Surface Water/Groundwater Indoor Inhalation
Equation 15 (non-radionuclides), equation 16 (radionuclides), and Table 11 present the exposure variables for the surface water/groundwater inhalation pathway from showering and from indoor water use. This pathway is conducted for the residential and agricultural scenarios only. The industrial and recreational default intake rates are set to 0 m3/day.
(15)
(16)
Table 11. Surface Water/Groundwater Inhalation while Showering Parameters
Parameter
Units
Residential
Industrial
Recreational
Agricultural
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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
Volatilization Factor = VF
L/m3
Chemical-specific
Chemical-specific
Chemical-specific
Chemical-specific
Inhalation rate = IRair
m3/hour
20
(EPA 1989a)
0
0
20
(EPA 1989a)
Exposure frequency = EF
day/year
350
(EPA 1991)
250
(EPA 1991a)
40
(EPA 1992)
350
(EPA 1991)
Exposure duration = ED
years
30
(EPA 1989a)
25
(EPA 1991a)
30
(EPA 1989a)
30
(EPA 1989a)
Inhalation exposure factor = IEF
(L hr)/
(m3 day)
0.2802 (Tritium)
7.603 (Radon)
0 (other radionuclides)
0.2802 (Tritium)
7.603 (Radon)
0 (other radionuclides)
0.2802 (Tritium)
7.603 (Radon)
0 (other radionuclides)
0.2802 (Tritium)
7.603 (Radon)
0 (other radionuclides)
Body weight = BW
kg
70
(EPA 1989a)
70
(EPA 1989a)
70
(EPA 1989a)
70
(EPA 1989a)
Conversion Factor = CF9
days/hr
1/24
1/24
1/24
1/24
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)