-18-
UCRL-3644
Table III
Estimation of radiation effect upon health and life span
Lifetime Shortening (in yr. )
Radiation received
If 1 r = -5 days
If 1 r = -10 days?
(r)
-
50
-0.7
-
1.4
100
-1.4
~ 2.7
200
-2.7
- 5.5
400
-5.5
-11.0
ee columns are given because of uncertainty whether 1 r = -& days or
ays.
Thus it is observed that, although the estimated effect of radiation upon life
span is a number worth attention, its magnitude of effect at low accumulated
dosage is slight compared with many public health problems. It must be
remembered that major problems such as smoking and overweight and fat
metabolism are so subtle that they are estimated and established not by clinical methods but rather by statistical (actuarial) researches involving large
population samples. The effect of smoking 1 pack of cigarettes per day, for
example, appears equivalent in reduction of health and life span to the effect
of between 200 and 400 r of accumulated whole-body radiation. This is several times as great as the 50-r limit currently recommended for occupational
exposure; and 50 r,
in turn, is on the order of 10 times as much as the in-
dividual would accumulate through fallout. If the life-span loss is estimated
as 5 to 10 days per r of whole-body exposure, the loss due to 50 r falls within
the range of -0.7 year to -1.4 years of life span. This effect is greatly exceeded by the magnitude of the smoking problem; the obesity problem; the
problems of atherosclerosis,
diabetes, and all the chronic diseases; the
benefits of marital status; etc. The effect of 50 r of whole-body exposure to
the general populace can also be viewed as being in the same category of lifespan loss as that which results in the population of the United States from use
of the automobile. This estimation, however, does not include the problem
of the mutation burden in the next generations following such radiation exposure.
Summary of the Fallout Problem on a Global Basis
On a global basis, the fallout intensity of radioactive materials is no
more than one millionth of the high-level fallout that occurred by mishap in
the vicinity of a thermonuclear explosion in the Marshall Islands in October
1954.
Current estimations made directly in humans throughout 1953-1956 place
the fallout exposure from strontium-90 as being, on the average,
sufficient
to produce an irradiation effect of approximately 0.004 r/yr to human bones.
This is a small quantity of radiation--2% of naturally occurring bone radiation- -