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Author's personal copy
SC IE N CE OF T H E TOT AL E N V I RO N ME N T 3 9 3 ( 2 00 8 ) 2 1 4–2 18
a v a i l a b l e a t w w w. s c i e n c e d i r e c t . c o m
w w w. e l s e v i e r. c o m / l o c a t e / s c i t o t e n v
Assessment of Committed Effective Dose due to consumption
of Red Sea coral reef fishes collected from the
local market (Sudan)
Rifaat K. Hassonaa,⁎, A.K. Sama , O.I. Osmanb , D.A. Sirelkhatima , J. LaRosac
a
Sudan Atomic Energy Commission, Khartoum, P.O. Box 3001, Sudan
Chemistry Department, Faculty of Science, University of Khartoum, Sudan
c
Formerly at IAEA Marine Environment Laboratory, 4 Quai Antoine 1er, MC 98000, Monaco
b
AR TIC LE I N FO
ABS TR ACT
Article history:
An assessment of Committed Effective Dose (CED) due to consumption of Red Sea fish
Received 3 September 2007
containing
Received in revised form
from the local market at Port Sudan. The fish were classified according to their feeding
30 November 2007
habits into three categories: carnivores, herbivores, and omnivores. Measured activity
Accepted 4 December 2007
concentrations of
Available online 19 February 2008
and 1.5–3.8 (herbivores) Bq/kg fresh weight. In the same study, activity concentrations of Cs-
210
Po and
137
Cs was performed for 23 different marine fish samples collected
210
Po were found in the ranges 0.25–6.42 (carnivores), 0.7–5 (omnivores)
137 were determined to be in the ranges 0.1–0.46 (carnivores), 0.09–0.35 (omnivores) and
Keywords:
0.09–0.32 (herbivores) Bq/kg fresh weight, which were several times lower than those of
Fish
210
Committed Effective Dose
0.012, 0.01 and 0.01 (µSv/yr) in carnivores, omnivores and herbivores, respectively, for 137Cs.
Red Sea
This contributes about 0.4% of the total dose exclusively by ingestion of fish. For 210Po, it was
Po. Appropriate conversion factors were used to derive the CED, which was found to be
found to be 3.47, 4.81 and 4.14 (µSv/yr) in carnivores, omnivores and herbivores, respectively,
which represents 99.6% of the total dose (exclusively by ingestion of fish). The results of CED
calculations suggest that the dose received by the Sudanese population from the
consumption of marine fish is rather small and that the contribution of
compared to
137
Cs is negligible
210
Po.
© 2007 Elsevier B.V. All rights reserved.
1.
Introduction
The consumption of marine foodstuffs containing radioactivity, including fish, seaweeds and manufactured products, is
ordinarily the exposure pathway of greatest importance. The
levels of radionuclides in the edible portions of marine plants
and animals may be many times higher than that in the
seawater because of biological re-concentration processes.
Among the natural radionuclides occurring in the oceans,
alpha emitters are considered the most important with respect
to potential internal radiation exposure of living tissues. A
large contribution to the radiation dose received by marine
fauna comes from members of the naturally occurring
uranium series accumulated in the body, especially polonium
as 210Po (Cherry et al., 1994). 210Po is found to be the major
contributor (90%) to the natural radiation dose coming from
alpha-emitting radionuclides received by most marine organisms (McDonald et al., 1991). Among the anthropogenic radionuclides, 137Cs is one of the most abundant and widely
distributed isotopes present in the environment. In contrast
to the almost constant supply of 210Po to the marine environment, 137Cs was released mainly during atmospheric nuclear
⁎ Corresponding author. Tel.: +249912869321.
E-mail address: rifaatk@yahoo.com (R.K. Hassona).
0048-9697/$ – see front matter © 2007 Elsevier B.V. All rights reserved.
doi:10.1016/j.scitotenv.2007.12.014
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S CIE N CE OF T H E TOT AL E N V I RO N ME N T 3 9 3 ( 2 00 8 ) 2 1 4–2 18
weapon testing in the late 1950s and early 1960s, from nuclear
fuel reprocessing plants and from the Chernobyl accident in
1986.
2.
Materials and methods
2.1.
Sample collection
Fish samples were collected in two different seasons, in
October 2002 and in April 2003. Twenty-three (23) different fish
species were obtained from the local market taking into
consideration the most popular as well as the available
species at time of collection. Fish samples were de-boned
using a stainless steel knife and weighed for the fresh (wet)
weight, then oven dried at 60 ° C for 2–3 days and ground in
stainless mill into powder for subsequent gamma measurements for Cs-137 and for radiochemical analyses for Po-210.
2.2.
Measurements of Cs-137 by gamma spectrometry
was filtered off before proceeding to the polonium separation
step.
Polonium was radiochemically separated from the digested,
dissolved fish samples using a supported liquid phase extraction
chromatography method (Vajda et al., 1997). Chromatography
columns were prepared from commercially available crown
ether extraction chromatography Sr-resin (100–150 μm particle
size) (Eichrom, Inc.) with initial bed dimensions of 1 cm inside
diameter and 11 cm height in glass columns (Bio-Rad). The resin
was soaked in de-ionized water for several hours before using.
Each column was successively rinsed with 100 ml of de-ionized
water and 100 ml of 1 M HNO3 and then conditioned with 100 ml
of 2 M HCl. The 2 M HCl sample load solutions (typical volume = 50 ml) were passed through the column followed by
beaker rinses of 2 × 5 ml 2 M HCl. Polonium(IV) and lead(II) are
selectively retained by the Sr-resin. Then 90 ml of 2 M HCl were
added to remove the non-retained ions from the columns.
Polonium was stripped with 100 ml of 6 M HNO3 (while any Pb(II)
Table 1 – Activity concentrations (Bq/kg w.w.) of 137Cs and
Po measured in the flesh part of Red Sea coral carnivore
fishes and their corresponding Committed Effective Dose
(CED) (µSv/yr)
210
The activity concentrations of Cs-137 in samples were measured directly using gamma spectrometry systems equipped
with coaxial N-type high-purity germanium (HPGe) detectors
connected through spectroscopy amplifiers to multi-channel
analyzers driven by a computer-based operating system using
the EG&G Ortec Gamma Vision software system for acquisition, analysis and storage of gamma spectra. The detectors
were calibrated for different geometries using mixed radionuclide standard gamma sources prepared by spiking nonactive fish powder. Samples were hermetically sealed in
70 mm diameter metal cans (120–135 g and 2.9–3.5 cm height)
for gamma spectrometry measurement. Samples were
counted for 2–5 days so as to obtain measurements within 5–
10% relative uncertainty (from counting statistics) at the 95%
confidence interval level.
2.3.
Chromatographic separation of polonium and alpha
source preparation
Fish powder (typically 10 g was weighed into a borosilicate
glass beaker and slurried with 1–2 M HNO3. A known amount
(0.94 dpm) of Po-208 tracer was added at this point followed by
a cautious addition of concentrated (65%) HNO3 and careful
heating to initiate the decomposition of organic matter. (Dryashing was not done due to expected serious losses of volatile
reduced polonium. Wet-ashing with strong oxidizing agents
was chosen to minimize polonium losses by keeping it
oxidized as much as possible during organic destruction, but
this meant that prolonged and tedious digestions had to be
carried out.) Many successive portions of boiling, concentrated
HNO3 were used to decompose organic matter. When redbrown fumes (nitrogen oxides) were no longer evolved upon
boiling a fresh addition of concentrated nitric acid, small
portions of 60% perchloric acid were cautiously added and
heated to extend the degradation beyond that achieved by the
nitric acid. After evaporation of the perchloric acid-digested
residue to a small volume (never to dryness) and cooling, it
was dissolved in 50 ml of 2 M HCl and any insoluble matter
Species name
Epinephelus
microdon
Lutjanus gibbus
Lethrinus mahsena
Epinephelus
chlorostigma
Carangoides bajad
Lutjanus bohar
Aethaloperca rogaa
Carnax mate
Macolor niger
Caranx emburi
Plectropomus
truncatus
Cephalopholis
argus
Vermilion grouper
Scarus sordidus
Scomberomorus
commersoni
Triaenodon obesus
Pomadasys
opercularis
Monotaxis
grandoculis
Caranx
sexfasclatus
Gymnosarda
unicolor
Plectropomus
maculates
Trachinotus blochii
Pristipomoides
filamentosus
Average
Standard
deviation
Max
Min
137
Cs
210
Po Cs-CED Po-CED Total CED
0.12
1.3
0.01
2.49
2.49
0.11
0.15
0.27
0.98
0.71
0.94
0.01
0.01
0.01
1.88
1.36
1.80
1.88
1.37
1.81
0.28
0.17
0.15
0.11
0.15
0.22
0.30
2.3
1.65
0.91
2.44
0.89
3.1
2.8
0.02
0.01
0.01
0.01
0.01
0.01
0.02
4.40
3.16
1.74
4.67
1.70
5.93
5.36
4.42
3.17
1.75
4.68
1.71
5.94
5.37
0.20
1.5
0.01
2.87
2.88
0.15
0.21
0.36
1.1
0.63
6.42
0.01
0.01
0.02
2.10
1.21
12.28
2.11
1.22
12.30
0.46
0.11
2.1
0.8
0.03
0.01
4.02
1.53
4.04
1.54
0.10
0.6
0.01
1.15
1.16
0.34
2.6
0.02
4.98
4.99
0.33
4.65
0.02
8.90
8.92
0.36
0.25
0.02
0.48
0.50
0.25
0.36
2.2
0.85
0.01
0.02
4.21
1.63
4.22
1.65
0.23
0.10
1.814
1.44
0.01
0.01
3.471
2.76
3.48
2.77
0.46
0.10
6.42
0.25
0.02
0.01
12.28
0.48
12.30
0.50
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SC IE N CE OF T H E TOT AL E N V I RO N ME N T 3 9 3 ( 2 00 8 ) 2 1 4–2 18
Table 2 – Activity concentrations (Bq/kg w.w.) of 137Cs and
Po measured in the flesh part of Red Sea coral herbivore
fishes and their corresponding Committed Effective Dose
(CED) (µSv/yr)
210
Species name
Acanthrus gahm
Acanthrus shoal
Siganus argenteus
Acanthulus gahm
Average
Standard deviation
Max
Min
137
Cs
0.09
0.32
0.28
0.12
0.20
0.11
0.32
0.09
210
Po
CsCED
PoCED
Total CED
1.52
1.7
3.8
1.64
2.165
1.09
3.80
1.52
0.005
0.017
0.015
0.005
0.010
0.01
0.02
0.00
2.91
3.25
7.27
3.14
4.14
2.09
7.27
2.91
2.9
3.3
7.3
3.1
4.2
2.1
7.3
2.9
was retained on the resin). One ml of 50 mg/ml NaHSO4 solution
was added to the polonium strip fraction, and then evaporated
carefully to dryness. The NaHSO4/organic residue was evaporated several times with 2–3 ml of concentrated HNO3. Then 2 ml
each of 70% HNO3 and 60% HClO4 were added, and the mixture
was evaporated and fumed strongly with the concentrated
HClO4 to destroy any remaining traces of organic material
(e.g., from the Sr resin). It was then carefully evaporated to the
NaHSO4 salt residue. Residues were dissolved in 10 ml of 0.5 M
HCl and transferred to a deposition cell (30 ml Nalgene polyethylene screw-cap bottle) with further beaker rinses totaling
5 ml of 0.5 M HCl. Approximately 50 mg of ascorbic acid were
added, a silver disk was placed in the cap of the cell and the
cap was screwed down tightly. A 5 mm diameter hole was cut
in the top of the cell and the cell was placed in a 150 ml glass
beaker filled with boiling de-ionized water for 2–6 h. The silver
disk containing spontaneously deposited polonium was
removed and washed with 0.5 M HCl and acetone and allowed
to dry.
These silver-disk polonium sources were alpha-counted
for 10 days using solid-state, planar silicon detectors in
evacuated chambers with approximately 25% counting geometry (e.g., EG&G Ortec model 576 alpha spectrometers
coupled to computer-based, signal-processing software). The
alpha spectra obtained were used to calculate the specific
activities of Po-210 using the following formula
Table 3 – Activity concentrations (Bq/kg w.w) of 137Cs and
Po measured in the flesh part of Red Sea coral omnivore
fishes and their corresponding Committed Effective Dose
(CED) (µSv/yr)
210
Species name
Naso unicornis
Chanos sp.
Oedalechilus
labiosus
Gaterin gaterinus
Average
Standard deviation
Max
Min
137
210
CsCED
PoCED
Total CED
0.14
0.09
0.35
0.72
2.1
5.04
0.01
0.01
0.02
1.38
4.02
9.64
1.39
4.02
9.66
0.14
0.18
0.11
0.35
0.09
2.2
2.515
1.81
5.04
0.72
0.01
0.01
0.01
0.02
0.01
4.21
4.81
3.47
9.64
1.38
4.22
4.82
3.48
9.66
1.39
Cs
Po
4.3 × 10−7 for 210Po. Therefore, the dose calculations proceeded
using the following formulas:
DCsQ137 ¼ 1:2 108 CCsQ137 Ir
ð1Þ
DPoQ120 ¼ 4:3 107 CPoQ210 Ir
ð2Þ
where DCs-137 and DPo-210 are the CED values for 137Cs and 210Po,
respectively (Sv yr− 1), CCs-137 and CPo-210 are the radionuclide
concentrations in the edible part of fish (Bq kg− 1 w.w.= wet
weight), and Ir is the ingestion rate (kg yr− 1). The ingestion rate
used for fish is the international mean (FAO, 1999) equal to
4.45 kg yr− 1.
3.
Results and discussion
The activity concentrations (Bq/kg w.w.) of 210Po and 137Cs
measured in the flesh part of coral reef fishes collected from
the Sudanese coast of the Red Sea are given in Tables 1,2 and 3.
For the purpose of better comparison of the results obtained
the fishes were classified into three categories based on their
feeding habits as carnivores, omnivores and herbivores. The
data show that the 210Po activity concentration (Bq/kg w.w.) in
the groups examined ranged from 0.25 to 6.42 (carnivores), 0.7
to 5 (omnivores) and 1.5 to 3.8 (herbivores). The ranges quoted
AðPo210Þ ¼ ½NðPo210ÞTðPo208Þ=½NðPo208ÞTm
where:
A (Po-210) = activity concentration of Po-210 in the sample
in Bq/kg.
A (Po-208) = added activity of the radiochemical yield tracer in Bq.
N (Po-210) = net counts in the Po-210 alpha spectral peak
region of interest (ROI).
N (Po-208) = net counts in the Po-208 alpha spectral peak ROI.
m = mass of sample in kg (wet basis).
2.4.
Committed Effective Dose (CED) calculations
Committed Effective Doses (CEDs) were calculated using conversion factors (Sv Bq− 1) for adults adopted in the coordinated
project MARDOS (IAEA, 1995), namely, 1.2 × 10− 8 for 137Cs and
Table 4 – Comparison of 210Po activity concentration
ranges (Bq/kg w.w.) measured in fish flesh collected
from the Red Sea with data from different areas around
the globe
Country
Sudan
Syria
Japan
Portugal
Australia
Denmark
Brazil
USA
Poland
Cuba
210
Po
0.25–2.52
0.27–27.48
0.60–2.60
0.20–11
0.90–44.10
0.35–0.90
0.50–5.30
0.40–153.30
0.90–5
5–89
Reference
This work
M. S. Al-Masri et al., 2000
Yamamoto et al., 1994
Carvalho, 1988
Smith and Towler, 1993
Dahlgaard, 1996
Saito and Cunha,1997
Noshkin et al., 1994
Skwarzec, 1997
Alonso-Hernandez, 2002
Author's personal copy
217
S CIE N CE OF T H E TOT AL E N V I RO N ME N T 3 9 3 ( 2 00 8 ) 2 1 4–2 18
Table 6 – Committed Effective Dose (CED) (μS v/yr) due to
Cs and 210Po from the consumption of Red Sea coral
carnivores fishes collected from the local market at Port
Sudan and their relative contribution (%)
137
Sample no.
Fig. 1 – Average activity concentration of Cs-137 and Po-210 in
coral fish samples from the Red Sea coast classified according
to their feeding habits.
here suggest some variation in 210Po activity concentration
among different species according to their feeding habits;
indeed, it is not unreasonable that the levels in different food
may influence the levels of 210Po noted among tissues of different species of fish because the main source of 210Po accumulated by fish is believed to be the food chain (Pentreath,
1985; Cherry et al., 1988). The highest value of 210Po concentration (6.42 Bq/kg w.w.) was observed in Scomberomorus commersoni; however, this value was only observed in one species
whereas the 210Po concentration is low in most of the other
species. As shown in Table (4), the activity concentration range
of 210Po in fish flesh collected from the Red Sea is generally low
in comparison with those reported elsewhere; however, it is
within the interval reported for Brazil (Saito and Cunha, 1997)
and by Skwarzec (1997) for Poland. This evaluation is complicated because very little data are available on 210Po concentrations in the seafood of tropical environments. Apart from data
reported for Denmark (Dahlgaard, 1996) and this work, a wide
scatter of data ranges is evident. Since the global data did not
take into consideration any classification according to feeding
habits, it was difficult to attribute that wide range variation to
the difference in feeding habits. In spite of that Noshkin et al.
(1994) attributed the wide variation in range observed in
Marshall Islands fishes studied to different trophic levels as
well as in the same trophic level and could not explain the
Table 5 – Comparison of 137Cs activity concentration
ranges (Bq/kg w.w.) measured in fish flesh collected
from the Red Sea with data from different areas around
the globe
Location
Red Sea
Cienfuegos, Cuba
Mediterranean Sea
Pacific Ocean
Atlantic Ocean
North Sea
Indian Ocean
Japan Sea
137
Cs
0.09–0.46
0.09–0.3
1
0.04–0.3
0.07–0.5
2.4
0.2
0.3
Reference
This work
Alonso-Hernandez, 2002
IAEA, TECDOC-383, 1995
Epinephelus
microdon
Lutjanus gibbus
Lethrinus mahsena
Epinephelus
chlorostigma
Carangoides bajad
Lutjanus bohar
Aethaloperca rogaa
Carnax mate
Macolor niger
Caranx emburi
Plectropomus
truncatus
Cephalopholis argus
Vermilion grouper
Scarus sordidus
Scomberomorus
commersoni
Triaenodon obesus
Pomadasys
opercularis
Monotaxis
grandoculis
Caranx sexfasclatus
Gymnosarda
unicolor
Plectropomus
maculates
Trachinotus blochii
Pristipomoides
filamentosus
Average
Standard
deviation
Max
Min
Cs-CED Po-CED Total CED Cs % Po %
0.01
2.49
2.49
0.3
99.7
0.01
0.01
0.01
1.88
1.36
1.80
1.88
1.37
1.81
0.3
0.6
0.8
99.7
99.4
99.2
0.02
0.01
0.01
0.01
0.01
0.01
0.02
4.40
3.16
1.74
4.67
1.70
5.93
5.36
4.42
3.17
1.75
4.68
1.71
5.94
5.37
0.3
0.3
0.5
0.1
0.5
0.2
0.3
99.7
99.7
99.5
99.9
99.5
99.8
99.7
0.01
0.01
0.01
0.02
2.87
2.10
1.21
12.28
2.88
2.11
1.22
12.30
0.4
0.4
0.9
0.2
99.6
99.6
99.1
99.8
0.03
0.01
4.02
1.53
4.04
1.54
0.6
0.4
99.4
99.6
0.01
1.15
1.16
0.5
99.5
0.02
0.02
4.98
8.90
4.99
8.92
0.4
0.2
99.6
99.8
0.02
0.48
0.50
3.9
96.1
0.01
0.02
4.21
1.63
4.22
1.65
0.3
1.2
99.7
98.8
0.01
0.01
3.471
2.76
3.48
2.77
0.6
0.8
99.4
0.8
12.30
0.50
3.9
0.1
99.9
96.1
0.02
0.01
12.28
0.48
variation within the same trophic level. It is also observable
that data from equatorial regions are generally higher than the
mean levels of polonium encountered in different species of
fish from colder, northern European waters (Noshkin et al.,
1994).
The average 210Po concentrations were 1.8, 2.5 and 2.16 Bq/kg
w.w. for carnivores, omnivores and herbivores, respectively
(Fig. 1). Although there are no distinct differences in the mean
concentration of 210Po among the three different categories
studied, omnivores showed the highest value. This can be
attributed to differences in feeding habits, as they feed upon
both plants and animals.
The 137Cs activity concentration levels (Bq/kg w.w.), ranged
from 0.1 to 0.46 (carnivores), 0.09 to 0.35 (omnivores) and 0.09 to
0.32 (herbivores). The similarity in range among these three
categories confirms that there are no differences in the amount
of 137Cs with the material ingested by fish. The highest value
(0.46) was observed in Triaaenodon obesus (carnivore). However,
this kind of fish feeds on small crustaceans such as half-grown
shrimp and living organisms like crabs, lobsters, squids and
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SC IE N CE OF T H E TOT AL E N V I RO N ME N T 3 9 3 ( 2 00 8 ) 2 1 4–2 18
some mid-water fishes which are very rich in 137Cs. Table (5)
shows that results obtained in this work for 137Cs are in a good
agreement with the previously reported 137Cs concentrations for
marine species coming from regions affected only by global
fallout (IAEA, 1995; Aarkrog et al., 1997). The average 137Cs concentrations in the flesh part of the analysed fish samples were
0.23, 0.18 and 0.2 Bq/kg w.w. for carnivores, omnivores and
herbivores, respectively (Fig. 1). These values are 10–15 times
lower than those observed for 210Po.
In general, Sudanese people's consumption of seafood is
relatively low in comparison with other nations such as Japan.
However, Sudanese living in the Red Sea coastal cities (Port
Sudan, Sawakin and Toker) may receive relatively high radiation
doses due to 210Po and 137Cs intake by high consumption rate.
The values of the calculated doses from fish consumption in the
Red Sea province are given in Table 6 which also represents the
percentage contribution of particular radionuclides to the
collective doses. The average doses from 137Cs are 0.012, 0.01
and 0.01 (µSv/yr) due to carnivores, omnivores and herbivores,
respectively, contributing about 0.4% to the dose due to fish
consumption from the Red Sea. These values are much lower
than the global average 0.42 µSv/yr (Aarkrog et al., 1997). The
average Committed Effective Doses from 210Po are 3.47, 4.81 and
4.14 (µSv/yr) in carnivores, omnivores and herbivores, respectively. The 210Po represents the most significant contribution to
the doses (99.6%) due to fish consumption from the Red Sea. The
DPo-210 values obtained of Sudanese population are much lower
than the global average, being comparable to other groups in the
world, e.g., the population of Syria (Al-Masri et al., 2000).
4.
Conclusion
The following conclusions can be derived:
1. The activity concentrations of Cs-137 in fish are much
lower than Po-210.
2. Among the categories, slight differences in Po-210 and Cs137 activity concentration uptake according to feeding
habits seem to be noticeable.
3. The Committed Effective Dose (CED) to the population from
the consumption of marine fish is mainly attributed to Po210 in comparison to Cs-137.
4. The Committed Effective Dose (CED) to the population from
the consumption of marine fish is negligible.
Acknowledgements
Sample analysis was performed with the help and guidance of
the staff of the IAEA Marine Environment Laboratory (MEL),
Monaco and the financial support of the International Atomic
Energy Agency (IAEA).The sampling campaign would not be
completed without the valuable assistance of Dr. Mohammed
Al-Amin, Dean, Faculty of Marine Sciences and Fisheries,
University of the Red Sea, Mr. Salah, Mr. Mohamed Haboura,
and Mr. Abdelmunium. Our gratitude is also conveyed to Dr.
Asma Abdel Rahman, Faculty of Science and Technology, Al
Neelain University, and to Dr. Alsir Adam, AlZaeem Alazhari
University for helping in the classification of fish samples.
REFERENCES
Aarkrog A, Baxter MS, Bettencourt AO, Bojanowski R, Bologga A,
Charmasson S, Cunha I, Delfanti R, Duran E, Holm E, Jeeree R,
Livingston HD, Mahapanyawong S, Nies H, Osvath I, Pingyu L,
Povinec PP, Sanchez A, Smith JN, Swift DA. Comparison of
doses from 137Cs and 210Po in marine food: a major
international study. J. Environ. Radioact. 1997;34:69–90.
Al-Masri MS, Mamish S, Budeir Y, Nashawati A. 210 Po and 210Pb
concentrations in fish consumed in Syria. J. Environ. Radioact.
2000;49(3):345–52.
Alonso-Hernandez C, Diaz-Aswncio M, Munos-Caravaca A,
Suarez-Morell E, Avila-Moreno R. 137Cs and 210Po dose
assessment from marine food in Cienfuegos Bay (Cuba).
J. Environ. Radioact. 2002;61(2):203–11.
Carvalho FP. 210Po in marine organisms: a wide range of natural
radiation dose domains. Radiat. Prot. Dosim. 1988;24:113–7.
Cherry RD, Shannon LV. Polonium-210 in selected categories of
marine organisms: interpretation of the data on the basis of
an unstructured marine food web model. In: Guary JC,
Guegueniat P, Pentreath RJ, editors. Radionuclides: a tool for
oceanography. London, New York: Elsevier Applied Science;
1988. p. 362–72.
Cherry RD, Heyraud M, Rindfuss R. Po-210 in teleost fish and in
marine mammals: interfamily differences and possible
association between polonium-210 and red muscle content.
J. Environ. Radioact. 1994;32:91–6.
Dahlgaard H. Po-210 in mussels and fish from the Baltic-North Sea
estuary. J. Environ. Radioact. 1996;32:91–6.
FAO. Report of the FAO Technical Working Group on the
Conservation and Management of Sharks. Tokyo, Japan, April
23–27 1998. FAO Fisheries Report. No. 583. Rome: FAO; 1999.
28p.
IAEA. Sources of radioactivity in the marine environment and their
relative contributions to overall dose assessment from marine
radioactivity (MARDOS), IAEA. Vienna, Austria: International
Atomic Energy Agency; 1995. TECDOC-383.
McDonald P, Cook GT, Baxter MS. Natural and artificial radioactivity
in coastal regions of the UK. In: Kershaw DS, Woodhead, editors.
Radionuclides in the study of marine processes, 329. London and
New York: Elsevier Applied Science; 1991.
Noshkin VE, William LR, Wong KM. Concentration of 210Po and
210Pb in the diet at the Marshal Island. Sci. Total Environ.
1994;155:87–104.
Pentreath RJ. General review of literature relevant to coastal water
discharges. Behavior of radionuclides released into coastal
waters, vol. 329. IAEA; 1985. p. 17–66. TECDOC.
Saito RT, Cunha IIT. Analysis of 210Po in marine samples.
J. Radioanal. Nucl. Chem. 1997;220(1):119–71.
Skwarzec B. Polonium, uranium and plutonium in the Southern
Baltic Sea. Ambio 1997;26(2):113–7.
Smith J, Towler PH. Polonium-210 in cartilaginous fishes
(Chondrichthyes) from South Eastern Australia waters. Aust. J.
Mar. Freshw. Res. 1993;44:727–33.
Vajda N, La Rosa J, Zeisler R, Danesi P, Kis-Benedek Gy. A novel
technique for the simultaneous determination of Pb-210 and
Po-210 using a crown ether. J. Environ. Radioact.
1997;37:355–72.
Yamamoto M, Abe T, Kuwabara J, Komura K, Takazia Y. Po-210
and Pb-210 in marine organisms: intake levels for Japanese.
J. Radioanal. Nucl. Chem. 1994;178:81–90.