Evening star. [volume] (Washington, D.C.) 1854-1972, 1956-10-26
By ALTON L. BLAKESLEE
Associated Press Science Editor

AsSOClabed Press science EDITOR
NEW YORK, Oct. 26 (P).-Is
radioactive fal-out planting a
time bomb in our heredity-
booming some future children
to shortened lives, illnesses, de-
formities?
If SO, how many and can it
be avoided?
These are points at issue in dis
cussionS over banning H-bomb
tests, and when and how best
to prevent nuclear war. They
touch upon some knowns and
unknowns in the sciences OF
genetics, and also involve mo-
rality.
Looking at some main as
poets of facts and opinions on
questions involving heredity and
fall-out:
@. How is human heredity
determined?
A. By genes, or carriers of
characteristics, in the sex Of
germ cells-the eggs and sperms.
The genes you inherit determine
color of eyes and hair, height,
susceptibility to some illnesses,
many other things about you.
@. How does radioactivity af-
feet sex cells and heredity?
A. X-rays and other radiation,
and certain chemicals. can make
genes change or mutate if they
strike the germ cells. The altered
genes can be transmitted to off,
spring, and then to their off,
spring.
@. Are gene changes always
occurring in humans naturally?
A. Yes. there are spontaneous
mutations. Many are induced by
the natural radioactivity around
us. But also non-spontaneous
changes can be produced by
medical radiation treatments,
and actually or potentially by
fall-out, most geneticistS believe.
@. How much radiation are we
getting now from each source?
A. In a study conducted by the
Independent National Academy
Of Sciences. leading geneticists
and other experts said:
BY age 30-the time at which
parents have conceived half of
their children-the average per-
son has received this dosage of
radiation:
From natural radioactivity
which is inevitable: 4.3 roent-
gems.
From medical X-rays and flu
oroscopy: 8 roentgens.
From fall-out from tests made
at the current rate: one tenth
up to one-half of one roentgen.
A roentgen is-a unit of meas
ure of radiation exposure.
The MAS study said the 30
year exposure from fall-out
would be twice as high-two-
tenths to one roentgen-if tests
were made annually at the rate
of the two most active test years
IN 1858 and 1855.
@. Doesthis mean that fall
out radiation is not important?
A. 1t shows fall-out is not
adding much relatively to the
existing radiation that could
produce genetic changes and
damage. But it is adding some
thing. which must be considered
as a risk.
@. How little radiation does it
take to make human genes
change?
A. No one knows. The MAS
experts assume, from animal
evidence, that it might take up
to 10 roentgens to the sex cells
from birth to age 80 to have an
appreciable effect upon descend
ants if person became a par
ent at that age.
@. Are all gene changes caused
by radiation bad ones?
"A. Yes, so far as is known in
virtually all cases. says the Ma
tional Academy report. OBJ
servable human mutations are
believed to be universally harm
full" One expert says the
changes in health or longevity
may be usually minor and might
not be easily apparent.
@. DO the genetic changes from
any radiation cause freaks?
A, They can, but this is prob
ably rare. Low levels of radia-
ton, such as we are exposed to
from all three sources, are more
likely to produce descendants
subject to certain illnesses. or
shorter life spans than normal,
or death before birth, rather
than freaks. Very rarely the
gene changes might produce
geniuses.
@. Would such changes be
be likely to appear in my own
children?
A. Only a small fraction Of
mutations actually cause defects