An official website of the United States government.

We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

National Air Toxics Assessment

Previous NATA Versions

NATA year Release date HAPs included
     1996 May 21, 2002             32
     1999 Feb 22, 2006           177
     2002 Jun 24, 2009           181
     2005 Mar 11, 2011           179
     2011 Dec 17, 2015           180

“NATA year” refers to the year for which assessment data were collected.

“Release date” is when NATA results were posted to EPA’s website.

“HAPs included” shows how many of the Clean Air Act’s list of 187 hazardous air pollutants (HAPs) were included in each assessment. Each NATA also includes one additional air toxic, diesel particulate matter, which was assessed for noncancer results only.

You can access the 2011 and 2005 NATAs from the links below:

For earlier versions of NATA, search the EPA Archives.