ndumenibeiandaliilililies,
3
-6e-
-pesence of livestock or related to ‘tmospheric precipitation, in
anv apparent 4y.
TheThe effective half-iife of 1131 tp che grass, obtained under
sur experimental conditions in 1963, was in the magnitude of 5 days.
“entamination of the Wilk
The secretion curves observed in our experiments result from
a combination of experimental curves obtained in controlled surroundings by various authors, and especially Lengemann ‘?),
The experimental curves described in the literature are of
two types:
as
Oral administration of a "single" or "unique" dose.
Graph 10
shows the concentration curve for I131 in cow's milk obtained
in this case.
If we examine the upper curve {physical decay
corrected), it seems that the half-life of 1231 in milk was about
1.5 days during the 3 or 4 days following administration of the
radio-element, so this period was about 3 days.
However, accord<-
ing to Glascock{9), this period of slow excretion only becomes
apparent after 9 days instead of Jor 4 cays,
According to Lout it (7)
this change in the slope of the excretior curve was due, mainly,
to the iodine combined with the proteins.
b.
e
‘
Daily oral administration of 133% over a long period of time,
Graph 1l shows the concentration curve for t23L in cow's milk
obtained in this so-called "muitirla-dose" type of experiment.
The upper curve (physical decay correctad) indicates that
We approach an equilibrium with the contaminated ration after
about 7 davs.
These two types of experiment constitute reletively simple
cases.
In our tests, undertaken in natural surroundings, conditions
Aamieintete ax aclamAylabubtnabandh OF yee
Weliomnetae