Site

State

PM AQI* (ug/m3)

Rossiter Pump House

MT

22

Maple Falls-Azure Way

WA

21

Mission C43

TX

19

Ellensburg-Ruby St

WA

18

Seeley Elementary School

MT

18

Lima

OH

18

San Antonio Old Hwy90 C677

TX

17

Laredo C313

TX

17

Oldtown

MD

17

Brownsville C80

TM

17