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Determination of Polonium-210 in various foodstuffs after microwave digestion

Published online by Cambridge University Press:  06 June 2009

J. Barescut ,
I. Louw ,
A. Faanhof  and
D. Kotze
I. Louw
Affiliation:
South African Nuclear Energy Corporation, PO Box 582, 0001 Pretoria, South Africa
A. Faanhof
Affiliation:
North-West University, Private Bag X2046, 2735 Mmabatho, South Africa
D. Kotze
Affiliation:
South African Nuclear Energy Corporation, PO Box 582, 0001 Pretoria, South Africa
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Abstract

Natural radioactivity is associated with the vast mineral resources in South Africa in such concentrations that the radionuclides from the natural uranium and thorium decay series are found to pose concern for public exposure to communities living around these areas. The radiological impact of all operations is monitored as part of the license obligations, imposed by the South African National Nuclear Regulator Act [1]. Two main pathways giving rise to significant exposures are of interest: (a) direct ingestion resulting from regular and continuous use of contaminated water for drinking purposes, and (b) regular consumption of fish and other food products harvested from and/or grown in contaminated areas. To measure the individual nuclides in foodstuffs at the required sensitivity level in order to evaluate the yearly dose due to an individual source at a screening level of 25 μSv/a, one is faced with a required lower limit of determination (LLD) of 0.1 to 0.5 Bq/kg for certain foodstuffs. For some of the nuclides this LLD can only be obtained with radiochemical separation through acid destruction of dried foodstuffs followed by individual element separations. In this study the digestion of foodstuffs in an open-vessel microwave system followed by the determination of 210Po through radiochemical separation by spontaneous deposition onto silver discs and subsequent measurement by α-spectrometry, has been evaluated. The levels of 210Po in a variety of foodstuffs were determined and the estimated dose for the adult age group, resulting from consumption was evaluated. The dose from 210Po varied from 4 to 250 μSv/a for the various foodstuffs, with the largest intake from fish (about 0.5 Bq/day). The assessment of natural radionuclides in foods allowed us to evaluate the items that present the highest risk to the population, and compare this to the limits established by the National Nuclear Regulator (NNR). Not much data of this kind is available in South Africa. However, one would need more accurate consumption/intake values to calculate the actual yearly dose and the potential radiological impact on the public.

Type
Research Article
Information
Radioprotection , Volume 44 , Issue 5: ECORAD 2008 - Radioecology and Environmental Radioactivity , 2009 , pp. 89 - 95
Copyright
© EDP Sciences, 2009

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References

National Nuclear Regulator Act, “Act no 47 on Safety Standards and Regulatory Practise”, South African Government Gazette, Vol. 414 no 20760, 1999.
Clayton, R.F. and Bradley, F.J., Sci. Total Environ. 173/174 (1995) 23–28. CrossRef
Beasly, T.M. and Palmer, H.E. Nature 187 (1960) 211–212. CrossRef
Khandekar, R.N., Health Phys. 33:2 (1977) 148–150.
Avadhani, D.N., Mahesh, H.M., Karunakara, N., Narayana, Y., Somashekarappa, H.M. and Siddappa, K. Health Phys. 81:4 (2001) 438–445. CrossRef
Al-Masri, M.S. and Al-Bich, F., J. Radioanal. Nucl. Chem. 251:3 (2002) 431–435. CrossRef
Carvalho, F.P., Health Phys. 69:4 (1995) 469–480. CrossRef
Cunha, I.L., Bueno, L., Favaro, D.I.T., Maihara, V.A. and Cozzollono, S., J. Radioanal. Nucl. Chem. 247:2 (2001) 447–450. CrossRef
Smith-Briggs, J.L., Bradley, E.J. and Potter, M.D., Sci. Total Environ. 54 (1986) 127–133. CrossRef
Kannan, V., Iyengar, M.A.R. and Ramesh, R., Appl. Radiation & Isotopes 54 (2001) 663–674. CrossRef
Pietrzak-Flik, Z., Chrzanowski, E.and Dembinska, S., Sci. Total Environ. 203 (1997) 157–165. CrossRef
Izak-Biran, T., Schlesinger, T., Weingarten, R. and Even, O., Health Phys. 56:3 (1989) 315–319. CrossRef
Skwarzec, B. and Jakusi, A., J. Environ. Monit. 5:5 (2003) 791–794. CrossRef
Yamamoto, M., Abe, T., Kuwabara, J., Komura, K., Ueno, K. and Takizawa, Y., J. Radioanal. Nucl. Chem. Articles 178:1 (1994) 81–90. CrossRef
Cherry, R.D., Heyraud, M. and Rindfuss, R., J. Environ. Radioactivity 24 (1994) 273–291. CrossRef
Heyraud, M., Cherry, R.D., Oschadleus, H.D., Augustyn, C.J., Cherry, M.I. and Sealy, J.C., J. Environ. Radioactivity 24 (1994) 253–272. CrossRef
Faanhof, A., Kotze, D. and Louw, I., “A first order assessment of the potential radiological impact of foodstuffs grown in a catchment area influenced by mining and mineral processing industries, using Instrumental Neutron Activation Analysis (INAA) and gamma-spectrometry”, The 5th African Conference on research reactor utilization, 2–3 December 2007, Cairo, Egypt.
Faanhof, A., Czech. J. Phys., 50:2 (2000) 281–288.
Faanhof, A. and Louw, I., J. Radioanal. Nucl. Chem. 249:1 (2001) 227–232.
World Health Organization (WHO), “World Health Organization Derived intervention levels for radionuclides in food”, Geneva, 1988.
Saito, R.T. and Cunha, I.I.L., J. Radioanal. Nucl. Chem. 220:1 (1997) 117–119. CrossRef
Holtzman, R.B., J. Radioanal. Nucl. Chem. Articles 115 (1987) 59–70. CrossRef
Towler, P.H. and Smith, J.D., Anal. Chim. Acta 292 (1994) 209–212. CrossRef
Ham, G.L., Ewers, L.T. and Clayton, R.F., J. Radioanal. Nucl. Chem. 226 (1997) 61–65. CrossRef
Institute for Water Quality Studies (DWAF), “Report on the Radioactivity Monitoring Programme in the Mooi River (Wonderfonteinspruit) Catchment Area”, Pretoria, 1999
International Commission on Radiological Protection (ICRP), “Age-dependent Doses from Intake of Radionuclides”, ICRP Publication 72, Oxford Pergamon, 1996.
The South African National Nuclear Regulator, “Guideline on the Assessment of Radiation Hazards to Members of the public from Mining and Mineral Processing Facilities”, LG-1032, Rev 0, 1997.
Louw, I. and Faanhof, A., In preparation.
United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), “Sources and effects of ionizing radiation”, Report to the General Assembly with Annexes, United Nations, New York, 2000.