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Information provided for informational purposes onlyNote: EPA no longer updates this information, but it may be useful as a reference or resource.
Statewide Estimates:
Displays a horizontal bar for each State that represents the central part of the distribution of the ambient concentrations in that State (the 25th to 75th percentile) as well as the median value for the selected pollutant.

Percent Contribution:
Contains horizontal bars representing the percent contribution of four source types (major, area and other, onroad mobile, and nonroad mobile) as well as the contribution of the estimated background to the statewide average concentration of the selected pollutant. Select a chart type (Statewide Estimates or Percent Contribution) and a pollutant below.


View a Chart in Adobe Acrobat PDF format
Statewide Estimates
Percent Contribution

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