Mercer 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
2
0.45
4
9%
3%
53%
8%
26%
Acrolein
0.01
0.020
6
0.02%
18%
67%
15%
0%
Arsenic Compounds
0.0001
0.00023
0.4
6%
94%
0%
0%
0%
Benzene
2
0.13
13
0.03%
7%
53%
14%
26%
Bis(2-ethylhexyl)phthalate
2
0.42
4
0.001%
0.1%
0%
0%
100%
1,3-Butadiene
0.2
0.033
5
0.002%
0.5%
46%
15%
38%
Cadmium Compounds
0.00007
0.00024
0.3
10%
89%
0%
0.8%
0%
Carbon Tetrachloride
0.3
0.067
4
0.2%
0.4%
0%
0%
99%
Chloroform
0.1
0.043
3
0.6%
64%
0%
0%
36%
Chromium (hexavalent form)
0.0002
0.000083
2
31%
60%
8%
0.4%
0%
1,4-Dichlorobenzene
0.07
0.091
0.8
0.4%
100%
0%
0%
0%
1,3-Dichloropropene
0.1
0.25
0.6
0%
100%
0%
0%
0%
Diesel Particulate Matter
2
0.0033
706
0%
0%
44%
56%
*
Ethylene Dibromide
0.03
0.0017
17
0.01%
0.003%
0%
0%
100%
Ethylene Dichloride
0.05
0.038
1.2
6%
0.2%
0%
0%
94%
Ethylene Oxide
0.005
0.011
0.4
15%
85%
0%
0%
0%
Formaldehyde
2
0.077
26
0.5%
5%
39%
12%
43%
Methyl Chloride
1
0.56
2
0.6%
0.7%
0%
0%
99%
Naphthalene
0.08
0.029
3
11%
57%
27%
5%
0%
Nickel Compounds
0.001
0.0064
0.2
3%
84%
5%
7%
0%
Perchloroethylene
0.2
0.17
1.4
1%
48%
0%
0%
51%
1,1,2,2-Tetrachloroethane
0.07
0.017
4
1%
0.6%
0%
0%
98%
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.
