approximately fifty, 18-35 year-old healthy volunteers to complete the study.

Procedure: After consenting to participate in the study, participants will undergo two exposures to approximately 500 μg/m3 woodsmoke. The two exposures will be held at least 3 weeks apart. Each exposure session will have a follow-up session approximately 24 hr later. During each exposure session, participants will wear a modified MAXAir Systems (Irvine, CA, USA) (TC 21C-1050) controlled air pressure respirator (CAPR) that will deliver filtered woodsmoke directly to the participant's breathing zone. During the first exposure, the CAPR will deliver woodsmoke from which virtually all particulate matter (PM) and volatile organic compounds (VOC's) will be removed. During the second exposure, only the PM will be removed from the woodsmoke, allowing the VOC to pass into the subject's breathing zone. During each session, participants will be exposed for 2 hours while exercising intermittently (15 min exercise followed by 15 min rest) on a stationary bike at a workload sufficient to maintain a minute ventilation of approximately 25 L/min/m2. Venous blood samples and measurements of respiratory, cardiac, and vascular function will be performed prior, immediately following and approximately 18 hrs post each exposure. Approximately 24 hours post-exposure, participants will undergo a bronchoscopy procedure to sample bronchoalveolar fluid and cells for evidence of an inflammatory response to the exposures. Nasal epithelial lining fluid will be also collected approximately 24 hours post each exposure.

Conditions

• Healthy

Interventions

OTHER

Filtration of all PM and VOC's

During each exposure session, participants will wear a modified MaxAIR controlled air pressure respirator (CAPR) manufactured by Syntech International (BMD), Irvine, CA, USA, that will deliver filtered woodsmoke directly to the participant. The MaxAIR CAPR is a NIOSH approved (TC 21C-1050) powered air purifying respirator used for infectious disease control in laboratory and medical settings. In the modified MAXAIR CAPR used during this study's exposure sessions, an external pump and different filtering media. For this intervention, virtually all particulate matter (PM) and volatile organic compounds (VOC's) will be removed using commercially available P100/VOC respirator filters (3M cartridge; 60925 or equivalent).

OTHER

Filtration of VOC's

During each exposure session, participants will wear a modified MaxAIR controlled air pressure respirator (CAPR) manufactured by Syntech International (BMD), Irvine, CA, USA, that will deliver filtered woodsmoke directly to the participant. The MaxAIR CAPR is a NIOSH approved (TC 21C-1050) powered air purifying respirator used for infectious disease control in laboratory and medical settings. In the modified MAXAIR CAPR used during this study's exposure sessions, an external pump and different filtering media. For this intervention, virtually all particulate matter (PM)will be removed using commercially available P100 respirator filters (DM; cat. # 2097).

Sponsors & Collaborators

• Environmental Protection Agency (EPA)

  collaborator FED

• University of North Carolina, Chapel Hill

  lead OTHER

Principal Investigators

• James Samet · Environmental Protection Agency (EPA)

Study Design

Allocation

NA

Purpose

OTHER

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

35 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-06-01

Primary Completion

2027-12-31

Completion

2027-12-31

Countries

• United States

Study Locations