Corrections
BIOCHEMISTRY
Correction for “Arginine ADP-ribosylation mechanism based on
structuralsnapshotsofiota-toxinandactincomplex,”byToshiharu
Tsurumura,YayoiTsumori,HaoQiu,MasatakaOda,JunSakurai,
MasahiroNagahama,andHideakiTsuge,whichappearedinissue
11,March12,2013,ofProcNatlAcadSciUSA(110:4267–4272;first
publishedFebruary4,2013;10.1073/pnas.1217227110).
The authors note that Fig. 7 appeared incorrectly. There
was a drawing error in the nicotinamide of NAD
+
within
Fig. 7A, and distance values were refined based on the last
coordinate. The corrected figure and its legend appear
below. This error does not affect the conclusions of the
article.
www.pnas.org/cgi/doi/10.1073/pnas.1304997110
Fig.7. Schematicillustrating g themechanismofADP-ribosylation.(A) SN1mechanisminIa:(i) NAD
+
-Ia-Actinas theprereaction state;(ii) nicotinamide
cleavageoccursviaanSN1reactioninducedbyanNMNring-likestructureandthefirstoxocarbeniumcationintermediateisformedwithastrainedcon-
formation;(iii)thesecondcationicintermediateisinducedthroughalleviationofthestrainedconformationmainlybyO3-NPandNP-NO5rotation,andthen
NC1ofN-ribosenucleophilicallyattacksArg177ofactin;(iv)Ia-ADPR-actinasthepostreactionstate.(B)SuccessivestructuresduringADP-ribosylationandthe
structureofeach reaction:step 1[apo-Ia-actin(apo-state)], step2[NAD
+
-Ia-actin(prereaction state)],step 3[βTAD-Ia-actin (transition state)],andstep4
[Ia-ADPR-actin(postreactionstate)].
7524–7528
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|
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|
vol.110
|
no.18
www.pnas.org
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ENVIRONMENTALSCIENCES
Correctionfor “Cesium-137depositionand contaminationof
JapanesesoilsduetotheFukushimanuclearaccident,”byTeppei
J.Yasunari,AndreasStohl,RyugoS.Hayano,JohnF.Burkhart,
SabineEckhardt,andTetsuzoYasunari,whichappearedinissue49,
December6,2011,ofProcNatlAcadSciUSA(108:19530–19534;
firstpublishedNovember14,2011;10.1073/pnas.1112058108).
Theauthorsnotethefollowing:“Dueto thecorrections on
someoftheobserveddaily
137
Cs depositionnumbersmadeby
theMEXT(MinistryofEducation,Culture,Sports,Scienceand
TechnologyinJapan;availableontheMEXTwebsiteinJapanese
athttp://radioactivity.mext.go.jp/ja/list/195/list-1.html)mainlyat
Kanagawaprefecturealongwithsomeminorcorrectionsatother
prefectures,theobjectivelyestimateddepositionvaluesinthepaper
havebeenrevisedbyusingtheupdatedinputdataontheobserved
137
CsdepositionbyMEXT.”
Theauthorsalsonotethatonpage19530,leftcolumn,within
the abstract,lines 22–23, “wereestimated to be more than 5.6
and 1.0PBq,respectively” should instead appearas “wereesti-
mated tobeapproximately6.7and 1.3PBq,respectively.”
On page19531, left column,second fullparagraph, line 5,
“(TRMM,3B42V6product)”omittedthefollowingreferences:
Onpage19531,rightcolumn,firstfullparagraph,lines4–8,
“Our estimatesshowthattheareaaroundNPPinFukushima,
secondarilyeffectedareas(MiyagiandIbarakiprefectures),and
othereffected areas(Iwate,Yamagata,Tochigi,andChibapre-
fectures)had
137
Csdepositionsofmorethan100,000,25,000,and
10,000MBq km
−2
,respectively” should instead appear as “Our
estimateinFig.2AforthecaseofDRTof0.005showedthat
theareaaroundtheNuclearPowerPlant(NPP)inFukushima,
secondarilyeffectedareas(Miyagiprefecture),andothereffected
areas(Iwate,Yamagata,Tochigi,Ibaraki,andChibaprefectures)
hadpartially
137
Csdepositionsofmorethan100,000,50,000,and
10,000MBqkm
−2
,respectively.”
Onpage19531,rightcolumn,firstfullparagraph,lines22–23,
“on the similar order of the MEXT/DOE observations using
aDRTvalueof0.001(Fig.S4)”shouldinsteadappearas“closer
to the order of theMEXT/DOE observations around the NPP
usingaDRTvalueof0.001(Fig.S4)”.
Onpage19533,leftcolumn,firstparagraph,lines1–6,“some
neighboringprefecturessuchasMiyagi,Tochigi,andIbarakiare
partiallyclosetothelimitunderourupperboundestimate(Movie
S4)and,therefore,local-scaleexceedanceislikelygiventhestrong
spatialvariability of
137
Csdeposition.For thosethreeprefectures,
detailed soil samplingisrecommendedin thenearfuture”should
insteadappearas“someneighboringprefecturessuchasIwate,
Yamagata,Miyagi,Tochigi,and Ibaraki arepartiallycloseto
thelimitundertheupper boundestimatewith DRTof0.001
(i.e.,“thehighest deposition estimate” in our estimates with
DRTsof0.001–0.1)[usingCCsof38,53,and68kgm
−2
(Movie
S4)] and,therefore,local-scale exceedance e is s likely given the
strongspatialvariabilityof
137
Csdeposition.Forthoseprefectures,
detailed soilsamplingisrecommendedinthenearfuture.”
Onpage19533,leftcolumn,secondfullparagraph,line1,“We
estimatethatatotalofmorethan5.6and1.0PBq
137
Cs”should
insteadappearas“Weestimatethatatotalofapproximately6.7
and1.3PBq
137
Cs”.
On page 19533, left column, second full paragraph, line 9,
“(Fig.3)”shouldinsteadappearas“withDRTof0.001usingCC
of53kgm
−2
(Fig.3)”.
On page19533,leftcolumn, second full paragraph,lines 13–
15,“suchasIwate,Miyagi,Yamagata,Niigata,Tochigi,Ibaraki,
and Chiba, where values of more than 250 Bq kg
−1
cannot be
excluded(Fig.3andMovieS4)”shouldinsteadappearas“such
as Iwate, Miyagi, Yamagata, Niigata, Tochigi, Ibaraki, Chiba,
etc.,wherevaluesofmorethan250Bqkg
−1
cannotbeexcluded
for the estimated soil contaminations under the upper bound
estimateonthedepositionwithDRTof0.001(i.e.,“thehighest
deposition estimate” in our estimates with DRTs of0.001-0.1)
usingCCsof38,53,and68kgm
−2
(Fig.3andMovieS4)”.
On page 19533, left column, second full paragraph, line 20
before “Therefore,” the following sentence should be added:
“Inaddition,thespatiotemporallylimited
137
Csdepositiondata
by theMEXTobservations wereused in our estimates, which
also included such as no measurements (Miyagi) and missing
observations(YamagataandFukushima)forthetimeperiodin
thisstudy.”
On page 19533, right column, first paragraph, lines 3–4,
“Fukushima,March18–March26andApril4;Gifu,March24,25,
27,28, and30; Nara,March18–21and April15–18” should in-
steadappearas“Fukushima,March18–March26;Gifu,March24;
Nara,March18–20and April15–18”.
On page19533,rightcolumn,second full paragraph,line18,
“countingNoneachday”should insteadappearas“countingN
oneachday,forwhichunavailable,missing,andnodetectionon
the observed depositions were all computationally treated as
zero deposition”.
Last,thelegendsfor Figs.1,2,3,and4appearedincorrectly.
Thefigures and their corrected legends appear below.These
errorsdo notaffecttheconclusions ofthearticle.
27. HuffmanGJ(1997) Estimatesofroot-mean-squarerandomerrorforfinite samples
ofestimatedprecipitation.JApplMeteor36:1191–1201.
28. HuffmanGJ,etal.(2007)TheTRMMmultisatelliteprecipitationanalysis(TMPA):Quasi-
global,multiyear,combined-sensorprecipitationestimatesatfine scales.J Hydro-
meteorol8(1):38–55.
PNAS
|
April 30,2013
|
vol.110
|
no.18
|
7525
CORRECTIONS
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Fig.1. Cesium-137depositionmaps.(A)RelativedepositioncontributionsbetweenMarch11and19,showingtheareaspotentiallyeffectedby
137
Csbefore
thestartofmeasurements.Thesumsofthedepositionsduringtheperiodweredividedbythemaximumdepositionintheaccumulatedfield.(B)Thesameas
inA,butforMarch20–April19.(C)Anexampleofestimateddailydepositionof
137
CsonMarch21.Squaresingrayandblackdenoteobservatories(TableS2)
thatdidhavecomputationalzero
137
Csdeposition(unavailable,missing,ornodetection)ordailyDR=0,anddetectedthedepositionsusedformakingthe
estimationmapforthedeposition,respectively.(D)DailyaccumulatedrainfallonMarch21byTRMM[3B42V6product:(27,28)].
7526
|
www.pnas.org
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0
20000
40000
60000
80000
100000
120000
140000
160000
Hokkaido
Aomori
Iwate
Miyagi
Akita
Yamagata
Fukushima
Ibaraki
Tochigi
Gunma
Saitama
Chiba
Tokyo
Kanagawa
Niigata
Total Cs137 deposition
-[MBq km]
Selected prefectures
Sum of observations
Case 0.1 estimate
Case 0.05 estimate
Case 0.01 estimate
Case 0.007 estimate
Case 0.005 estimate
Case 0.001 estimate
A
B
Fig.2. Totaldepositionof
137
Cs.(A)Griddedtotal
137
CsdepositionvaluesfortheperiodMarch20–April19usingourreferenceDRTvalueof0.005.Outputs
with0.2°×0.2°wereinterpolatedtofinergridusingcubicinterpolation.Squaresinblackdenotetheobservationlocationsineachprefecture(TableS2).
(B)ComparisonsbetweentotalobserveddepositionsfortheperiodMarch20–April19andestimatesatthegridpointofeachobservatorylocation(TableS2)
intheselectedprefectures,usingdifferentDRTvaluestoderivethescalingfactorforthemodeloutput.Orange,black,andgrayboxesdenotenoobservation
(Miyagi)andmissingobservations(Yamagata,betweenMarch29andApril3;Fukushima,beforeMarch27),respectively.
Fig.3. Theestimated
137
Csconcentrationinsoil.WeusedDRTof0.001(upperboundestimateon
137
CsdepositionwithinallofourestimateswithDRTsof
0.001–0.1)andCCof53kgm
−2
.Outputswith0.2°×0.2°wereinterpolatedtofinerresolutionusingcubicinterpolation.TheMergedIBCAO/ETOPO5Global
TopographicDataProduct(25)wasusedtomaskoutoceanareabelow0mabovesealevel(a.s.l.).
PNAS
|
April 30,2013
|
vol.110
|
no.18
|
7527
CORRECTIONS
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www.pnas.org/cgi/doi/10.1073/pnas.1301231110
1.0E-01
1.0E+00
1.0E+01
1.0E+02
1.0E+03
1.0E+04
Ibaraki
Tochigi
Gunma
Saitama
Chiba
Tokyo
Kanagawa
Niigata
Cs137 concentration
-in soil [Bq kg]
Selected prefectures
1.0E-02
1.0E-01
1.0E+00
1.0E+01
1.0E+02
1.0E+03
1.0E+04
1.0E+05
Hokkaido
Aomori
Iwate
Miyagi
Akita
Yamagata
Fukushima
Cs137 concentration
-in soil [Bq kg]
Selected prefectures
Estimated from depositions (MEXT)
Case 0.1 estimate
Case 0.05 estimate
Case 0.01 estimate
Case 0.007 estimate
Case 0.005 estimate
Case 0.001 estimate
Obs. from soil or grass samplings
A
B
Fig.4. Observation-based
137
Csconcentrationsinsoil(estimatesfromthedepositionsbyMEXT;thedirectsoilsamples;conversionfromthegrasssamples;
thedatasourcesforthesoilandgrasssamplesareshowninTableS1)andestimatesoftheconcentrationinsoilbasedonthescaledmodeloutputwiththe
differentDRTsof0.001–0.1andtheCCsof38,53,and68kgm
−2
.(A)Comparisonsinnorthernprefectures.AomoriandMiyagiprefectureshadno
137
Cs
detectionsonthedaily depositiondataand no measurements, respectively.Theminimumvaluein Yamagataprefectureforthesoilobservations isno
detection andnolowererrorbar isshown. (B) ThesameasinA,but aroundKantoarea. Lowerandupper error bars denoteminimumandmaximum
concentrationsforwhichtheestimatesusetheCCsof68and38kgm
−2
basedonFig.S5,respectively.Orange,black,andgrayboxesdenotenoobservation
(Miyagi)andmissingobservations(Yamagata,betweenMarch29andApril3;Fukushima,beforeMarch27),respectively.Asoil-to-grasstransferfactorof0.13
(23) wasusedtoconvertgrasstosoilcontamination.ForFukushimaprefecture,onlythesoilobservationsinFukushimaCitywereused,excludingother
observationsclosetotheFukushimaNPP.ThedatasourceforthecomparisonsaresummarizedinTableS1.Theestimatesbasedontheobserveddepositions
bytheMEXTandtheDRTsof0.001–0.1weretheestimatesatthelocationsofeachobservatoryineachprefectureasshowninTableS2.Thoseestimated
numbersforthecaseswithCCof53kgm
−2
werealsoshowninTableS4.
7528
|
www.pnas.org
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Cesium-137 deposition and contamination of
Japanese soils due to the Fukushima nuclear accident
Teppei J. Yasunari
a,1
,Andreas Stohl
b
,Ryugo S. Hayano
c
,JohnF.Burkhart
b,d
,SabineEckhardt
b
,and TetsuzoYasunari
e
aUniversitiesSpaceResearchAssociation,GoddardEarthSciencesTechnologyandResearch,Columbia,MD
21044;bNorwegianInstituteforAirResearch,
P.O.Box100,N-2027Kjeller,Norway;cDepartmentofPhysics,UniversityofTokyo,7-3-1Hongo,Bukyo-ku,Tokyo113-0033,Japan;dSierraNevada
ResearchInstitute,UniversityofCalifornia,Merced,5200NorthLakeRoad,Merced,CA95343;andeHydrosphericAtmosphericResearchCenter,
NagoyaUniversity,Nagoya,Aichi464-8601,Japan
EditedbyJamesE.Hansen,GoddardInstituteforSpaceStudies,NewYork,NY,andapprovedOctober5,2011(receivedforreviewJuly25,2011)
Thelargestconcern on thecesium-137(137Cs) deposition and its
soilcontaminationduetotheemissionfromtheFukushimaDaiichi
NuclearPowerPlant(NPP) showed up afteramassivequakeon
March11,2011.Cesium-137(137Cs)withahalf-lifeof30.1ycauses
thelargestconcernsbecauseofitsdeleteriouseffectonagriculture
and stock farming, and, thus, human life for decades. Removal
of137Cscontaminatedsoilsorlanduselimitationsinareaswhere
removalisnotpossibleis,therefore,anurgentissue.Achallenge
liesinthefactthatestimatesof137CsemissionsfromtheFukush-
ima NPP are extremely uncertain, therefore, the distribution of
137Csintheenvironmentispoorlyconstrained.Here,weestimate
total137Csdeposition byintegrating daily observationsof 137Cs
depositionineachprefectureinJapanwithrelativedepositiondis-
tribution patterns from a Lagrangian particle dispersion model,
FLEXPART.Weshowthat137Csstronglycontaminatedthesoilsin
largeareasofeastern andnortheastern Japan,whereaswestern
Japanwasshelteredbymountainranges.ThesoilsaroundFukush-
imaNPPandneighboringprefectureshavebeenextensivelycon-
taminatedwithdepositionsofmorethan100,000and10,000MBq
km−2,respectively.Total137Csdepositionsovertwodomains:(i)the
JapanIslandsandthesurroundingocean(130–150°Eand30–46°N)
and, (ii) the Japan Islands,wereestimated to be morethan 5.6
and1.0PBq,respectively.Wehopeour137Csdepositionmapswill
help to coordinatedecontamination efforts and plan regulatory
measuresinJapan.
aerosol∣dispersionmodeling∣radioactivefallout
A
catastrophicearthquakeandtsunamioccurredonMarch11,
2011,which caused destruction in northeastern Japan and
severely damaged theFukushima Daiichi Nuclear Power Plant
(NPP).Thiseventledtoemissionsofradioactivematerialsfrom
theNPP(1),albeitatunknownandlikelystronglyvaryingrelease
rates(1–3).Amongthesematerials,withahalf-lifeof30.1y(4),
cesium-137 (137Cs) causes the largest concerns because of its
deleterious effect on agriculture and stock farming, and, thus,
humanlifefor decades.Removal of
137
Cs-contaminated soilsor
land use limitations in areas where removal is not possible is,
therefore, an urgent issue. The Japanese government, general
public,andscientistshavebeenwaitingfortheinformationofthe
spatialdistributionsof137Csdepositionanditssoilcontamination
over allofJapan.
Theaerosol-bound
137
Cscanberemovedfromtheatmosphere
and brought to the surface by dry or wet deposition. Analysis
of data collected after theChernobyl accidenthas shown that
137Csadsorbedinthetopsoillayercanremainthereformany
years (5, 6), restricting land use, e.g., for food production, of
highlycontaminatedareas for alongtime.To minimizetheim-
pactsonhumanhealthofsoilcontaminationinJapanduetothe
Fukushima NPPaccident,spatial maps of137Cs deposition and
concentrationsinsoilareurgentlyneeded.Sporadicsamplingof
thesoils in andaround Fukushimaprefecture has been carried
outaftertheNPPaccidentundertheinstructionbytheMinistry
ofEducation,Culture,Sports,ScienceandTechnology(MEXT)
(7)andothers(TableS1).However,itisimpossibletofullycap-
turethedistributionof137CsdepositionacrossJapanfromalim-
itednumber ofinsitumeasurementsalone.On theother hand,
reliableestimatesusingdispersionmodelsarealso notavailable
becauseofthelargelyunknownsourceterm.Notonlyisthetotal
releaseof137CsfromthedamagedNPPpoorlyknown,butalso
its variation with time is even more uncertain. Although first
attempts to estimateit havebeen made (2) and another study
triedto estimateits deposition basedon theprevious study (2)
overthelimitedareasaroundFukushimaprefecturewitharegio-
nalchemicaltransportmodel(8),theseestimatesontheemission
ratearehighlyuncertain and thediscussionondeposition over
all ofJapanhasnotbeen made.
Inthisstudywequantitativelyestimatethespatialdistribution
of the
137
Cs deposition and its soil contamination over all of
Japan.We take relative deposition distribution patterns froma
Lagrangianparticledispersionmodel,FLEXPART(Materialsand
MethodsandSIText)(9),usingaconstantsourceterm[asassumed
also in some simulations because of high uncertainty of the
emissionamount(10–16)].Wefusedailyvaryingobservations of
137
CsdepositionineachJapaneseprefecture(17)into themod-
eleddepositionfieldstoobtainquantitativedepositionestimates.
Results
Ourestimateof
137
Csdepositionismadefortheperiodbetween
March20andApril19becausenoobservationsof137Csdeposi-
tion weremade between March 12and 17 and the dispersion
modeldidnotsimulateany depositionsattheobservationloca-
tions onMarch18and19(Fig.S1).Thus,our quantitativeesti-
matesdonotincludethefirst8daftertheNPPaccident,yetfor
thatperiodweproviderelativecontributionstothedeposition.In
Fig.1Aweshowtherelativecontribution mapofthedeposition
overtheperiod when our estimatewas notapplicable.Itshows
thatbeforeMarch 20,potentiallycontaminated airmasseswere
mainlytransported toward thePacific Ocean and137Cs deposi-
tion would have occurred mostly over the ocean, except for
Fukushimaprefectureandsomeneighboringprovinces.Between
March20andApril19(Fig.1B),amuchwiderareawaseffected
bythedeposition.Inparticular,easternandnortheasternpartsof
Japan had a greater potential for 137Cs deposition,whereas in
westernJapanthepotentialfor137Csdepositionwaslow.Overall,
however, the highest potential deposition occurred over the
PacificOcean,whereafewobservationsof137Csdepositionexist
Author contributions: : T.J.Y. designed research; T.J.Y., A.S., J.F.B., and d S.E. performed
research;T.J.Y.andR.S.H.analyzeddata;andT.J.Y.,A.S.,J.F.B.,andT.Y.wrotethepaper.
The authorsdeclarenoconflictofinterest.
ThisarticleisaPNASDirectSubmission.
Freelyavailable onlinethroughthePNASopenaccessoption.
SeeCommentaryonpage 19447.
1Towhom
correspondenceshouldbeaddressed:E-mail:tyasunari@usra.edu.
This article contains supporting information online at www.pnas.org/lookup/suppl/
doi:10.1073/pnas.1112058108/-/DCSupplemental.
19530–19534∣ PNAS∣December 6, 2011∣vol.108∣no. 49
www.pnas.org/cgi/doi/10.1073/pnas.1112058108
(18),showingthatwindsweregenerallyquitefavorableand car-
riedmostradiationawayfrompopulatedareas.
FromMarch20,wecanestimate
137
Cs deposition fields over
Japanmorereliablybecausedailyobservations havebeenmade
in most Japanese prefectures (17) (Table S2). For days from
March 20, we create deposition estimates using scaled model
values [hereafter called, deposition ratio (DR); see Materials
andMethods]fromaconstantsourcetermsimulationinconjunc-
tionwiththemeasurementsfromtheMEXTobservationnetwork
(17).Anexampleofathree-hourlyDRanimation map is avail-
ableinMovieS1.ForperiodswhenthesimulateddailyDRvalue
is closetozeroyetdeposition is observed,athresholdfactor is
employedinEq.2(MaterialsandMethodsandSIText).Insuch
cases,aminimumpositivedepositionratiovalue,hereaftercalled
DR threshold (DRT), needs to be used to derive the scaling
(Materials and Methods and SI Text). The choice of this DRT
is subjective and also effects the estimated deposition amount
inourmethod.Afterperformingcomparisonswiththeobserved
depositionsineachprefecture(SIText,Fig.S2,andTableS3),we
usedaDRTof0.005forthebestguessestimateofdailydeposi-
tionbetween March 20and April19(MovieS2)butwealsore-
portderived deposition estimates for otherDRTvalues.
Thesimulateddistributionof137Csdepositioniscloselylinked
to precipitation as shown for the case of March 21 (Fig. 1 C
andD).ThehighestdepositionvaluesdownwindoftheNPPare
clearly aligned with satellite-observed precipitation by tropical
rainfall measuring mission (TRMM, 3B42 V6 product) in a
frontal rain band, which causes washout of the radionuclides
(MovieS2andS3).Comparisonofdailyobservedprecipitation
fields with the estimated deposition maps shows that 137Cs
depositionissimulatedmainlywhenfrontalrainbandspassover
Japan (Movie S2).Itwas reported previously (19) that around
90% ofthetotal deposition of 137Cs occurs with precipitation.
Thus,thegeneralagreementbetweenobservedprecipitationand
simulateddeposition confirmsthatthemodelcapturesthemain
deposition events, which is also consistent with the discussion
fromthestudybyusingaregionalchemicaltransportmodel(8).
The daily137Cs deposition was frequently detected atobserva-
tories(17)in theeasternandnortheasternprefecturesofJapan
from March 20. Furthermore, large increases of atmospheric
radioactivityintheprefecturesaroundFukushimawereobserved
(20) on March 22 (Fig.S3), probably reflecting ground shine
radiation from the radionuclides deposited during the rainfall
event on March 21(Fig.1C and D).
Mapsofthetotal137CsdepositionbetweenMarch20andApril
19areshown inFig.2A.Asageneralcharacteristic,mostofthe
easternpartsofJapanwereeffectedbyatotal137Csdepositionof
morethan 1;000MBqkm−2. Our estimates show that the area
around NPP in Fukushima, secondarily effected areas (Miyagi
andIbarakiprefectures),andothereffectedareas(Iwate,Yama-
gata, Tochigi, and Chiba prefectures) had
137
Cs depositions of
morethan100,000,25,000,and10;000MBqkm−2, respectively.
Airborneandground-basedsurveymeasurementsjointlycarried
outby MEXTand theUS Department of Energy (DOE) (21)
show high137Cs deposition amounts were observed northwest-
ward and up to a distance of 80 km from Fukushima NPP. It
wasestimatedfromthefirstmeasurementthatbyApril29,more
than 600;000MBqkm−2 hadbeen deposited inthearea,which
is greater than our estimate of less than 500;000MBqkm−2
(Fig.2A),yetwellwithintherangeofuncertaintyofourmethod
(Fig.S4).Furthermore,becausenoobservationsondailydeposi-
tionwereavailablebeforeMarch27inFukushimaCity(Fig.2B)
andnodailydepositionobservationsaroundNPP,ourestimates
areexpectedtounderestimatethetotaldepositioninthevicinity
oftheNPP.Inconductingsensitivity studieswith DRT,ouresti-
mates provide values on thesimilar order of the MEXT/DOE
observationsusingaDRTvalueof0.001(Fig.S4).
Usingan approximaterelationship between137Cs deposition
and its topsoil concentration (22) [conversion coefficient (CC)
of5315kgm−2](Fig.S5),weconvertedtheestimateddeposi-
tionsintotopsoilconcentrations(Fig.3,MovieS4,andTableS4).
Wecompared
137
Csconcentrationsinthetopsoilderivedfrom
both observed137Cs deposition values (17) and from our esti-
mates,withdirectmeasurementsof137Csconcentrationsinsoils
andgrasseswithasoil-to-grasstransferfactorof0.13(23)(SIText
andTableS1)(Fig.4).TheMEXTdeposition-basedsoilcontam-
inationtendstobelowerthanthesoil-andgrass-basedsamplings
becauseofthelatterincludingthetimeperiodjustaftertheNPP
accident.Ourscaledmodeldepositionfieldsagreewellwithboth
thepointmeasurementsincludingtheMEXTarealsurveys and
Fig.1. Cesium-137depositionmaps.(A)RelativedepositioncontributionsbetweenMarch11and19,showingtheareaspotentiallyeffectedby137Csbefore
thestartofmeasurements.Thesumsofthedepositionsduringtheperiodweredividedbythemaximumdepositionintheaccumulatedfield.(B)Thesameasin
A,butforMarch20–April19.(C)Anexampleofestimateddailydepositionof137CsonMarch21.Squaresinblackdenotetheobservationlocationsineach
prefecture(TableS2).(D)DailyaccumulatedrainfallonMarch21byTRMM.
Yasunarietal.
PNAS ∣ December r 6, 2011 ∣ vol.108 ∣ no.49 ∣ 19531
ENVIRONMENTAL
SCIENCES
SEECOMMENTARY
otheravailableobservations(Fig.4),generallyfallingintherange
betweenthetwotechniques.Ifthesoilcontaminationscloserto
theFukushimaNPPareincluded,theobserved soilcontamina-
tion has a wider range of 190–310;000Bqkg−1 with mean and
median values of 20,575 and 5;750Bqkg−1, respectively. The
observations in Fukushima City give a lower range of 620–
21;000Bqkg−1 (mean,5;969Bqkg−1; median,4;200Bqkg−1).
Ourestimateddistributionswerewithintherangeoftheobserva-
tions aroundtheNPP,butclosetothelowerbound (Fig.3and
Fig.4A).Fromthesporadicobservations(7,21)(TableS1)and
our estimate in this study,Fukushima prefecture as a wholeis
highlycontaminated,especiallytothenorthwestoftheNPP,with
soil 137Cs concentrations above 1;000Bqkg−1 throughout the
eastprefecturefromour estimate(Fig. 3).Neighboringprefec-
tures are less contaminated, but 137Cs concentrations thereare
stillabove250Bqkg−1 inmostoftheareas.Thus ourapproach
providesanecessaryestimateofdepositionbeyondtheimmedi-
ateareaoftheFukushimaprefecture,wheremonitoringactivities
areless intensive.
Discussion
There are many important agricultural regions in Japan. In
Japan, the limit for thesum of 134Cs and137Cs concentrations
(astotalcesium)insoilis5;000Bqkg−1 undertheFood Sanita-
tion Law (24). Considering that about half (2;500Bqkg−1) of
thetotalradioactivecesiumdepositionisdueto
137
Cs,theeast
A
B
0
10,000
20,000
30,000
40,000
50,000
60,000
Hokkaido
Aomori
Iwate
Miyagi
Akita
Yamagata
Fukushima
Ibaraki
Tochigi
Gunma
Saitama
Chiba
Tokyo
Kanagawa
Niigata
Selected prefectures
Total Cs137 deposition
-[MBq km]
Sum of observations
Case 0.1 estimate
Case 0.05 estimate
Case 0.01 estimate
Case 0.007 estimate
Case 0.005 estimate
Case 0.001 estimate
500,000
1e+06
250,000
100,000
50,000
25,000
5,000
10,000
2,500
1,000
500
250
100
50
0
Fig.2. Totaldepositionof137Cs.(A)Gridded d total137Csdepositionvalues
fortheperiod March 20–April19using ourreferenceDRTvalueof 0.005.
Outputswith0.2°×0.2°wereinterpolatedto finer gridusing cubicinter-
polation.Squaresinblackdenotetheobservationlocationsineachprefec-
ture(TableS2).(B)Comparisonsbetweentotalobserveddepositionsforthe
periodMarch20–April19andestimatesatthegridpointofeachobservatory
location (Table S2) in theselected d prefectures, using different t DRT values
toderivethescalingfactorforthemodeloutput.Orange,gray,andblackboxes
denotenoobservation(Miyagi)andmissingobservations(Yamagata,between
March29andApril3;Fukushima,beforeMarch27andApril4),respectively.
Fig. 3. The
137
Csconcentration insoil.We used DRTof 0.001andCC of
53kgm
−2
. Outputs with 0.2°×0.2° were interpolated to finer resolution
using cubicinterpolation. TheMerged IBCAO/ETOPO5GlobalTopographic
DataProduct(25) wasusedtomaskoutoceanareabelow0mabovesea
level(a.s.l.).
A
B
Estimated from depositions (MEXT)
Case 0.1 estimate
Case 0.05 estimate
Case 0.01 estimate
Case 0.007 estimate
Case 0.005 estimate
Case 0.001 estimate
Obs. from soil or grass samplings
1.0E-01
1.0E+00
1.0E+01
1.0E+02
1.0E+03
1.0E+04
Ibaraki
Tochigi
Gunma
Saitama
Chiba
Tokyo
Kanagawa
Niigata
Selected prefectures
Cs137 concentration
-in soil [Bq kg]
Fukushimaprefectureexceededthislimitandsomeneighboring
prefecturessuchasMiyagi,Tochigi,andIbarakiarepartiallyclose
to the limit under our upper bound estimate (Movie S4) and,
therefore,local-scaleexceedanceislikelygiventhestrongspatial
variability of 137Cs deposition. For those three prefectures,
detailed soil samplingis recommendedinthenearfuture.Esti-
matedandobservedcontaminationsinthewesternpartsofJapan
were not as serious, even though someprefectures were likely
effected to some extent(Fig.3,MovieS4,andTableS4).Con-
centrations in these areas are below 25Bqkg−1, which is far
below the threshold for farming. However, we strongly recom-
mend eachprefecturetoquicklycarry outsomesupplementary
soilsamplingsatcitylevelstovalidateourestimateseven ifthe
concentrations arelow.
TherelativelylowcontaminationlevelsoverwesternJapancan
bewellexplainedby theJapanesetopography.Theeasternand
northeastern partsofJapanaresurrounded bymountainranges
suchastheKanto,Echigo,andOhwumountainranges(Fig.S6)
(25), which, to a large extent, sheltered the northwestern and
westernpartsofJapanfromthedispersionofradioactivemateri-
al.Itisworthnoting,however,thatrelativelyhighercontamina-
tion levels can be seen over the Hida, Chugoku, and Shikoku
mountainranges(Fig.3,Fig.S6,andMovieS4),probablydueto
orographicenhancementofprecipitationand,thus,wetdeposi-
tionof137Cs.InHokkaido,to thenorthofJapan’smainisland,
bothloweraltitudeand higheraltitudessuchastheYubariand
Hidakamountain ranges areeffected by137Cs deposition,par-
tially dueto direct transport fromtheFukushima NPP via the
PacificOceanasshowninMoviesS1andS2andalsoassimulated
by another atmospheric transportmodel(12).
Weestimatethatatotal ofmorethan5.6and1.0PBq
137
Cs
were deposited over Japan and the surrounding ocean (130–
150°Eand30–46°N),andtheJapanIslandsinthisdomainonly,
respectively (Fig. 2A).Althoughtheestimatefor thelarger do-
mainisquiteuncertainbecauseitisconstrainedonlybymeasure-
ments in Japan, these numbers areconsistentwith a suspected
total releaseofabout12PBq
137
Cs (2).Mostofthedeposition
occurredoverthePacificOcean,yetsoilconcentrationsof137Cs
areabove100Bqkg−1 overlargeareasofeasternJapan(Fig.3).
Accordingtoourresults,foodproductionin easternFukushima
prefectureislikelyseverelyimpairedbythe137Csloadsofmore
than2;500Bqkg−1(upperlimitoffarming)andalsopartiallyim-
pactedinneighboringprovincessuchasIwate,Miyagi,Yamagata,
Niigata,Tochigi,Ibaraki,andChiba,wherevalues ofmorethan
250Bqkg−1 cannotbe excluded (Fig.3 andMovie S4).Notice
alsothatourestimatesarebasedonatransportmodeldrivenwith
meteorologicalanalysisdatafromaglobalmodel.Suchamodel
cannotfully capture all complexities oftheregional wind field
overJapanand,inparticular,doesnotresolvethehighspatiotem-
poralvariabilityofprecipitation.Therefore,weexpectthetruesoil
contaminationacrossJapantobeconsiderablymorevariablethan
inourestimate.Eveninregionswherewefindrelativelylowsoil
contaminationlevels,hotspotswithhighconcentrations(e.g.,due
to convective rain fall, orographic enhancement of rainfall, or
fine-grainsoilflowbyrainwaterontheground)maybepossible.
Incontrast,relativelyclean patchesmayalso bepresentinareas
with high overall contamination levels. Despite these shortcom-
ings,weexpectourresultstobeusefulforregulatorymeasuresand
for guidingmonitoringactivities towardareaswith expectedhigh
137Csburdens.Wehopethisstudywillcontributetounderstanding
thecontaminationissuein Japan.
MaterialsandMethods
Observations of Cesium-137 Deposition and Concentration in Soil in each
Prefecture.FromMarch18,MEXThasbeenobservingdailyradioactivitylevels
indepositioninmost of theprefecture(17).Theexactcoordinates of the
samplinglocationswereindividuallyaccessiblethroughourcontactstoMEXT
(TableS2).ThedepositiondatabetweenMarch18and19werenotusedin
ourestimatebecauseofnodepositionsatobservatoriesfromthemodeled
DRmapsasmentionedinthemaintext.Insomeprefectures,dataweremiss-
ingorunavailable[Miyagi,March18–April19(completelynoobservations);
Yamagata,March 29–April3;Fukushima,March 18–March26andApril4;
Gifu,March24,25,27,28,and30;Nara,March18–21andApril15–18;Oita,
March22–26).
FLEXPART and Estimated 137Cs Deposition. FLEXPART (9) is a Lagrangian
particledispersionmodel simulatingtransport, diffusion,dryand wet de-
position,andradioactivedecay of radioactivematerialssuch as131I,137Cs,
and133Xe(Seehttp://transport.nilu.no forfurtherdetailson FLEXPART).In
thisstudy,continuousemissionfromtheFukushimaDaiichiNPPwasassumed
after1800hourscoordinateduniversaltime(UTC) on March11,2011.The
simulationendedat0000hoursUTConApril20.FLEXPARTwasforcedwith
theEuropeanCenterforMedium-RangeWeatherForecasts(ECMWF)opera-
tionalanalysisdatawithaglobalresolutionof1°×1°and0.18°×0.18°for
120–168°Eand25–50°N.Theoutputhadaresolutionof0.2°×0.2°andwas
recordedevery3h(SIText).
For each day, we first normalized the modeled daily accumulated
depositionineachgridcellwiththemaximumaccumulateddepositionvalue
forthemodeldomain,hereaftercalleddailydepositionratio(DDR)maps:
DDR
ðx;yÞ
¼
1
FPD
max
i
T
i¼1
FPD
ðx;yÞ
i
;
[1]
whereFPD
ðx;yÞi
isthethree-hourlymodeleddepositioningridcellðx;yÞand
FPD
max
isthemaximumdaily deposition valuefound in theentire model
domain.Tisthenumberofmodeloutputtimestepsperday(T¼8).Daily
griddeddepositionvaluesof137CswereestimatedbyscalingtheDDRmap
withavailabledailyobserved137CsdepositionsineachprefecturebyMEXT
(17) bythefollowingequation:
Depo
ðx;yÞ
¼
DDR
ðx;yÞ
N
N
i¼1
Depo
iðObs:Þ
DDR
iðObs:LocÞ
;
[2]
whereDepo
ðx;yÞ
istheestimateddailytotal137Csdepositioningridcellðx;yÞ,
Depo
iðObs:Þ
istheobserved137Csdepositionatlocationi (TableS2),N≤47
isthenumberofavailablecountsonacertaindayinJapan’s47prefectures,
DDR
iðObs:Loc:Þ
is theDDR
ðx;yÞ
in the grid point where
137
Cs deposition was
observed,andDDR
ðx;yÞ
istheDDRingridcellðx;yÞ.Onlythecaseswithboth
theobserveddepositionandtheDDR
iðObs:Loc:Þ
notequaltozeroateachob-
servatory location n were used for counting g N on each day. Because the
Depo
iðObs:Þ
to DDR
iðObs:Loc:Þ
scaling factor in n Eq. 2becomes infinite when
thesimulatedDDRvalueisclosetozerobutdepositionisactuallyobserved,
aminimumpositiveDDRvalue,DRT,needstobeusedtoderivethescaling.
SeveralDRTsof0.001,0.005,0.007,0.01,0.05,and0.1forDDR
iðObs:Loc:Þ
within
thesimulation domainon each day wereusedto avoidabnormally high
Depo
ðx;yÞ
valuesduetodividing bysmallvalues(SIText).If DDR
iðObs:Loc:Þ
at
acertaingridpointwaslessthanaDRTvalue,DDR
iðObs:Loc:Þ
wassettothe
DRTvalue.
Forcomputingtotal137CsdepositionbetweenMarch20andApril19,we
correctedallvaluestoApril19usingahalf-lifeof137Csof30.1y(4).Thesum
ofallthedailyobservedorestimated137Csdepositionsisthetotal137Csde-
position(Fig.2andFig.S4A).
Observations on
137
Cs ConcentrationsinSoilandGrass.Forcomparisonwith
our estimates,measurementsof
137
Csconcentrations in soil or grasswere
used(SITextandTableS1).Meantransferfactorofsoil-to-grassof0.13,which
wasobtainedfromtheobservationsinJapanesesoilandgrass,wasusedto
convertgrasscontaminationtosoilequivalentcontamination(grasscontam-
inationdividedbythetransferfactor)(23).Thetimesandlocationsofthose
samplingsvaried.Tocoverthetimeperiodofourstudy(March20–April19),
wealsousedsomesoilsamplesfromlaterdates,butwedidnotuseanydata
afterMay19.Noticealsothatthesoilsampleswerealsoeffectedby137Cs
deposition before March 20(SI Text).Someobservatories measured total
cesiumconcentrationincludingboth137Csand134Cs.Inthatcase,weassumed
thathalfofthetotalCswas137Cs.
Toconvert the137Cs depositioninto soil concentration,soil depthand
densityinformationareneeded.However,itiscurrentlydifficulttoobtain
thisinformation acrossall of Japan. Thereisan empiricalrelationshipon
theratiobetween137Csconcentrationand deposition from0to5cmsoil,
paddysoil,andfieldsoilsamples(22)(Fig.S5).Weconsideredthemeanvalue
oftheratioasCCof5315kgm−2 reflectingthe5-cmdepthsoilinforma-
tion and its density. Our estimated CC valueis closeto the CC valueof
65kgm
−2
assumed by MEXT (26) with 5-cm soil and a soil density of
Yasunarietal.
PNAS ∣ December r 6, 2011 ∣ vol.108 ∣ no.49 ∣ 19533
ENVIRONMENTAL
SCIENCES
SEECOMMENTARY
1;300kgm
−3
.
Dividing our estimated deposition (MBqkm
−2
¼Bqm
−2
) by the CCs, we
empiricallyobtainedthemean
137
Csconcentrationinsoil(Bqkg
−1
).
ACKNOWLEDGMENTS. Useful comments were obtained from K.-M. Kim
Morgan State University (MSU)/Goddard Earth Sciences Technology and
Research (GESTAR) and Q. Tan Universities Space Research Association
(USRA)/GESTAR. Daily deposition of radioactive materials, atmospheric
radiations, and concentrationsinsoilused in thisstudy wereobservedby
theMinistryofEducation,Culture,Sports,Science,andTechnology(MEXT),
eachprefectureinJapan,theMinistryofAgriculture,ForestryandFisheries
(MAFF),andProf.Yamazakietal.atKinkiUniversity.Wealsoappreciateall
thepeopleworkingonthesemeasurements.Thetropicalrainfallmeasuring
mission(TRMM,3B42V6product)datausedinthisstudywereacquiredusing
the Goddard Earth Sciences (GES)-Data and Information Services s Center
(DISC) as part of the National Aeronautics and Space Administration’s
GES-DISC.TheGridAnalysisandDisplaySystem(GrADS)wasuseforplotting.
This paper was s partially supported by Universities Space Research h Asso-
ciation.
1. NuclearandIndustrialSafetyAgency(2011).Availableat:http://www.nisa.meti.go.jp/
english/files/en20110321-1.pdf.March20,2011.
2. ChinoM, et al. (2011) Preliminary estimationof release amount of 131I and137Cs
accidentallydischarged from the e Fukushima Daiichi Nuclear Power Plantinto o the
atmosphere.JNuclSciTechnol(Tokyo)48:1129–1134.
3. Hoetzlein RC (2011) Fukushima radiation—comparison map., Available at: http://
www.rchoetzlein.com/theory/2011/fukushima-radiation-comparison-map/.
4. UnterwegerMP,HoppesDD,SchimaFJ(1992)Newandrevisedhalf-lifemeasurements
results.NuclInstrumMethodsPhysResSectA312:349–352.
5. Filipovic-VincekovicN,Barisic D,MasicN,LulicS(1991)Distributionoffalloutradio-
nuclidesthroughsoilsurfacelayer.JRadioanNuclChAr148:53–62.
6. GianiL,HelmersH(1997) MigrationofCesium-137intypicalsoilsofNorthGermany
tenyearsaftertheChernobylaccident.ZPflanzBodenkunde160:81–83.
7. Japanese Ministry y of Education, Culture, Sports, , Science, and d Technology(MEXT)
(2011) Readings of environmental radiationlevel of dust and d soil by monitoring
in schools in Fukushima Prefecture., Available at: http://www.mext.go.jp/english/
incident/1305657.htm.
8. MorinoY,OharaT,NishizawaM(2011)Atmosphericbehavior,deposition,andbudget
ofradioactivematerialsfromthe FukushimaDaiichinuclear powerplantinMarch
2011.GeophysResLettL00G11.
9. Stohl A, Forster C, Frank A, , Seibert P, Wotawa a G G (2005) The e Lagrangian n particle
dispersionmodelFLEXPARTversion6.2.AtmosChemPhys5:2461–2474.
10. Japanese Ministry y of Education, Culture, Sports, , Science, and d Technology(MEXT)
(2011)Systemforpredictionofenvironmentemergencydoseinformation(SPEEDI).,
Availableat:http://www.nsc.go.jp/mext_speedi/index.html(inJapanese).
11. JapanMeteorologicalAgency(2011)EnvironmentalEmergencyResponse.,Available
at:http://www.jma.go.jp/jma/kokusai/eer_list.html.
12. TakemuraT,etal.(2011)Anumericalsimulationofglobaltransportofatmospheric
particlesemittedfromtheFukushimaDaiichiNuclearPowerPlant.SOLA7:101–104.
13. VisibleInformationCenterInc.(2011)Simulationon137Csdepositionduetotheemis-
sionfromFukushimaDaiichiNuclearPlant.,Availableat:http://www.vic.jp/fukushima/
global/global-e.html.
14. JapanAtomicEnergyAgency(2011)Atrialcalculationontotalamountofradiation
exposure during2 months afterthe accidentofFukushima Daiichi Nuclear Power
PlantinTEPCO.,Available at:http://www.jaea.go.jp/jishin/kaisetsu03/kaisetsu03.htm
(inJapanese).
15. The EURADproject (2011) Potential l dispersion of the radioactive cloud over r the
northernhemisphere.,Availableat:http://www.eurad.uni-koeln.de/index_e.html.
16. DeutscherWetterdienst(2011)DeutscherWetterdienstzudenFolgenderFukushima-
Katastrophe Wetter sorgt für starke Verdünnung der radioaktiven Konzentra-
tion., Available at: http://www.dwd.de/bvbw/generator/DWDWWW/Content/Presse/
Pressemitteilungen/2011/20110323__Japan,templateId=raw,property=publicationFile
.pdf/20110323_Japan.pdf.
17. Japanese Ministry of Education, Culture, Sports, Science, andTechnology (MEXT)
(2011) Readingof radioactivity y levelinfallout byprefecture., Available at: http://
www.mext.go.jp/english/incident/1305529.htm.
18. Japanese Ministry of Education, Culture, Sports, Science, andTechnology (MEXT)
(2011) Readings of sea area monitoring., Available at: http://www.mext.go.jp/
english/incident/1304192.htm.
19. UnitedNationsScientific CommitteeontheEffectsofAtomicRadiation(UNSCEAR)
(2000)Sourcesandeffectsofionizingradiation.SourcesAnnexA, VolI(UnitedNa-
tions, New York), Available at: http://www.unscear.org/unscear/en/publications/
2000_1.html.
20. Japanese Ministry of Education, Culture, Sports, Science, andTechnology (MEXT)
(2011) Readings s of environmental radioactivity level by y prefecture., Available at:
http://www.mext.go.jp/english/incident/1304080.htm.
21. Japanese Ministry of Education, Culture, Sports, Science, andTechnology (MEXT)
andthe USDepartmentofEnergy(DOE) (2011) ResultsofAirborneMonitoringby
theMinistryofEducation,Culture,Sports,Science,andTechnologyandtheUSDepart-
mentofEnergy.,Available at:http://www.mext.go.jp/english/incident/1304796.htm.
22. Japanese Ministry of Education, Culture, Sports, Science, andTechnology (MEXT)
(2011) Environmental radiation database., Available at: http://search.kankyo-
hoshano.go.jp/servlet/search.top.
23. Tsukada H, , Hisamatsu S, Inaba J (2003) Transfer of137Cs and stable Cs in soil-to-
grass-milk pathwayinAomori.,Japan.JRadioanalNuclChem255:455–458.
24. Ministry of Agriculture, Forestry, andFisheries (MAFF) (2011) Apoint ofview on
planting rice plant., Available at: http://www.maff.go.jp/j/kanbo/joho/saigai/pdf/
ine_sakutuke.pdf(inJapanese).
25. Holland DM (2000) Merged IBCAO/ETOPO5 global topographic data product.
National Geophysical Data Center r (NGDC), Boulder Colorado, Available at: http://
efdl.cims.nyu.edu/project_aomip/forcing_data/topography/merged/overview.html.
26. Japanese Ministry of Education, Culture, Sports, Science, andTechnology (MEXT)
(2011)Calculationresultsandbasisregardinginternalexposurestudiedinsummariz-
ingthetentativeapproach.,Availableat:http://www.mext.go.jp/component/english/
__icsFiles/afieldfile/2011/05/27/1306601_0512_1.pdf.
19534 ∣ www.pnas.org/cgi/doi/10.1073/pnas.1112058108
Yasunarietal.
Documents you may be interested
Documents you may be interested