RADIATION STANDARDS, INCLUDING FALLOUT
47
water supplies come from deep wells, the children there have radium
226 and 228 levels that are producing radiation to the bone two to
three times background. This is many times the dose from levels of
strontium 90 expected from fallout from weaponstests to date.
Chairman Hoxmrexp. Are the amounts you speak of of strontium
90 absorbed in infants’ and children’s bones, is this enough to start
cancerous action on the bonecells?
Dr. Dounuam. We don’t know. This is the area that we are trying
to work on very hard. Wehad a 2-day session last week with people
from the Argonne and Oak Ridge National Laboratories to get the
final signals on these large-scale multimouse experiments aimed at
trying to get the shape of the curve at these low levels.
As I pointed out in my testimony, most of the newer information
coming in suggests that when you are talking about a low level chronic
exposures situation you are dealing with muchless effect than taking
the original straight linearity proportional curves that were developed
several years ago in relation to acute whole body radiation.
Chairman Houirierp. Is this buildup to strontium 90 to, I believe
you said, as much as 60 percent of the maximum permissible level
which has been set-——
Dr. Dunuam. That is not in the bone, sir. That is the general
ground rule for what is permissible in milk. The bones are running
an average of around three strontium units as opposed to 66.
Chairman Horirrerp. I am glad to have that clarified. I could
hardly accept the fact that the bones have absorbed up to 40 percent
of the allowable.
Dr. Dunuam. No.
Chairman Hotiriecp. The evidence you have to date is that it is 5
percent.
Dr. Dunuam. The average is about 4 to 5 percent.
Chairman Hoxtrietp. Of the allowable?
Dr. Dunuam. Yes. There have been a few samples that have been
as high as 5.1 strontium units which would be roughly 8 percent.
Chairman Ho.irieirp. When we are talking about micromicrocuries,
as we are talking now, we are talking about the tremendously small
particles or elements, are we not ?
Dr. Dunnam. Weare talking about very small quantities.
Chairman Hotreretp. Is there any laboratory evidence to show that
a 38-percent absorption of the allowable has produced somatic effects
to the bones of mice?
Dr. Duniiam. No; it would take several million mice to show that.
Weare having enoughtrouble showing that a hundred times that producesan effect.
;
Chairman Howirrerp. I am asking these questions not to minimize——
Dr. Dunnam. No; this isa practical problem.
Chairman Hoxirratp. But to put it in the proper perspective. I
think this committee’s work in producing the facts is probably the
most valuable work that it has done in that we havetried to bring
the facts out from the most credible witnesses possible. We leave up
to people the interpretation of those facts. Some of them are interpreted in very sensational ways and they cause a great deal of concern
and anxiety among people whoare notqualified to recognize the rela-
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