Plutonium was chemically separated and electrodeposited on a stainless steel disk, and the a-activity was measured by an a-spectro- meter with a Si (Au) ...
RADIOISOTOPES,
Plutonium and Uranium in Japanese Yasuhito
IGARASHI*,
Atsushi
36, 433-439 (1987)
Human Tissues
YAMAKAWA
and
Nagao
IKEDA
Department of Chemistry, University of Tsukuba Sakura-mura, Ibaraki-Pref. 305, Japan Received
Plutonium
and
determined of
each
element
concentrated whole of
uranium
in
human
by ƒ¿-spectrometry was
in
body. stable
and
special
This
on
the
of
states
of
track basis
while
from
of
in
body
of
the
respectively.
mean is is
to
Pu4+
area
be
due
pattern
Plutonium
generally
for
were
distribution
obtained. rather
considered
fluid;
Tokyo
The
concentration
distributed
tendency
elements
residents
method,
uranium
distribution
the
28, 1987
obtained
fission
organs,
difference
chemical
tissues
the
estimated
some
March
is
throughout
to
the
plutonium
the
characteristics and
UO22+
for
uranium.
Key Words:
plutonium, uranium, organ burden, total
human tissue, body burden
are 1.
Introduction
Several
compared
mentioned
transuranium
elements
have
to
tions
during
have
entered
time
and
will
elements.
human
level
From
exposure
this
of
artificial
of
in
the
behaviors
the
of
the
important,
these
amounts
long
years,
half
are
their
high
toxicity,
released
lives
of
nium
authors
reported
on
determination
the
and uranium Japanese.
uranium additional * Present tional Isozaki,
In
this
samples
human
Division
Nakaminato,
Ibaraki-Pref.
Sciences,
at
smaller
in
determination
same
(about of
a
uranium,
and
sam-
sufficiently. into
mg)
lyosamdish
the
mortar
10
bone quartz
ashing,
divided
The first
or on
agate
was
uranium
samples.
sample
an
sub-
death
were
After
of during
the
of
samples
was
part
died
and
470-500•Ž
sample
from
residents
who
cause
the
oven.
mixed each
of
plutonium
for
electric
was
Then a
asked an
ple
two
parts;
was
for
the
the
rest
for
plutonium.
Plutonium
of and
in the
of Radioecology,
was
using
pluto-
and the analytical
determined
ple
kCi1))
plutonium
work,
lyophilized
in
tissues
this
Each
6.6•~103
are determined
of Radiological
above-
concerning and
philized.
rela-
fallout
In
sex
of
previous pa-pers2)-4)
of
paper,
tissues
address : Institute
the
in several
in human tissue
in
information
age,
bone
future.
330 and
No
except
respectively.
The
the
obtained
study area
samples
give
were
medical
metropolitan
except
were
especially
(about
2.4•~104
a
the
nuclides
240Pu
analyzed
in
available.
prediction
and
Tokyo
these
could
the
the
1980-82.
those
in
autopsy
ject
of
the
tissues
the
these
future.
with
elements
239Pu
large
and
distant
transuranium
considering
tively
the
comparison
facilitate
man-made
environment,
that
environment
to
of
hazardous
actinides
information
Among
most
seems
in
view,
natural
ones
some
of
of
naturally
potentially
even
point
behaviors
it
beings
lapse
to
Since
from
view.
Methods
Human
nuclides
the
similarly
discussed
of
detona-
These with
a-emitters,
bring
nuclear
decades.
biosphere behave
long-lived
low
by
four
the
actinide
might
the
environment
these
occurring are
the
and
point
been
2. released
individual
data Na-
was
chemically
separated
and
electrodeposited on a stainless steel disk, and the a-activity was measured by an a-spectrometer with a Si (Au) surface barrier type semiconductor detector. Uranium was determined by the fission track method with calibration curves. Details for the analytical procedures are described in the previous papers2)-4). 3.
Results
and
Discussion
3609, 3.1
311-12, Japan.
(3)
Concentration
distribution
of plutonium
434
RADIOISOTOPES
Table
1
Concentrations
* The
number
of arithmetic parentheses ** Bone samples Table
2
of plutonium
of samples
available
and geometric were
Concentrations
taken
Vol.36,
in human
for calculation
means
is shown
in
from rib and femur
of uranium
in human Fig. l
Cumulative trations
* Bone
samples
were
No.9
taken
from
skull
frequency
in human
curves
lung
of Pu concen-
and liver samples.
, rib and
femur and uranium
in human
tissues
The results obtained for plutonium are summarized in Table 1. In the table geometric mean values with geometric standard deviations are given in addition to arithmetic mean values, because plutonium concentrations in tissues indicate a log-normal distribution as shown in Fig. 1, as other authors have pointed out5)-8). The results for uranium are given in Table 2. Uranium concentrations in individual tissue also reveal a log-normal distribution as shown in Fig. 2, which is of the same tendency as most of other trace elements in human tissues. It should be noted that plutonium and uranium concentrations in bones, regardless of the kind of bone, may compose a single population (Fig. 3). Generally speaking, the concentrations of essen(4)
Fig. 2
Cumulative centrations
tial
elements
in
if they
are
even
tain nearly Their
tion tions
the
constant
increase
amounts,
curves human
tissues
trace
concentrations,
by the
frequency in several
values
and
their
living
beings,
tend
to main-
by the homeokinesis.
therefore,
or decrease
in the tissues
of
elements,
of U consoft tissues.
are
in intake
not
affected or excre-
concentration
of living
beings
distribuare
normal
Y. Igarashi
Sep. 1987
Table
et al.:
3
Plutonium
Weights
and uranium
and compositions
in Japanese
human
of the composite
Table
4
Errors
435
tissues
samples
Concentrations of composite samples
represent
counting
plutonium
statistics
in
of
the
1ƒÐ
adding new data. As plutonium activities in muscle, kidney and spleen are rather low and the corresponding counting statistics are not so good, the analytical values previously obtained for these tissues were not sufficiently accurate. Therefore, in order to obtain more reliable data for the plutonium levels in the tissues, a com-
Fig. 3
Cumulative
frequency
concentrations distributions. tration by
of
their
ment,
thus
or
their
other
elements in
concentration
of Pu and U
bones.
hand,
decrease
distributions9).
uranium,
essential
the
non-essential increase
log-normal facts,
On
curve
in human
Table
4
shows
concen-
found
are
affected
contents
were
the
environ-
kidney,
while
the
distributions Considering
as well as plutonium,
element
posite sample for each tissue was analyzed. Each composite sample was prepared by mixing each corresponding tissue from six or seven subjects, the weights and compositions of which are shown with age and sex in Table 3. in these
Okabayashi11
are
concentrated
these is a non-
for man.
plutonium
composite rather
significant
unexpectedly pointed
out
in spleen.
with
about
0.4 kg
high
concentration
concentrations
samples.
of
In
in low
that our
spleen,
as in liver
Plutonium spleen
and
in
muscle . plutonium is
result
obtained
however,
not
nor
in lung
so was
observed. 3.2
Distribution uranium
patterns among
of plutonium
human
The individual organ burden total body burden (TBB) of the ICRP Reference Man10), which in the previous papers2),9), were
Based on the results,
and
a new TBB value of
plutonium was estimated as shown in Table 5. The TBB value is smaller than the previously reported one by about 40 mBq (1 pCi). It. should be noted that this estimation was made on the basis of mean concentration. The IOB .
tissues
(IOB) and the elements for the were estimated re-estimated by
(5)
436
RADIOISOTOPES
Table
5
* An assumed
Table
Estimated
organs
and total
body
burdens
Vol.36,
of 239,240Pu for the ICRP
Reference
No.9
Man
value
6
Estimated
* See Ref . 2 ** A value estimated
uranium
organs
from the average
and total body
of liver,
kidney,
burdens
spleen,
for the ICRP
muscle , heart
Reference
Man
and brain
Using the data, the distribuiton patterns of these elements among human tissues and organs were illustrated as shown in Fig. 4, comparing with the weight distribution of tissues for the ICRP Reference Man10). It is evident that uranium is distributed rather uniformly all over the body, while plutonium is concentrated in skele-
Fig. 4
Distribution patterns human tissues with for the ICRP
and
of Pu and U among weight distribution
Reference
TBB
values
of
uranium
using
the
mean
concentrations
Table
6.
ton (60%) and liver (30%), reconfirming that these two organs are important for systemic distribution of plutonium. ICRP Publication 48 reviewed and summarized the distribution of fallout plutonium in members of the general
Man.
also are
obtained shown
population from various geographical regions, suggesting the deposition percentage of 45% for liver and 35% for skeleton as weighted mean of the data12). It also shows, however, the
by in
( 6)
Sep.
Y. Igarashi
1987
variations in relative in these organs, which 55% for liver and 25 Major uncertainty may how the total skeletal mated from fragmentary the scope of the present 6, the skeletal contents
et al. ; Plutonium
and uranium
partition of plutonium ranged between 23 and and 56% for skeleton. be due to the difficulty content should be estidata, which is beyond work. In Tables 5 and of plutonium and ura-
first
to
at
not
exist
fluid,
naturally
supposed
higher
charge
by
itself
there
proteins,
amino
etc.
act
that
in
are
The
complex
ions
decreases
be
acids
>Pu(VI)>Pu(V)13),14) by
Taylor14),
as
rather
plasma etc.
major
stable
human
other
organic
ligands
for
ability order
of
of
Pu
part
complexes globulin beings
and
to
of
the
plutonium of
such several
as
transf
the
would
be
of
5•~10-14
of of
was
and
ion
all 150
that
it
its
concentra-
were
is attributed
and
the
followed on
also
in
pH
body,
in the liver the
polymer
system
the
found
that
human
blood10),
hydroxide,
Spleen
step In
M.
of
the
system16).
4, to
between
the
deposition
formation
(OH)
second
Pu(IV)
239Pu
ml
hydrolysis
Pu
Provided in
5200
Plutonium
thelial
of
calculated
irreversible13).
that
were
in
hydroproceed
as •gpseudocolloid•h
pCi),
position
mostly
was
be
present
(4
ions
6.8•~10-8M14).
plutonium
to the
to
at
Therefore,
addition,
described
at
dissolved
the
de-
reticuloendothelial
contains
its
polymer
by
reticuloendo-
tissuel7),
relatively
high
plutonium concentration in spleen might to the deposition of plutonium polymer
be due on this
cell system. As
for
form
uranium,
stable
it
14.6
-15.6
at
acids, ions.
is
bound
U(VI)
60%
of
with
bicarbonate
the
20%
errin,
and
with
bound
tein
cytic
lipoprotein.
and the tendency towards hydrolysis decreases in the order of Pu(IV)>Pu(VI)>Pu(III)> Pu(V)13>,14). The equilibrium constant for the
plex
ions
of
were
physiological body.
are
the
most
the
review,
number for and
of U(VI)
lipopro-
n=1.7
for
bi-
n=0.6 n=0.46
behaviors
of the
protein
given
albumin
albumin; ƒÀ=8.90, Thus,
47%
with
the
uranyl important, of
uranium
is
blood
with
In and
it
that
32%
plasma
around
the
associated
also
high,
R3
in
complex; ƒÀ=10.48,
plasma
(7)
(VI)
erythrocyte; ƒÀ=18.04,
carbonate
man
for
and is
(ƒÀ)
bicarbonate,
On the other hand, hydrolysis is closely related to the complex formation of an ion. It is said that the Pu(IV) ion undergoes the most extensive hydrolysis of all the plutonium ions,
U
of
are
Gindlerl8),
erythrocytes.
(n)
with
constants
by
plasma,
constants
ligand
mammals.
blood of
ions
ions
literature
18.3-23
that
part
stability
and
review
in
and
with
the
the
inorganic
review
N2 In
uranyl
[UO2(CO3)2]2-or
stability
in
for
25•Ž14).
described
(III)
as
The
carbonate
that
complex
such
[UO2(CO3)3]4-.
as
seems
soluble ions,
uranyl
exists
Pu(IV)
is
-1.06
hydrolysis,
which
said
present
mBq
plutonium
(IV)>Pu
be
of
body
metal
it
carbonate
such
In is
reported
and
polymers
of
10-5013).
2.8-7.5
does In
matters
According a
proteins, ƒÀ1 in
and
formation the
fluid.
7 x
(IV)
insoluble
hydrolysis
to
Pu
product
was
25•Ž
successive
proton
nomenclature
temperature14).
pH,
highly
review,
plutonium radius
body
organic
complex
in
the
smaller
human
many
as
that
and
form
the
Martell15), at
body
through
solubility
tion
is
and
to
radius and electric charge (the so-called charge density of the ion). The different trend of distribution of the two elements in human body can be interpreted by the difference of stable species present in body fluid. Both plutonium and uranium similarly have four oxidation states from III to VI and they take normally either IV or VI (Pu4+, U4+ or PuO22+, UO22+)13). It seems, however, that plutonium is most stable in the tetravalent state in body fluid, while uranium is most stable in the hexavalent state.
and
to
with
to
-1.26
physiological
lyse,
of
of
Sillen
close
437
hydrolysis
according
-1.94-
34•Ž,
tissues
Pu(IV) *K1,
by
be
human
of
defined
therefore, provides preliminary estimates of skeletal burdens of both plutonium and uranium. Behaviors of these elements in human body should be associated with hydrolysis and the complex formation of the ions in body fluid. Generally speaking, the activity of an ion species in a solution is affected by its ionic
It
step
eliminaiton,
nium calculated from small number of different bone samples are shown. The present work,
ion
in Japanese
for
for erythro-
carbonate
com-
considering in
the
hu-
438
RADIOISOTOPES
On
the
hydrolysis
of
uranium
ions,
the
Vol.36,
No.9
same
References observation
can
ions.
The
the
order
in
-4-
of
the
U(IV)
mers
in
of
curring
to
in
ions
In
plexes
in
a
state
insoluble
is polymers
liver,
while
with
deposited
in
un
sible
to
of
conclude
extremely
low
naturally
occurring
level
the
at
the
results
plutonium
10)
poseven
the
and
Dentistry, discussion. This
Kazunari
Nihon
work
was
Inter-University of
the
Japan part
Atomic of
from Culture are
the
the
supported
Program
Reactors
at
expenses
of Japan,
the
by
Maruzen,
Tokyo
International
part
by
by
authors'
of
Man•h,
ICRP
Press,
Ed.)•h,
Chemical.
(1975)
Commission
Oxford
Society,
(in
Japanese)
on
Radiological
the
Task
Group
on
Publication
23,
(1974)
(in Japanese) Commission
on
Protection, •gThe
Metabolism
nium
Elements•h,
and
Related
licaiton
the
48,
Pergamon
Radiological of
Pluto-
ICRP Press,
PubOxford
(1986) 13)
at
Katz,
J.J.
istry
A
by
a grant
Science
Japan
in
(3rd
International
Use
and
Elements
Nutrition
12)
kind
Institute.
covered
translated
(1984)
of
the Common
Education,
to which
their
University
Research was
of
in
for
Rikkyo
Energy
Ministry
for
School
Animal
Okabayashi, H.: Project Report for a Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture of Japan, (A) 57380017, 15-19
to Professor
Moriwaki,
University
E.J.: •gTrace and
11)
Tokuzo Kojima, School of Medicine, Nihon University, Professors Tadashi Kitagawa, Eiko Sairenji
Underwood,
Pergamon
uranium.
greatly appreciate
(1980) Popplewell, D.S., Ham, G.J., Johnson, T.E. and Barry, S.F.: Health Phys., 49, 304-309 (1985) Takizawa, Y., Hisamatsu, S. and Abe, T.: Radiat. Res., 109, 245-255 (1987)
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Acknowledgement
The authors
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Protection, •gReport
at
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Hardy, E.P., Krey, P.W. and Volchok, H.L.: Nature, 241, 444-445 (1973) Igarashi, Y., Seki, R. and Ikeda, N.: Radioisotopes, 33, 55-59 (1984) (in Japanese) Igarashi, Y., Yamakawa, A., Seki, R. and Ikeda, N.: Health Phys., 49, 707-712
Human
The
seems
holds
9)
and
body.
it
8)
the
reasonable
fact
of
in in soluble
From
of level
tetra-
stable
human
this
7)
distributed
work,
that
com-
resulting
is
present
6)
taken as
deposits
levels.
the
tissues
expected.
respectively.
is
part
concentration
obtained
the
in
finally
discussion
5)
If
uranium
forming
every
not18).
tetravalent
be
hydrolysed,
carbonate,
above-mentioned higher
U(VI), plutonium
4)
citrate
oc-
mainly
of
uranium,
complexes
in
and
that
that
hydrolysis.
fluid
readily
as
among
and part
3)
addition
is
would
body
Pu(IV)
Consequently, valent
the were
plutonium
exist of
in
plutonium
conclusion, man
said
phenomenon
pattern
of
is the
hydroxide
man
distribution
and
poly-
such
similar
into
that
It by
U (IV) a
2)
al-
25•Ž15),18).
hydroxide
agents
Pu(IV)
to
into
form
be
U(IV)
at
process.
be
taken a
1)
in
to
for
dissolved
while
uranium
similar
-2
complexing
seems
decreases
around
is
bicarbonate,
state,
-1-
hydrolysis
strongly
plutonium
reported
U(VI)
hydroxide
There
was
U(VI) and
the
U(VI)
for
hydrolysis
*K1
for
Both
as
U(IV)>U(VI)>U(III)13),18).
range
-6
or
of
constant
most
made
tendency
Stability
of
be
of
thanks
(1962)
due.
14)
Taylor, Properties
(8)
Seaborg,
Actinide
Miyake,
mura,
and
and the
Y.,
Y.
et
(in
G.T.: •gThe Elements•h,
Tominaga, al.,
Chemtranslated
H,
and
Asakurashoten,
SugiTokyo
Japanese)
D.M.: •gChemical of
Plutonium•h
and
Physical
in •gUranium,
Y.Igarashi et al.: Plutonium and uranium in Japanese human tissues
Sep. 1987
Plutonium, (Ed.
Transplutonium
by
Hodge,
Hursh,
J.B.),
lag, 15)
and
Constants
Suzuki,
of
and
XVII-2,
要
and
17)
Ver-
Complexes•h,
by
The
Yamada, F.
T.,
et
18)
Precautionary
T.,
(1967)
Gindler,
(Ed.
Saito,
(in
Uranium•h
and
J.B.
Berlin
(1973)
),
To-
H.C., pp.69-164,
Chemical
in •gUranium,
Transplutonium Hodge,
Elements•h Stannard, Springer
J.N.
旨 日本 人 臓 器 中 の プ ル トニ ウ ム と ウ ラ ン 五 十 嵐 康 人,山 川 敦 志,池
田長 生
城県 新 治郡 桜村 天 王 台1-1-1
東 京 近 郊 居 住 者 の 臓 器 中 の プ ル トニ ウ ム と ウ ラ ン を 定 量 し,そ ウ ム は α 線 ス ペ ク ト ロ メ ト リで,ウ
れ ら の 分 布 を 比 較 し た 。 プ ル トニ ラ ン は フ ィ ッ シ ョ ン トラ ッ ク 法 で 定 量 し た 。 プ ル トニ ウ ム と ウ
ラ ン の 体 内 分 布 の パ タ ー ン を 平 均 濃 度 値 を も と に 見 積 っ た 。 プ ル トニ ウ ム は 特 定 の 臓 器 に 集 積 す る の に 対 し,ウ
ラ ン は 比 較 的 体 全 体 に 分 布 す る 傾 向 が 認 め られ る 。 両 元 素 の 分 布 の 違 い は,体 液 中 で ル トニ ウ ムPu4+,ウ ラ ンUO22+)や 化学的性質の差 による
安 定 に 存 在 す る 両 元 素 の 化 学 状 態(プ と こ ろ が 大 き い と考 え られ る 。
(9)
and
Verlag,
Japa-
筑 波 大 学 化 学 系,305茨
and
Biology
Iwanamishoten,
of
Hursh,
F. in
Japanese)
J.E.: •gPhysical
by
Maekawa,
al.: •gDictionary
(in
Plutonium, in
Mukikagaku-zensho
Tokyo
(1983)
Properties
yoboutaisaku)•h Nakai,
T.),
kyo
(1964) and
to
(Ed.
Maruzen,
by
Egami,
A.E.: •gStability
London
(Shougai
Ishimori,
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(Seibutsugaku-jiten)•h, Martell,
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Plutonium•h N.
Springer
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Measures •g
J.N.
(1973)
L.G.
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