Surface Water/Groundwater Produce Ingestion

Equation 18 (non-radionuclides), equation 19 (radionuclides), and Table 13 present the exposure variables for the surface water/groundwater produce ingestion pathway. The produce ingestion pathway is conducted for the agricultural pathway only.

 

image\v4ht0216.gif  (18)

 

 

image\v4ht0217.gif  (19)

 

Table 13. Surface Water/Groundwater Produce Ingestion Parameters

 

Parameter

 

Units

 

Agricultural

 

Non-radionuclide chemical concentration in water = Cwn

 

mg/L

 

Chemical-specific

 

Radionuclide chemical concentration in water = Cwr

 

pCi/L

 

Chemical-specific

 

Irrigation rate = rirr

 

L/m2 day

 

2.08

(Kennedy and Strenge 1992)

 

Irrigation period = firr

 

unitless

 

0.25

(3 months)

 

Soil to plant uptake factor (wet) = BVwet

 

kg/kg

 

Chemical-specific

 

Mass loading factor = MLF

 

unitless

 

0.26

(Pinder and McLeod 1989)

 

Effective removal rate = r

 

1/day

 

l+hl

 

Soil leaching rate = l

 

1/day

 

2.7E-5

(NCRP 1989)

 

Radionuclide half-life = hl

 

1/day

 

Chemical-specific

 

Long-term deposition and buildup = tb

 

day

 

10950

(NCRP 1985)

 

Areal density for root zone = P

 

kg/m2

 

240

(Hoffman et al. 1982)

 

Interception fraction = If

 

unitless

 

0.42

(Miller 1980)

 

Translocation factor = T

 

unitless

 

1

(McKone 1994)

 

Decay for removal on produce = E

 

1/day

 

l+0.693/tw

(NCRP 1989)

 

Weathering half-life = tw

 

1/day

 

14

(NCRP 1985)

 

Above ground exposure time = tv

 

days

 

60

(NCRP 1985)

 

Plant yield (wet) = Yv

 

kg/m2

 

2

(NCRP 1985)

 

Diet fraction = FIv

 

unitless

 

0.4

(EPA 1989b)

 

Ingestion rate = IRv

 

kg/d

 

0.2

(EPA 1989b)

 

Exposure frequency = EF

 

d/year

 

350

(EPA 1989a)

 

Exposure duration = ED

 

years

 

30

(EPA 1989a)

 

Body weight (adult) = BW

 

kg

 

70

(EPA 1989a)

 

Conversion Factor = CF2

 

days/yr

 

365

 

Lifetime = LT

 

years

 

70

(EPA 1989a)

 

Averaging time = AT

 

years

 

LT (carcinogen)

ED (noncarcinogen)