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Search / Trial NCT05323240

Health Effects of Repeated Exposure to Low Levels of Concentrated Ambient Particles in Healthy Young Volunteers

Launched by U.S. EPA HUMAN STUDIES FACILITY · Apr 11, 2022

Trial Information

Current as of July 26, 2025

Recruiting

Keywords

ClinConnect Summary

This clinical trial is studying how repeated exposure to low levels of air pollution, specifically fine particulate matter (PM2.5), affects the health of healthy young adults. Over a period of six days, participants will spend four hours each day either breathing filtered air or air with fine particles to see if there are any changes in their inflammation levels, heart health, and lung function. The researchers are particularly interested in how these exposures might impact factors like heart rate and respiratory function.

To be eligible for the trial, participants must be healthy males or females between the ages of 18 and 35, with a normal body weight and good physical fitness. They should not have any significant health issues, such as heart or lung diseases, and must not be smokers or have a history of certain medical conditions. Throughout the study, participants will undergo blood tests and lung function assessments before and after each exposure to track any changes in their health. This trial is a great opportunity to contribute to important research on the effects of air pollution on health.

Gender

ALL

Eligibility criteria

  • 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.

About U.S. Epa Human Studies Facility

The U.S. Environmental Protection Agency (EPA) Human Studies Facility is dedicated to conducting rigorous and ethical research aimed at understanding the effects of environmental exposures on human health. By leveraging state-of-the-art methodologies and adhering to stringent regulatory standards, the facility focuses on generating high-quality data that informs environmental policy and public health decisions. Committed to transparency and scientific integrity, the EPA Human Studies Facility collaborates with various stakeholders to ensure that its findings contribute meaningfully to the protection of human health and the environment.

Locations

Chapel Hill, North Carolina, United States

Patients applied

0 patients applied

Timeline

First submit

Trial launched

Trial updated

Estimated completion

Not reported

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