National Scale Air Toxics Assessment - (NATA)

NATA is a National-Scale Air Toxics Assessment to characterize potential public health risks from exposure to air toxic emissions. The US EPA, mandated under the Clean Air Act to control air pollutants, designed and implemented a national study to prioritize efforts to address the sources of air toxic pollution. These sources include source categories such as mobile sources, power plants, factories and any other source category included in the National Emissions Inventory.

The Commonwealth of Virginia, in cooperation with  EPA, participates in projects to determine and prevent public health impacts of air toxic emissions. NATA provides an additional tool to address potential areas of health impacts to citizens. VADEQ is currently analysing the 1999 NATA .

NATA is conducted every three years. EPA released the 1996 study in 2002 and the 1999 study in 2005.  Since the 1999 data was collected, reductions have been made in air toxics emissions as a result of the implementation of recent regulations.  The 1999 study may not capture all of the recent reductions in air toxics.  The 1999 study included the following steps:

1. An inventory of all 1999 emissions
2. An estimate of the annual average air toxic concentrations modeled from those emissions.
3. An estimate of what people breathe.
4. An estimate of the potential public health risks.

• Air Toxics Reduction
• About the Assessment
• Technical Fact Sheet
• Frequently Asked Questions
• National Emissions Inventory
• List of Pollutants in the Assessment
• Background Concentrations
• ASPEN Air Dispersion Model
• The Hazardous Air Pollutant Exposure Model (HAPEM)
• Background on Risk Characterization
• Background on Risk Characterization
• The Limitations of the Assessment NATA Limitations according to EPA
• Use of Assessment Results