Cumberland County Average 1999 NATA Modeled Air Concentrations Compared to Health Benchmarks
Pollutant
Modeled
Air Concentration (ug/m3)
Health
Benchmark (ug/m3)
Risk
Ratio
%
Contribution from
Major Sources
Area
Sources
On-road
Mobile Sources
Nonroad
Mobile Sources
Background
Acetaldehyde
1
0.45
2
0.9%
3%
29%
17%
51%
Acrolein
0.05
0.020
2
3%
19%
47%
32%
0%
Arsenic Compounds
0.0001
0.00023
0.4
66%
34%
0%
0%
0%
Benzene
0.9
0.13
7
0.7%
6%
29%
20%
44%
Bis(2-ethylhexyl)phthalate
2
0.42
4
0.0003%
0%
0%
0%
100%
1,3-Butadiene
0.07
0.033
2
0.2%
2%
34%
15%
49%
Cadmium Compounds
0.00004
0.00024
0.2
39%
61%
0%
0.3%
0%
Carbon Tetrachloride
0.3
0.067
4
0%
0.1%
0%
0%
100%
Chloroform
0.05
0.043
1.2
0.4%
21%
0%
0%
78%
Chromium (hexavalent form)
0.00006
0.000083
0.7
7%
86%
7%
0.6%
0%
1,4-Dichlorobenzene
0.02
0.091
0.3
2%
98%
0%
0%
0%
1,3-Dichloropropene
0.05
0.25
0.2
0.001%
100%
0%
0%
0%
Diesel Particulate Matter
1
0.0033
369
0%
0%
43%
57%
*
Ethylene Dibromide
0.02
0.0017
11
0%
0.001%
0%
0%
100%
Ethylene Dichloride
0.03
0.038
0.9
0.2%
0.4%
0%
0%
99%
Ethylene Oxide
0.002
0.011
0.1
9%
91%
0%
0%
0%
Formaldehyde
1
0.077
14
0.8%
4%
20%
11%
65%
Methyl Chloride
1
0.56
2
0.2%
0.3%
0%
0%
100%
Naphthalene
0.03
0.029
0.9
4%
64%
26%
6%
0%
Nickel Compounds
0.0007
0.0064
0.1
59%
34%
2%
4%
0%
Perchloroethylene
0.1
0.17
0.7
0.004%
31%
0%
0%
69%
1,1,2,2-Tetrachloroethane
0.05
0.017
3
0%
0.2%
0%
0%
100%
Chemicals with risk ratios greater than or equal to 1 are
in bold.
Risk Ratios in italics are based on noncarcinogenic effects.
The seymbol ug/m3 is micrograms per cubic meter,
the amount (in micrograms) of a chemical in a cubic
meter of air. This is also known as a concentration.
* For diesel particulate matter, onroad and nonroad
concentrations include a model-estimated background
concentration.
