Dioxin Exposure Initiative Ongoing Projects

Following is a listing and descriptions of projects that are underway in EPA's Dioxin Exposure Initiative

SOURCES:

1. National Modeling of Sources: All known anthropogenic sources of dioxin air emissions in the United States are being fed into EPA's long-range transport and deposition model known as the REgional LagrangianModel of Air Pollution (RELMAP), to study the relationship between emissions and depositions.

2. Comparison of Air Transport Models: This project compares the outputs from several long-range transport models to each other and to measured air levels.

3. Field Study To Evaluate Uncontrolled Combustion Emissions: The purpose of this work is to conduct field studies to estimate dioxin emission factors for various types of uncontrolled burning and non-combustion area sources such as agricultural burning.

EXPOSURES:

1. National Study on Animal Feeds: The purpose of this study will be to characterize feeds for cattle, poultry, and swine nationally. The components of feeds will be described, and samples of feed components will be taken in attempts to determine which components contribute the bulk of dioxin to these terrestrial food animals.

2. National Dioxin Air Monitoring Network: A number of stations nationally will be established to periodically measure for dioxins in ambient air.

3. Urban Air Transect Study: By measuring the air concentrations of dioxins within an urban center, and upwind and downwind of this center, it may be possible to connect sources of dioxin release within the urban center to concentrations within and distant from the urban center.

4. National Milk Study on PBTs: A national milk sampling network will be used to measure the concentrations of dioxins and other persistent and bioaccumulative toxics (PBTs).

5. Exposure of Hobbyists to Dioxins in Ball Clay: This project investigates the potential dioxin exposure to artists/hobbyists who use ball clay to make pottery and related products.

6. Pilot Survey of Dioxins in Soils: This study develops a protocol for soil sample collection and collects samples from a number of background sites in order to make initial estimates of background levels of dioxins in soils.

7. Pharmacokinetic Modeling of Dioxin-Like Compounds: A principal finding of the Dioxin Reassessment is that health effects are more tied to body burden rather than exposure. This project develops and tests pharmacokinetic modeling approaches for predicting body burdens based on dose.

TRENDS

• There are no projects on trends at the present time.

Related Link(s)

• Exposure and Human Health Reassessment of 2,3,7,8-Tetrachlorodibenzo-P-Dioxin (Tcdd) and Related Compounds National Academy Sciences (External Review Draft) (2004)