ae ed
than 607 of the RaD, the dose rate te the skeleton
is,abaut 10 times
trabecular and cortical samples are not uniformly distributed between
that to the other parts of the bocy.
the two sexes, the average for each respective type of bone is higher
in men than in women.
Finally, the problem of the RaF-RaD equilib
rivm in the skeleton
was considered,
sampling procedures, these results do indicate the RaD concentration
This is important beceise the dose is essenti
ally due
to the alpha-emitting RaF.
While there are many questions involved in the
is higher in trabecular than in cortical bone and is higher in men than
The results were obtained by analyzing the
in women.
naP within a few weeks after Surgery and then
again efter several months.
On a regional basis, there is no apparent correlation in the
Table 4 (Slide 5) shows the RaF to RaD ratio to oe
1.0 + 6.2 end thus
the metabolic properties are essentially control
led by those of ReD,
measured copulation as’ show: in Table 6 (Slide 6).
that is, on the average, there is littie excess
or deficiency of RaF
of measurements on rib specimens from 14 people who lived in Chicago 15
over RaD.
years or more,
The concentrations reage over a factor of 6, but average
O.177 pe/g ash, vnich is slightly higher than the overall average of
Fig. 2 (Slide 6) is a plot cf the RaD vs. the
pae26 concentrations
in 1238 samples from about 100 individuals.
This is a series
0.146 pe/g ech but it
There is littie correlation
is about the same as the average trabecular bone.
and in a given pa@6 interval of 0.01 pe/e ash, the RaD concentrations
The pa-“° values average 0.015 pe/g ash, which is about that expected
may vance over a factor of 6.
in Chicago residents, (22)
The RaD joes appear to increase with pae?o
We have also tried to determine the source of ReD in the body
( mcentration ard all points, except two,
lie above the line:
and, &5 shown in Table 7 (Slide 9) six sources are considered:
raat
(Rab) = 0.56 (raé25y' +72
226
and no? in the boey, RaD in potable water, RaD in the atmospnere,
222
short lived Rn 2 Gaughters in the air and RaD in food,
where the pareatheses refer to the concentration
in units of pc/g ash
of the enclosed species.
Ra
The significance of this dine is unknown,
Using the exponential model for excretion and the parameters
The
two points below the curve are less Slgificeny than
the others because
Tor leed aid Rad metabolism in the "Standard man? (9s12;15) based on
taey are data trom specimens cbtained from chi):irer
and there 1: some
those given in the Report ef the International Commissicn of Radiation
Protection, we have estimated the contr.isutions of these various sources
evidence that children have lower RaD concentrat:01s
than do adults. (9)
The overail average of RaD was 0.146 + 0.020 pe/g esh and of
pa@*6
to the body content,
0.037 + 0.007 pe/g ash.
significant, but the values used is extremely digh,
220
Rn
bone samples to average 3.13 pe/g ash, about 75% greater than
that in
about 10 times
value of 3. pe/l is also
(14)
high.
The
We conclude, therefore, that
in most individuals the only significant sources of RaD to the body are
The average RaD concentration in men, 0.16 ve/g¢
ash, Was 35% higher than the 0.119 peg ash in women.
(9)
the average, and cons2quently, few people would be exposed to this.
rable 5 .Slije 7) shows the RaD concentration in the
trabecular
cortical bone sample:,
The contribution of drinking water appears
_ food and air,
While the
The general agreement of the calculated with the measured
vaiues 1s significant, although, because of the assumptions in the
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