pigmentation persisted for several yearn before it
haally disappeared. These pigmented streaks are
notte be confused with conjunctival and corneal
pigmentation of genetic origin noted in some of
these people, which is in the superticial epiheiiun
and is permanent
Pten gia and pingueculite, During the early surveys
the incidence of ptervaia and pingucculae was
thought ta be greater i the exposed Rongelap
people than inthe unexpesed comparison popula.
tion. Hlawever, as the later group hos increase,
this ne loguer appear to be the caw (ace Fable 14).
Opactties uf the dens. Op aeitios at ihe lens have
been a comin tindiog athe Miarstistlose (sce
Table Db. They are scored tn order of decreasing
Size as Cataracts (arbitrarily considered as a lens
opacity dnpairing visual acuity bs > 20040), lens
opacities, polychromatic shecte. and fecks. Special
ticruscuple examinations for lens Hecks were
made in 100, '4
trradiation of the lens in sullicient dosages may
result ina spectrum of opacities ranging from
polychromatic sheens to ftull-blow a cataracts, bess
Only tn the early stages of cataract formation ean
changes characterbue of radiation generally be
recognized; more mture Cataracts due toradios
Hon usually canner be ditherentioted fron these
due to aging or disease. The development of bens
opacities due te radiation depends on the charaeteristics of the radiation, the age of the individual
al caposure, and the unterval after irradiauon,
Neutrons are known to be several uimes as cataractogenic as ganinaoar bela rays and plaved an
inportint role in cataract development in the
Japanese exposed to the atone bombs and abe in
evclotron workers!" Tn the Murshallese only
ganas radiation need be considered because
hu peutrons were javalved in the Cadlout wad the
beta radiation dad not have sulficient energy te ine
part a savmificant dose to the leas, The gamma
rachation bad a fairly cnergetic spectrum (100 tu
1200 keV). Vhe U7)-rad dose was delivered ata
decreasing mite over the two days of exposure. The
discrete opacities were at most only a few niicrots
in size and voukl inne way tapaic vision. Phe
number of flecks increased with age in all groups,
but they developed more rapidly in adolescent te-
niales.'4° \ higher score in females aged 1310 20
atexpesure may dive been related to the radiation,
Vhe higher tncidence of tleeks in adulescent feMales was thought to be assaciitled with cher high
estrogen levels,
Other lens opacities observed in the exposed
Marshallese didi net dit the descriptions of raclistion-iaducedd types and were simian to those seen
la the anes posed population. Phe abscuce of racliation-induced cabinets is hot anes pectea, since
the dose te the Miusastiaatlese wars dechow the mini
Munn dase of s niveer gai cays needed. The
lapee of 20 years is well bevond the usual luteni
period and ioseeis uolikely thist any such lesiuns
will dhewelop. ALL the cataracts seen have been of
the senile or presenile ype and no juvenile cata-
racts have been noted. Possible correkition with die
betes is discussed in Section TL G. a. Uhe slivhily
higher incidence of cataracts in the exposed Rouvelip people over the year may be rebated toa
slight: preponderance of older peaple in the es.
posed population.
Polvehromatic sheens, vellowish or “beaten
brass” to blue-green in color. were noted in wine
Miuarshullose, beth exposed vind nones pesca. “Phese
were not associated with any lenticular opacities
characteristie of radiation exposure,
F. GROWTH AND DEVELOPMENT STUDIES
OF EXPOSED CHILDREN
1. Dota Taken
Dining cach anedical survey of the Matshatlese
people, svstematne pedtatoe cxaniinations lave
been conducted on subjects ander the chraacloyicalage of 20 vears (sce Vable 14) with the UNCepe
Hon of adolescent girls who were pregnant or whe
had hack babies. Vhe studies cetpisted af’ a brictin
rays is considered te be ~ 200 rads and the dane te
produce progressive lesions, ~ 300 cads.!" The
terval hustory, poutine pliveicil ¢Namainition, palpeiion of the thyroid: vlan. and: axsexsament af
growth aud development,
Vhe growth status of the children expend to
larger dases the latent period mii be shorter, and
with lower doses it may be 38 vears.
The sraallest lens opacities observed with slit-
examination. From 05} te 1938 the growth data
consisted of ronting measurements of stature and
TOE Cabtaractowerie diese all x FoWs OME Qcud ibe nas
latent period averages about 2 tab years. With
lamp microscopy were lens flecks, which are
thought te be defects in single lens fibers. These
Toatih
fallout bas been followed reguba Iv since the: initial
weight. Tn E999) rocatgenographic evaluation of
*Vheexe tiabes were cba da De. J. Bateman, BNE