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Completed No phase listed Observational

Children's Exposures/Health Effects/Diesel Exhaust

ClinicalTrials.gov ID: NCT00527345

Public ClinicalTrials.gov record NCT00527345. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

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Official title

Children's Exposure and Health Effects From Diesel Exhaust Before and After Switch of Schoool Bus Fleets

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

The contribution of diesel exhaust (DE) to health, especially children's health, is of tremendous public health interest. DE has been associated with worsening asthma and allergies, among other important health effects. Reducing DE exposures has become a major regulatory initiative, and federal, state, and local jurisdictions are investing hundreds of millions of dollars in retrofitting diesel engines in school buses and other changes to reach this goal. The U.S. Environmental Protection Agency's recent regulations require all on-road diesel vehicles to change to low emission engines and ultra-low-sulfur fuels by 2007 (US EPA '00). In spring 2003, the U.S. EPA announced a nationwide voluntary school bus retrofit initiative. In July 2003, the Washington Legislature enacted a statewide "Diesel Solutions" program that provides 25 million dollars by 2008 to retrofit school diesel buses with cleaner burning engines and fuels, making it one of the largest and most active voluntary school bus retrofit program in the country. If risk assessment estimates are accurate, these changes will have a large public health impact, especially on children who ride school buses daily. However, no studies to-date have rigorously examined school children's exposure to diesel exhaust (DE) and its health effects, nor such a significant change in vehicular pollution control. We propose to seize this opportunity of a large natural experiment taking place in the Puget Sound area and conduct a study to assess health effects from diesel bus exhaust before and after the retrofit of diesel bus fleets between 2005 and 2007. The specific aims of the study are to: 1. Determine whether asthmatic children changing to retrofitted buses with cleaner fuels and engines have a reduction in sub-clinical and clinical asthma severity. 2. Determine if increased levels of DE exposure lead to an increase in acute clinical and sub-clinical features of asthma in children. 3. Quantify the levels and changes in particle and toxic gas exposures to DE in 3 groups of children commuting to school by retrofitted buses or private cars, old diesel buses to be retrofitted later, and old diesel buses through the study. Sub-aim 3: Use the time-activity information, personal exposure measurements, and on-bus monitoring data to construct an exposure model to predict individual exposures to DE for all subjects.

Study identification

NCT ID
NCT00527345
Recruitment status
Completed
Study type
Observational
Phase
Not listed
Enrollment
450 participants

Conditions and interventions

Interventions

Not listed

Eligibility (public fields only)

Age range
6 Years to 11 Years
Sex
All
Healthy volunteers
Healthy volunteers not accepted

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Feb 28, 2005
Primary completion
Jun 30, 2009
Completion
Jun 30, 2009
Last update posted
Apr 13, 2015

2005 – 2009

United States locations

U.S. sites
1
U.S. states
1
U.S. cities
1
Facility City State ZIP Site status
University of Washington Dept. Environmental and Occupational Health Sciences Seattle Washington 98195

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT00527345, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Apr 13, 2015 · Synced Sep 4, 2026

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