# Technology Transfer Network 2002 National-Scale Air Toxics Assessment Contact Us 

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### Announcement August 17, 2009 - EPA has updated the 2002 NATA results for census tracts near Cerritos, CA based on corrected emissions and location data.

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### Updated Table

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### Updated Map Maps

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### Summary Risk Maps

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### 2002 Google Earth Risk Maps In June 2009, EPA released the results of its 2002 national-scale assessment of air toxics emissions. The purpose of the national-scale assessment is to identify and prioritize air toxics, emission source types and locations which are of greatest potential concern in terms of contributing to population risk. EPA uses the results of these assessments in many ways, including:

● To work with communities in designing their own local-scale assessments,

● To set priorities for improving data in emissions inventories, and

● To help direct priorities for expanding and improving the network of air toxics monitoring. The national-scale assessment modeled 180 of the 187 Clean Air Act air toxics (PDF) (3pp, 15k) plus diesel particulate matter (diesel PM). The assessment includes four steps that focus on the year 2002:
1. Compiling a national emissions inventory of air toxics emissions from outdoor sources 2. Estimating ambient concentrations of air toxics across the United States 3. Estimating population exposures across the United States 4. Characterizing potential public health risk due to inhalation of air toxics including both cancer and noncancer effects For information summarizing the 2002 assessment, see the Fact Sheet and 2002 National-Scale Air Toxics Assessment | Technology Transfer Network Air Toxics Web site | US EPA

● Air Toxics Web site

❍ NATA Overview
❍ NATA 1996
❍ NATA 1999
❍ NATA 2002

❍ 2002 Assessment Home
❍ About the 2002 Assessment
❍ Frequent Questions
❍ Assessment Methods
❍ 2002 Results
❍ Risk Characterization
❍ Limitations
❍ Air Toxics Reduction
❍ Glossary
❍ Site Map

http://www.epa.gov/ttn/atw/nata2002/index.html (1 of 2) [12/31/2009 1:11:32 PM] ● Share2002 National-Scale Air Toxics Assessment | Technology Transfer Network Air Toxics Web site | US EPA Summary of Results pages. The Summary of Results page also provides national maps of cancer and noncancer effects.
The emissions used in the current assessment are from the 2002 emission inventory which is the most complete and up-to-date available. Working with the states, EPA updates air toxics emission inventories every 3 years. The next national-scale assessment will focus on 2005 emissions and will be available in late 2009 or early 2010. As part of EPA's National Air Toxics Assessment activities, EPA conducted its first national-scale assessment for the year 1996 . That assessment included 33 air pollutants (a subset of 32 air toxics on the Clean Air Act's list of 187 air toxics plus diesel particulate matter (diesel PM). In February of 2006, EPA released the second of its NATA assessments . This assessment was based on emissions from the 1999 National Emission Inventory and included the assessment of 177 hazardous air toxics plus diesel particulate matter.

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Last updated on Tuesday, August 18th, 2009. http://www.epa.gov/ttn/atw/nata2002/index.html Print As-Is

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