(11)Equation 11 (non-radionuclides), equation 12 (radionuclides), and Table 8 present the exposure variables for the soil/sediment milk ingestion pathway. The milk ingestion pathway is conducted for the agricultural pathway only.
(11)
(12)
Table 8. Soil/Sediment Milk Ingestion Parameters
|
Parameter |
Units |
Agricultural |
|
Non-radionuclide chemical concentration in soil = Csn |
mg/kg |
Chemical-specific |
|
Radionuclide chemical concentration in soil = Csr |
pCi/g |
Chemical-specific |
|
Milk transfer coefficient = Fm |
day/L |
Chemical-specific |
|
Fraction of year animal is on site = fp |
unitless |
1 (Site-specific) |
|
Soil to plant uptake factor (dry) = BVdry |
kg/kg |
Chemical-specific |
|
Mass loading factor = MLF |
unitless |
0.26 (Pinder and McLeod 1989) |
|
Quantity of pasture ingested = Qp |
kg/day |
16.1 (IAEA 1994) |
|
Quantity of soil ingested = Qs |
kg/day |
1 (Darwin 1990) |
|
Fraction of animal feed from site = fs |
unitless |
1 (Site-specific) |
|
Conversion factor = CF5 |
g/kg |
1000 |
|
Diet fraction = FI |
unitless |
1 (Site-specific) |
|
Ingestion Rate = IRm |
L/d |
0.509 (adult) 0.305 (child) (EPA 1989b) |
|
Exposure frequency = EF |
d/year |
350 (EPA 1989a) |
|
Exposure duration = ED |
years |
24 (adult) 6 (child) (EPA 1989a) |
|
Body weight = BW |
kg |
70 (adult) 15 (child) (EPA 1991a) |
|
Lifetime = LT |
years |
70 (EPA 1989a) |
|
Averaging time = AT |
yr H day/yr |
70 H 365 (carcinogen) ED H 365 (noncarcinogen) |