PM-2.5 (1997) Nonattainment Area Summary

Data is current as of November 30, 2025

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Classification	Number of Areas	Number of Counties	2010 Population
Serious	1	8	3,842,165
Moderate	1	4	15,716,335
SUBTOTAL	2	12	19,558,500
Former Subpart 1	0	0	0
SUBTOTAL	0	0	0
GRAND TOTAL	2	12	19,558,500

County subtotals and grand totals may not equal sum of parts. Part counties are only counted one time across groupings. Multi-state nonattainment areas are not considered maintenance areas until all states in the area have been redesignated