Environmental Engineering Reference
In-Depth Information
in which
C
a,i
=
concentration of contaminant in animal tissue i [mg/kg
dw
]
I
a
=
average contaminant daily intake for the animal [mg/d]
B
Ta , i
=
contaminant biotransfer factor for animal tissue i (meat, milk, egg)
[d/kg]
Depending on the available data, the concentration in animal tissue can also be
calculated with a bioconcentration factor (the ratio of animal tissue concentration
and the diet concentration):
I
a
Q
a
,
j
×
C
a
,
i
=
BCF
a
,
i
=
C
j
×
BCF
a
,
i
(11.6)
in which
BCF
a,i
=
bioconcentration factor for tissue
i
of animal
a
[-]
Q
a,j
=
daily quantity of media j ingested by animal
a
[kg/d]
C
j
=
animal-consumption-rate-weighed media concentration [mg/kg]
B
Ta , i
and
BCF
a,i
are linked by the following expression:
BCF
a
,
i
j
B
Ta
,
i
=
(11.7)
Q
a
,
j
Dynamic Approaches
Meat Concentration
It is assumed that:
•
animals can be represented by a unique compartment in which contaminant has
a uniform concentration,
•
contaminant is eliminated and metabolised according to a first-order reaction rate.
Under these conditions the development of the contaminant concentration in the
animal can be described as follows:
dm
a
,1
dt
=
f
abs a
×
I
a
−
k
a
m
a
,1
−
λ
a
m
a
,1
(11.8)
in which
m
a
,1
=
mass of contaminant in the animal [mg]
f
abs, a
=
absorption fraction of contaminant by the animal [-]
I
a
=
contaminant daily intake of the animal [mg/d]
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