Mercer 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
2
0.45
4
0.04%
4%
41%
8%
47%
Acrolein
0.1
0.020
5
0.07%
12%
70%
18%
0%
Arsenic Compounds
0.0005
0.00023
2
4%
12%
8%
7%
69%
Benzene
2
0.13
13
0.2%
12%
43%
12%
33%
1,3-Butadiene
0.1
0.033
3
0.2%
0.02%
46%
19%
35%
Cadmium Compounds
0.0001
0.00024
0.4
4%
45%
0%
1%
50%
Carbon Tetrachloride
0.6
0.067
9
0.001%
0.2%
0%
0%
99.8%
Chloroform
0.1
0.043
3
0.1%
56%
0%
0%
44%
Chromium (hexavalent form)
0.0002
0.000083
1.9
13%
15%
10%
1%
61%
1,4-Dichlorobenzene
0.1
0.091
1.2
0.2%
57%
0%
0%
43%
1,3-Dichloropropene
0.1
0.25
0.5
0.00001%
100%
0%
0%
0%
Diesel Particulate Matter
2
0.0033
548
0%
0%
33%
67%
*
Ethylbenzene
0.4
0.4
1.1
1%
7%
66%
26%
0%
Ethylene Oxide
0.01
0.011
1
0.3%
34%
0%
0%
66%
Formaldehyde
2
0.077
27
0.06%
3%
26%
11%
60%
Methyl Chloride
1
0.56
2
0.008%
1%
0%
0%
99%
Methyl tert-butyl ether
2
3.8
0.6
0.2%
14%
43%
43%
0%
Naphthalene
0.1
0.029
3
3%
45%
18%
3%
31%
PAH/POM
0.02
0.0075
2
1%
78%
14%
7%
0%
Perchloroethylene
0.2
0.17
1
1%
60%
0%
0%
39%
1,1,2-Trichloroethane
1.3E-6
0.063
2.0E-5
15%
85%
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.
