STOCHASTIC SIMULATION OF RADIONUCLIDE UPTAKE
813
Table 4— ANALYSES OF THYROID !21] IN TWO SAMPLES OF
JACKRABBITS TAKEN IN PENOYER VALLEY DURING JULY 1962
_
Observations,
ne !#!T per thyroid
July 16
July 26
388, 209, 205, 195, 172,
117, 37.1, 29.2, 28.6,
9
187.7
7097
174.5
0.0287
8
32.4
11038
29.1
0.0789
170, 130, 115, 106
Number
Arithmetic mean
Variance
Geometric mean
Variance of logarithms
26.1, 20.9, 20.7, 12.6
of observations
Table 5—- COMPARISON OF FOUR OBSERVED FREQUENCY
DISTRIBU TIONS WITH NORMAL DISTRIBUTIONS OF THE SAME
MEAN AND VARIANCE
Size
Degrees
of
Radio-
Reference
of sample
nuclide Total X? freedom* X? 95
P
Turekian and Kulp”?
227
Sr
56.23
10
Andersonetal.?!
254
0K
27.31
9
16.92
0.001
Libby*
53
Sr
7.86
8
15.51
0.4 to 0.5
Palmer and Queen*4
50
226Ra
7.53
3
7.81
18.31 <0,.001
0.06
*Taken as n— 3, where nis equal to the number of intervals in the frequency
distribution.”
that the other two distributions tested are not normal, although data
of Bryant et al.?’ indicated a non-Gaussian distribution of strontium/
calcium ratios in British stillborn.
.
More recently, other evidence has accumulated indicating that
frequency distributions of radionuclides in consumers are not normal.
Walton et al.”® and Muth et al.*® have studied the concentration of
226Ra in human skeletons. In both investigations the observed frequency
distributions were non-Gaussian, and Waltonet al.
stated that the
distribution they observed was lognormal (See also Kulp and Schu-
lert®’), Onstead et al.3! have determined the amount of '°’Cs in 751 men
and 259 women. A comparison of these distributions with appropriate
normal distributions implies that the observations are not distributed
normally (Table 6). However, when a logarithmic probability plot of
the cumulative frequency distribution of '*’Cs in all 1010 subjects is
made, a straight line results (see Fig. 7). This indicates that the distribution is lognormal, Similarly, Yamagata™ has stated that the frequency distribution of natural '°*Cs in 78 samples of human muscleis
lognormal.