Recruiting

Observational Study

Sponsor:

U.S. EPA Human Studies Facility

Code:

NCT05323240

Conditions

Air Pollution

Eligibility Criteria

Sex: All

Age: 18 - 35

Healthy Volunteers: Accepted

Interventions

PM exposure

Filtered air exposure

Study Details

Brief summary:

Purpose: To determine whether 3-day consecutive exposures to levels of fine particulate matter (PM2.5) that are close to the current 24-hr national standard will cause changes in inflammatory and cardiopulmonary endpoints in healthy young individuals.

Participants: 20 healthy males and females aged 18-35 years.

Procedures (methods): Subjects will be randomly exposed to three consecutive days of filtered air (4 hr/day) and three consecutive days of PM2.5 (approximately 35 µg/m3; 4 hr/day) in an exposure chamber. Blood collection for inflammatory factors such as C-reactive protein (CRP), clotting factors; heart rate variability (HRV); spirometry; and a symptom questionnaire will be conducted before and after each exposure.

Conditions

Air Pollution

Study ID

NCT05323240

Start date

May 12, 2022

Status verified date

Nov, 2023

Completion date

Dec 20, 2025

Anticipated

Primary completion date

Jun 20, 2024

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 35

Healthy Volunteers: Accepted

Inclusion Criteria:

1. . Age 18-35 years old healthy male and female (BMI values between 19 and 30).
2. . Physical conditioning allowing intermittent, moderate exercise for 2 hours, and ability to complete the exposure exercise regimen to induce a minute ventilation rate of 20 L/min/m2 for 15 min without exceeding 80% of projected maximal heart rate. Predicted maximal heart rate will be calculated using the equation \[described by Tanaka et al.: (2001) J. Am. Coll. Cardiol: 208bpm-((0.7) x (age in years))\]
3. . Normal baseline 12-lead EKG.
4. . Normal lung function based on NHANES III reference values. i. Forced vital capacity (FVC) ≥ 80% of that predicted for age, gender, ethnicity, and height.

ii. 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.
5. . Oxygen saturation greater than 94% at the time of physical exam.

Exclusion Criteria:

1. . Individuals with a diagnosis of COVID-19 and/or hospitalized for COVID-19.
2. . Individuals not vaccinated for COVID-19, or, not 14 days beyond the final dose of receiving a COVID-19 vaccine.
3. . Individuals with a history of acute or chronic cardiovascular disease, chronic respiratory disease, diabetes, rheumatologic diseases, or immunodeficiency state.
4. . Individuals with a CVD 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.
5. . Individuals with asthma and a history of asthma.
6. . Individuals who are allergic to chemical vapors or gases.
7. . Females who are pregnant, attempting to become pregnant, or breastfeeding.
8. . Individuals who are currently smoking (including vaping, hookah, e-cigarette) or have a smoking history within 1 year of study.
9. . Individuals living with a smoker who smokes inside the house.
10. . Individuals with a body mass index (BMI) >30 or <19. Body mass index is calculated by dividing the weight in kilograms by the square of the height in meters.
11. . Individuals with occupational exposures to high levels of vapors, dust, gases, or fumes on an on-going basis.
12. . Individuals with uncontrolled hypertension (>140 systolic or >90 diastolic).
13. . Individuals who do not understand or speak English.
14. . Individuals who are unable to perform the exercise required for the study.
15. . Individuals with a history of skin allergies to adhesives used in securing EKG electrodes.
16. . Individuals with unspecified diseases, conditions, or medications that might influence the responses to the exposures, as judged by the medical staff.
17. . Individuals who are unwilling or unable to stop taking over-the-counter pain medications such as aspirin, ibuprofen (Advil, Motrin), naproxen (Aleve), or other non-steroidal anti-inflammatory ("NSAID") medications for 48 hours prior to the exposures and post-exposure visits. Individuals taking vitamins or supplements that the investigators believe may impact the results of the study who are unwilling or unable to stop taking them for at least two weeks before the study. Those not specifically mentioned here may be reviewed by the investigators prior to an individual's inclusion in the study.
18. . Individuals taking systemic steroids or beta-blocker medications.
19. . Individuals with a hemoglobin A1c (HbA1c) level > 6.4%.
20. . Individuals who are claustrophobic.

Study Design

Enrollment

20 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Filtered air exposure

Subjects will be randomly exposed to three consecutive days of filtered air exposure arm in a double-blind cross-over fashion in an exposure chamber, and exposures will be separated by a minimum of 13 days from the PM2.5 arm.

experimental: PM exposure

Subjects will be randomly exposed to three consecutive days of PM2.5 exposure arm in a double-blind cross-over fashion in an exposure chamber, and exposures will be separated by a minimum of 13 days from the filtered air arm.

Interventions

PM exposure

To determine whether 3-day consecutive exposures to levels of fine particulate matter (PM2.5) that are close to the current 24-hr national standard will cause changes in inflammatory and cardiopulmonary endpoints.

Filtered air exposure

To determine whether 3-day consecutive exposures to filtered air will cause changes in inflammatory and cardiopulmonary endpoints.

Primary outcome measure

  • Blood inflammation marker, CRP, will be measured 2 hours before each air exposure day and follow up day in 20 subjects [ Time Frame: Four days ]
  • Blood inflammation marker, CRP, will be measured 2 hours before each PM exposure day and follow up day in 20 subjects [ Time Frame: Four days ]
  • Blood inflammation marker, CRP, will be measured 1 hour after each air exposure day in 20 subjects [ Time Frame: Three days ]
  • Blood inflammation marker, CRP, will be measured 1 hour after each PM exposure day in 20 subjects [ Time Frame: Three days ]

Central Contacts and Locations

Central contacts

Patrice Ratliffe

919-966-0607Ratliffe.Patrice@epa.gov

Locations

EPA Human Studies Facility

Recruiting

Chapel Hill, North Carolina, United States, 27514

Contacts

Patrice Ratliffe

919-966-0607Ratliffe.patrice@epa.gov

Principal Investigator:

Haiyan Tong, MD, PhD

More Information

Sponsor

U.S. EPA Human Studies Facility

Last update posted

Nov 28, 2023

Last verified

Nov, 2023

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by U.S. EPA Human Studies Facility on 2023-11-28.