Environmental Engineering Reference
In-Depth Information
Appendix10
U.S. National Ambient
Air Quality Standards
Primary Standards
Secondary Standards
Pollutant
Level
Averaging Time
Level
Averaging Time
9 ppm (10 mg/m
3
)
Carbon monoxide
8 h
None
35 ppm
(40 mg/m
3
)
1h
g/m
3
Lead
1.5
μ
Quarterly average
Same as primary
Nitrogen dioxide
0.053 ppm
(100
Annual (arithmetic
mean)
Same as primary
g/m
3
)
μ
150
μ
g/m
3
Particulate matter
(PM
10
)
24 h
Same as primary
15.0
μ
g/m
3
Particulate matter
(PM
2.5
)
Annual (arithmetic
mean)
Same as primary
35
μ
g/m
3
24 h
Same as primary
Ozone
0.075 ppm
(2008 Standard)
8 h
Same as primary
0.08 ppm
(1997 Standard)
8 h
Same as primary
0.12 ppm
1 h (applies only in
limited areas)
Same as primary
Sulfur dioxide
0.03 ppm
Annual (arithmetic
mean)
0.5 ppm
(1300
μ
g/m
3
)
3h
0.14 ppm 24 h
Source:
Available at http://www.epa.gov/air/criteria.html#1.
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