MIDDLESEX
COUNTY
Middlesex 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 |
3 |
0.45 |
6 |
0.01% |
3% |
35% |
8% |
54% |
Acrolein |
0.1 |
0.020 |
5 |
0.1% |
11% |
70% |
19% |
0% |
Arsenic Compounds |
0.0007 |
0.00023 |
3 |
2% |
6% |
6% |
4% |
82% |
Benzene |
2 |
0.13 |
14 |
1% |
13% |
41% |
11% |
34% |
1,3-Butadiene |
0.1 |
0.033 |
3 |
0.4% |
0.03% |
50% |
18% |
32% |
Cadmium Compounds |
0.0001 |
0.00024 |
0.4 |
10% |
37% |
0% |
1% |
52% |
Carbon Tetrachloride |
0.6 |
0.067 |
9 |
0.001% |
0.2% |
0% |
0% |
99.8% |
Chloroform |
0.1 |
0.043 |
3 |
1% |
52% |
0% |
0% |
47% |
Chromium (hexavalent form) |
0.0003 |
0.000083 |
4 |
17% |
8% |
5% |
1% |
69% |
1,4-Dichlorobenzene |
0.1 |
0.091 |
1.1 |
0.4% |
55% |
0% |
0% |
45% |
1,3-Dichloropropene |
0.1 |
0.25 |
0.4 |
0.00008% |
100% |
0% |
0% |
0% |
Diesel Particulate Matter |
2 |
0.0033 |
498 |
0% |
0% |
32% |
68% |
* |
Ethylbenzene |
0.5 |
0.4 |
1.3 |
4% |
25% |
52% |
19% |
0% |
Ethylene Oxide |
0.009 |
0.011 |
0.8 |
8% |
6% |
0% |
0% |
86% |
Formaldehyde |
2 |
0.077 |
30 |
0.1% |
3% |
26% |
12% |
59% |
Methyl Chloride |
1 |
0.56 |
2 |
0.04% |
0.5% |
0% |
0% |
99.5% |
Methyl tert-butyl ether |
2 |
3.8 |
0.6 |
2% |
13% |
41% |
44% |
0% |
Naphthalene |
0.1 |
0.029 |
4 |
3% |
54% |
13% |
3% |
27% |
PAH/POM |
0.01 |
0.0075 |
1.7 |
1% |
77% |
14% |
8% |
0% |
Perchloroethylene |
0.3 |
0.17 |
1.7 |
1% |
42% |
0% |
0% |
57% |
1,1,2-Trichloroethane |
2.9E-6 |
0.063 |
5.0E-5 |
66% |
34% |
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. |
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