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AsthmaNCT00013728

Asthma & Exposure to Peaks in Particulate Air Pollution

An observational study of Asthma, run by National Institute of Environmental Health Sciences (NIEHS).

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

We are testing the following two hypotheses: 1) Peaks in hourly exposures to airborne particulate matter (PM) of outdoor origin will be more closely associated with acute asthmatic responses to particles than 24-hour average exposures in susceptible individuals; 2) Personal exposure to PM, and estimated particle dose… Read more about this study

Who is it for?
Ages 9 to 18 years
Conditions the study is for
Asthma
How many people
24 participants
Where
No sites listed yet
Study dates
Sep 2000to Oct 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 9 to 18 years
  • All sexes
  • No healthy volunteers
  • Child, Adult
  1. physician-diagnosed asthma, at least a 1 yr. history, including episodic symptoms of wheezing, cough and dyspnea; 2) mild to moderate severity of asthma: i) a history of at least several weeks during the warm seasons (Mar-Oct) during which the subject required regular daily use of prescribed prophylactic asthma medications; \& ii) asthma exacerbations at least 2 days/week requiring as-needed bronchodilators during an extended period of 1-2 warm season months; 3) age from 9-18; 4) home, school or work addresses in Alpine, CA area; 5) no history of smoking by the subjects and no person smoking in the subject?s home.

About this study

We are testing the following two hypotheses: 1) Peaks in hourly exposures to airborne particulate matter (PM) of outdoor origin will be more closely associated with acute asthmatic responses to particles than 24-hour average exposures in susceptible individuals; 2) Personal exposure to PM, and estimated particle dose to the lungs, will be more closely associated with daily asthma severity than standard outdoor particle concentrations measured as 24-hour averages at governmental monitoring sites.

Read the detailed description

We are testing the following two hypotheses: 1) Peaks in hourly exposures to airborne particulate matter (PM) of outdoor origin will be more closely associated with acute asthmatic responses to particles than 24-hour average exposures in susceptible individuals; 2) Personal exposure to PM, and estimated particle dose to the lungs, will be more closely associated with daily asthma severity than standard outdoor particle concentrations measured as 24-hour averages at governmental monitoring sites. Toxicological data for asthma exacerbations from particulate matter (PM) suggests that particle deposition in the lower respiratory tract can cause inflammatory and lung function changes suggestive of asthma pathology. There is now a scientific need to explain epidemiological findings of ambient PM effects on asthmatics at mass concentrations below what is expected (from toxicological data) to be harmful. One possibility is that study participants are encountering unmeasured short-term excursions of particle mass levels capable of inducing adverse reactions in the lung, but this effect is only captured somewhat by the regulatory standard of 24-hour averages. Our research in southern California is vital to the current controversy regarding regulatory standards given that a health-based scientific rationale for any specific PM averaging time is not established.

Conditions
Asthma
Keywords
asthma, particulate matter
Medical subject headings
Asthma

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 startSep 2000
  3. Study completionOct 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
Defined population
Time perspective
Prospective
Enrolment
24 participants
IDs, dates and publications
ClinicalTrials.gov ID
NCT00013728
Sponsor's protocol ID
6214-CP-001
Status last verified
Mar 2006
First submitted
28 Mar 2001
Last updated
23 Mar 2006
Results posted
No

Questions about this trial

What is this clinical trial studying?

An observational study of Asthma, run by National Institute of Environmental Health Sciences (NIEHS).

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.

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; AzTrials last refreshed its copy on 7 Nov 2026.

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