Essex 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
5
0.04%
6%
47%
10%
37%
Acrolein
0.1
0.020
7
0.3%
14%
67%
19%
0%
Arsenic Compounds
0.0006
0.00023
2
2%
19%
10%
6%
63%
Benzene
2
0.13
16
1%
11%
49%
13%
26%
1,3-Butadiene
0.1
0.033
4
1%
0.03%
52%
17%
30%
Cadmium Compounds
0.0002
0.00024
0.6
14%
52%
0%
1%
33%
Carbon Tetrachloride
0.6
0.067
9
0.0004%
0.4%
0%
0%
99.6%
Chloroform
0.2
0.043
4
0.2%
67%
0%
0%
33%
Chromium (hexavalent form)
0.0002
0.000083
3
23%
19%
10%
1%
47%
1,4-Dichlorobenzene
0.2
0.091
1.8
0.2%
71%
0%
0%
29%
1,3-Dichloropropene
0.2
0.25
0.9
0.00003%
100%
0%
0%
0%
Diesel Particulate Matter
2
0.0033
501
0%
0%
28%
72%
*
Ethylbenzene
0.7
0.4
1.6
1%
20%
60%
19%
0%
Ethylene Oxide
0.01
0.011
1.2
6%
34%
0%
0%
60%
Formaldehyde
2
0.077
31
0.4%
4%
30%
14%
52%
Methyl Chloride
1
0.56
2
0.07%
1%
0%
0%
99%
Methyl tert-butyl ether
3
3.8
0.8
1%
13%
44%
42%
0%
Naphthalene
0.2
0.029
6
2%
62%
13%
2%
21%
PAH/POM
0.01
0.0075
1.8
4%
69%
17%
10%
0%
Perchloroethylene
0.4
0.17
2
0.4%
81%
0%
0%
19%
1,1,2-Trichloroethane
0.0000032
0.063
5.0E-5
37%
63%
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.
