98
Fluorine Intoxication of Cattle in India
EXPERIMENTAL
Our investigations were pursued along two
definite channels. The first was to establish some
diagnostic means by which cases of fluorosis might
be recognized by chemical examination of the
tissue samples and, secondly, to produce the patho-
logical symptoms described by field conditions of
feeding. We have been fairly successful in both
our attempts, the details of which are given below.
Chemical diagnostic method
It has been long known that normal bones and
teeth contain fluorine and that ingestion of fluo-
rine raises the fluorine content of these tissues
by 10-30 times the normal amount [Roholm,
1937]. Consequently, the level of the fluorine
content of the bones of animals suffering from
fluorine intoxication would at once determine the
degree of its severity. The drawback to such a
procedure is that, though fluorine has been found
in normal bones, no systematic work had been
done to find out the normal range, which has been
given as from 0.01 to 0.15 gm. of fluorine per 100
gm. of bone ash [Pierce, 1939]. The reason of
such a variation is probably due, partly to the
difference in the feed of the animals examined by
the different investigators, and partly, and this is
more important, to the types of bone examined
and the ages of the animals. Evans, Phillips and
Hart [1938] found that the fluorine contents of the
bones of mature cows on a fluorine low ration was
3-4 times greater than that of calf bones. As we
could not find any other reference regarding the
rate of immobilization of fluorine in the bones
and teeth of bovines with the age of the animals,
it was decided to study this aspect in greater detail.
Our results are given in Table II.
Before the work could be taken up, we had to
perfect a method for the determination of fluorine
in biological materials. The original Willard and
Winter method [1933], as modified by Armstrong
[1933], was at first used and was found to give
somewhat inconsistent results, duplicate deter-
minations often varying by 50-200 per cent.
By effecting a few modifications, a satisfactory
method was evolved and amounts as low as 25 to
30 microgrammes can now be easily estimated,
the error at this low level seldom exceeding 10
per cent. The details of the method will be pub-
lished in a separate article.
Fluorine contents of normal bones and teeth
Samples of the bones and teeth of cattle and
buffaloes of varying age were obtained from the
local slaughter house as well as from the animals
of the production section of this Institute. A
few samples were also obtained from Calcutta.
All the animals chosen were healthy. The ages of
the animals were also ascertained at the time of
collection. The following samples were examin-
ed :—(1) femur (2) pelvis (3) lumber vertebra (4)
molar (5) incisor. The analytical results are
given in Table II.
TABLE II
Concentration of fluorine in the different bones and
teeth of cattle and buffaloes of varying age
No.
1
2
3
4
5
6
7
8
9
10
Species & sex
Hill bull . .
„ . .
„ . .
„ . .
„ . .
Buffalo . .
„ . .
Cow . .
Bullock . .
Cow . .
Age
3½
4
4
5
5½
7
8
8
11
15
Fluorine in mg./100 gm.
of dry fat-free material
Fe¬
mur
20.7
18.7
18.1
49.3
38.2
68.9
112.0
114.9
62.7
62.7
Pel-
vis
27.0
39.7
36.2
46.7
73.9
97.6
160.0
144.1
286.2
327.4
Ver-
tebra
40.0
29.8
36.5
62.3
132.8
89.8
103.5
139.1
125.4
206.4
Mo-
lar
29.4
15.2
20.2
33.2
35.7
68.1
94.3
...
...
...
In-
cisor
24.0
27.6
14.3
34.5
34.3
63.2
83.9
...
...
...
The average ash percentages were (1) femur
70.4 (2) pelvis 62.8 (3) vertebra 60.7 (4) molar
81.7 (5) incisor 83.3. The following points
of interest can be seen from the table : (a) The
amount of fluorine in the pelvis or vertebra is
much greater than that in the femur or teeth.
The increased contents of fluorine in cancellous
bones had been previously observed [Roholm,
1937], but no reasons for this preferential deposi-
tion are forthcoming ; (b) the amounts of fluorine
in the bones and teeth increase with advancing
age. This is especially true as regards the pelvis,
where the
concentration of fluorine per unit
weight of the bone is proportional to the age of the
animal and the data can be represented by a
smooth curve. The figures for other samples
cannot be represented by so smooth a curve, but a
somewhat similar type of curve is obtained for the
molar. These results are similar to those reported
by Lowater and Murray [1941] who found that in