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2002 Assessment Results

The following may be useful in analyzing the results in the tables:
  • Document detailing units (PDF) (5pp, 130k) for the tables provided on this webpage.

  • Important Note: Files available below may be large. You should save these file before opening.

State-specific Emission by County (Microsoft Excel 2003 format)

The tables accessed below provide the pollutant-specific tons/year emissions for the year 2002 for every state (including Puerto Rico, the Virgin Islands, and the District of Columbia) and for every county in each state. These tables also provide a breakdown of the emissions by source sector (i.e., major, area, mobile, and background). There is also a file that provides the total emissions of all HAPs for the U.S. This file shows the contribution of each source sector to the total emissions.

2002 County-Level Modeled Ambient Concentrations, Exposures, and Risks (Microsoft Access or Excel 2003 format)

The following tables present the EPA's 2002 national-scale assessment estimates across the United States plus Puerto Rico, the Virgin Islands, and the District of Columbia using 2002 national air toxics emission inventory as input to the air dispersion models ASPEN, and an inhalation exposure model (HAPEM5). Exposure modeling is an important step in this assessment because it takes into account that people move from one location to another, (e.g., from outside environments to inside environments).

These data are presented in different ways. The nationwide, county-level files, (i.e., the Excel files listed below), present each endpoint risk or hazard quotient estimate by state and county. Additionally, the data are presented by source sector, (i.e., stationary, mobile, and background). The Microsoft Access files present individual pollutant results for each state and county in the assessment. Conversely, the state summary files present the results by state and county for all pollutants.

County-level Pollutants

State Summaries

2002 Tract-Level Modeled Ambient Concentrations, Exposures, and Risks (Microsoft Access 2003 format)

In the following section, the focus of the presentation is at the census tract level. This was the smallest spatial resolution for the NATA. The initial group of zipped files contains MS Access files for each of the endpoints listed. As with the county-level files, these results also provide the contribution of each source sector to the total risk or hazard quotient. The tract-level results are also presented by pollutant and by state.

  • August 17, 2009 - The cancer risk tract file below reflects the updated results for census tracts near Cerritos, CA.

Tract-level Pollutants


State Summaries

Note:These are large files (190KB-56MB).


2002 Google Earth Risk Maps (KMZ Format)

These maps show the geographic patterns of estimated cumulative cancer or noncancer risk due to inhalation of air toxics. EPA developed these maps to inform both national and more localized efforts to collect air toxics information and characterize emissions (e.g., prioritize pollutants/geographic areas of interest for more refined data collection such as monitoring). See more information about limitations. These files not only present the risk levels for each tract, but also the HAPs contributing to risk levels and their percent contribution. An additional overlay provides the names and locations for each source indentified in the 2002 NEI for that tract.

  • August 17, 2009 - The Google Earth Risk map for southern California reflects the updated results for census tracts near Cerritos, CA.

State Summaries
Note: These zipped files must be saved and the contents extracted before opening. See Map instructions (PDF) (1pg, 75k) for further details.


If you have questions about this assessment, please contact Ted Palma at palma.ted@epa.gov

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