i lnmen
Low-le el adioac i i y s udies in he ma ine en
o he Sou h o Spain *
G. Manjón, A. Ma ínez-Agui e and M. Ga cía-León
Facul ad de Física, UniL·e sidad de Sel'illa, 41080 Sel'illa, Spain
In his pape p elimina y le els o na u al and man-made adionuclides in he Sou h Spanish ma ine en i onmen a e
p esen ed. Local man-made sou ces a e ound o be he main con ibu o s o he na u al en i onmen al adioac i i y in such a eas
while allou is mainly esponsible o he occu ence o a i icial adioac i i y in ou zone.
. In oduc ion
So a , he p esence o en i onmen al adioac i i y
in Andalucía (Sou h o Spah) had no been s udied.
Thus, since 1988 a la gc p ojec o hc de e mina ion
o na u al and man-made adionuclidcs in his egion
was s a ed.
*Wo k pa ially suppo ed by he con ac PB89-0621 o he
Spanish CICYT and he AMA o he Jun a de Andalucía.
Andalucía (sec ig. 1) occupies he whole Sou h o
Spain and he majo i y o he Sou h o he lbe ian
peninsula. The esea ch p og amme consis s o he
measu emcn o 9<JTc, 137Cs. U-. Ra- and Th-iso opes
and 210Po in a la ge g oup o samples, such as seaweed,
i e wa e s, ainwa e s, sedimen s, e c. (see ig. 1 ).
Wc p esen he c so ne esul s ob ained o he
ma ine sidc o hc en i onmen s udied. We will de
sc ibe in he nex sec ions, le els o 99Tc and 137Cs in
scawecd samples. U-iso opes and 2Hl Po in i c wa e
and sedimen samples will also be gi cn.
MEOITERRANEAN SEA
Q k: '.'Ei' -,.ATI.R SAMPLES
D S�.A�"El:.'.J SAMPLES
& üNDERGROUND WATERS
• RAINWATER SAMPLES
• MAIS TCXJNS
Fig. l. Map o Andalucía (Sou h o Spain) showing he ype o samples and s:::11p!ing s a ions included in he esea ch p ojec .
Thc mc hods o dc c mina ion o hc abo c-mcn
ioncd iso opcs and hc esul s ob aincd a e ou lincd in
hc ollowing scc ions.
2. Expe imen al
Low-backg ound GM gas- low �-coun ing. -y- and
a-spcc ome y ha e been used o ('9Tc, 137 Cs and
a-emi e measu cmen s, espec i ely. A b ie accoun
o he indi idual me hods is gi en in hc ollowing
pa ag aphs.
2.1. 99Tc
A sol en ex ac ion cchniquc is uscd o 99Tc
de e mina ion. Fi s , so ne 15-30 g o d ied and pow
de cd seaweed a e spiked wi h a known 99mTc ac i i y.
The sample is hen calcina ed a 600 º C. The ashes a e
dissol ed wi h 2% HCI, and echnc ium is ex ac cd
wi h ibu ylphospha e (TBP). Subsequen ly, Te is
back-ex ac ed om he o ganic phase wi h 2M NaOH.
This solu ion is elec opla ed a 0.35 A o 2 h and
echne ium is deposi ed on o a s ainless s eel planche
(1,2]. Due o he ela i ely so 99Tc �-spec um (Emax
= 292.3 ke V) an elec odeposi ion echnique o hc
p epa a ion o he inal sou ce is mo e adequa e han a
simple e apo a ion o he 2M NaOH solu ion, since in
his way sel -abso p ion e ec s a e minimized.
The adiochemical yicld Y o hc p ocess is calcu
la ed by measu ing he 99mTc ac i i y cco c ed. This is
accomplished wi h a 76 mm X 76 mm Nal(TI) -y-spec
omc c , aking ad an age o he 140-kcV pho on
emi ed by his adionuclidc.
A e i e o six days, when ali he 99mTc (T112 = 6.02
h) has dccayed, he 99Tc (3-ac i i y om h · samplc is
measu ed. Due o he e y Iow 99Tc concen a ion in
na u e, a low-le el coun ing echnique has o be ap-
Table 1
plicd. Thus, a low-backg ound (0.2 cpm) gas- low GM
coun c is uscd o (J9Tc mcasu cmcn s. The c iciency
o he de ec o cachcs a aluc o 37%. I was calcu
la cd wi h 99Tc s anda d samplcs o wcll-known ac i i
ics.
2.2. 137Cs
mes is di cc ly de c mined by HPGc -y-spec omc
y. Fo ha , a gi cn mass o d icd and powdc ed
scaweed is placed in a s anda d geomc y and coun ed
wi h he spec omc c [3]. The de ec o backg ound is
educed by using a passi e lead shielding 1 O cm hick,
in c nally co e ed wi h a ew mm o coppe .
The coun ing e iciency was ob ained by coun ing
algae ma e ial, in hc s anda d geomc y. homoge
ncously spiked wi h known mes and 152 Eu ac i i ies.
2.3. U-iso opes and 210
Po
Thc a-ac i i y om 238 U. 234U, 235 U and 210Po was
measu ed by Si su acc ba ic o ion implan ed a
spec ome y [4,5]. Fo ha , so ne ew g ams o d ied
and powde ed sedimen a e spikcd wi h known 232 U
and 208Po ac i i ies. Then he sample is diges ed wi h
HN03 and aqua egia. The esiduc is dissol ed in 8M
HN03 and he solu ion il e ed in o a decan a ion
unnel which con ains TBP. A e shaking, U and Th
pass o he o ganic phasc while Po and Ra emain in
he aqueous phasc. Bo h phases a e scpa a ed.
The aqueous phasc is e apo a ed o nea d yness
and he csidue dissol ed wi h concen a ed HCI. A e
ha , Po is sel -deposi ed on o Ni planche s a 60 º C.
acco ding o he me hod o Flynn e al. [6]. l is
impo an o no e ha so ne mg o asco bic acid a e
added o he elec oly e o a oid he deposi ion o Fe.
The o ganic phasc is dissol ed wi h xylenc and Th is
back-ex ac cd om i wi h 1.5M HCI. Thc cmaining
o ganic phase is mixed wi h dis illed H :!O o back-cx-
137Cs le els in seaweed samples collec ed along he coas s o Andalucía egion (Sou h o Spain) du ing 1988 and 1989
Type o Species Numbe o Ac i i y (d y weigh ) [mBq/g]
alga da a mínimum maximum a e age
B own halop e is scopa ia 10 0.7±0.2 2.9±0.3 l.4±0.7
G een ul a ígida 7 0.6±0.5 2.3 ± 0.3 l.4±0.6
G een codium 7 0.7 ±0.3 3.8± 1.7 2.2± 1.1
B own ucus ó 0.6±0.2 1.5 ±0.3 1.2±0.3
G een sa gassum ulga e 6 0.7 ±0.4 2.8±0.6 l.3±0.8
B own dyc io a dicho oma 2 0.6±0.4 1.4±0.6 l.0±0.6
B own cys osei a e icoides 2 0.3±0.7 0.8±0.3 0.6±0.3
B own co allina medi e anea l.6±0.6
B own cimodocea modosa l.2±0.4
Red holopi is incunous 0.8±0.3
ac U. Thc inal solu ion is d icd and U is clcc o
pla cd on o s ainless s eel planche s by he ne hod o
eís. [7] and [8]. As o wa e sa nples, so ne 1 o 5 1 a e
spiked wi h a known m U ac i i y and c apo a cd. Thc
csiduc is ca ed as a scdimcn samplc o U cx ac
ion.
3. Resul s
3.1. Le els in seaweed
mes and 99 Tc ac i i ies ha c becn s udicd in a widc
nu nbe o scawccd specics. In able 1 hc mes nini
mu n, naxi num and a e age ac i i y alues o so ne o
such species a e p escn ed. Ve y simila , and low, B7Cs
spcci ic ac i i ies, oughly 1.3 nBq/ g d y weigh , a e
ob ained ei hc o he ed, b own o g een alga species.
Such low alues do no allow o de e mine hc bes
bioindica o o ou zonc. On he o he hand, sincc
he e is no local sou ce o adioac i i y o ou egion,
he le els ob ained seem o be cp escn a i e o hc
wo ldwide allou backg ound in he Sou h o Spain.
This idea can be con i med when ou esul s and he
e y sca ce p e ious da a exis ing in hc cu en li e a
u e a e compa ed.
Table 2
n7Cs and ""'Te lc cls ound in ucu!ii spi alis and VC!iiiculo!iius
samples collcc c,• along hc Sou h Spanish coa!-ih du ing 19kK
and 19H9. Thc silc numhc co csponds o hc !-iampling si c
shown in hc map o ig. 1. Mean alucs o hc Mcdi c 
ancan and A lan ic coas s a e also gi cn.
Sampling Ac i i y (d y wcigh ) (mBq/g}
si e (da e) 1'7Cs l,l lTc
ac i i y ac i i y
Paloma es (1988)
[1] 0,6±0.2 0.25±0.04
Paloma es (1989)
(1) 1.3±0.5 0.31 ±0.03
Cabo de Ga a (1988) [2] 1.6±0.3 O.IS ±0.04
Pun a Palomas (1988)(3) 1.1 ±0.4 0.43±0.06
Ro a ( 1989) (4) n.m.ª 0.1 ±0.2
Isla C is ina (1989) [5] 1.2±0.5 0.30 ± (l.03
Ayamon e (1988) (6) 1.5 ±0.4 0.14±0.oJ
Medi e anean coas s 1.1 ±0.4 0.25±0.13
A lan ic coas s 1.3 ±0.2 0.22+0.11
ª n.m. = no measu ed
Thus, le e Is o 0.8 nBq/ g wc c ound in Galicia,
No h-Wes o Spain, du ing 1984 [9] and o abou 0.9
nBq/g in he coas s o Po ugal du ing 1985 [10], bo h
o Fucus spccics. They wc c a ibu cd essen ially o
allou , which suppo s ou p e ious commen .
O Wa e Samples
6 Sedimen 5a lPleS
Fig. 2. Map co esponding o he sampling s a ions o Tin o and Odiel i e s a ound he own o Huel a (see also ig. 1 ).
Table 3
U-iso opes ac i i y concen a ion. oge he wi h he
234U ¡ 2Jsu ac i i y a io o i e wa e samples aken a he
Odiel (O) and Tin o (T) i e s. Samples OT we e aken a he
con luence o bo h i e s. The pH o he wa e s a e also gi cn.
See ig. 2. o an easie comp ehension o he able.
Sample pH Ac i i y
concen a ion [mBq/1)
T1
T2
T3
T4
OTl
OT2
07
06
05
04
03
02
01
2.0
5.0
5.0
5.5
5.5
6.0
5.5
4.5
4.5
4.5
5.5
5.5
3.0
23NU
170.0± 11.0
37.0± 3.8
24.8± 3.0
26.0± 2.0
31.0± 5.1
31.1± 1.7
30.0± 4.0
'60.0± 8.1
778.0±50.0
206.5± 18.8
13.9± 2.6
20.0± 2.7
66.0± 8.0
350.0±20.2
41.0± 4.1
30.3± 3.4
23.0± 2.0
46.0± 6.4
38.0± 2.0
36.0± 4.6
SO.O± 7.0
777.0±50.0
206.5± 18.9
20.3± 3.11
22.0± 2.8
121.0± 13.0
Ac i i y
a io
2.02±0.06
1.09±0.11
1.22±0.20
0.88±0.10
1.40±0.09
l.22±0.08
1.20±0.18
0.83±0.12
l.00±0.02
1.00±0.07
1.47±0.35
1.10±0.17
1.83±0.30
In able 2, wc p esen so ne ew addi ional 137es
esul s oge he wi h he q9Tc ac i i ies in Fucus sam
ples. The c is no di e encc, bo h o mes and 99Tc,
be wecn hc ac i i ics ob aincd in hc mcdi c anean
and hc a lan ic sidcs o he Andalusian coas . eon
cc ning hc 99Tc csul s, c y simila commen s o
hose gi en in able 1 o 137es can be made. Thus, an
a e age aluc o 0.2 mBq/g d y weigh can be ob
sc cd. which is in modc a c ag ccmen wi h alucs
ound in Galicia [21 and Po ugal [10) coas s, o abou
0.4 and 0.6 mBq/g d y weigh , cspcc i cly, bo h du 
ing 1985.
Table 4
3.2. Lel'el.,· in sedimcn and il'en a e
U-iso opes and 2111Po ha e been dc c mina ed in
scdimen and i c wa e samplcs collec cd a he Odiel
and Tin o i c s (Sou h-Wes o Spain).
Such i c s (scc ig. l and 2) su ound a la gc indus
ial complcx, which includes se e al phospha e e iliz
e s ac o ies nea hei mou hs a he A lan ic Ocean.
I is well known ha such acili ies p oduce a clca
adiological impac in hei immcdia c en i onmen
[11]. Ou csul s, using U and 210Po as indica o s,
con i m such obsc a ions.
In able 3 he U-iso opc ac i i ics ound in wa c s o
hc Odicl and Tin o i e s a e p esen cd (sec ig. 2 o
an casie comp ehension o able 3). In gene al, hc
ac i i ies in hc Odicl i e a e highc han in he Tin o
i c . Thus, in hc Odiel wa e s, a clca peak o ac i i y
can be seen. This co esponds o samples aken nca
he place whc e he phospha c e ilize complex is
loca ed.
I seems, he e o c, ha such indus ies a e di ec ly
elcasing hci was es o hc Odiel i c . I does no
occu so, o hc case o hc Tin o i c . In ac , hc U
le els ound in i s wa e s a e o ally compa ible wi h
ac i i ics ob ained in he Guadalqui i i e [12], which
c osses ou cgion om Eas o Wes , and ha ha c
bcen akcn as a backg ound le el o ou s udy. Thc
esul s o samplcs Tl and O 1 a e specially in c cs ing.
Such wa e s wc c akcn nea hc sou ces o he Tin o
and Odiel i e s, cspcc i cly. Thc na u al Iow pH o
such wa c s a ou s hc cdissolu ion o U om hc
bcd o he i c s o hc aqucous phasc, which would
cxplain hc cla i ely high lc cls o ac i i ics ound.
Fu hc mo c. his would accoun o hc high 234U
cn ichmen obsc ed in hcse samplcs.
I would be in c cs ing o s udy he o m in which
hc was cs om he e ilize ac o ics a e cleased
U-iso opes and zwpo ac i i y concen a ions (in mBq/g) o sedimen samples aken ,: he Odiel (SO) and Tin o (ST) i e s.
Sample SOT was aken a he con luence o bo h i e s. Sec ig. 2 o and easie comp ehension o he able.
Sample Ac i i y concen a ion [mBq/1]
:!JNU z35u z3..iu :iwpo
ST2 100.0± 7.8 3.60± 0.72 110.0± 8.1 n.m:1
ST3 250.0
± 1.7 11.0 ± 1.2 260.0 ± 1.7 252.0± 10.0
ST4 277.0± 13.0 l().3 ± 0.8 290.0± 14.0 341 ± 12.0
SOT 264.1 ± 29.6 n.d.h 275.7± 30.8
339.4 ±
13.3
S07 1060.0± 75.0 48.0 ±
4.9
1060.0± 75.0 1194.8 ±
112.2
SOó 42.0± 3.9 2.80± 0.66 45.0±
4.2
41.6± 2.7
sos 1100.0 ± 130.0 55.0 ± 1
o.o 1200.0 ± 130.0 820.9± 50.2
S04 160.0± 11.0 7.7 ± 1.0 170.0 � 12.0 615.2 ± 28.0
ª n.m. = no measu ed.
h n.d. = no de cc cd.
in o hci immcdia c cn i onmcn . This wo k is cu 
cn ly bcing ca :-icd ou in ou g oup.
Howc c , om hc da a wc p cscn in able 4. i
seems ha bo h i e beds, hose o Odiel and Tin o
i c s, a e accumula ing U and 2111Po adi i ics. lndccd,
hc lc els obsc cd in scdimcn s a e clea ly highc ,
bo h o U-iso opcs and o 2H>Po, han o hc le cls
ound in di c cn i c s, including Spanish sys ems
[13,14]. Thc case o samplc S06 is no su p ising, sincc
so ne o hc chemical ma c ials, wi hou adioac i i y,
a e bcing clcascd in such sampling poin ogc hc wi h
hc was cs om hc c ilizc indus ies. This would
con ibu c o Iowc ing he spcci ic ac i i y.
Re e ences
[1] E. Holm, J. Rioseco and M. Ga cía-León, Nucl. lns .
and Me h. 223 (1984) 204.
[2] G. Manjón and M. Ga cía-León, An. Fís. 886 (1990) (in
Spanish) 63.
(3) C.I. Sánchez-Angulo and M. Ga cía-León, Nucl. Geo
phys. 2 (1988) 69.
(4) A. Ma íncz-Agui c. M.C. Monín and M. Ga da-Lcún.
o he puhlishcd in J. Radionanal. Nucl. n.�m.
(5) A. Ma íncz-Agui c and M. Ga cía-Lc<,n. o he puh-
lishcd in J. Radioanal. Nucl. Chcm. Lc .
(6) W.W. Flynn, Anal. Chcm. Ac a 43 (1968) 221.
(7) L. Halls adim,. Nucl. lns . and Mc h. 22J ( 1984) 266.
lXJ R. Ga cía-Teno io, M. Ga cía-León, G. Madu ga and C.
Piazza, An. Fís. 882 (1986) 238 (in Spanish).
(9) P.I. Mi chell. A. Vidal-Quad as. J.L. Fon and M. Oli a.
J. En i on. Rad. 6 ( 1988) 77.
[ 10) A. Aa k og, S. Boelski e, E. Buch. G.C. Ch is cnsen. H.
Dahlgaa d, L. Halls adius. H. Hansen. E. Holm and J.
Rioseco, Ris0 Na ional Labo a o y Repo -R-510 (1987)
74.
(11] R.J. Guimond and J.M. Ha din, Radia . Phys. Chem. 2
(1989) 309.
(12] A. Ma ínez-Agui c and M. Ga cía-León. in p cpa a
ion.
(13) F. Ve a-Tomé and A. Ma ín-Sánchez, J. Radioanal.
Nucl. Chem. 1 ( 1989) 73.
(14) M.C. Mo ón, A. Ma ínez-Agui e and M. Ga cía-León.
P oc. ln . Con . on En i onmen al Radioac i i y in he
Medi e anean A ca. Ba celona. 1988 (SNE-ENS. 1988)
p. 111.