Pulmonary and Inflammatory Responses Following Exposure to a Low Concentration of Ozone or Clean Air — LOCONOZ2  

Symptoms and Signs Clinical Trial

Official title: Pulmonary and Inflammatory Responses Following Exposure to a Low Concentration of Ozone or Clean Air for 6.6 Hours With Moderate Exercise in Healthy Young Adults

Status Recruiting

Clinical Trial Summary

Purpose: The primary purpose of this study is to measure pulmonary function, symptoms, and pulmonary inflammatory responses in healthy young adults during and immediately after exposure to a low concentration of ozone (0.070 ppm) or clean air for 6.6 hours while undergoing moderate intermittent exercise. This concentration is the current EPA NAAQS standard for ozone.

Clinical Trial Description

Potential health effects of ozone have been extensively studied over decades at various levels of exposure concentration and for varying time periods in young healthy adult subjects. Effects of ozone have been well documented particularly for decrements of lung function and an influx of neutrophils and other markers of pulmonary inflammation. The majority of those studies were done at ozone concentrations between 0.12 and 0.40 ppm, considerably higher than the current EPA NAAQS ozone standard of 0.070 ppm, and at exposure durations of two hours, even though the current standard is an 8-hour standard. However, a small number of studies have assessed changes in lung function following exposure to low levels of ozone for several hours. These latter studies have shown that exposure to ozone for 6.6 hours at concentrations between 0.06 and 0.08 ppm causes mild reversible decrements in lung function (1.7-10%) as measured by forced vital capacity (FVC) and forced expired volume at 1 s (FEV1) immediately after exposure in healthy young adults. In addition, in one study an increase in ozone-induced neutrophils was seen in induced sputum following exposure to 0.06 ppm ozone (8) and in bronchoalveolar lavage fluid) following exposure to 0.08 ppm ozone (9). The EPA is considering whether the current ozone NAAQS standard at 0.070 is protective and has asked EPA researchers to conduct a study similar to those done at 0.06 and 0.08 ppm. ;

Related Conditions & MeSH terms

• Acute Lung Injury
• Lung Injury
• Lung Injury, Acute
• Symptoms and Signs

• NCT number: NCT05680831
• Study type: Interventional
• Source: Environmental Protection Agency (EPA)
• Contact: Martin W Case, B.S.
• Phone: 919-966-6211
• Email: case.martin@epa.gov
• Status: Recruiting
• Phase: Phase 1
• Start date: October 13, 2022
• Completion date: February 1, 2025