Trial Outcomes & Findings for Air Pollution Study: The Effect of Ozone on the Lung (NCT NCT02673775)

NCT ID: NCT02673775

Last Updated: 2025-09-25

Results Overview

The relative concentrations of M1 and M2 macrophages in the induced sputum sample will be assessed.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

135 participants

Primary outcome timeframe

24 hours after exposure.

Results posted on

2025-09-25

Participant Flow

135 participants from the local community were screened for eligibility between 2/1/2016 and 5/4/2022.

57 were ineligible and 16 were lost to follow-up. 62 were randomized to the first exposure.

Participant milestones

Participant milestones
Measure
Ozone Exposure Was First, Followed by Clean Air Exposure
Subjects randomized to ozone first and clean air second. A washout period (at least 2 weeks) took place between exposures.
Clean Air Exposure Was First, Followed by Ozone Exposure
Subjects randomized to clean air first and ozone second. A washout period (at least 2 weeks) took place between exposures.
First Exposure
STARTED
25
37
First Exposure
COMPLETED
25
37
First Exposure
NOT COMPLETED
0
0
Washout (at Least 2 Weeks)
STARTED
25
37
Washout (at Least 2 Weeks)
COMPLETED
21
33
Washout (at Least 2 Weeks)
NOT COMPLETED
4
4
Second Exposure
STARTED
21
33
Second Exposure
COMPLETED
21
33
Second Exposure
NOT COMPLETED
0
0

Reasons for withdrawal

Reasons for withdrawal
Measure
Ozone Exposure Was First, Followed by Clean Air Exposure
Subjects randomized to ozone first and clean air second. A washout period (at least 2 weeks) took place between exposures.
Clean Air Exposure Was First, Followed by Ozone Exposure
Subjects randomized to clean air first and ozone second. A washout period (at least 2 weeks) took place between exposures.
Washout (at Least 2 Weeks)
Lost to Follow-up
1
0
Washout (at Least 2 Weeks)
Physician Decision
1
0
Washout (at Least 2 Weeks)
Withdrawal by Subject
0
2
Washout (at Least 2 Weeks)
Study paused during COVID pandemic (3/5/2020 to 9/15/2021)
2
2

Baseline Characteristics

Air Pollution Study: The Effect of Ozone on the Lung

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Overall
n=62 Participants
All participants who were randomized to a first exposure (N=62)
Age, Continuous
23.2 years
STANDARD_DEVIATION 4.8 • n=99 Participants
Sex: Female, Male
Female
36 Participants
n=99 Participants
Sex: Female, Male
Male
26 Participants
n=99 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
14 Participants
n=99 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
48 Participants
n=99 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
n=99 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
n=99 Participants
Race (NIH/OMB)
Asian
21 Participants
n=99 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
n=99 Participants
Race (NIH/OMB)
Black or African American
6 Participants
n=99 Participants
Race (NIH/OMB)
White
30 Participants
n=99 Participants
Race (NIH/OMB)
More than one race
2 Participants
n=99 Participants
Race (NIH/OMB)
Unknown or Not Reported
3 Participants
n=99 Participants

PRIMARY outcome

Timeframe: 24 hours after exposure.

Population: The number of participants who had an adequate sputum sample collected 24 hours after each exposure.

The relative concentrations of M1 and M2 macrophages in the induced sputum sample will be assessed.

Outcome measures

Outcome measures
Measure
Clean Air
n=13 Participants
Subjects will be exposed to clean air for 3 hours. Clean Air: Subjects will have the clean air exposure first, followed by the ozone exposure
Ozone
n=13 Participants
Subjects will be exposed to 0.2 ppm ozone for 3 hours. Ozone: Subjects will have the ozone exposure first, followed by the clean air exposure
Concentrations of M1 and M2 Macrophages in the Sputum 24 Hours After Exposure.
6.823 ratio of M2 to M1 macrophages
Standard Error 2.413
1.367 ratio of M2 to M1 macrophages
Standard Error 0.367

PRIMARY outcome

Timeframe: 48 hours after exposure

Population: The number of participants who had an adequate sputum sample collected 48 hours after each exposure.

The relative concentrations of M1 and M2 macrophages in the induced sputum sample will be assessed.

Outcome measures

Outcome measures
Measure
Clean Air
n=9 Participants
Subjects will be exposed to clean air for 3 hours. Clean Air: Subjects will have the clean air exposure first, followed by the ozone exposure
Ozone
n=9 Participants
Subjects will be exposed to 0.2 ppm ozone for 3 hours. Ozone: Subjects will have the ozone exposure first, followed by the clean air exposure
Concentrations of M1 and M2 Macrophages in the Sputum 48 Hours After Exposure.
9.783 ratio of M2 to M1 macrophages
Standard Error 3.239
3.449 ratio of M2 to M1 macrophages
Standard Error 1.116

PRIMARY outcome

Timeframe: 72 hours after exposure.

Population: The number of participants who had an adequate sputum sample collected 72 hours after each exposure.

Relative concentrations of M1 and M2 macrophages in the induced sputum sample will be assessed.

Outcome measures

Outcome measures
Measure
Clean Air
n=12 Participants
Subjects will be exposed to clean air for 3 hours. Clean Air: Subjects will have the clean air exposure first, followed by the ozone exposure
Ozone
n=12 Participants
Subjects will be exposed to 0.2 ppm ozone for 3 hours. Ozone: Subjects will have the ozone exposure first, followed by the clean air exposure
Concentrations of M1 and M2 Macrophages in the Sputum 72 Hours After Exposure.
4.623 ratio of M2 to M1 macrophages
Standard Error 0.782
4.379 ratio of M2 to M1 macrophages
Standard Error 0.623

Adverse Events

Clean Air

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Ozone

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Andrew Gow, PhD

Rutgers, the State University of New Jersey

Phone: 848-445-4612

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place