EPA National Air Toxics Assessment for North Carolina
What is NATA?
The National-Scale Air Toxics Assessment (NATA) is a screening assessment that estimates inhalation health risk for cancer and non-cancer health effects. NATA evaluates risk for the 50 states, the District of Columbia, Puerto Rico and the Virgin Islands.
Data are obtained from the National Emission Inventory (NEI), mobile source emission estimates, Residual Risk Technology, the NC Urban Air Toxics (UAT) monitoring network and other ambient air monitoring sources. Population data are taken from the most recent US Census.
How are the results estimated?
Cancer risk is based on the following assumptions: a person is exposed for 24 hours per day, for a 70 year lifetime while living and working in the same geographic area and maintaining the same activity pattern.
How I can interpret NATA results?
NATA estimates are based on computer modeling. For cancer, estimates indicate the additional number of people who may develop cancer given a lifetime exposure to a toxic air pollutant. Other factors, such as genetics and lifestyle, are not considered in these estimates. The results are presented in the number of cases per million population.
Estimates for non-cancer health effects are determined by summing effects of exposure to the same group of organs. The non-cancer results are reported as a "hazard index" where a value of less than one represents a low probability of causing adverse health effects.
What limitations do the NATA results have?
NATA provides a snapshot of how airborne concentrations of air toxics, exposure and risk vary throughout the United States. The study does not focus on individuals, or on the variation in exposure and risk among individuals. It focuses on variation between well-defined geographic areas, such as counties or states.
Comparison of results between NATA study years is not recommended because computer model methodologies used and source data are not the same from year to year.
Select a year from the drop down menu to view cancer and non-cancer results maps from 1999, 2002 or 2005 NATA,
as well as information related to Inhalation Exposure to Hazardous Air Pollutant by NC County.
N.C. Division of Air Quality • Mailing Address: 1641 Mail Service Center, Raleigh, NC 27699-1641
Physical Address: 217 West Jones Street, Raleigh, NC 27603 • Phone: 919-707-8400 • Fax: 919-707-0718
Email us: DENR.DAQ.Webmaster@lists.ncmail.net