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

Sponsor

University of North Carolina, Chapel Hill (Other)

Overall Status

Not yet recruiting

CT.gov ID

NCT06066749

Collaborator

Environmental Protection Agency (EPA) (U.S. Fed)

Enrollment

Arms

Anticipated Duration (Months)

Study Details

Study Description

Brief Summary

Purpose: The study is designed to investigate cardiovascular effects of young healthy human subjects exposed to wood smoke.

Participants: Approximately 30 young (18-35 years old) healthy subjects to complete.

Procedure (methods): After consenting to participate in the study, participants will undergo exposure to approximately 500 μg/m^{3 wood smoke for 2 hours while exercising intermittently
(15 min exercise followed by 15 min rest) on a stationary bike at a workload sufficient to
maintain approximately 12 L/min/m}2 minute ventilation. There are a total of three separate exposure sessions. During the first two exposure sessions, participants will wear, in randomized order, a half-face elastomeric respirator fitted with particulate filters alone (hereafter referred to as "PM mask") or particulate filters and a hydrocarbon sorbent (hereafter referred to as "VOC mask"). During the third exposure session, participants will be randomly assigned to wear either a surgical mask or an N95 respirator. Venous blood samples and measurements of lung, cardiac and vascular function will be made prior to and immediately following each exposure. Induced sputum samples and nasal epithelial lining fluid will be collected approximately 24 hours post each exposure.

Condition or Disease	Intervention/Treatment	Phase
Healthy	Other: NIOSH certified N95 personal face covering (mask) Other: Surgical Mask	N/A

Detailed Description

Wood smoke pollution is a common problem across the world, including in the US. This wood smoke comes from people using wood to heat and cook, as well as from wildfires. The purpose of this research study is to investigate the cardiovascular effects of exposure to wood smoke in young, healthy human subjects. Results from this study will also increase understanding of how wood smoke exposure adversely affects the functioning of the human cardiovascular and respiratory systems. This understanding may be especially important for patients with cardiopulmonary diseases.

Consenting Day:

The consent day visit is expected to last about 4-5 hours. The investigators will review the inclusion and exclusion criteria and the participants' medical conditions and current medications. The investigators will go over the study in detail so the participant is as informed as possible before consenting to being part of this study. The participant will then sign all consent forms and receive one set of signed copies. The participant will also tour the exposure chambers following the consenting process.

The participant will perform a breathing test (spirometry) to measure lung function. The participant will breathe through a filter into a plastic tube, while being coached by members of the study team. Participants will be asked to take a full breath in, follow by a hard and fast maximal exhalation. The participant will be asked to do this several times. This test measures the volume of air that can be exhaled and the rate of airflow during exhalation after a maximal inhalation. This is a method to measure lung function which must meet certain criteria (lung capacity and volume) prior to exposure in order for the participant to remain in the study. Lung function test results should be equal to or greater than 80% of the reference value to continue participation in the study.

Participants will then be fitted for a half-face elastomeric respirator to ensure they are wearing the proper size. Participants will also undergo procedures for nasal epithelial lining fluid sampling (nasal mucosa) and induced sputum collection. It is known that less than half of normal, healthy people can produce a sputum sample that is of acceptable quality for analysis. The study will end if a participant is a non-producer or the quality of the sputum produced does not meet the study inclusion criteria. In this event, the participant will be reimbursed for the consenting session. Participants who meet all inclusion criteria will be contacted with further instructions.

Exposure days:

The study team will contact and send reminders to all participants a few days before the exposure session. Participants should avoid smoke, fumes, alcohol, and strenuous exercise 24 hours prior to all visits, and abstain from pan fried or grilled meat after midnight of the exposure day. Participants will be asked to eat a light breakfast and arrive at the EPA medical station by 8:00 am. The study team will make ensure that all participants understand the importance of arriving earlier to ensure the investigators have adequate time to process all samples and data. Participants who arrive after 8:00 am will be unenrolled from the study.

Prior to exposure, a study team member will collect the follow from each participant:

Vital signs (heart rate, respiratory rate, blood pressure, oxygen saturation level) and an electronic symptom questionnaire.
Heart Rate Variability via a Holter monitor. A study team member will attach ten electrocardiogram (ECG) leads to the participants' chest. It may be necessary to clean and shave areas of the chest where these leads will be placed. Participants will be asked to not apply excessive deodorant, skin lotions, and body sprays on as these may interfere with data recording. The leads will be connected to 2 monitors (small recording devices about the size and weight of a cell phone) to obtain heart rate and rhythm readings. It is preferable that the electrodes will stay in place for approximately 4 days as these measurements will be collected several times during the study, however, participants will be given the option to remove the electrodes by the end of each exposure day. To begin recording, participants will be asked to recline quietly for 30 minutes. It is important that the participant does not fall asleep during this 30-minute period. These measurements will allow the investigators to determine whether wood smoke exposure causes small changes in the ability of your nervous system to regulate how your heart beats.
Retinal Imaging. An ophthalmic camera will be employed to collect retinal images of all participants before and after each exposure and on the follow-up visit. The participants chin will be rested in front of the camera, while a study team member takes pictures of both eyes. Glasses or contacts must be removed for this test. Participants will be notified to bring contact lens cases and solutions.
The study team will continue to store the images for future undesignated studies given the participant's consent. This allows the team to make the best use of the images collected from subjects. Participants will be given a separate consent form for this storage and do not have to allow images to be stored indefinitely in order to participate in this study.
Blood Draw. Approximately 60 ml of blood will be drawn (about 4 tablespoons) before and after each exposure and on the follow-up visit. The study team will test this blood to see blood cell function is affected by exposure to wood smoke. A small portion of the blood sample will be used to measure the relative content of various fatty acids present in blood. With permission, the investigators will also store some of the blood obtained during the study for yet-to-be-determined tests.
Spirometry will be performed following the same procedure used on the consent day.
Ventilation Rate. BioPac bands will be placed around the participants' thorax and abdomen. These bands will be connected to a monitor that wirelessly transmits readings of breathing volume and rate. These measurements will allow the investigators to determine if the participants' exercise workload is sufficient to meet the study's target minute ventilation rate.

Participants will enter the exposure chamber following the pre-exposure protocol listed above. While in the chamber, participants will undergo exposure to approximately 500 μg/m^{3
wood smoke for 2 hours while exercising intermittently (15 min exercise followed by 15 min
rest) on a stationary bike at a workload sufficient to maintain approximately 12 L/min/m}2 minute ventilation. There are a total of three separate exposure sessions. During the first two exposure sessions, participants will wear, in randomized order, a half-face elastomeric respirator fitted with particulate filters alone (hereafter referred to as "PM mask") or particulate filters and a hydrocarbon sorbent (hereafter referred to as "VOC mask"). During the third exposure session, participants will be randomly assigned to wear either a surgical mask or an N95 respirator. The concentration of wood smoke used in this study (approximately 500 μg/m^{3) is below what is reported for those using biomass burning for heating and food
preparation, those firefighters are exposed to, and those living in the area of a forest fire
or agricultural burning are exposed to. Chamber conditions will be at a comfortable
temperature and relative humidity. Participants will perform mild exercise on a stationary
bicycle in the chamber every other 15 minutes alternating with resting period for a total of
1 hour of exercise per chamber exposure. The target ventilation rate will be maintained at
approximately 12 L/min/m}2 and monitored using pneumotach and BioPac methods. A study coordinator or other trained person will be observing from outside the chamber at all times. During the exposure, heart rate and oxygen saturation will be monitored by placing a device (pulse oximeter) on the participants' finger. If it appears the participant is experiencing significant discomfort, breathing or heart problems, the exposure will be terminated immediately. In addition, the participant may elect to terminate the exposure at any time for any reason. Participants who do not complete the study protocol will be fully compensated that day's session but will be ineligible for further participation in the study.

Immediately following the exposure, participants will:

Fill out a symptom score questionnaire electronically.
Have your vital signs checked.
Have blood drawn (Approximately 60 ml, about 4 tablespoons).
Have a breathing test (spirometry).
Recline quietly for 30 minutes while heart rhythm is recorded.
Have retinal pictures will be taken.
Eat a low-fat lunch brought from home. At this time, the study team will encourage participants to take a shower in a private shower facility at the HSF to get rid of the wood smoke odor. Towel, soap, and shampoo will be provided. The participant's belongings will be securely stored during all visits.

Participants will be assessed and discharged by the study team following the completion of each exposure day.

Follow up visit (about 4 hours):

Participants will return to the HSF the next morning (approximately 24 hours after exposure) and will:

Have vital signs checked.
Recline quietly for 30 minutes while your heart rhythm is recorded. Electrodes will be removed from the participants' chest at the end of this test.
Have blood pressure and heart rate measured.
Fill out a symptom score questionnaire electronically.
Complete TracMyAir Questionnaire (see below)
Have NELF samples collected.
Have samples of induced sputum collected.
Have a breathing test (spirometry).
Have blood drawn (approximately 60 ml) for analysis.
Have retinal pictures taken.

TracMyAir is an application that uses data from nearby monitoring stations to report on local air pollution levels. The study team will use TracMyAir to determine each study participant's daily (24 hour average) ambient PM2.5 and ozone exposure and inhaled dose. TracMyAir calculates daily 24 hour average exposure and dose for the previous 4 days, which allows for a lag analysis. TracMyAir uses EPA's previously developed and evaluated Exposure Model for Individuals (EMI). The EPA staff will enter input data (shown below) into the TracMyAir software for each study participant.

If there are any samples left over after all study information is collected, the study team will continue to store the samples for future undesignated studies given the participant's consent. This allows the team to make the best use of the samples collected from subjects. Participants will be given a separate consent form for this storage and do not have to allow samples to be stored indefinitely in order to participate in this study.

Study Design

Study Type:

Interventional

Anticipated Enrollment :

30 participants

Allocation:

Randomized

Intervention Model:

Sequential Assignment

Masking:

None (Open Label)

Primary Purpose:

Other

Official Title:

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

Anticipated Study Start Date :

Oct 1, 2023

Anticipated Primary Completion Date :

Dec 1, 2024

Anticipated Study Completion Date :

Dec 1, 2024

Arms and Interventions

Arm	Intervention/Treatment
Experimental: NIOSH certified N95 personal face covering (mask) During the third woodsmoke exposure, half of the subjects will be randomly assigned to wear a NIOSH (National Institute of Occupational Safety & Health) certified N95 personal face covering (mask) while undergoing an exposure to approximately 500 μg/m^3 wood smoke for 2 hours while exercising intermittently (15 min exercise followed by 15 min rest) on a stationary bike at a workload sufficient to maintain approximately 12 L/min/m^2 minute ventilation.	Other: NIOSH certified N95 personal face covering (mask) During the this final exposure session, participants will be randomly assigned to wear an N95 respirator (3M cat. #: 9205+). Participants will be instructed on how to wear the mask to ensure a proper fit before entering the chamber.
Experimental: Surgical Mask During the third woodsmoke exposure, half of the subjects will be randomly assigned to wear a surgical mask while undergoing an exposure to approximately 500 μg/m^3 wood smoke for 2 hours while exercising intermittently (15 min exercise followed by 15 min rest) on a stationary bike at a workload sufficient to maintain approximately 12 L/min/m^2 minute ventilation.	Other: Surgical Mask During the this final exposure session, participants will be randomly assigned to wear an ear loop style surgical mask. Participants will be instructed on how to wear the mask to ensure a proper fit before entering the chamber.

Arm

Intervention/Treatment

Experimental: NIOSH certified N95 personal face covering (mask)

During the third woodsmoke exposure, half of the subjects will be randomly assigned to wear a NIOSH (National Institute of Occupational Safety & Health) certified N95 personal face covering (mask) while undergoing an exposure to approximately 500 μg/m^3 wood smoke for 2 hours while exercising intermittently (15 min exercise followed by 15 min rest) on a stationary bike at a workload sufficient to maintain approximately 12 L/min/m^2 minute ventilation.

Other: NIOSH certified N95 personal face covering (mask)

During the this final exposure session, participants will be randomly assigned to wear an N95 respirator (3M cat. #: 9205+). Participants will be instructed on how to wear the mask to ensure a proper fit before entering the chamber.

Experimental: Surgical Mask

During the third woodsmoke exposure, half of the subjects will be randomly assigned to wear a surgical mask while undergoing an exposure to approximately 500 μg/m^3 wood smoke for 2 hours while exercising intermittently (15 min exercise followed by 15 min rest) on a stationary bike at a workload sufficient to maintain approximately 12 L/min/m^2 minute ventilation.

Other: Surgical Mask

During the this final exposure session, participants will be randomly assigned to wear an ear loop style surgical mask. Participants will be instructed on how to wear the mask to ensure a proper fit before entering the chamber.

Outcome Measures

Primary Outcome Measures

Change in polymorphonuclear neutrophils (PMN%) in the Sputum [Approximately 24 hours post exposure.]
Airway inflammation will be assessed by the % PMN in the sputum

Secondary Outcome Measures

Change in Forced Expired Volume in the First Second (FEV1) (liter) [Immediately after each exposure and approximately 24 hours post exposure.]
FEV1 is determined by spirometry
Change in Forced Vital Capacity (FVC) (liter) [Immediately after each exposure and approximately 24 hours post exposure.]
FVC is determined by spirometry
Change in Diameters (mm) of Retinal Arteries and Veins [Immediately after each exposure and approximately 24 hours post exposure.]
Retinal images will be taken using an FDA-approved, commercially available, non-mydriatic fundus camera. Images will be taken from both eyes.
Percent Change in Heart Rate Variability [Immediately after each exposure and approximately 24 hours post exposure.]
Heart rate variability will be collected by the Holter monitor recording.
Change in concentration of Blood Fatty Acids (ng/mL) [Immediately after each exposure and approximately 24 hours post exposure.]
Blood sample will be collected for fatty acids analysis.
Change in concentration of Blood Cholesterol (ng/mL) [Immediately after each exposure and approximately 24 hours post exposure.]
Blood sample will be collected for blood cholesterol analysis.
Change in concentration of Cytokines in Nasal Epithelial Lining Fluid (NELF) (ng/mL) [Immediately after each exposure and approximately 24 hours post exposure.]
NELF samples will be collected for cytokine measurements.
Change in concentration of interleukin-6, interleukin-8, interleukin-1 beta, and tumor-necrosis factor alpha in blood. (pg/mL) [Immediately after each exposure and approximately 24 hours post exposure.]
Blood will be collected prior to and post exposure to analyze for inflammatory markers.
Change in concentration of C-reactive protein in blood. [Immediately after each exposure and approximately 24 hours post exposure.]
Blood will be collected prior to and post exposure to analyze for inflammatory markers.

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 35 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion criteria:

Age 18-35 years old , healthy, with a Body Mass Index (BMI, kg/m^2) values ≥ 19 and ≤ 30, inclusive).
Physical conditioning that allows intermittent, mild exercise for approximately 60 min during a 2 hour exposure session. The volunteer must be able to complete the exposure exercise regimen at a workload sufficient to induce a minute ventilation rate of approximately 12 L/min/m^2 for 15 min without exceeding 80% of projected maximal heart rate.
Normal ECG.
Normal lung function based on NHANES III reference values. i. Forced vital capacity (FVC) ≥ 80% of that predicted for age, gender, ethnicity, and height.

Forced expiratory volume in one second (FEV1) ≥ 80% of that predicted for age, gender, ethnicity, and height.

iii: FEV1/FVC ratio ≥ 80% of predicted values.

Oxygen saturation greater than 94% at the time of physical exam.
Up to date COVID-19 vaccination status per CDC recommendations.

Exclusion criteria:

Individuals with the following conditions:

A history of acute or chronic cardiovascular disease, chronic respiratory disease, cancer, rheumatologic disease, neuromuscular disease, or immunodeficiency state.
BMI (kg/m^2) values < 19 and > 30.
Blood pressure readings ≥ 140 systolic and/or ≥ 90 diastolic.
Diabetes (previously diagnosed or with hemoglobin A1c level equal to or greater than 6.4%).
Asthma or a history of asthma.
Bleeding/clotting disorders.

Individuals with a cardiovascular disease risk score greater than 10% using the ACC/AHA ASCVD risk calculator. (Based on the 10-year risk of heart disease or stroke using the Atherosclerotic Cardiovascular Disease algorithm published in 2013 American College of Cardiology/American Heart Association Guideline on the Assessment of Cardiovascular risk.)
Individuals who have unspecified illnesses, which in the judgment of the medical staff might increase the risk associated with wood smoke inhalation will be a basis for exclusion.
Individuals who have had recent (within 6 months) abdominal an/or eye surgery, or with any types of hernia, as well as any other contraindicators for raised intra-abdominal pressure.
Individuals who are currently taking systemic steroids or oral anticoagulants long term.
Individuals who are taking prescribed medications such as ß-blocker medications, that may impact the results of wood smoke challenge for the duration of the study. Other medications not specifically mentioned here may be reviewed by the medical staff prior to an individual's inclusion in the study. Use of other medications will be evaluated on a case-by-case basis. There is the potential that an individual's current medication use will preclude them from participating in the study at the current time, but they may be reassessed and potentially rescheduled for participation later based on the judgement of the medical staff.
Individuals who are allergic to:

Chemical vapors or gases.
Tape or electrodes on their skin.
Or individuals with active allergies or currently experience allergy related symptoms

Individuals who are pregnant, attempting to become pregnant or breastfeeding.
Individuals who are currently smoking (including vaping, hookah and e-cigarette) or have smoking history within 1 year of study or have an equal to greater than or a 5-pack year smoking history.
Individuals living with a smoker who smokes inside the house.
Individuals who are regularly exposed to high levels of vapors, dust, gases, or fumes.
Individuals who do not read, speak, or understand English well enough to give informed consent.
Individuals that are unable to perform the exercise required for the study.
Individuals who are unwilling or unable to stop taking any current dietary supplements or vitamins for the duration of the study.
Individuals currently taking prebiotics, probiotics, or antihistamines.
Individuals who have experienced an acute respiratory illness within the last 6 weeks.
Individuals who have a facial hair style that will interfere with the facemask seal and are not willing to shave for the study session.
Individuals that will NOT comply with the following requirements:

Avoid smoke and fumes for 24 hours before all visits.
Avoid exposure to unvented household combustion sources (gas stoves, lit fireplaces, oil/kerosene heaters) for 48 hours before all visits.
Avoid over-the-counter pain medications such as aspirin, Advil, Aleve, or NSAIDs for 48 hours before all visits.
Avoid drinking alcohol 34 hours before all visits
Avoid strenuous exercise for 24 hours prior to an after all visits.
Eat a light breakfast and low-fat lunch on the exposure day.
Refrain from eating pan fried and/or grilled foods 12 hours prior to the exposure days.
Refrain from consuming caffeine for 12 hours prior to all study visits.
Refrain from consuming food 2 hours prior to the consenting and follow up sessions, as this may interfere with induced sputum collection.
Wear a N95 mask during all visits to the HSF. A mask will be provided to participants upon check-in.

Since examining changes of cells in the induced sputum is an important test for this study, if a subject is a non-producer, or if the quality of their sputum sample does not meet the requirements, they will be disqualified and imbursed for participation up to this point.

Contacts and Locations

Locations

No locations specified.

Sponsors and Collaborators

University of North Carolina, Chapel Hill
Environmental Protection Agency (EPA)

Investigators

Principal Investigator: James Samet, Environmental Protection Agency (EPA)

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

Responsible Party:

University of North Carolina, Chapel Hill

ClinicalTrials.gov Identifier:

NCT06066749

Other Study ID Numbers:

23-1135

First Posted:

Oct 4, 2023

Last Update Posted:

Oct 4, 2023

Last Verified:

Sep 1, 2023

Studies a U.S. FDA-regulated Drug Product:

Studies a U.S. FDA-regulated Device Product:

Keywords provided by University of North Carolina, Chapel Hill

Wood Smoke

Respirators

Masking

Study Results

No Results Posted as of Oct 4, 2023