SOMERSET
COUNTY
Somerset County Average 2011 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 |
1.8 |
0.45 |
4.1 |
<1% |
2% |
6% |
4% |
88%* |
Acrolein |
0.028 |
0.020 |
1.4 |
5% |
13% |
43% |
21% |
18%* |
Acrylonitrile |
0.00025 |
0.015 |
0.02 |
95% |
5% |
0% |
0% |
0% |
Arsenic compounds |
0.00014 |
0.00023 |
0.6 |
2% |
23% |
29% |
46% |
<1% |
Benzene |
1.1 |
0.13 |
8.8 |
<1% |
14% |
43% |
42% |
1% |
1,3-Butadiene |
0.12 |
0.033 |
3.5 |
<1% |
10% |
47% |
42% |
1% |
Cadmium Compounds |
0.000051 |
0.00024 |
0.2 |
22% |
77% |
0% |
1% |
<1% |
Carbon Tetrachloride |
0.55 |
0.17 |
3.2 |
0% |
0% |
0% |
0% |
100% |
Chromium (hexavalent form) |
0.000061 |
0.000083 |
0.7 |
48% |
21% |
1% |
30% |
<1% |
Diesel Particulate Matter |
1.0 |
0.0033 |
306 |
0% |
0% |
35% |
65% |
0% |
Ethylbenzene |
0.32 |
0.4 |
0.8 |
<1% |
8% |
44% |
43% |
5% |
Ethylene dibromide |
0.000029 |
0.0017 |
0.02 |
100% |
0% |
0% |
0% |
0% |
Ethylene oxide |
0.00046 |
0.011 |
0.04 |
99% |
1% |
0% |
0% |
0% |
Formaldehyde |
1.5 |
0.077 |
20 |
1% |
3% |
7% |
6% |
83%* |
Hydrazine |
0.000056 |
0.0002 |
0.3 |
100% |
0% |
0% |
0% |
0% |
Naphthalene |
0.055 |
0.029 |
1.9 |
3% |
23% |
55% |
19% |
0% |
Nickel compounds |
0.00065 |
0.0021 |
0.3 |
27% |
21% |
9% |
43% |
<1% |
Trichloroethylene |
0.017 |
0.2 |
0.08 |
4% |
96% |
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. |
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