Cumberland County Average 2002 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
3
0.01%
2%
16%
10%
72%
Acrolein
0.03
0.020
1.4
0.07%
16%
58%
26%
0%
Arsenic Compounds
0.0004
0.00023
1.7
1%
6%
3%
3%
87%
Benzene
1
0.13
9
0.2%
27%
18%
8%
47%
1,3-Butadiene
0.06
0.033
1.9
1%
0.03%
26%
11%
62%
Cadmium Compounds
0.00006
0.00024
0.3
3%
30%
0%
1%
66%
Carbon Tetrachloride
0.6
0.067
9
0.0002%
0.05%
0%
0%
99.95%
Chloroform
0.07
0.043
1.6
0.06%
16%
0%
0%
84%
Chromium (hexavalent form)
0.0001
0.000083
1.3
4%
5%
4%
1%
86%
1,4-Dichlorobenzene
0.07
0.091
0.8
0.1%
34%
0%
0%
66%
1,3-Dichloropropene
0.04
0.25
0.2
0.0004%
100%
0%
0%
0%
Diesel Particulate Matter
0.9
0.0033
273
0%
0%
30%
70%
*
Ethylbenzene
0.1
0.4
0.3
1%
7%
66%
26%
0%
Ethylene Oxide
0.007
0.011
0.6
1%
10%
0%
0%
89%
Formaldehyde
1
0.077
19
0.1%
2%
10%
5%
83%
Methyl Chloride
1
0.56
2
0.001%
0.2%
0%
0%
99.8%
Methyl tert-butyl ether
0.9
3.8
0.2
0.1%
14%
33%
53%
0%
Naphthalene
0.04
0.029
1.3
1%
42%
12%
3%
42%
PAH/POM
0.007
0.0075
0.9
2%
84%
9%
5%
0%
Perchloroethylene
0.1
0.17
0.6
0.1%
37%
0%
0%
63%
1,1,2-Trichloroethane
0.02
0.063
0.1
0.0004%
100%
0%
0%
0%
Chemicals with risk ratios greater than or equal to 1 are
in bold.
Risk Ratios in italics are based on noncarcinogenic effects.
The symbol 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.
