Effects of Low Dose Ozone on Airway Inflammatory Responses in Adults With Asthma - Sedentary Nasal Ozone (Asthma SNOZ)

NCT04109807 | Suspended

• 1 other identifier: 18-2425
• Study Type: interventional
• Target: 18
• Locations: 1 country
• Sites: 1

Brief Summary

To determine if low levels of ozone (O3) encountered on a typical day in Chapel Hill will decrease spirometric values in mild asthmatics.

Conditions

Asthma, Allergic

Outcome Measures

Primary Outcomes (1)

• Change in Percent (%) predicted forced expiratory volume at one second (FEV1)

  Change from baseline %predicted FEV1 post-O3 versus post-air exposure.

  6 hours post-O3 versus post-air exposure versus pre-exposure

Secondary Outcomes (10)

• Change in Percent (%) predicted forced vital capacity (FVC)

  6 hours post-O3 versus post-air exposure versus pre-exposure

• Change in Percent eosinophils in induced sputum

  24 hours post-O3 versus post-air exposure

• Change in Percent (%) neutrophils in induced sputum

  24 hours post-O3 versus post-air exposure

• Change in Eosinophils per mg of induced sputum

  24 hours post-O3 versus post-air exposure

• Change in neutrophils per mg of induced sputum

  24 hours post-O3 versus post-air exposure

Study Arms (2)

6 hour Filtered Air (FA) followed by O3 exposure

EXPERIMENTAL

For the first exposure session, participants are exposed to filtered air (FA) for 6 hours. For the second exposure session, the same participant will be exposed to ozone at a concentration of 0.07ppm for 6 hours.

Other: Ozone; Other: FA

6 hour O3 exposure followed by FA exposure

EXPERIMENTAL

For the first exposure session, a participant will be exposed to ozone at a concentration of 0.07ppm for 6 hours. For the second exposure session, the same participant will be exposed to FA for 6 hours.

Other: Ozone; Other: FA

Interventions

Ozone OTHER

ozone exposure

6 hour Filtered Air (FA) followed by O3 exposure; 6 hour O3 exposure followed by FA exposure

FA OTHER

Filtered air exposure

6 hour Filtered Air (FA) followed by O3 exposure; 6 hour O3 exposure followed by FA exposure

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Ages 18-45, both sexes included
• Mild intermittent asthma, defined as daytime asthma symptoms no more than 2 times per week, night time asthma symptoms no more than 2 times per month, FEV1 \>80% of predicted, and asthma exacerbation requiring oral steroids 1 time or less per year.
• Good general health as evidenced by medical history
• Vital signs will be within normal limits on admission to the study: oxygen saturation by pulse oximetry (SpO2) \> 94%, systolic blood pressure between 150-90 mm Hg, diastolic blood pressure between 100-60 mm Hg, afebrile.
• FEV1 of at least 80% of predicted at baseline
• Able to provide informed consent
• Proof of Covid Vaccination

You may not qualify if:

• Any chronic medical condition considered by the PI as a contraindication to the exposure study including significant cardiovascular disease, diabetes, chronic renal disease, chronic thyroid disease, history of chronic infections/immunodeficiency, history of tuberculosis
• Physician directed emergency treatment for an asthma exacerbation within the preceding 12 months
• Orthopedic injuries or impediments that would preclude bicycle or treadmill exercise
• Viral upper respiratory tract infection within 4 weeks of challenge.
• Any acute infection requiring antibiotics within 4 weeks of exposure or fever of unknown origin within 2 weeks of challenge.
• Individuals who use daily controller medication for asthma. Pre-treatment with a short acting bronchodilator prior to exercise is allowed.
• Nasal surgery within 6 months
• Mental illness or history of drug or alcohol abuse that, in the opinion of the investigator, would interfere with the participant's ability to comply with study requirements.
• Any recent or current use of nicotine
• History of intubation for asthma
• Pregnancy or nursing an infant as EPA strictly prohibits intentional exposure for research to this population.
• Covid infection in the past 90 days

Sponsors & Collaborators

• University of North Carolina, Chapel Hill: lead
• Environmental Protection Agency (EPA): collaborator
• North Carolina State University: collaborator

Study Sites (1)

University of North Carolina CEMALB

Chapel Hill, North Carolina, 27599, United States

Location

MeSH Terms

Conditions

Asthma

Interventions

Ozone

Condition Hierarchy (Ancestors)

Bronchial Diseases; Respiratory Tract Diseases; Lung Diseases, Obstructive; Lung Diseases; Respiratory Hypersensitivity; Hypersensitivity, Immediate; Hypersensitivity; Immune System Diseases

Intervention Hierarchy (Ancestors)

Oxygen; Gases; Inorganic Chemicals

Study Officials

• David Peden, MD

  UNC SOM

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 23, 2019
• First Posted: September 30, 2019
• Study Start: December 16, 2019
• Primary Completion (Estimated): August 1, 2027
• Study Completion (Estimated): August 1, 2027
• Last Updated: December 17, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL
• Time Frame: 9 to 36 months following publication
• Access Criteria: Approval from an IRB, IEC, or REB and an executed data use/sharing agreement with UNC.

Locations

US (1)