Human Biological Responses to Low Level Ozone (SNOZ)

University of North Carolina (UNC)

Status

Completed

Conditions

Environmental Exposure

Nasal Inflammation

Treatments

Device: Health and Exposure Tracker (HET)

Other: Ozone

Other: Filtered Air

Study type

Interventional

Funder types

Other

Other U.S. Federal agency

Identifiers

NCT02857283

15-2677

Details and patient eligibility

About

To investigate if low level ozone exposure will cause measurable inflammation in nasal cells.

Full description

Air pollutants including ozone have been implicated in affecting health outcomes. In particular, high level ozone exposure has been shown to affect pulmonary function and cause pulmonary inflammation. Troubling community-based work has implicated high ozone levels as being correlated with increased pediatric asthma emergency room visits. Because of adverse health effects, EPA standards for safe ozone levels have been set, currently at 0.07 ppm. Still, it is estimated that 100 million Americans live in areas where ozone levels periodically remain above the EPA standard. And while this EPA standard had been set based on available data, it remained unclear at the time whether naturalistic low-level ozone exposure, such as fluctuations between 0.06-0.08 ppm throughout the day, might affect health as well.

This group previously examined lung function and inflammatory response in adults exposed to low-level ozone, 0.06 ppm exposure for 6.6 hours, while undergoing intermittent moderate exercise. The investigators found that in response to low-level ozone exposure (0.06 ppm) with exercise, lung function declines and neutrophilic airway inflammation is observed. What remains unclear, is whether low-level ozone alone - without exercise - will cause similar health effects.

To mimic exposure to ozone on a typical summer day in a polluted city, the investigators will expose subjects to a varying level of ozone, form 0.06 ppm to 0.08 ppm, rather than a constant 0.07ppm. The variation from 0.06ppm to 0.08ppm, then back to 0.06ppm will occur each hour.

Enrollment

15 patients

Sex

All

Ages

18 to 50 years old

Volunteers

Accepts Healthy Volunteers

Inclusion criteria

Males and females between 18 and 50 years of age.
Vital signs within normal limits on admission to the study: Peripheral oxygen saturation (SpO2) > 94%, systolic blood pressure between 150-90 mm Hg, diastolic blood pressure between 100-60 mm Hg, afebrile.
Forced Expiratory Volume (FEV1) of at least 80% of predicted.

Exclusion criteria

Any chronic medical condition considered by the PI as a contraindication to the exposure study, including significant cardiovascular disease, diabetes requiring medication, chronic renal disease, chronic thyroid disease, or kidney disease.
Use of systemic or inhaled steroids.
Use of NSAID or aspirin within 7days of each study visit, and inability to withhold these medications prior to each session of the study.
Pregnant or nursing women
Use of cigarettes or other inhaled nicotine products within the past year, or more than a lifetime 5 pack year history of cigarette smoking.