Site

State

PM AQI* (ug/m3)

Lancaster

PA

27

York

PA

26

Johnstown

PA

24

Chester

PA

24

Harrisburg

PA

24

Marcus Hook

PA

22

Charleroi

PA

21

Rte 9 Del. City

DE

21

Freemansburg

PA

21

Arendtsville

PA

21