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Lung DiseaseNCT00013780

Ozone Exposure and Dose Delivered to Human Lungs

An observational study of Lung Disease, run by National Institute of Environmental Health Sciences (NIEHS) at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Ozone is an air pollutant formed in at ground level by the chemical reaction between oxygen and automobile emissions in the presence of sunlight. The objective of this research is to determine how lung size, chemical composition, and normal functioning of the respiratory system affect the amount of inhaled ozone that… Read more about this study

Who is it for?
Ages 18 to 30 yearsHealthy volunteers can take part
Conditions the study is for
Lung Disease
How many people
50 participants
Where
1 siteUnited States
Study dates
Jul 1998to Jun 2003
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 30 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

A subject will be enrolled in the study only if he or she: has not smoked within the past 3 years; and does not have hay fever, asthma, allergic rhinitis, nasal breathing disorders or anatomical abnormalities, chronic respiratory disease, or any other chronic diseases. Women will not be included in the study if they are pregnant. Subjects who regularly take mediation will be excluded from the study.

Trial locations and contacts

1 site in 1 country.

United States1 site
  • General Clinical Research Center, Penn State University

    University Park, Pennsylvania, 16802

Other trials in United States

About this study

Ozone is an air pollutant formed in at ground level by the chemical reaction between oxygen and automobile emissions in the presence of sunlight. The objective of this research is to determine how lung size, chemical composition, and normal functioning of the respiratory system affect the amount of inhaled ozone that reaches internal sites of tissue irritation and damage. To infer the distribution of inhaled ozone within the respiratory system, measurements of ozone concentration and air flow are made just outside the nose and mouth of healthy subjects who breathe laboratory-generated, ozonated air for about one hour. Biochemical composition of respiratory mucus is then inferred from nasal washings made with salt water. The amount of ozone that a subject retains in one of these experiments is less than the daily exposure in a large city such as New York or Los Angeles.

Read the detailed description

Ozone is a ground-level air pollutant generated primarily by the photochemical reaction of automobile emissions. The primary objective of this research is to determine the mechanism by which anatomical, physiological, and biochemical factors influence the longitudinal distribution of respiratory ozone dose that is delivered to respiratory tissue during a particular exposure condition. The specific aims are: 1) test the hypothesis that an increase in respiratory flow increases the sensitivity of ozone dose to antioxidant levels in the epithelial lining fluid. Ozone absorption will be measured in the nose of healthy nonsmokers at different nasal flows while antioxidant levels are measured in nasal liquid; 2) test the hypothesis that the continuous inhalation of ozone and co-pollutant gases affects antioxidant levels in the epithelial lining fluid, thereby modulating the ozone dose. Ozone absorption and antioxidant levels in nasal lavage will be intermittently measured in the nose of healthy nonsmokers while these subjects are continuously exposed to clean air, ozone, nitrogen dioxide or sulfur dioxide during quiet nasal breathing for two hours; 3) test the hypothesis that antioxidant concentrations in epithelial lining fluid are directly related to plasma concentrations so that ozone absorption are modulated by the appropriate pharmacological or dietary interventions. The longitudinal distribution of ozone absorption will be measured throughout the conducting airways of healthy nonsmokers during quiet nasal breathing. Measurements will be repeated at baseline conditions, after using probenecid to pharmacologically reduce systemic urate, and after vitamin C supplementation to increase systemic ascorbate; 4) quantify the reaction kinetics between ozone and antioxidants in epithelial lining fluid. Samples of nasal liquid will be reacted with a controlled flow of ozone in a miniature bioreactor to determine the reaction rate constant and reaction order of ozone consumption; and 5) further develop a single-path diffusion model. Respiratory absorption as well as in vitro reaction kinetics data will be used to validate a mathematical ozone dosimetry model that can predict the longitudinal distribution of ozone dose to airway tissue.

Conditions
Lung Disease
Keywords
ozone uptake, inhalation toxicology, nasal cavities, antioxidants
Medical subject headings
Lung Diseases

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted30 Mar 2001 (estimated)
  2. Study startJul 1998
  3. Study completionJun 2003

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Natural history
Time perspective
Other
Enrolment
50 participants
IDs, dates and publications
ClinicalTrials.gov ID
NCT00013780
Sponsor's protocol ID
6075-CP-001
Other IDs
R01ES006075
Status last verified
Mar 2006
First submitted
29 Mar 2001
Last updated
23 Mar 2006
Results posted
No

Questions about this trial

What is this clinical trial studying?

An observational study of Lung Disease, run by National Institute of Environmental Health Sciences (NIEHS) at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 23 Mar 2006. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Mar 2006.

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