Contaminant Risk Factors - Urban Watersheds: Geology, Contamination, and Sustainable Development - page 369

TABLE 10.13
Summary of CRF air Values and Exposure Risk Potential

Percent of
Potential
Exposure Risk
from Particulate
Phase

Percent of
Potential
Exposure Risk
from Gas Phase

Contaminant Risk
Factors for Air
(CRF air )

Approximate Ratio
of Exposure Risk
Particulate:Gas

Chemical
Compound

LNAPL compounds
Benzene 36.05 55.69 44.31 4:5

Ethyl benzene 18.18 11.00 89.00 9:1

Toluene 7.75 13.22 86.88 8.5:1.5

Xylenes 18.95 2.07 97.93 97:3

Mean LNAPL 20.23 81.98 318.02

20.49% 79.51% 4:1

DNAPL compounds
PCE

91.09 1.63 98.37 98:2

TCE 9.37 1.05 98.94 99:1

111-TCA 7.71 0.08 99.92 99:1

cis -12-DCE 34.10 0.18 99.82 99:1

Trans -12-DCE 18.90 0.10 99.90 99:1

Vinyl chloride 243.97 8.30 91.70 92:8

Mean DNAPL 67.52 11.34 588.66 98:2

1.89% 98.11%

PAHs
Naphthalene

30.44 0.003 99.997 1,000:1

Chrysene 162.09 0.0003 99.9997 1,000:1

Benzo (b)
fluoranthene

167.19 0.0004 99.9996 1,000:1

Benzo (k)
fluoranthene

97.74 0.01 99.99 1,000:1

Phenanthrene 40.40 0.0009 99.9991 1,000:1

Benzo (g,h,i)
perylene

184.13 0.0002 99.9998 1,000:1

Benzo (a) pyrene 94.59 0.000008 99.999992 100,000:1

Mean PAHs 124.82 0.0148 699.985

0.003% 99.997% 1,000:1

Metals
Arsenic 44.50 3.6 96.4 24:1

Chromium VI 210.25 44.59 55.41 5:4

Mercury 166.33 83.36 16.64 1:5.6

Lead 3.45 12.68 87.32 7:1

Mean metals 106.13 144.23 255.77

36.06% 63.94% 16:9

Mean PCBs 37.02 0.009 99.99 1,000:1

Chlordane 173.02 0.017 99.983 500:1