CAMDEN County Average 2005 NATA Modeled Air Concentrations Compared to Health Benchmarks
Pollutant
Modeled
Air Concentration (ug/m3)
Health
Benchmark (ug/m3)
Risk
Ratio
%
Contribution from
Point Sources
Nonpoint
Sources
On-road
Mobile Sources
Nonroad
Mobile Sources
Background & Secondary
Acetaldehyde
1.9
0.45
4.2
<1%
3%
4%
2%
91%*
Acrolein
0.056
0.020
2.8
<1%
20%
15%
8%
57%*
Arsenic Compounds
0.00067
0.00023
2.9
3%
7%
4%
3%
83%
Benzene
1.4
0.13
11
1%
8%
25%
8%
58%
1,3-Butadiene
0.093
0.033
2.8
<1%
<1%
40%
13%
47%
Cadmium Compounds
0.0001
0.00024
0.4
17%
34%
0%
1%
48%
Carbon Tetrachloride
0.61
0.067
9.1
0%
<1%
0%
0%
100%
Chloroform
0.11
0.043
2.6
1%
46%
0%
0%
53%
Chromium (hexavalent form)
0.00036
0.000083
4.4
18%
2%
3%
1%
76%
Cobalt Compounds
0.000045
0.00011
0.4
100%
<1%
0%
0%
0%
1,4-Dichlorobenzene
0.13
0.091
1.4
<1%
34%
0%
0%
66%
1,3-Dichloropropene
0.079
0.25
0.3
0%
100%
0%
0%
0%
Diesel Particulate Matter
1.2
0.0033
378
0%
0%
59%
41%
0%
Ethylbenzene
0.22
0.4
0.6
3%
10%
63%
24%
0%
Ethylene Oxide
0.0094
0.011
0.8
10%
16%
0%
0%
74%
Formaldehyde
2.4
0.077
31
<1%
2%
9%
4%
85%*
Methyl Chloride
1.2
0.56
2.2
<1%
1%
0%
0%
99%
Naphthalene
0.093
0.029
3.2
2%
35%
33%
4%
26%
Nickel Compounds
0.0014
0.0021
0.7
63%
7%
2%
10%
18%
PAH/POM
0.013
0.0072**
1.9
2%
80%
9%
9%
0%
Perchloroethylene
0.3
0.17
1.8
<1%
28%
0%
0%
72%
1,1,2-Trichloroethane
0.024
0.063
0.4
0%
100%
0%
0%
0%
Chemicals with risk ratios greater than or equal to 1 are
in bold.
Risk Ratios based on noncarcinogenic effects are in italics.
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. *Acetaldehyde, acrolein and formaldehyde concentration estimates include secondary formation, which is the process by which chemicals in the air are transformed into other chemicals.
**PAH/POM is "polycyclic aromatic hydrocarbons/polycyclic organic matter." These define a broad class of compounds. The chemicals making up this class were broken up into 8 groups based on toxicity, and each group was assigned a cancer-weighted toxicity estimate. 0.0072 ug/m3 is the health benchmark average across the 8 groups.
