ce EE Sgt
nog.
wo
rer
er
oe es
aya
RADIATION STANDARDS, INCLUDING FALLOUT
121
DATA ON STRONTIUM 980
The milk networks described above aiso provide data on the concentrations
of strontium 89. These data have been published regularly in Radiological Health
Data. Since the inception of these networks there have been two periods when
strontium 89 has been present in measurable levels in milk. The data for
these periods are summarized in tables VII and VII. The tables give the
monthly average concentrations of strontium 89 in milk collected at each of the
processed milk stations from September 1961 through March 1962, and the
quarterly valnes from the raw milk network from the fall of 1957 to the spring
of 1961.
They also give an average for all the stations for each period.
ESTIMATED INTAKE OF STRONTIUM 89
In order to evaluate the significance of these concentrations of strontinm 89
in milk, it is necessary to compare estimates of total daily intake of this radionuclide derived from the milk concentrations with the guidance of the Federal
Radiation Council. For strontium 88 the FRC gives the following ranges:
Range I
Range II
Range III
0 to 200 puc per day.
200 to 2,000 wuc per day.:
2,000 to 20,000 wuc per day.
Using the same assumptions specified for converting strontium 90 concentrations in milk to total intake figures. the data on tables VII and VIII can be
used to estimate average U.S. intakes for strontium 89 for each period. These
are presented in table IT.
Tasie Il.—Estiniates of average daily intake of strontium 89 fer specified
periods, 1957-62
.
Strontium 89
Date
1957 1—3d quarter..__..---_----- eee eee eee eee
4th quarter___.20--0 ee ee ee ne
1958 1—Ist quarter____..----_.----------------------- eee ee
2d quarter.___.-.2__.--- one eee eee ee
3d quarter_....---..---- eee ee eee
4th quarter... 2. eee eee eee
1959 1—1st quarter. -___-2.----- 22 eee eee ee eee eee eee
2d quarter..___--.------2------..-----+-----+---------3d quarter... 2-2-2 ee
dth quarter.__--. --- 2-2 -- ee eee eee nee
(Essentially no strontium 89 detected through August 1961.)
1961—-September_.____.... 22-22 ee eee eee
October... ee ee ee ee en
November_._-- 8 ee ee eee
December. .__....--- 22-222 ee eee ee
1962—~—January_--._- 2 eee een ee ee
February... 0. eee eee ee
March__.--2- 2-2. ee ee eee
1 Raw milk network.
Average
milk concentration
{upe/i)
Daily intake range (upc)
Conversion
factor, 1.2
OConverson
factor, 1.3
80
50
&
50
90
50
30
40
10
<5
96
66
6
60
108
&0
36
43
12
3
104
65
6
85
V7
65
39
52
13
3
10
40
54
a5
25
3a
35
\2
48
66
42
30
36
42
13
52
72
46
32
39
46
ee Tah vay. ety Ute ade lod etnbe MALE Deshi
LatHRattESE
:
:
reoepe
nthe ye
hood, yeliies
2g5e ASERE T