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The problem of radioactive fallout may also be examined in comparison
with other ways of acquiring exposures to radiation (English values for radiological exposure are generally much less than in America 4)
See Table VI.
Thus, it is possible that, from common use of X-ray-generating
devices, the average person in the United States has already begun to accumulate an exposure to radiation effect that is sizable compared with the fallout problem. That no gross evidence of disease has become evident during
these past few years of increasing radiation exposure does not disprove the
existence of slight average effects of radiation. For example, at current
estimation of leukemia .
induction by radiation, about 20% of the relatively
rare cases of leukemia (0.5% of adult fatalities) may be attributable to natural
radiation. There is no difficulty in believing that supplementary radiation
resulting from our modern activities may have been responsible for the other
80% of known cases of leukemia; the average additional artificial radiation
exposure per year would only have had to be 0.8 r to account for this difference.
Considering the generous use of unshielded and unfiltered X-ray equipment
in dental offices and shoe stores alone, and the lack of public and professional
appreciation of need to minimize radiation exposure, it is even reasonable to
conjecture that the addition of artificially created radiation exposure to natural
irradiation may essentially account for leukemia. Faber has analyzed 828
cases of leukemia registered in Denmark in the period 1950-53 with regard to
the amount and type of irradiation each patient received for 20 years prior to
development of leukemia. The incidence of previous incidental X-ray or ra-
diation exposure for the chronic lymphatic leukemia cases was 18%, for myeloid leukemia, 30%, and for acute leukemia, 32%. It appears that both acute
leukemia and myeloid leukemia can be induced by radiation; and the traceable
X-radiation induction may account for a sizable percentage of current cases
in Denmark. Faber's information does not rule out that lymphatic leukemia
may also be induced by radiation. The analysis of leukemia incidence in followup of three groups of individuals who had had varying exposures to X-rays or
other radiation strongly suggests that the radiation induction of leukemia is
proportional to the radiation exposure,
and that for whole-body radiation ex-
posure the number would be entirely consistent with an estimation that 50 r
doubles the chance of development of leukemia.”
Radioiodine Fallout
Of all the problems that we can currently evaluate, the radioiodine
fallout problem is disposed of most readily. Radioiodine is produced in thousands of curies by some of the nuclear detonations; and, in falling to the earth's
surface, it contaminates grass and is eaten by foraging animals. In its fallout,
it is greatly diluted and does not at any time become a human problem. The
herbivorous animal, however, eats large quantities of grass; and in the cow,
for example, essentially all the iodine-131 ingested accumulates in the thyroid
gland.
Over a few days' time,
several hundred pounds of grass may be eaten,
and all the iodine contained becomes concentrated in the 15 to 30 grams of
**
Court-Brown and Doll, Summary of Leukemia Induction, British Report, 4
pp. 84-89.
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