CUMBERLAND County Average 2005 NATA Modeled Air Concentrations Compared to Health Benchmarks
Pollutant
Modeled
Air Concentration (ug/m3)
Health
Benchmark (ug/m3)
Risk
Ratio
%
Contribution from
Point Sources
Nonpoint
Sources
On-road
Mobile Sources
Nonroad
Mobile Sources
Background & Secondary
Acetaldehyde
1.5
0.45
3.4
<1%
1%
1%
1%
97%*
Acrolein
0.026
0.020
1.3
<1%
20%
5%
6%
69%*
Arsenic Compounds
0.00040
0.00023
1.7
1%
7%
1%
1%
90%
Benzene
0.68
0.13
5.3
<1%
7%
9%
5%
79%
1,3-Butadiene
0.048
0.033
1.5
<1%
<1%
12%
6%
82%
Cadmium Compounds
0.000067
0.00024
0.3
2%
33%
0%
<1%
65%
Carbon Tetrachloride
0.61
0.067
9.1
0%
<1%
0%
0%
100%
Chloroform
0.071
0.043
1.6
<1%
17%
0%
0%
83%
Chromium (hexavalent form)
0.00012
0.000083
1.5
17%
4%
1%
<1%
78%
Cobalt Compounds
0.00016
0.00011
1.4
100%
0%
0%
0%
0%
1,4-Dichlorobenzene
0.072
0.091
0.8
<1%
36%
0%
0%
64%
1,3-Dichloropropene
0.047
0.25
0.2
0%
100%
0%
0%
0%
Diesel Particulate Matter
0.19
0.0033
57
0%
0%
42%
58%
0%
Ethylbenzene
0.048
0.4
0.1
3%
20%
44%
33%
0%
Ethylene Oxide
0.0072
0.011
0.6
3%
11%
0%
0%
86%
Formaldehyde
1.6
0.077
21
<1%
2%
2%
1%
95%*
Methyl Chloride
1.2
0.56
2.1
<1%
<1%
0%
0%
100%
Naphthalene
0.041
0.029
1.4
1%
44%
11%
3%
41%
Nickel Compounds
0.00024
0.0021
0.1
26%
26%
2%
6%
40%
PAH/POM
0.0067
0.0072**
0.9
2%
91%
2%
5%
0%
Perchloroethylene
0.10
0.17
0.6
<1%
38%
0%
0%
62%
1,1,2-Trichloroethane
0.019
0.063
0.3
0%
100%
0%
0%
0%
Chemicals with risk ratios greater than or equal to 1 are
in bold.
Risk Ratios based on noncarcinogenic effects are in italics.
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. *Acetaldehyde, acrolein and formaldehyde concentration estimates include secondary formation, which is the process by which chemicals in the air are transformed into other chemicals.
**PAH/POM is "polycyclic aromatic hydrocarbons/polycyclic organic matter." These define a broad class of compounds. The chemicals making up this class were broken up into 8 groups based on toxicity, and each group was assigned a cancer-weighted toxicity estimate. 0.0072 ug/m3 is the health benchmark average across the 8 groups.
