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Iodine-129 in soils from Northern Ukraine and the retrospective dosimetry of the iodine-131 exposure after the Chernobyl accident
Forty-eight soil profiles down to a depth of 40 cm were taken in Russia and Ukraine in 1995 and 1997, respectively, in order to investigate the feasibility of retrospective dosimetry of the 131I exposure after the Chernobyl accident via the long-lived 129I. The sampling sites covered areas almost no...
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Published in: | The Science of the total environment 2005-03, Vol.340 (1), p.35-55 |
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Main Authors: | , , , , , , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that cite this one |
Online Access: | Get full text |
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Summary: | Forty-eight soil profiles down to a depth of 40 cm were taken in Russia and Ukraine in 1995 and 1997, respectively, in order to investigate the feasibility of retrospective dosimetry of the
131I exposure after the Chernobyl accident via the long-lived
129I. The sampling sites covered areas almost not affected by fallout from the Chernobyl accident such as Moscow/Russia and the Zhitomir district in Ukraine as well as the highly contaminated Korosten and Narodici districts in Ukraine.
129I was analyzed by radiochemical neutron activation analysis (RNAA) and accelerator mass spectrometry (AMS).
127I was measured for some profiles by RNAA or ion chromatography (IC). The results for
127I demonstrated large differences in the capabilities of the soils to store iodine over long time spans. The depth profiles of
129I and of
137Cs showed large differences in the migration behavior between the two nuclides but also for each nuclide among the different sampling sites. Though it cannot be quantified how much
129I and
137Cs was lost out of the soil columns into deeper depths, the inventories in the columns were taken as proxies for the total inventories. For
129I, these inventories were at least three orders of magnitude higher than a pre-nuclear value of 0.084±0.017 mBq m
−2 derived from a soil profile taken in 1939 in Lutovinovo/Russia. From the samples from Moscow and Zhitomir, a pre-Chernobyl
129I inventory of (44±24) mBq m
−2 was determined, limiting the feasibility of
129I retrospective dosimetry to areas where the
129I inventories exceed 100 mBq m
−2. Higher average
129I inventories in the Korosten and Narodici districts of 130 and 848 mBq m
−2, respectively, allowed determination of the
129I fallout due to the Chernobyl accident. Based on the total
129I inventories and on literature data for the atomic ratio of
129I/
131I=13.6±2.8 for the Chernobyl emissions and on aggregated dose coefficients for
131I, the thyroid exposure due to
131I after the Chernobyl accident was estimated for the inhabitants of four villages in the Korosten and of three villages in the Narodici districts. The limitations and uncertainties of the
129I retrospective dosimetry are discussed. |
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ISSN: | 0048-9697 1879-1026 |
DOI: | 10.1016/j.scitotenv.2004.08.006 |