Octuber 1965
Sutow and Conard
ences in ine incidence or leukemia have been
found among a number of metropolitan areas
cc
of the United S:aies with citeren: cosmic
radiation backgrounds.**? The question
re2
garding the possibility that the irradiate
sample may not be renresentative of the
whole chiidhood ponulation needs io be more
precisely answered.>*
Chromosomal aberrations in peripheral
leukocytes have been reported following diagnostic X-irradiation doses of + io 12 r.7°
Vhat similar changes may occur at lower
doses is suggested by a report of the development of chromosome abnormalities aher $25
mr (0.8 rad} total body exposure.’® None
were noted aiter 20 to 60 mr radiazion.*?
Current asvailable datz on human subjecis
do not permit any Cefnitive assessment or
ihe development of otmer somatic efects
‘nerediiary and nonhereditary)a in chilcren
o: persons now living hus been estimated to
be bezween +,0C0,0G0 and 6,000,000. The
number of additional cases occurring In ine
i2xt ogeneration has been estimated to be 100
wrange 20 to 500) due to fallout and 10 (2
Q 30) to carbon-l4. The risk to the inrencration (of genetic
M..eCcis Man
mental or pnyst
tal a
r
yas f
alas ara
ical
defect,
nas been4 calculated
as- 1,/1,000,-
PAX tee
Phe UNSCEAR report concludes that for
whai lower than 36 rad but moc less than 13
rac. For chronic irradiation, t.c most prob-
able value is 100 rad or possibly nigher.”+
+4
from exposure to low-level irradiation. In
reference to life shortening, extrapolation
from animal to human has been attempted
Dur the ciinical observations are inconclusive.
Geiects in man, the total of gross physical
anc mentai cufects from all atomic weapons
tests through 196] and all future generations
been estimaied’ 286 as 1,000 (range
00} zrom fallout and 2,000 (ran
,005; trom carbon-l+. The vote!
number of such defecis Cue to ail causes
3
clearly indicates the rneed ior further daia on
human beings.“If
e leukemia does resutt
trom pelvimeiry, it may indicate that the
fetus is extremely sensitive or that in reality
there is no tnreshold.’*8 However, no diler-
p
664
FALLOUT RADIATION
éren.** Stucies of growth and development
in chiidren have not been reported other
than inose carried out on populations ex-
The voluminous data on tie levels and
mavards of environmental
coniamination
with radioactive materials (primarily from
nuclear weapons tests) have been effectively
suzumarized, on an mternational basis, by
UNSCEARI® * The published records of
hearings before the Subcommiuttce on Re1. Development, and Radiation and before the Svecial Suscommittee on Radic-
posed to whole-body coses of 69 r or more.
n, both of the
1 Jolnt (Committee on Atomic
Meron we Cunicahy signiicant cataract for-
mation probably has not occurred below 660
rads, anhough it is generally believed that
the minima Ciect ive dose is lower in chil
1
oaeul
macrecitary ehecr. There exists no bodyof
direct odservation oz human population
which perimits the precise quantitative determination of the genetic effect of low-levei
radiation.®**"8
The potential genetic consequences Of exposure to radiation have
OQ: radioactive fa.lout from
{ weapons depend
¢
on the amount
cogre alc Jocation
osion, meteoro.wyical conditions,
been usiimated indirectly in such terms as
“lethai-equivaients,7'* total estimated numbers “ol gross physical or mental defects in
future generations,!"% res and) “gonacail
doses” cr “doubling doses” or radiation.” lus, idt
Based on radiation-induced mut
in man and on the spontaneous inci
idence OL
and
other
factors.t: 9° >»
tuo,
Po,
120
Woy
IN Gd10-
rogiciily important nuchdes which account
iOr inOst of the external irradiation srom Baie
out include the
95 (halr-uie, 9 weeks
life, 3 weeks), and cesiu