Environmental Engineering Reference
In-Depth Information
Table 11.4 Consumption and subsistence farming of plants and animal products in France
(calculated from INSEE 1991 )
Agricultural population
Non agricultural population
Subsistence
farming
[%]
Subsistence
farming
[%]
Consumption
[kg/person/year]
Consumption
[kg/person/year]
Vegetables
115.8
67.9
93.0
25.7
Fruit
47.9
28.0
38.5
12.0
Beef
18.1
32.3
15.1
3.3
Pork
24.15
27.5
19.9
3.5
Poultry
17.5
68.3
13.2
15.3
Eggs $
165.5
58.7
138.0
16.9
Dairy products
121.7
18.7
106.7
2.3
Excluding tropical fruit
$ Consumption expressed in unit per year
Uncertainties and variability related to transfer parameters are large, as described
in Section 11.3.3.2 . If a regression relation is used instead of empirical data, the
uncertainties linked to the definition of the equation have to be added.
In case of a linear regression ( y
=
ax + b ), like for the relation of Travis and Arms
( 1988 ) (where log B T =
y and log Kow
=
x ), the (1-
α
) confidence interval of log B T
for a new contaminant is given by:
S 2
( x −¯
x ) 2
×
( n
+
1)
x +
a
×
b
±
t
α ×
+
(11.48)
i = 1
n
n
x ) 2
( x i −¯
in which
x =
log Kow for a new contaminant
x
¯
=
average of the x i observed in the dataset used to define the regression
relationship
t
α =
value of t-distribution with n -2 degrees of freedom, at
α
level
n
=
number of ( y i , x i ) in the dataset used to define the regression relationship
[-]
s
=
residual standard deviation
There are also uncertainties linked to the assessment of animal exposure,
because:
Some phenomena are not
taken into account
in models,
like ingestion of
earthworms by hens which are kept (partly) outdoors.
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