Essex 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
3
0.45
6
2%
5%
63%
11%
19%
Acrolein
0.03
0.020
13
0.06%
26%
54%
20%
0%
Arsenic Compounds
0.0001
0.00023
0.5
4%
96%
0%
0%
0%
Benzene
2
0.13
18
0.2%
7%
59%
13%
21%
Bis(2-ethylhexyl)phthalate
2
0.42
4
0.7%
0.01%
0%
0%
99%
1,3-Butadiene
0.2
0.033
7
0.01%
4%
46%
12%
38%
Cadmium Compounds
0.00009
0.00024
0.4
17%
83%
0%
0.4%
0%
Carbon Tetrachloride
0.3
0.067
4
0.006%
0.8%
0%
0%
99%
Chloroform
0.2
0.043
4
0.6%
73%
0%
0%
27%
Chromium (hexavalent form)
0.0001
0.000083
1.4
14%
67%
19%
0.5%
0%
1,4-Dichlorobenzene
0.1
0.091
1.3
2%
98%
0%
0%
0%
1,3-Dichloropropene
0.2
0.25
0.9
0%
100%
0%
0%
0%
Diesel Particulate Matter
2
0.0033
658
0%
0%
45%
55%
*
Ethylene Dibromide
0.04
0.0017
22
0.04%
0.02%
0%
0%
100%
Ethylene Dichloride
0.05
0.038
1.4
0.6%
0.3%
0%
0%
99%
Ethylene Oxide
0.008
0.011
0.7
8%
92%
0%
0%
0%
Formaldehyde
3
0.077
36
1%
3%
43%
17%
35%
Methyl Chloride
1
0.56
2
0.2%
1%
0%
0%
99%
Naphthalene
0.1
0.029
5
0.4%
70%
23%
6%
0%
Nickel Compounds
0.002
0.0064
0.3
3%
92%
5%
0.4%
0%
Perchloroethylene
0.4
0.17
3
0.2%
64%
0%
0%
36%
1,1,2,2-Tetrachloroethane
0.08
0.017
5
0.06%
0.3%
0%
0%
100%
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.
