(17)Equation 17 (non-radionuclides) and Table 12 present the exposure variables for the surface water/groundwater dermal contact pathway. This pathway is conducted for the residential, recreational, and agricultural scenarios only. The industrial scenario has the skin surface area exposed set to 0 m3 and the exposure time is set to 0 hours.
(17)
Table 12. Surface Water/Groundwater Dermal Contact Parameters
|
Parameter |
Units |
Residential |
Industrial |
Recreational |
Agricultural |
|
Non-radionuclide chemical concentration in water = Cwn |
mg/L |
Chemical-specific |
Chemical-specific |
Chemical-specific |
Chemical-specific |
|
Radionuclide chemical concentration in water = Cwr |
pCi/L |
Chemical-specific |
Chemical-specific |
Chemical-specific |
Chemical-specific |
|
Skin surface area exposedc = SA |
m2 |
1.94 (EPA 1989a) |
0 |
1.94 (EPA 1989a) |
1.94 (EPA 1989a) |
|
Skin permeability constant = Pc |
cm/hr |
Chemical-specific |
Chemical-specific |
Chemical-specific |
Chemical-specific |
|
Conversion Factor = CF6 |
(L-m)/ (cm-m3) |
10 |
10 |
10 |
10 |
|
Exposure duration = ED |
years |
30 (EPA 1989a) |
25 (EPA 1991a) |
30 (EPA 1989a) |
30 (EPA 1989a) |
|
Exposure frequency = EF |
events/yr |
350 (EPA 1989a) |
250 (EPA 1991a) |
40 (EPA 1992) |
350 (EPA 1989a) |
|
Exposure time = ET |
hrs/event |
0.2 (EPA 1992) |
0 |
2.6 (EPA 1989a) |
0.2 (EPA 1992) |
|
Body weight = BW |
kg |
70 (EPA 1989a) |
70 (EPA 1989a) |
70 (EPA 1989a) |
70 (EPA 1989a) |
|
Conversion Factor = CF2 |
days/yr |
365 |
365 |
365 |
365 |
|
Lifetime = LT |
years |
70 (EPA 1989a) |
70 (EPA 1989a) |
70 (EPA 1989a) |
70 (EPA 1989a) |
|
Averaging time = AT |
years |
LT (carcinogen) ED (noncarcinogen) |
LT (carcinogen) ED (noncarcinogen) |
LT (carcinogen) ED (noncarcinogen) |
LT (carcinogen) ED (noncarcinogen) |