NCT04109807

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

Effects of Low Dose Ozone on Airway Inflammatory Responses in Adults With Asthma Asthma SNOZ

• Status: Suspended
• Phase: N/A
• Study type: Interventional
• Enrollment: 18 (estimated)
• Sponsor: University of North Carolina, Chapel Hill · Academic / Other
• Sex: All
• Age: 18 Years – 45 Years
• Healthy volunteers: Not accepted

Summary

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

Detailed description

Short-term exposure to ambient air ozone has been recognized for decades to be adversely associated with impacts on the respiratory system. Indeed the evidence is such that the Environmental Protection Agency (EPA) has determined that there is a causal relationship, and even lowered the 8-hour exposure standard to 0.07 parts per million (ppm) in 2015. Controlled human exposure studies and epidemiological studies have consistently observed ozone-associated decrements in lung function and increased respiratory symptoms. Most controlled human exposure studies have been performed with high ozone concentrations. Additionally, epidemiologic studies have focused on populations engaged in outdoor activities (increasing ozone exposure through increased minute ventilation), or in cities such as Los Angeles or Mexico City where ambient ozone levels are especially high. Evidence has recently emerged that exposure to low ozone concentrations also produces adverse health effects, especially among susceptible groups including children with asthma. The objective of this study is to examine if low level ozone exposure (compared to a clean air exposure), reflective of a typical metropolitan summer day, will cause decrements in lung function and measurable upper and lower airway inflammation in mild asthmatics (who are not on asthma controller medications) while performing typical daily activities.

Conditions

• Asthma, Allergic

Interventions

Type	Name	Description
OTHER	Ozone	ozone exposure
OTHER	FA	Filtered air exposure

Timeline

• Start date: 2019-12-16
• Primary completion: 2027-08-01
• Completion: 2027-08-01
• First posted: 2019-09-30
• Last updated: 2025-12-17

Locations

1 site across 1 country: United States