Impact/Purpose:

This work will support the following programmatic goals: 1. Exposure relationships: What are the exposures to the most biologically important constituents and characteristics of particulate matter (PM) that cause responses in potentially susceptible subpopulations and the general population? 2. Pollutant Characteristics & Mechanisms of Injury: A) What is the role of biological, chemical and physical characteristics of PM in eliciting adverse health effects? B) What are the underlying mechanisms (local pulmonary and systemic) that can explain the epidemiological findings of mortality/morbidity associated with exposure to ambient PM? 3. Susceptibility: What subpopulations are at increased risk of adverse health outcomes from PM?

Description:

Diesel exhaust is a major source of pollution especially in urban areas. The contribution of the diesel exhaust particles and gases to increases in deaths, asthma symptoms, lung infections, and other health effects is unclear. This study will examine the lung, blood, heart, and other responses of healthy adolescent volunteers to a short (2 hr) exposure at a level of diesel exhaust that is similar to urban hot spots of diesel emissions, but below occupational exposure levels. The health endpoints examined in this study are believed to be important to the development of adverse heath responses in sensitive human populations such as persons with heart and lung diseases. Findings from this study will complement findings from other EPA studies that are examining adverse health effects from exposure to high levels of ambient airborne particles. Ten (10) healthy subjects (male or female, between the age of 18-40 years old) will be exposed to either filtered air or 0.1 milligrams per cubic meter diesel exhaust particulate matter (along with the associated gases such as carbonyls). The exposure duration will be two (2) hours with intermittent exercise on a bicycle or treadmill. The responses (heart, lung, blood, and symptoms) induced by the exposure will be measured immediately after a volunteer finishes the exposure and the next morning and compared to a baseline, pre-exposure value. The next day, the exposed subject will have a bronchscopy performed on his/her lungs by a certified and trained physician in order to sample lung fluid and a few cells. The state of the subject's heart and lung physiology, blood chemistry, and other endpoints will be compared between the exposures to filtered air and diesel exhaust.

Record Details: