radioactive pollution from fukushima daiichi nuclear power plant in the terrestrial environment

6
RADIOACTIVE POLLUTION FROM FUKUSHIMA DAIICHI NUCLEAR POWER PLANT IN THE TERRESTRIAL ENVIRONMENT H. Tazoe 1, *, M. Hosoda 2 , A. Sorimachi 1 , A. Nakata 1 , M. A. Yoshida 1 , S. Tokonami 1 and M Yamada 1 1 Hirosaki University, Institute of Radiation Emergency Medicine, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan 2 Hirosaki University, Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan *Corresponding author: [email protected] Major contaminants from venting and hydrogen explosions at the Fukushima Daiichi nuclear reactors between 12 and 15 March 2011 were transported northwestward and deposited on soil and plants via precipitation. Surface soils and plant leaves were sampled at 64 sites in the Fukushima Prefecture. The highest concentrations of 134 Cs (84.4 kBq kg 21 ) and 137 Cs (82.0 kBq kg 21 ) in surface soils were observed at Nagadoro in Iidate village located 32 km northwest from the Fukushima Daiichi nuclear power plant. Furthermore, 131 I, 129 Te, 129m Te, 110m Ag and 140 La were detected in the same samples. Outer surface of plant leaves, such as bamboo, cabbage and grasses were highly contaminated at the high-dose rate areas of Tsushima and Minami-Tsushima in Namie town. Mugwort leaves that grew after the pollution event had extremely low concentration of radionuclides; however, the plant/soil radiocaesium ratio was 0.023 +0.006. It is anticipated that decomposition of fallen leaves will promote recycling of radionuclides in the environment. INTRODUCTION A catastrophic earthquake (9.0 Mw) and tsunami occurred on 11 March 2011, which caused major de- struction in northeastern Japan and severe damage at the Fukushima Daiichi nuclear power plant. Electrical generators were shut off and three nuclear reactors suffered explosions due to hydrogen gas after the cooling system failed. Residents within 20- km radius of the Fukushima Daiichi nuclear power plant were evacuated; densely populated areas such as the cities of Fukushima and Koriyama were highly contaminated. Major contaminants origi- nated from venting and hydrogen explosions at reac- tors from 12 March to 15 March 2011. Total 137 Cs depositions over the Japanese islands were estimated to be .1.0 PBq (1, 2) . Fission products were trans- ported northwestward and deposited on the ground via precipitation, which resulted in heterogeneous contamination and geographical distribution of ratios of radionuclides such as 131 I/ 137 Cs, 134 Cs/ 137 Cs and 110m Ag/ 137 Cs (3) . In addition, hydrogen explosions and metrological conditions such as wind direction and precipitation caused 137 Cs, 131 I, 110m Ag and 129m Te in the surface soil tovary. MATERIALS AND METHODS Surface soils (0–1 cm) and plant leaves were col- lected from 64 sites in the Fukushima Prefecture (Fig. 1) on four sampling expeditions from 12 to 16 April, 26 to 28 April, 6 to 10 June and 15 to 16 June 2011, and then these samples were analysed for radionuclides. For the soil analysis, stones and plant roots were removed by handpicking and soil was transferred to a 100-ml polystyrene container. To compare the deposition to soils and leaves and the plant uptake after deposition, leaves of Japanese mugwort that grew after the pollution event were also collected. We collected leaves from the upper part of the plant to minimise contamination from the soil. Plant leaves were cut into 11 cm with a scissor. The concentrations of 134 Cs, 136 Cs, 137 Cs, 131 I, 110m Ag, 129 Te and 129m Te were determined by gamma-ray spectroscopy. Gamma-ray emissions at energies of 460 keV ( 129 Te), 604 keV ( 134 Cs), 636 keV ( 131 I), 662 keV ( 137 Cs), 730 keV ( 129m Te) and 885 keV ( 110m Ag) were measured for 1000 up to 80 000 s by a high-purity coaxial Ge gamma-ray de- tector (ORTEC GEM-40190, SEIKO-EG&G). Mixed gamma standard sources with different sample heights distributed from the Japan Radioisotope Association were used for efficiency correction. Because the measurements were started in the middle of May 2011, some short half-life radionuclides such as 131 I(T 1/2 ¼8.02 d) and 136 Cs (T 1/2 ¼13.16 d) could not be detected. RESULTS AND DISCUSSION Heterogeneous deposition of radionuclides on the ground The highest concentration of 134 Cs (84.4 kBq kg 21 ) in surface soil was observed at the Nagadoro (S54) in Iidate village located 32 km northwest from the Fukushima Daiichi nuclear power plant (Table 1). In addition, 137 Cs (82.0 kBq kg 21 ), 131 I (924 kBq # The Author 2012. Published by Oxford University Press. All rights reserved. For Permissions, please email: [email protected] Radiation Protection Dosimetry (2012), Vol. 152, No. 1–3, pp. 198–203 doi:10.1093/rpd/ncs222 Advance Access publication 29 August 2012 at St Petersburg State University on February 3, 2014 http://rpd.oxfordjournals.org/ Downloaded from

Upload: m

Post on 09-Mar-2017

240 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Radioactive pollution from Fukushima Daiichi nuclear power plant in the terrestrial environment

RADIOACTIVE POLLUTION FROM FUKUSHIMA DAIICHINUCLEAR POWER PLANT IN THE TERRESTRIAL ENVIRONMENTH Tazoe1 M Hosoda2 A Sorimachi1 A Nakata1 M A Yoshida1 S Tokonami1 and M Yamada11Hirosaki University Institute of Radiation Emergency Medicine 66-1 Hon-cho HirosakiAomori 036-8564 Japan2Hirosaki University Graduate School of Health Sciences 66-1 Hon-cho Hirosaki Aomori 036-8564Japan

Corresponding author tazoecchirosaki-uacjp

Major contaminants from venting and hydrogen explosions at the Fukushima Daiichi nuclear reactors between 12 and 15March 2011 were transported northwestward and deposited on soil and plants via precipitation Surface soils and plant leaveswere sampled at 64 sites in the Fukushima Prefecture The highest concentrations of 134Cs (844 kBq kg21) and 137Cs (820kBq kg21) in surface soils were observed at Nagadoro in Iidate village located 32 km northwest from the Fukushima Daiichinuclear power plant Furthermore 131I 129Te 129mTe 110mAg and 140La were detected in the same samples Outer surface ofplant leaves such as bamboo cabbage and grasses were highly contaminated at the high-dose rate areas of Tsushima andMinami-Tsushima in Namie town Mugwort leaves that grew after the pollution event had extremely low concentration ofradionuclides however the plantsoil radiocaesium ratio was 0023+++++0006 It is anticipated that decomposition of fallenleaves will promote recycling of radionuclides in the environment

INTRODUCTION

A catastrophic earthquake (90 Mw) and tsunamioccurred on 11 March 2011 which caused major de-struction in northeastern Japan and severe damageat the Fukushima Daiichi nuclear power plantElectrical generators were shut off and three nuclearreactors suffered explosions due to hydrogen gasafter the cooling system failed Residents within 20-km radius of the Fukushima Daiichi nuclear powerplant were evacuated densely populated areas suchas the cities of Fukushima and Koriyama werehighly contaminated Major contaminants origi-nated from venting and hydrogen explosions at reac-tors from 12 March to 15 March 2011 Total 137Csdepositions over the Japanese islands were estimatedto be 10 PBq(1 2) Fission products were trans-ported northwestward and deposited on the groundvia precipitation which resulted in heterogeneouscontamination and geographical distribution ofratios of radionuclides such as 131I137Cs 134Cs137Cs and 110mAg137Cs(3) In addition hydrogenexplosions and metrological conditions such aswind direction and precipitation caused 137Cs 131I110mAg and 129mTe in the surface soil to vary

MATERIALS AND METHODS

Surface soils (0ndash1 cm) and plant leaves were col-lected from 64 sites in the Fukushima Prefecture(Fig 1) on four sampling expeditions from 12 to 16April 26 to 28 April 6 to 10 June and 15 to 16June 2011 and then these samples were analysed forradionuclides For the soil analysis stones and plant

roots were removed by handpicking and soil wastransferred to a 100-ml polystyrene container Tocompare the deposition to soils and leaves and theplant uptake after deposition leaves of Japanesemugwort that grew after the pollution event werealso collected We collected leaves from the upperpart of the plant to minimise contamination fromthe soil Plant leaves were cut into 11 cm with ascissor The concentrations of 134Cs 136Cs 137Cs131I 110mAg 129Te and 129mTe were determined bygamma-ray spectroscopy Gamma-ray emissions atenergies of 460 keV (129Te) 604 keV (134Cs) 636keV (131I) 662 keV (137Cs) 730 keV (129mTe) and885 keV (110mAg) were measured for 1000 up to80 000 s by a high-purity coaxial Ge gamma-ray de-tector (ORTEC GEM-40190 SEIKO-EGampG)Mixed gamma standard sources with differentsample heights distributed from the JapanRadioisotope Association were used for efficiencycorrection Because the measurements were startedin the middle of May 2011 some short half-liferadionuclides such as 131I (T12frac14802 d) and 136Cs(T12frac141316 d) could not be detected

RESULTS AND DISCUSSION

Heterogeneous deposition of radionuclides on theground

The highest concentration of 134Cs (844 kBq kg21)in surface soil was observed at the Nagadoro (S54)in Iidate village located 32 km northwest from theFukushima Daiichi nuclear power plant (Table 1)In addition 137Cs (820 kBq kg21) 131I (924 kBq

The Author 2012 Published by Oxford University Press All rights reserved For Permissions please email journalspermissionsoupcom

Radiation Protection Dosimetry (2012) Vol 152 No 1ndash3 pp 198ndash203 doi101093rpdncs222Advance Access publication 29 August 2012

at St Petersburg State University on February 3 2014

httprpdoxfordjournalsorgD

ownloaded from

kg21 concentration is corrected to March 11)110mAg (040 kBq kg21) 129Te (563 kBq kg21) and129mTe (894 kBq kg21) were detected for the samesample on March and April Furthermore the ex-tremely high-dose rates after dispersion from thenuclear power plant were thought to be mainlycaused by 132Te and its daughter 132I based on thein situ gamma-ray spectrum(3) High radiocaesiumconcentrations were observed in the northwesternNamie town (S46) and southwestern Minamisohmacity near the Tetsuzan dam (S12) which are locatednorthwest of the Fukushima Daiichi nuclear powerplant This is consistent with the results of aircraftmonitoring by the Ministry of Education CultureSports Science and Technology Japan (MEXT httpwwwmextgojpenglishincident1304796htm)Fukushima city is located on the major contamin-ation path that also shows heterogeneous geograph-ical distribution particularly anomalous highconcentrations for S63 (Table 1) This resulted fromgeographical features such as the surrounding moun-tains and the setting of buildings and trees becauseFukushima city is densely populated

Concentration ratios against 137Cs for 134Cs and129mTe are mostly constant (Fig 2) although thosefor the 131I and 129mTe are observed different trends131I137Cs ratios decrease from 32 to 10 with 137Csconcentration (10 kBq kg21) On the contrary110mAg137Cs increase for high 137Cs samples (50kBq kg21) These fractionations were caused by thephysical andor chemical properties for each nuclideduring transportation and deposition processes

Hosoda et al(4) reported that the highestambient-dose rate in air was 36 mGy h21 atHirusone Namie town (37558N 1408478E) on thebasis of the carborne survey conducted on 12 April2011 Regional heterogeneity in radiocaesium

distribution was observed at Minami-TsushimaNamie town (Fig 3) Concentrations of 137Cs col-lected from the three paddies (S19 S27 and S36)widely vary ranging from 024 to 99 kBq kg21 Inthe same paddy much lower radiocaesium concen-trations are observed in samples S19-1 and S36-1relative to the other soil samples The heterogeneousdistribution of 137Cs concentration can reflect boththe initial deposition in the surface soil and the post-depositional redistribution such as transportationadsorbed soil particles by the rainfall in the soil

The soil sample from inside a greenhouse inTsushima Namie town had much lower 137Cs con-centration than the soil outside the greenhouse(Fig 4) This indicates that the major deposition tookplace during wet precipitation and that the inside wasnot contaminated The radiocaesium deposition pri-marily occurs in association with precipitation (3)This indicates that the intrusion of radiocaesiumindoors could be prevented easily

Deposition and translocation of radionuclides to theplant

Figure 5 shows the concentration of radionuclides insoils (S12ndashS14) and plant samples (L11ndashL13) nearthe Tetsuzan dam corrected to 12 April Plantsamples L11 L12 and L13 are leaves of Japaneseceder bamboo and clinopodium gracile respectivelyThe concentrations of radionuclides in S12 arenearly twice of that in others On the other handplant samples show much wider variation in radio-caesium concentration Japanese ceder leaves havelow radiocaesium concentrations (134Csfrac14118 kBqkg21 and 137Csfrac14118 kBq kg21) Bamboo leaveshave concentrations several folds higher than thoseof soils and other plants In cryptomeria this could

Figure 1 Map of the soil sampling locations and total radioactive caesium concentrations (134Csthorn137Cs) The soilsamples observed high radiocaesium concentration (134Csthorn137Cs 100 kBq kg21) are shown on the map and Table 1

RADIOACTIVE POLLUTION FROM FUKUSHIMA DAIICHI NUCLEAR POWER PLANT

199

at St Petersburg State University on February 3 2014

httprpdoxfordjournalsorgD

ownloaded from

depend on the height of the branch Since Japaneseceder leaf samples were collected from the lowerpart of trees overlapped with other branches the de-position of radionuclides was inhibited and theobserved radiocaesium concentrations were low Onthe other hand bamboo leaves did not overlap witheach other and the radionuclides were well depositedon the entire leaf Furthermore the low moisturecontent of the bamboo leaves resulted in higherradioactive caesium

Plant samples were collected in Namie town in 13and 14 April The samples were located close to thetown and the radiocaesium concentration consider-ably fluctuated (Fig 6) For example the concentra-tion in the outer leaves of cabbages was 50 timeshigher than that in the inner leaves The radionu-clides except 134Cs and 137Cs in the inner cabbageleaves were below the detection limit in the gamma-ray measurements The translocation from the outerleaves caused 090 kBq kg21 of 134Cs and 101 kBqkg21 of 137Cs which originated from the nuclearaccident

For the period between March and June 2011137Cs in soils and plants from Koriyama city wascompared (Fig 7) Bamboo clover and pine leaveswere collected on 17 March Japanese mugwort wascollected in 16 June Japanese mugwort is a peren-nial plant and only the underground stem is over-wintering In the part that grew after the nuclearplant accident the 137Cs concentration reflects ab-sorption via the root from the soil The root of theJapanese mugwort splits at shallow depths Thedeposited radiocaesium was transferred to the rest ofthe plant by root uptake and translocation

Radioactive caesium was compared between soilsand plants (Table 2) Plants were mainly collectedfrom Japanese mugwort except for clover from theZenpo pond and grass leaves from the Keiko parkin June and July 2011 Although 137Cs in the soilsamples ranges from 63 to 271 kBq kg21 theJapanese mugwort shows extremely low concentra-tions 05 Bq kg21 of 137Cs Only grass leaf showshigh radioactive caesium The concentration ratiosbetween plant and soil 137Csraw plant

137Cssoil formugwort were relatively constant (0023+0006)For the radiocaesium uptake from agricultural soilsthe transfer factors range up to three orders of mag-nitude even for individual soilndashcrop combinations(5)The high 137Csraw plant

137Cssoil ratio of 0706 in thegrass samples could be caused by direct adsorptionof radioactive caesium deposited on the leaves androot uptake which spreads the roots to groundsurface similar to an open net The clover samplesalso have a shallow root system and spreads roots Itwas difficult to distinguish whether radiocaesiumoriginated from root uptake or direct adsorption onthe leaves just after the nuclear accident It isexpected that in future radioactive caesium willT

able

1R

adio

activ

ities

for

high

lyco

ntam

inat

edso

ilsa

mpl

es(13

4 Cs

gt50

kBq

kg2

1 )an

ddi

stan

cefr

omth

eFu

kush

ima

Dai

ichi

Nuc

lear

pow

erpl

ant

Rad

ioac

tivie

sar

eco

rrec

ted

to11

Mar

ch20

11

Sam

ple

Lat

itud

eL

ongi

tude

Dis

tanc

efr

omth

eF

D1N

PP

(km

)

Dat

e13

4 Cs

(kB

qkg

21 )

137 C

s(k

Bq

kg2

1 )

131 I

(kB

qkg

21 )

110m

Ag

(kB

qkg

21 )

129m

Te(k

Bq

kg2

1 )12

9Te

(kB

qkg

21 )

Col

lect

ion

Mea

sure

men

t

S12

3783

450

N14

0852

90 E

218

14A

pr20

1130

May

2011

821+

02

835+

02

426+

700

52+

004

75+

647

+4

S15

3783

440

N14

0847

60 E

272

14A

pr20

1131

May

2011

511+

02

516+

02

555+

580

17+

003

64+

541

+3

S46

3783

390

N14

0847

00 E

273

6Ju

ne20

1122

July

2011

699+

02

722+

02

778+

620

27+

004

89+

556

+3

S48

3783

390

N14

0847

00 E

273

6Ju

ne20

1122

July

2011

601+

04

597+

02

743+

600

26+

003

82+

552

+3

S49

3783

530

N14

0847

50 E

283

6Ju

ne20

1123

July

2011

610+

02

622+

02

692+

590

23+

004

69+

543

+3

S54

3783

700

N14

0846

00 E

322

7Ju

ne20

1123

July

2011

844+

03

820+

03

924+

840

40+

005

89+

756

+5

S63

3784

650

N14

0828

30 E

633

6Ju

ne20

1122

July

2011

542+

01

542+

01

mdash0

12+

001

60+

538

+3

H TAZOE ET AL

200

at St Petersburg State University on February 3 2014

httprpdoxfordjournalsorgD

ownloaded from

migrate to the environmental ecosystem Thereforeit is necessary to investigate the processes and trans-fer parameters

CONCLUSIONS

We investigated radionuclides for the soil and plantsamples in Fukushima Prefecture just after the acci-dent of the Fukushima Daiichi nuclear reactors

between 12 and 15 March 2011 The pollution wasgenerally spread to the northwestward as reportedby the MEXT survey However regional heterogene-ities of deposition and differences between radionu-clides were observed It indicates that more detailedstudies are necessary for effective decontaminationBamboo leaves grasses and pine trees were highlycontaminated at the high dose rate areas of

Figure 3 134Cs and 137Cs concentrations for paddy soilsamples collected at Minami-Tsushima Namie town Concen-

trations are corrected to the sampling data of 12 April

Figure 2 Concentration ratios against 137Cs for soil samples

Figure 4 Comparison of radiocaesium concentration insoil between the outside and inside of the greenhouse

RADIOACTIVE POLLUTION FROM FUKUSHIMA DAIICHI NUCLEAR POWER PLANT

201

at St Petersburg State University on February 3 2014

httprpdoxfordjournalsorgD

ownloaded from

Tsushim

aand

Minam

i-Tsushim

ain

Nam

ietow

nM

ugwort

leavesthat

grewafter

thepollution

eventhad

extremely

lowconcentration

ofradionuclides

however

theplantsoil

radiocaesiumratio

was

Figure

5C

oncentrationof

radioactivenuclides

forplant

leaves(L

11cryptom

eriaL

12bam

booand

L13

clinopodiumgracile)

andneighbouring

soilcollectedfrom

theTetsuzan

dam(S12

ndashS14)C

oncentrationsare

correctedto

12A

pril

Figure

6R

adiocaesiumconcentration

variousplant

sample

onA

prilfromthe

Nam

ietow

n

Figure

7C

omparison

ofthe

137Cs

concentrationfor

soiland

plantsam

plescollected

onM

archand

July

Table 2 Comparisons of radioactive caesium concentration between soil and plant samples

Location City Soil 134Cs137Cs Law plant 137CsLaw Plant137CsSoil

134Cs(kBq kg21)

137Cs(kBq kg21)

134Cs(kBq kg21)

137Cs(kBq kg21)

134Cs137Cs

Shinobuyama Park Fukushima 2689+003 2709+003 099 Mugwort 0264+0002 0268+0002 099 0010Asaka Town Koriyama 1138+001 1164+001 098 Mugwort 0232+0002 0234+0002 099 0020Aasaka-NagamoriStation

Koriyama 609+001 625+001 097 Mugwort 0126+0001 0123+0001 103 0020

Kaiseizan Park Koriyama 1674+002 1659+002 101 Mugwort 0488+0008 0499+0008 098 0030Araike Park Koriyama 1612+002 1588+002 102 Mugwort 0287+0006 0292+0006 098 0018Takako Pond Date 948+001 959+001 099 Mugwort 0267+0003 0277+0002 097 0029Zenpo Pond Koriyama 1047+001 1077+001 097 Clover 0277+0005 0281+0005 099 0026Keiko Park Motomiya 846+001 836+001 101 Grass 5975+0013 5902+0013 101 0706

HTA

ZO

EE

TA

L

202

at St Petersburg State University on February 3 2014 httprpdoxfordjournalsorg Downloaded from

0023+0006 Finally it is anticipated that the de-composition of fallen leaves will promote recyclingof radionuclides in the environment

FUNDING

This work was supported by MEXTJSPSKAKENHI Grant-in-Aid for Scientific Research B(2431002)

REFERENCES

1 Chino M Nakayama H Nagai H Terada HKatata G and Yamazawa H Preliminary estimation ofrelease amount of 131I and 137Cs accidentally dischargedfrom the Fukushima Daiichi Nuclear Power Plant intothe atmosphere J Nucl Sci Tech 48 1129ndash1134(2011)

2 Yasunari J T Stohl A Hayano R S Burkhart J FEckhardt S and Yasunari T Cesium-137 depositionand contamination of Japanese soils due to theFukushima nuclear accident Proc Natl Acad Sci USA(2011) Doi101073pnas1112058108

3 Kinoshita N Sueki K Sasa K Kitagawa JIkarashia S Nishimura T Wong Y Satou YHanda K Takahashi T Sato M and Yamagata TAssessment of individual radionuclide distributions fromthe Fukushima nuclear accident covering central-eastJapan Proc Natl Acad Sci USA (2011) Doi101073pnas1111724108

4 Hosoda M Tokonami S Sorimachi A Monzen SOsanai M Yamada M Kashiwakura I and AkibaS The time variation of dose rate artificially increased bythe Fukushima nuclear crisis Scientific Reports 87 doi101038sep00087

5 Nisbet A F and Woodman R F M Soil-to-planttransfer factors for radio caesium and strontium in agri-cultural systems Health Phys 78 279ndash288 (2000)

RADIOACTIVE POLLUTION FROM FUKUSHIMA DAIICHI NUCLEAR POWER PLANT

203

at St Petersburg State University on February 3 2014

httprpdoxfordjournalsorgD

ownloaded from

  • INTRODUCTION
  • MATERIALS AND METHODS
  • RESULTS AND DISCUSSION
    • Heterogeneous deposition of radionuclides on the ground
    • Deposition and translocation of radionuclides to the plant
      • CONCLUSIONS
      • FUNDING
      • REFERENCES
Page 2: Radioactive pollution from Fukushima Daiichi nuclear power plant in the terrestrial environment

kg21 concentration is corrected to March 11)110mAg (040 kBq kg21) 129Te (563 kBq kg21) and129mTe (894 kBq kg21) were detected for the samesample on March and April Furthermore the ex-tremely high-dose rates after dispersion from thenuclear power plant were thought to be mainlycaused by 132Te and its daughter 132I based on thein situ gamma-ray spectrum(3) High radiocaesiumconcentrations were observed in the northwesternNamie town (S46) and southwestern Minamisohmacity near the Tetsuzan dam (S12) which are locatednorthwest of the Fukushima Daiichi nuclear powerplant This is consistent with the results of aircraftmonitoring by the Ministry of Education CultureSports Science and Technology Japan (MEXT httpwwwmextgojpenglishincident1304796htm)Fukushima city is located on the major contamin-ation path that also shows heterogeneous geograph-ical distribution particularly anomalous highconcentrations for S63 (Table 1) This resulted fromgeographical features such as the surrounding moun-tains and the setting of buildings and trees becauseFukushima city is densely populated

Concentration ratios against 137Cs for 134Cs and129mTe are mostly constant (Fig 2) although thosefor the 131I and 129mTe are observed different trends131I137Cs ratios decrease from 32 to 10 with 137Csconcentration (10 kBq kg21) On the contrary110mAg137Cs increase for high 137Cs samples (50kBq kg21) These fractionations were caused by thephysical andor chemical properties for each nuclideduring transportation and deposition processes

Hosoda et al(4) reported that the highestambient-dose rate in air was 36 mGy h21 atHirusone Namie town (37558N 1408478E) on thebasis of the carborne survey conducted on 12 April2011 Regional heterogeneity in radiocaesium

distribution was observed at Minami-TsushimaNamie town (Fig 3) Concentrations of 137Cs col-lected from the three paddies (S19 S27 and S36)widely vary ranging from 024 to 99 kBq kg21 Inthe same paddy much lower radiocaesium concen-trations are observed in samples S19-1 and S36-1relative to the other soil samples The heterogeneousdistribution of 137Cs concentration can reflect boththe initial deposition in the surface soil and the post-depositional redistribution such as transportationadsorbed soil particles by the rainfall in the soil

The soil sample from inside a greenhouse inTsushima Namie town had much lower 137Cs con-centration than the soil outside the greenhouse(Fig 4) This indicates that the major deposition tookplace during wet precipitation and that the inside wasnot contaminated The radiocaesium deposition pri-marily occurs in association with precipitation (3)This indicates that the intrusion of radiocaesiumindoors could be prevented easily

Deposition and translocation of radionuclides to theplant

Figure 5 shows the concentration of radionuclides insoils (S12ndashS14) and plant samples (L11ndashL13) nearthe Tetsuzan dam corrected to 12 April Plantsamples L11 L12 and L13 are leaves of Japaneseceder bamboo and clinopodium gracile respectivelyThe concentrations of radionuclides in S12 arenearly twice of that in others On the other handplant samples show much wider variation in radio-caesium concentration Japanese ceder leaves havelow radiocaesium concentrations (134Csfrac14118 kBqkg21 and 137Csfrac14118 kBq kg21) Bamboo leaveshave concentrations several folds higher than thoseof soils and other plants In cryptomeria this could

Figure 1 Map of the soil sampling locations and total radioactive caesium concentrations (134Csthorn137Cs) The soilsamples observed high radiocaesium concentration (134Csthorn137Cs 100 kBq kg21) are shown on the map and Table 1

RADIOACTIVE POLLUTION FROM FUKUSHIMA DAIICHI NUCLEAR POWER PLANT

199

at St Petersburg State University on February 3 2014

httprpdoxfordjournalsorgD

ownloaded from

depend on the height of the branch Since Japaneseceder leaf samples were collected from the lowerpart of trees overlapped with other branches the de-position of radionuclides was inhibited and theobserved radiocaesium concentrations were low Onthe other hand bamboo leaves did not overlap witheach other and the radionuclides were well depositedon the entire leaf Furthermore the low moisturecontent of the bamboo leaves resulted in higherradioactive caesium

Plant samples were collected in Namie town in 13and 14 April The samples were located close to thetown and the radiocaesium concentration consider-ably fluctuated (Fig 6) For example the concentra-tion in the outer leaves of cabbages was 50 timeshigher than that in the inner leaves The radionu-clides except 134Cs and 137Cs in the inner cabbageleaves were below the detection limit in the gamma-ray measurements The translocation from the outerleaves caused 090 kBq kg21 of 134Cs and 101 kBqkg21 of 137Cs which originated from the nuclearaccident

For the period between March and June 2011137Cs in soils and plants from Koriyama city wascompared (Fig 7) Bamboo clover and pine leaveswere collected on 17 March Japanese mugwort wascollected in 16 June Japanese mugwort is a peren-nial plant and only the underground stem is over-wintering In the part that grew after the nuclearplant accident the 137Cs concentration reflects ab-sorption via the root from the soil The root of theJapanese mugwort splits at shallow depths Thedeposited radiocaesium was transferred to the rest ofthe plant by root uptake and translocation

Radioactive caesium was compared between soilsand plants (Table 2) Plants were mainly collectedfrom Japanese mugwort except for clover from theZenpo pond and grass leaves from the Keiko parkin June and July 2011 Although 137Cs in the soilsamples ranges from 63 to 271 kBq kg21 theJapanese mugwort shows extremely low concentra-tions 05 Bq kg21 of 137Cs Only grass leaf showshigh radioactive caesium The concentration ratiosbetween plant and soil 137Csraw plant

137Cssoil formugwort were relatively constant (0023+0006)For the radiocaesium uptake from agricultural soilsthe transfer factors range up to three orders of mag-nitude even for individual soilndashcrop combinations(5)The high 137Csraw plant

137Cssoil ratio of 0706 in thegrass samples could be caused by direct adsorptionof radioactive caesium deposited on the leaves androot uptake which spreads the roots to groundsurface similar to an open net The clover samplesalso have a shallow root system and spreads roots Itwas difficult to distinguish whether radiocaesiumoriginated from root uptake or direct adsorption onthe leaves just after the nuclear accident It isexpected that in future radioactive caesium willT

able

1R

adio

activ

ities

for

high

lyco

ntam

inat

edso

ilsa

mpl

es(13

4 Cs

gt50

kBq

kg2

1 )an

ddi

stan

cefr

omth

eFu

kush

ima

Dai

ichi

Nuc

lear

pow

erpl

ant

Rad

ioac

tivie

sar

eco

rrec

ted

to11

Mar

ch20

11

Sam

ple

Lat

itud

eL

ongi

tude

Dis

tanc

efr

omth

eF

D1N

PP

(km

)

Dat

e13

4 Cs

(kB

qkg

21 )

137 C

s(k

Bq

kg2

1 )

131 I

(kB

qkg

21 )

110m

Ag

(kB

qkg

21 )

129m

Te(k

Bq

kg2

1 )12

9Te

(kB

qkg

21 )

Col

lect

ion

Mea

sure

men

t

S12

3783

450

N14

0852

90 E

218

14A

pr20

1130

May

2011

821+

02

835+

02

426+

700

52+

004

75+

647

+4

S15

3783

440

N14

0847

60 E

272

14A

pr20

1131

May

2011

511+

02

516+

02

555+

580

17+

003

64+

541

+3

S46

3783

390

N14

0847

00 E

273

6Ju

ne20

1122

July

2011

699+

02

722+

02

778+

620

27+

004

89+

556

+3

S48

3783

390

N14

0847

00 E

273

6Ju

ne20

1122

July

2011

601+

04

597+

02

743+

600

26+

003

82+

552

+3

S49

3783

530

N14

0847

50 E

283

6Ju

ne20

1123

July

2011

610+

02

622+

02

692+

590

23+

004

69+

543

+3

S54

3783

700

N14

0846

00 E

322

7Ju

ne20

1123

July

2011

844+

03

820+

03

924+

840

40+

005

89+

756

+5

S63

3784

650

N14

0828

30 E

633

6Ju

ne20

1122

July

2011

542+

01

542+

01

mdash0

12+

001

60+

538

+3

H TAZOE ET AL

200

at St Petersburg State University on February 3 2014

httprpdoxfordjournalsorgD

ownloaded from

migrate to the environmental ecosystem Thereforeit is necessary to investigate the processes and trans-fer parameters

CONCLUSIONS

We investigated radionuclides for the soil and plantsamples in Fukushima Prefecture just after the acci-dent of the Fukushima Daiichi nuclear reactors

between 12 and 15 March 2011 The pollution wasgenerally spread to the northwestward as reportedby the MEXT survey However regional heterogene-ities of deposition and differences between radionu-clides were observed It indicates that more detailedstudies are necessary for effective decontaminationBamboo leaves grasses and pine trees were highlycontaminated at the high dose rate areas of

Figure 3 134Cs and 137Cs concentrations for paddy soilsamples collected at Minami-Tsushima Namie town Concen-

trations are corrected to the sampling data of 12 April

Figure 2 Concentration ratios against 137Cs for soil samples

Figure 4 Comparison of radiocaesium concentration insoil between the outside and inside of the greenhouse

RADIOACTIVE POLLUTION FROM FUKUSHIMA DAIICHI NUCLEAR POWER PLANT

201

at St Petersburg State University on February 3 2014

httprpdoxfordjournalsorgD

ownloaded from

Tsushim

aand

Minam

i-Tsushim

ain

Nam

ietow

nM

ugwort

leavesthat

grewafter

thepollution

eventhad

extremely

lowconcentration

ofradionuclides

however

theplantsoil

radiocaesiumratio

was

Figure

5C

oncentrationof

radioactivenuclides

forplant

leaves(L

11cryptom

eriaL

12bam

booand

L13

clinopodiumgracile)

andneighbouring

soilcollectedfrom

theTetsuzan

dam(S12

ndashS14)C

oncentrationsare

correctedto

12A

pril

Figure

6R

adiocaesiumconcentration

variousplant

sample

onA

prilfromthe

Nam

ietow

n

Figure

7C

omparison

ofthe

137Cs

concentrationfor

soiland

plantsam

plescollected

onM

archand

July

Table 2 Comparisons of radioactive caesium concentration between soil and plant samples

Location City Soil 134Cs137Cs Law plant 137CsLaw Plant137CsSoil

134Cs(kBq kg21)

137Cs(kBq kg21)

134Cs(kBq kg21)

137Cs(kBq kg21)

134Cs137Cs

Shinobuyama Park Fukushima 2689+003 2709+003 099 Mugwort 0264+0002 0268+0002 099 0010Asaka Town Koriyama 1138+001 1164+001 098 Mugwort 0232+0002 0234+0002 099 0020Aasaka-NagamoriStation

Koriyama 609+001 625+001 097 Mugwort 0126+0001 0123+0001 103 0020

Kaiseizan Park Koriyama 1674+002 1659+002 101 Mugwort 0488+0008 0499+0008 098 0030Araike Park Koriyama 1612+002 1588+002 102 Mugwort 0287+0006 0292+0006 098 0018Takako Pond Date 948+001 959+001 099 Mugwort 0267+0003 0277+0002 097 0029Zenpo Pond Koriyama 1047+001 1077+001 097 Clover 0277+0005 0281+0005 099 0026Keiko Park Motomiya 846+001 836+001 101 Grass 5975+0013 5902+0013 101 0706

HTA

ZO

EE

TA

L

202

at St Petersburg State University on February 3 2014 httprpdoxfordjournalsorg Downloaded from

0023+0006 Finally it is anticipated that the de-composition of fallen leaves will promote recyclingof radionuclides in the environment

FUNDING

This work was supported by MEXTJSPSKAKENHI Grant-in-Aid for Scientific Research B(2431002)

REFERENCES

1 Chino M Nakayama H Nagai H Terada HKatata G and Yamazawa H Preliminary estimation ofrelease amount of 131I and 137Cs accidentally dischargedfrom the Fukushima Daiichi Nuclear Power Plant intothe atmosphere J Nucl Sci Tech 48 1129ndash1134(2011)

2 Yasunari J T Stohl A Hayano R S Burkhart J FEckhardt S and Yasunari T Cesium-137 depositionand contamination of Japanese soils due to theFukushima nuclear accident Proc Natl Acad Sci USA(2011) Doi101073pnas1112058108

3 Kinoshita N Sueki K Sasa K Kitagawa JIkarashia S Nishimura T Wong Y Satou YHanda K Takahashi T Sato M and Yamagata TAssessment of individual radionuclide distributions fromthe Fukushima nuclear accident covering central-eastJapan Proc Natl Acad Sci USA (2011) Doi101073pnas1111724108

4 Hosoda M Tokonami S Sorimachi A Monzen SOsanai M Yamada M Kashiwakura I and AkibaS The time variation of dose rate artificially increased bythe Fukushima nuclear crisis Scientific Reports 87 doi101038sep00087

5 Nisbet A F and Woodman R F M Soil-to-planttransfer factors for radio caesium and strontium in agri-cultural systems Health Phys 78 279ndash288 (2000)

RADIOACTIVE POLLUTION FROM FUKUSHIMA DAIICHI NUCLEAR POWER PLANT

203

at St Petersburg State University on February 3 2014

httprpdoxfordjournalsorgD

ownloaded from

  • INTRODUCTION
  • MATERIALS AND METHODS
  • RESULTS AND DISCUSSION
    • Heterogeneous deposition of radionuclides on the ground
    • Deposition and translocation of radionuclides to the plant
      • CONCLUSIONS
      • FUNDING
      • REFERENCES
Page 3: Radioactive pollution from Fukushima Daiichi nuclear power plant in the terrestrial environment

depend on the height of the branch Since Japaneseceder leaf samples were collected from the lowerpart of trees overlapped with other branches the de-position of radionuclides was inhibited and theobserved radiocaesium concentrations were low Onthe other hand bamboo leaves did not overlap witheach other and the radionuclides were well depositedon the entire leaf Furthermore the low moisturecontent of the bamboo leaves resulted in higherradioactive caesium

Plant samples were collected in Namie town in 13and 14 April The samples were located close to thetown and the radiocaesium concentration consider-ably fluctuated (Fig 6) For example the concentra-tion in the outer leaves of cabbages was 50 timeshigher than that in the inner leaves The radionu-clides except 134Cs and 137Cs in the inner cabbageleaves were below the detection limit in the gamma-ray measurements The translocation from the outerleaves caused 090 kBq kg21 of 134Cs and 101 kBqkg21 of 137Cs which originated from the nuclearaccident

For the period between March and June 2011137Cs in soils and plants from Koriyama city wascompared (Fig 7) Bamboo clover and pine leaveswere collected on 17 March Japanese mugwort wascollected in 16 June Japanese mugwort is a peren-nial plant and only the underground stem is over-wintering In the part that grew after the nuclearplant accident the 137Cs concentration reflects ab-sorption via the root from the soil The root of theJapanese mugwort splits at shallow depths Thedeposited radiocaesium was transferred to the rest ofthe plant by root uptake and translocation

Radioactive caesium was compared between soilsand plants (Table 2) Plants were mainly collectedfrom Japanese mugwort except for clover from theZenpo pond and grass leaves from the Keiko parkin June and July 2011 Although 137Cs in the soilsamples ranges from 63 to 271 kBq kg21 theJapanese mugwort shows extremely low concentra-tions 05 Bq kg21 of 137Cs Only grass leaf showshigh radioactive caesium The concentration ratiosbetween plant and soil 137Csraw plant

137Cssoil formugwort were relatively constant (0023+0006)For the radiocaesium uptake from agricultural soilsthe transfer factors range up to three orders of mag-nitude even for individual soilndashcrop combinations(5)The high 137Csraw plant

137Cssoil ratio of 0706 in thegrass samples could be caused by direct adsorptionof radioactive caesium deposited on the leaves androot uptake which spreads the roots to groundsurface similar to an open net The clover samplesalso have a shallow root system and spreads roots Itwas difficult to distinguish whether radiocaesiumoriginated from root uptake or direct adsorption onthe leaves just after the nuclear accident It isexpected that in future radioactive caesium willT

able

1R

adio

activ

ities

for

high

lyco

ntam

inat

edso

ilsa

mpl

es(13

4 Cs

gt50

kBq

kg2

1 )an

ddi

stan

cefr

omth

eFu

kush

ima

Dai

ichi

Nuc

lear

pow

erpl

ant

Rad

ioac

tivie

sar

eco

rrec

ted

to11

Mar

ch20

11

Sam

ple

Lat

itud

eL

ongi

tude

Dis

tanc

efr

omth

eF

D1N

PP

(km

)

Dat

e13

4 Cs

(kB

qkg

21 )

137 C

s(k

Bq

kg2

1 )

131 I

(kB

qkg

21 )

110m

Ag

(kB

qkg

21 )

129m

Te(k

Bq

kg2

1 )12

9Te

(kB

qkg

21 )

Col

lect

ion

Mea

sure

men

t

S12

3783

450

N14

0852

90 E

218

14A

pr20

1130

May

2011

821+

02

835+

02

426+

700

52+

004

75+

647

+4

S15

3783

440

N14

0847

60 E

272

14A

pr20

1131

May

2011

511+

02

516+

02

555+

580

17+

003

64+

541

+3

S46

3783

390

N14

0847

00 E

273

6Ju

ne20

1122

July

2011

699+

02

722+

02

778+

620

27+

004

89+

556

+3

S48

3783

390

N14

0847

00 E

273

6Ju

ne20

1122

July

2011

601+

04

597+

02

743+

600

26+

003

82+

552

+3

S49

3783

530

N14

0847

50 E

283

6Ju

ne20

1123

July

2011

610+

02

622+

02

692+

590

23+

004

69+

543

+3

S54

3783

700

N14

0846

00 E

322

7Ju

ne20

1123

July

2011

844+

03

820+

03

924+

840

40+

005

89+

756

+5

S63

3784

650

N14

0828

30 E

633

6Ju

ne20

1122

July

2011

542+

01

542+

01

mdash0

12+

001

60+

538

+3

H TAZOE ET AL

200

at St Petersburg State University on February 3 2014

httprpdoxfordjournalsorgD

ownloaded from

migrate to the environmental ecosystem Thereforeit is necessary to investigate the processes and trans-fer parameters

CONCLUSIONS

We investigated radionuclides for the soil and plantsamples in Fukushima Prefecture just after the acci-dent of the Fukushima Daiichi nuclear reactors

between 12 and 15 March 2011 The pollution wasgenerally spread to the northwestward as reportedby the MEXT survey However regional heterogene-ities of deposition and differences between radionu-clides were observed It indicates that more detailedstudies are necessary for effective decontaminationBamboo leaves grasses and pine trees were highlycontaminated at the high dose rate areas of

Figure 3 134Cs and 137Cs concentrations for paddy soilsamples collected at Minami-Tsushima Namie town Concen-

trations are corrected to the sampling data of 12 April

Figure 2 Concentration ratios against 137Cs for soil samples

Figure 4 Comparison of radiocaesium concentration insoil between the outside and inside of the greenhouse

RADIOACTIVE POLLUTION FROM FUKUSHIMA DAIICHI NUCLEAR POWER PLANT

201

at St Petersburg State University on February 3 2014

httprpdoxfordjournalsorgD

ownloaded from

Tsushim

aand

Minam

i-Tsushim

ain

Nam

ietow

nM

ugwort

leavesthat

grewafter

thepollution

eventhad

extremely

lowconcentration

ofradionuclides

however

theplantsoil

radiocaesiumratio

was

Figure

5C

oncentrationof

radioactivenuclides

forplant

leaves(L

11cryptom

eriaL

12bam

booand

L13

clinopodiumgracile)

andneighbouring

soilcollectedfrom

theTetsuzan

dam(S12

ndashS14)C

oncentrationsare

correctedto

12A

pril

Figure

6R

adiocaesiumconcentration

variousplant

sample

onA

prilfromthe

Nam

ietow

n

Figure

7C

omparison

ofthe

137Cs

concentrationfor

soiland

plantsam

plescollected

onM

archand

July

Table 2 Comparisons of radioactive caesium concentration between soil and plant samples

Location City Soil 134Cs137Cs Law plant 137CsLaw Plant137CsSoil

134Cs(kBq kg21)

137Cs(kBq kg21)

134Cs(kBq kg21)

137Cs(kBq kg21)

134Cs137Cs

Shinobuyama Park Fukushima 2689+003 2709+003 099 Mugwort 0264+0002 0268+0002 099 0010Asaka Town Koriyama 1138+001 1164+001 098 Mugwort 0232+0002 0234+0002 099 0020Aasaka-NagamoriStation

Koriyama 609+001 625+001 097 Mugwort 0126+0001 0123+0001 103 0020

Kaiseizan Park Koriyama 1674+002 1659+002 101 Mugwort 0488+0008 0499+0008 098 0030Araike Park Koriyama 1612+002 1588+002 102 Mugwort 0287+0006 0292+0006 098 0018Takako Pond Date 948+001 959+001 099 Mugwort 0267+0003 0277+0002 097 0029Zenpo Pond Koriyama 1047+001 1077+001 097 Clover 0277+0005 0281+0005 099 0026Keiko Park Motomiya 846+001 836+001 101 Grass 5975+0013 5902+0013 101 0706

HTA

ZO

EE

TA

L

202

at St Petersburg State University on February 3 2014 httprpdoxfordjournalsorg Downloaded from

0023+0006 Finally it is anticipated that the de-composition of fallen leaves will promote recyclingof radionuclides in the environment

FUNDING

This work was supported by MEXTJSPSKAKENHI Grant-in-Aid for Scientific Research B(2431002)

REFERENCES

1 Chino M Nakayama H Nagai H Terada HKatata G and Yamazawa H Preliminary estimation ofrelease amount of 131I and 137Cs accidentally dischargedfrom the Fukushima Daiichi Nuclear Power Plant intothe atmosphere J Nucl Sci Tech 48 1129ndash1134(2011)

2 Yasunari J T Stohl A Hayano R S Burkhart J FEckhardt S and Yasunari T Cesium-137 depositionand contamination of Japanese soils due to theFukushima nuclear accident Proc Natl Acad Sci USA(2011) Doi101073pnas1112058108

3 Kinoshita N Sueki K Sasa K Kitagawa JIkarashia S Nishimura T Wong Y Satou YHanda K Takahashi T Sato M and Yamagata TAssessment of individual radionuclide distributions fromthe Fukushima nuclear accident covering central-eastJapan Proc Natl Acad Sci USA (2011) Doi101073pnas1111724108

4 Hosoda M Tokonami S Sorimachi A Monzen SOsanai M Yamada M Kashiwakura I and AkibaS The time variation of dose rate artificially increased bythe Fukushima nuclear crisis Scientific Reports 87 doi101038sep00087

5 Nisbet A F and Woodman R F M Soil-to-planttransfer factors for radio caesium and strontium in agri-cultural systems Health Phys 78 279ndash288 (2000)

RADIOACTIVE POLLUTION FROM FUKUSHIMA DAIICHI NUCLEAR POWER PLANT

203

at St Petersburg State University on February 3 2014

httprpdoxfordjournalsorgD

ownloaded from

  • INTRODUCTION
  • MATERIALS AND METHODS
  • RESULTS AND DISCUSSION
    • Heterogeneous deposition of radionuclides on the ground
    • Deposition and translocation of radionuclides to the plant
      • CONCLUSIONS
      • FUNDING
      • REFERENCES
Page 4: Radioactive pollution from Fukushima Daiichi nuclear power plant in the terrestrial environment

migrate to the environmental ecosystem Thereforeit is necessary to investigate the processes and trans-fer parameters

CONCLUSIONS

We investigated radionuclides for the soil and plantsamples in Fukushima Prefecture just after the acci-dent of the Fukushima Daiichi nuclear reactors

between 12 and 15 March 2011 The pollution wasgenerally spread to the northwestward as reportedby the MEXT survey However regional heterogene-ities of deposition and differences between radionu-clides were observed It indicates that more detailedstudies are necessary for effective decontaminationBamboo leaves grasses and pine trees were highlycontaminated at the high dose rate areas of

Figure 3 134Cs and 137Cs concentrations for paddy soilsamples collected at Minami-Tsushima Namie town Concen-

trations are corrected to the sampling data of 12 April

Figure 2 Concentration ratios against 137Cs for soil samples

Figure 4 Comparison of radiocaesium concentration insoil between the outside and inside of the greenhouse

RADIOACTIVE POLLUTION FROM FUKUSHIMA DAIICHI NUCLEAR POWER PLANT

201

at St Petersburg State University on February 3 2014

httprpdoxfordjournalsorgD

ownloaded from

Tsushim

aand

Minam

i-Tsushim

ain

Nam

ietow

nM

ugwort

leavesthat

grewafter

thepollution

eventhad

extremely

lowconcentration

ofradionuclides

however

theplantsoil

radiocaesiumratio

was

Figure

5C

oncentrationof

radioactivenuclides

forplant

leaves(L

11cryptom

eriaL

12bam

booand

L13

clinopodiumgracile)

andneighbouring

soilcollectedfrom

theTetsuzan

dam(S12

ndashS14)C

oncentrationsare

correctedto

12A

pril

Figure

6R

adiocaesiumconcentration

variousplant

sample

onA

prilfromthe

Nam

ietow

n

Figure

7C

omparison

ofthe

137Cs

concentrationfor

soiland

plantsam

plescollected

onM

archand

July

Table 2 Comparisons of radioactive caesium concentration between soil and plant samples

Location City Soil 134Cs137Cs Law plant 137CsLaw Plant137CsSoil

134Cs(kBq kg21)

137Cs(kBq kg21)

134Cs(kBq kg21)

137Cs(kBq kg21)

134Cs137Cs

Shinobuyama Park Fukushima 2689+003 2709+003 099 Mugwort 0264+0002 0268+0002 099 0010Asaka Town Koriyama 1138+001 1164+001 098 Mugwort 0232+0002 0234+0002 099 0020Aasaka-NagamoriStation

Koriyama 609+001 625+001 097 Mugwort 0126+0001 0123+0001 103 0020

Kaiseizan Park Koriyama 1674+002 1659+002 101 Mugwort 0488+0008 0499+0008 098 0030Araike Park Koriyama 1612+002 1588+002 102 Mugwort 0287+0006 0292+0006 098 0018Takako Pond Date 948+001 959+001 099 Mugwort 0267+0003 0277+0002 097 0029Zenpo Pond Koriyama 1047+001 1077+001 097 Clover 0277+0005 0281+0005 099 0026Keiko Park Motomiya 846+001 836+001 101 Grass 5975+0013 5902+0013 101 0706

HTA

ZO

EE

TA

L

202

at St Petersburg State University on February 3 2014 httprpdoxfordjournalsorg Downloaded from

0023+0006 Finally it is anticipated that the de-composition of fallen leaves will promote recyclingof radionuclides in the environment

FUNDING

This work was supported by MEXTJSPSKAKENHI Grant-in-Aid for Scientific Research B(2431002)

REFERENCES

1 Chino M Nakayama H Nagai H Terada HKatata G and Yamazawa H Preliminary estimation ofrelease amount of 131I and 137Cs accidentally dischargedfrom the Fukushima Daiichi Nuclear Power Plant intothe atmosphere J Nucl Sci Tech 48 1129ndash1134(2011)

2 Yasunari J T Stohl A Hayano R S Burkhart J FEckhardt S and Yasunari T Cesium-137 depositionand contamination of Japanese soils due to theFukushima nuclear accident Proc Natl Acad Sci USA(2011) Doi101073pnas1112058108

3 Kinoshita N Sueki K Sasa K Kitagawa JIkarashia S Nishimura T Wong Y Satou YHanda K Takahashi T Sato M and Yamagata TAssessment of individual radionuclide distributions fromthe Fukushima nuclear accident covering central-eastJapan Proc Natl Acad Sci USA (2011) Doi101073pnas1111724108

4 Hosoda M Tokonami S Sorimachi A Monzen SOsanai M Yamada M Kashiwakura I and AkibaS The time variation of dose rate artificially increased bythe Fukushima nuclear crisis Scientific Reports 87 doi101038sep00087

5 Nisbet A F and Woodman R F M Soil-to-planttransfer factors for radio caesium and strontium in agri-cultural systems Health Phys 78 279ndash288 (2000)

RADIOACTIVE POLLUTION FROM FUKUSHIMA DAIICHI NUCLEAR POWER PLANT

203

at St Petersburg State University on February 3 2014

httprpdoxfordjournalsorgD

ownloaded from

  • INTRODUCTION
  • MATERIALS AND METHODS
  • RESULTS AND DISCUSSION
    • Heterogeneous deposition of radionuclides on the ground
    • Deposition and translocation of radionuclides to the plant
      • CONCLUSIONS
      • FUNDING
      • REFERENCES
Page 5: Radioactive pollution from Fukushima Daiichi nuclear power plant in the terrestrial environment

Tsushim

aand

Minam

i-Tsushim

ain

Nam

ietow

nM

ugwort

leavesthat

grewafter

thepollution

eventhad

extremely

lowconcentration

ofradionuclides

however

theplantsoil

radiocaesiumratio

was

Figure

5C

oncentrationof

radioactivenuclides

forplant

leaves(L

11cryptom

eriaL

12bam

booand

L13

clinopodiumgracile)

andneighbouring

soilcollectedfrom

theTetsuzan

dam(S12

ndashS14)C

oncentrationsare

correctedto

12A

pril

Figure

6R

adiocaesiumconcentration

variousplant

sample

onA

prilfromthe

Nam

ietow

n

Figure

7C

omparison

ofthe

137Cs

concentrationfor

soiland

plantsam

plescollected

onM

archand

July

Table 2 Comparisons of radioactive caesium concentration between soil and plant samples

Location City Soil 134Cs137Cs Law plant 137CsLaw Plant137CsSoil

134Cs(kBq kg21)

137Cs(kBq kg21)

134Cs(kBq kg21)

137Cs(kBq kg21)

134Cs137Cs

Shinobuyama Park Fukushima 2689+003 2709+003 099 Mugwort 0264+0002 0268+0002 099 0010Asaka Town Koriyama 1138+001 1164+001 098 Mugwort 0232+0002 0234+0002 099 0020Aasaka-NagamoriStation

Koriyama 609+001 625+001 097 Mugwort 0126+0001 0123+0001 103 0020

Kaiseizan Park Koriyama 1674+002 1659+002 101 Mugwort 0488+0008 0499+0008 098 0030Araike Park Koriyama 1612+002 1588+002 102 Mugwort 0287+0006 0292+0006 098 0018Takako Pond Date 948+001 959+001 099 Mugwort 0267+0003 0277+0002 097 0029Zenpo Pond Koriyama 1047+001 1077+001 097 Clover 0277+0005 0281+0005 099 0026Keiko Park Motomiya 846+001 836+001 101 Grass 5975+0013 5902+0013 101 0706

HTA

ZO

EE

TA

L

202

at St Petersburg State University on February 3 2014 httprpdoxfordjournalsorg Downloaded from

0023+0006 Finally it is anticipated that the de-composition of fallen leaves will promote recyclingof radionuclides in the environment

FUNDING

This work was supported by MEXTJSPSKAKENHI Grant-in-Aid for Scientific Research B(2431002)

REFERENCES

1 Chino M Nakayama H Nagai H Terada HKatata G and Yamazawa H Preliminary estimation ofrelease amount of 131I and 137Cs accidentally dischargedfrom the Fukushima Daiichi Nuclear Power Plant intothe atmosphere J Nucl Sci Tech 48 1129ndash1134(2011)

2 Yasunari J T Stohl A Hayano R S Burkhart J FEckhardt S and Yasunari T Cesium-137 depositionand contamination of Japanese soils due to theFukushima nuclear accident Proc Natl Acad Sci USA(2011) Doi101073pnas1112058108

3 Kinoshita N Sueki K Sasa K Kitagawa JIkarashia S Nishimura T Wong Y Satou YHanda K Takahashi T Sato M and Yamagata TAssessment of individual radionuclide distributions fromthe Fukushima nuclear accident covering central-eastJapan Proc Natl Acad Sci USA (2011) Doi101073pnas1111724108

4 Hosoda M Tokonami S Sorimachi A Monzen SOsanai M Yamada M Kashiwakura I and AkibaS The time variation of dose rate artificially increased bythe Fukushima nuclear crisis Scientific Reports 87 doi101038sep00087

5 Nisbet A F and Woodman R F M Soil-to-planttransfer factors for radio caesium and strontium in agri-cultural systems Health Phys 78 279ndash288 (2000)

RADIOACTIVE POLLUTION FROM FUKUSHIMA DAIICHI NUCLEAR POWER PLANT

203

at St Petersburg State University on February 3 2014

httprpdoxfordjournalsorgD

ownloaded from

  • INTRODUCTION
  • MATERIALS AND METHODS
  • RESULTS AND DISCUSSION
    • Heterogeneous deposition of radionuclides on the ground
    • Deposition and translocation of radionuclides to the plant
      • CONCLUSIONS
      • FUNDING
      • REFERENCES
Page 6: Radioactive pollution from Fukushima Daiichi nuclear power plant in the terrestrial environment

0023+0006 Finally it is anticipated that the de-composition of fallen leaves will promote recyclingof radionuclides in the environment

FUNDING

This work was supported by MEXTJSPSKAKENHI Grant-in-Aid for Scientific Research B(2431002)

REFERENCES

1 Chino M Nakayama H Nagai H Terada HKatata G and Yamazawa H Preliminary estimation ofrelease amount of 131I and 137Cs accidentally dischargedfrom the Fukushima Daiichi Nuclear Power Plant intothe atmosphere J Nucl Sci Tech 48 1129ndash1134(2011)

2 Yasunari J T Stohl A Hayano R S Burkhart J FEckhardt S and Yasunari T Cesium-137 depositionand contamination of Japanese soils due to theFukushima nuclear accident Proc Natl Acad Sci USA(2011) Doi101073pnas1112058108

3 Kinoshita N Sueki K Sasa K Kitagawa JIkarashia S Nishimura T Wong Y Satou YHanda K Takahashi T Sato M and Yamagata TAssessment of individual radionuclide distributions fromthe Fukushima nuclear accident covering central-eastJapan Proc Natl Acad Sci USA (2011) Doi101073pnas1111724108

4 Hosoda M Tokonami S Sorimachi A Monzen SOsanai M Yamada M Kashiwakura I and AkibaS The time variation of dose rate artificially increased bythe Fukushima nuclear crisis Scientific Reports 87 doi101038sep00087

5 Nisbet A F and Woodman R F M Soil-to-planttransfer factors for radio caesium and strontium in agri-cultural systems Health Phys 78 279ndash288 (2000)

RADIOACTIVE POLLUTION FROM FUKUSHIMA DAIICHI NUCLEAR POWER PLANT

203

at St Petersburg State University on February 3 2014

httprpdoxfordjournalsorgD

ownloaded from

  • INTRODUCTION
  • MATERIALS AND METHODS
  • RESULTS AND DISCUSSION
    • Heterogeneous deposition of radionuclides on the ground
    • Deposition and translocation of radionuclides to the plant
      • CONCLUSIONS
      • FUNDING
      • REFERENCES