Human Health Risk Assessment - Raytheon

R = Ideal gas constant (cm 3 -atm/mole-K)
T = Temperature (K)
4.2.7 Homegrown Produce
26
Human Health Risk Assessment
DRAFT
For residents who maintain a home garden and irrigate their crops or trees with groundwater,
potential exposures to COPCs may occur via ingestion of homegrown produce and incidental
ingestion of soil while gardening. As previously mentioned, most of the COPCs present in off-
Site groundwater are volatile constituents, which will tend to be released to outdoor air during
irrigation rather than accumulate in soil or taken up by plants.
COPC concentrations in homegrown produce were estimated for root vegetables and aboveground
fruits and vegetables using empirical correlations with octanol-water partition coefficient
(Kow) established by Briggs et al. (1982, 1983) and later updated by Ryan et al. (1988). The
root concentration factor (RCF) is defined in equation (4-15)
RCF
and estimated according to equation (4-16).
( mg / kg fresh weight)
pore water ( mg / L)
concentration
in root
= (4-15)
concentration
in soil
0.
77 log Kow −1.
52
RCF = 10
+ 0.
82
(4-16)
A stem concentration factor (SCF) derived by Briggs is used to estimate COPC concentrations
in above-ground fruits and vegetables. The SCF is defined in equation (4-17)
SCF
and calculated according to equation (4-18).
( mg / kg fresh weight)
pore water ( mg / L)
concentration
in stem
= (4-17)
concentration
in soil
2
−0.
434(
log Kow − 1.
78)
−
=
⋅ ⎜
2.
44
SCF 0.
748 ⋅10
⎟
(4-18)
0.
95 log Kow 2.
05
( 0.
82 + 10
)
⎛
⎜
⎝
⎞
⎟
⎠