The document summarizes evidence of radioactive fallout detected in environmental samples collected in Krasnoyarsk, Russia following the Fukushima nuclear accident in Japan. Samples of melted snow, rainwater, pine needles and air filters collected between April and May 2011 contained radioactive isotopes like iodine-131, cesium-134 and cesium-137 released from Fukushima. The detection of these isotopes in central Asia provides evidence of the long-range transport of radioactive contamination from Fukushima across the Pacific and Eurasia, similar to fallout patterns observed after Chernobyl. Levels of iodine-131 and ratios of cesium isotopes in Russian samples were comparable to those measured in Greece, suggesting linkage

1. Journal of Environmental Radioactivity 102 (2011) 1062e1064
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Journal of Environmental Radioactivity
journal homepage: www.elsevier.com/locate/jenvrad
Short communication
Evidence of the radioactive fallout in the center of Asia (Russia)
following the Fukushima Nuclear Accident
A. Bolsunovsky*, D. Dementyev
Radioecology Laboratory, Institute of Biophysics, Siberian Branch of Russian Academy of Sciences, Akademgorodok, 50-50, 660036 Krasnoyarsk, Russian Federation
a r t i c l e i n f o a b s t r a c t
Article history: It was recently reported that radioactive fallout due to the Fukushima Nuclear Accident was detected in
Received 11 May 2011 environmental samples collected in the USA and Greece, which are very far away from Japan. In April
Received in revised form eMay 2011, fallout radionuclides (134Cs, 137Cs, 131I) released in the Fukushima Nuclear Accident were
15 June 2011
detected in environmental samples at the city of Krasnoyarsk (Russia), situated in the center of Asia.
Accepted 18 June 2011
Available online 13 July 2011
Similar maximum levels of 131I and 137Cs/134Cs and 131I/137Cs ratios in water samples collected in Russia
and Greece suggest the high-velocity movement of the radioactive contamination from the Fukushima
Nuclear Accident and the global effects of this accident, similar to those caused by the Chernobyl
Keywords:
Radioactive fallout
accident.
Environmental samples Ó 2011 Elsevier Ltd. All rights reserved.
Fukushima nuclear accident
Fission product radionuclides
Russia
An earthquake followed by a tsunami that occurred at the radioactivity moved over the USA and the Atlantic Ocean and then
Fukushima Daiichi complex on March 11, 2011 caused release of diffused over the European continent. The first data on radioactive
radionuclides into the environment (Brumfiel and Cyranoski, 2011; fallout in Europe (Greece) were reported by scientists of Aristotle
Butler, 2011; Reardon, 2011). On April 12, 2011, the Nuclear and University of Thessaloniki (40 380 N, 22 580 E) (Manolopoulou et al.,
Industrial Safety Agency of Japan (NISA) submitted a provisional 2011). From March 24 through April 9, radionuclides (134Cs, 137Cs,
131
International Nuclear and Radiological Event Scale Level 7 rating for I) released in the nuclear accident at Fukushima were recorded
the Fukushima accident (IAEA, 2011). The only other accident to in air samples collected at Thessaloniki. The only isotope detected
have an INES Level 7 rating was the Chernobyl accident in 1986. in rainwater and in the sheep milk collected on March 29e30, 2011
However, NISA estimates that the Fukushima nuclear releases to in Greece was 131I (Manolopoulou et al., 2011).
the atmosphere were approximately 10% of the Chernobyl accident The cloud containing radioactivity was expected to move
(IAEA, 2011). The Fukushima Nuclear Accident has also caused toward Asia, but until now, no data have been published on
global effects, as suggested by the first measurements of 133Xe that radioactive fallouts in Asian countries. From April 3 through May 3
were conducted at the Pacific Northwest National Laboratory (USA) 2011, environmental samples were collected in the city of Kras-
(46160 4700 N, 119160 5300 W) located more than 7000 km from noyarsk (Russia) (Krasnoyarsk-1, 55 590 2100 N, 92 450 3600 E) and in
Fukushima (37 2501700 N, 141105700 E) (Bowyer et al., 2011). First its environs (Krasnoyarsk-2, 56 050 5000 N, 92 350 0300 E). Analysis was
detections of 133Xe were made starting early March 16, only four performed on samples of rainwater, melted snow, pine (Pinus syl-
days following the accident, and then high concentrations of 133Xe vestris L.) needles, and the air filter membrane. Samples of fresh
were determined daily. On March 22, 2011, the U.S. Environmental snow collected from an area of 2e9 m2 were melted at room
Protection Agency (EPA, 2011) reported that analysis of samples temperature. Rainwater samples were collected in plastic
captured by RadNet air monitor filters in the states of California and containers. All water samples were filtered. One liter of water was
Washington on March 18 detected fission product radionuclides taken immediately after filtering to perform preliminary rapid
(137Cs, 132Te, 132I, 131I). Subsequently, the cloud containing analysis for radionuclides using g-ray-spectrometry. Then, the
water was concentrated by evaporation on an electric stove to
a volume of 1 L, in order to attain a more accurate determination of
* Corresponding author. Tel.: þ7 391 2494572; fax: þ7 391 2433400.
radionuclides. To avoid any loss by evaporation of iodine isotopes
E-mail address: radecol@ibp.ru (A. Bolsunovsky). during heating, a method approved by the Russian Ministry of
URL: http://www.ibp.ru/ Health was used: 10 drops of 1% phenolphthalein solution were
0265-931X/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.jenvrad.2011.06.007

2. A. Bolsunovsky, D. Dementyev / Journal of Environmental Radioactivity 102 (2011) 1062e1064 1063
Table 1
Fission product radionuclides in environmental samples collected at Krasnoyarsk (Russia) between April 4 and May 3, 2011.
131 134 137 137
Sampled material, sampling date and area I Cs Cs Cs/134Cs 131 137
I/ Cs
Melted snow April 04.2011, KrasnoyarskÀ1 0.62 Æ 0.05 Bq/L 0.095 Æ 0.02 Bq/L 0.075 Æ 0.03 Bq/L 0.79 8.3
Melted snow April 04.2011, Krasnoyarske2 0.39 Æ 0.02 Bq/L 0.031 Æ 0.002 Bq/L 0.037 Æ 0.004 Bq/L 1.19 10.5
Melted snow April 06.2011, KrasnoyarskÀ1 0.405 Æ 0.015 Bq/L 0.026 Æ 0.002 Bq/L 0.024 Æ 0.004 Bq/L 0.92 16.9
Melted snow April 06.2011, Krasnoyarske2 0.53 Æ 0.04 Bq/L 0.048 Æ 0.004 Bq/L 0.055 Æ 0.007 Bq/L 1.15 9.6
Rainwater April 28.2011, Krasnoyarsk-1 0.052 Æ 0.004 Bq/L 0.005 Æ 0.001 Bq/L 0.007 Æ 0.003 Bq/L 1.40 7.4
Rainwater April 27.2011, Krasnoyarsk-2 0.058 Æ 0.019 Bq/L MDA MDA e e
Rainwater May 03.2011, Krasnoyarsk-2 0.031 Æ 0.007 Bq/L 0.006 Æ 0.002 Bq/L MDA e e
Pine needles April 10.2011, Krasnoyarsk-1 3.28 Æ 0.31 Bq/kg DW 0.74 Æ 0.11 Bq/kg DW 1.03 Æ 0.20 Bq/kg DW 1.39 3.2
0.83 Æ 0.20 Bq/kg DWa 1.12a 4.0a
Air filter membrane March 01eApril 03. 2011, 0.63 Æ 0.05 Bq 0.11 Æ 0.02 Bq 0.20 Æ 0.04 Bq 1.82 3.2
Krasnoyarsk-1
Rainwater in Northern Greeceb March 29.2011 Up to 0.7 Bq/L MDA MDA
Samples of air in Northern Greeceb 340 Æ 36=497 Æ 53 mBq mÀ3 15 Æ 3=126 Æ 11 mBq mÀ3 23 Æ 7=145 Æ 18 mBq mÀ3 1:5=1:2 14:8=3:4
April 1e4.2011/April 4e5.2011
a 137 137
Cs activity concentrations and radionuclide ratios in pine needles are the data obtained after deduction of Cs background activity.
b
The data reported by Manolopoulou et al. (2011) are given for comparison purposes.
added to the filtered water, and then we gradually added K2CO3 was similar to that obtained for air samples collected in Greece
till the solution turned bright crimson and did not change color between April 1 and 5, 2011: 1.2 O 1.5 (Table 1). The 131I/137Cs ratio
when mixed. The concentrated water samples were analyzed by varied within a range of 7.4e16.9 for water samples collected at
g-ray-spectrometry. Needles collected from individually growing Krasnoyarsk and was equal to 3.2 for both pine needles and the air
pine trees (P. sylvestris L.) were dried. For rapid detection of filter membrane. In order to interpret the results correctly, the
radionuclides in the needles, an aliquot of needles was placed in activity of 137Cs accumulated in pine needles before the accident
a 1-L Marinelli beaker and analyzed by g-ray-spectrometry. To needs to be deducted from the obtained activity concentrations.
attain a more accurate determination of radionuclides, the nee- Based on previous measurements of 137Cs in the environmental
dles were concentrated by ashing. To avoid any loss by evapora- samples collected at Krasnoyarsk (Dementyev and Bolsunovsky,
tion of iodine isotopes during ashing, a method approved by the 2009) and estimated pre-accident 137Cs activity concentrations in
Russian Ministry of Health was used. K2CO3 amounting to 20% of pine needles, post-accident 137Cs concentration in pine needles
the sample mass was added to dry needles. The mixture was after deduction of the global background value amounted to
wetted with water, mixed thoroughly, and dried. Then the sample 0.83 Bq/kg DW (Table 1). Radionuclide ratios did not change
was ashed in a muffle furnace, at a temperature gradually significantly after deduction of the background activity of 137Cs in
increased (by 50 C every 30 min) to 450 C. The ashed sample pine needles (Table 1). The range of the 131I/137Cs ratios for the
was analyzed by g-ray-spectrometry. The membrane of the air Krasnoyarsk samples (Table 1) was similar to that obtained for
filter that had worked to purify the air for at least a month by air samples in Greece: from 3.4 to 14.8 in April (Table 1) and up to
April 3, 2011, the sampling date, was first dried in a drying oven 18.4 in March 2011. The Greek scientists did not record cesium
and then prepared for g-ray-spectrometry. The activity concen- isotopes in rainwater samples (Manolopoulou et al., 2011).
trations of the radionuclides (131I, 134Cs, 137Cs, etc.) in the samples Manolopoulou et al. (2011) reported measurements data of Japa-
were measured on a Canberra g-spectrometer (USA) coupled to nese researchers, showing that in Japan the 137Cs/134Cs ratio was
a GX2320 23% hyper-pure germanium detector in a 1-L Marinelli equal to 0.97. This value, within the margin of error, is similar to
beaker. our results obtained between April 4 and 6, 2011 (Table 1).
From April 4 through 6, fresh snow samples were collected in The obtained results show that fission products released in
the city of Krasnoyarsk (Russia) (Krasnoyarsk-1) and in its environs the Fukushima Nuclear Accident were detected in the center of
(Krasnoyarsk-2); the snow was melted, and the water was found to Asia in AprileMay and the highest level of 131I in water (melted
contain radionuclides released in the Fukushima Nuclear Accident snow) collected after a snowfall in Krasnoyarsk (Russia) was
(134Cs, 137Cs, 131I) (Table 1). The highest 131I activity that we similar to the level of 131I in water collected after a rainfall in
recorded was 0.62 Bq/L and the highest 137Cs and 134Cs activities Greece. The 137Cs/134Cs and 131I/137Cs ratios varied within the
were 0.075 and 0.095 Bq/L, respectively. The highest 131I activity same range for the samples collected in Greece and Russia,
concentration in the melted snow sample collected on April 4, 2011 suggesting a high-velocity movement of radioactive contami-
was similar to the 131I concentration in the rainwater collected in nation. The cloud containing radioactivity evidently moved
Greece on March 29, 2011: 0.7 Bq/L (Manolopoulou et al., 2011) toward the Russian Far East and Japan, and, hence, it had trav-
(Table 1). Rainwater samples collected in Krasnoyarsk on April eled around the Earth. Thus, the detections of radiocesium and
27eMay 3, 2011 contained much lower concentrations of 131I and radioiodine in environmental samples in North America (USA),
cesium isotopes (Table 1). Additional evidence for radioactive Europe, and Asia (Russia) prove the global effects of the nuclear
fallout at Krasnoyarsk due to the Fukushima Accident was found by accident at Fukushima, similar to those caused by the Chernobyl
analyzing pine (P. sylvestris L.) needles collected on April 10, 2011 accident.
and the membrane of the air filter that had worked for at least
a month by April 3, 2011. These samples, pine needles in particular,
contained rather high levels of fission product radionuclides. In Acknowledgments
pine needles, activity concentrations of 131I, 137Cs, and 134Cs
reached 3.28, 1.03, and 0.74 Bq/kg DW, respectively. The data The authors acknowledge the work of researchers of the Insti-
reported by Calmon et al. (2009) suggest effective accumulation of tute of Biophysics SB RAS (Yu. Alexandrova) and the Institute of
radiocesium by pine needles. In all Krasnoyarsk samples, the Forest SB RAS, who took part in sample collection and preparation
137
Cs/134Cs ratio varied within a range of 0.79e1.8, and this range for measurements.

3. 1064 A. Bolsunovsky, D. Dementyev / Journal of Environmental Radioactivity 102 (2011) 1062e1064
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