Site
State
PM AQI* (ug/m3)
Badlands
SD
42
Maple Falls-Azure Way
WA
25
St. Maries
ID
24
Shuttlesworth
AL
Marysville-7th Ave
23
Rossiter Pump House
MT
Nogales Post Office
AZ
Portola
CA
21
Pinehurst
Colville-E 1st St
20