risk

放射線健康リスク放射線健康リスク- - その認知・受容・制御その認知・受容・制御

長崎大学先導生命科学研究支援センター（大学院医歯薬学総合研究科）

放射線生物・防護学分野松田　尚樹　

2009.3.2　岡山大

Two general categories of adverse health effects of radiationTwo general categories of adverse health effects of radiationfrom biological aspects of radiation protectionfrom biological aspects of radiation protection

Deterministic effectsDeterministic effects killing/malfunction of cells following killing/malfunction of cells following

doses higher than the thresholddoses higher than the threshold harmful tissue reactionsharmful tissue reactions

Stochastic effectsStochastic effects mutation of somatic or germ cellsmutation of somatic or germ cells cancer and heritable effectscancer and heritable effects

1010

55

00

radiation doseradiation dose

freq

uen

cy (

%)

freq

uen

cy (

%)

100100

5050

00

thresholdthreshold

risk

(%)

risk

(%)

radiation doseradiation dose

Primary target for radiation Primary target for radiation

DNADNA

3 billion (3x103 billion (3x1099) nucleotides / cell) nucleotides / cell

cellcell

60 trillion (6x1060 trillion (6x101313) / body) / body

Radiation-induced chromosomal aberrationRadiation-induced chromosomal aberration

typetype naturally occurringnaturally occurring（（ /cell/da/cell/dayy）） radiation-inducedradiation-induced（（ /cell/Gy/cell/Gy ））

base damagebase damage 20,00020,000 300300

single-strand breaksingle-strand break 50,00050,000 1,0001,000

double-strand breakdouble-strand break 1010 300300

double-strand DNAdouble-strand DNA

RadiationRadiation

single-strand single-strand breakbreak

double-strand double-strand breakbreak

repair enzymesrepair enzymes

repairrepair

unrepaired damageunrepaired damageincorrect repairincorrect repair

biological effectbiological effect

base damagebase damage

NHEJ/HRNHEJ/HR

unable to replicate DNA unable to replicate DNA cell growth arrestcell growth arrest

unable to transcript DNAunable to transcript DNA no protein synthesisno protein synthesis

induction of apoptosisinduction of apoptosis

changes to the nucleotide changes to the nucleotide sequencesequence incorrect genetic informationincorrect genetic information

DNA damageDNA damage

cell deathcell death mutationmutation

unrepairedunrepaired repaired incorrectlyrepaired incorrectly

Cellular outcome of DNA damageCellular outcome of DNA damage

cell deathcell death

mutationmutation

loss of structural loss of structural and functional and functional integrity of tissueintegrity of tissue

genetic instabilitygenetic instability・・ cancercancer・・ heritable effectheritable effect

deterministic deterministic effectseffects

stochastic stochastic effectseffects

DNA damage is DNA damage is completely repaired completely repaired within the repair within the repair capacity of cellscapacity of cells

biological effect biological effect occurs at doses higher occurs at doses higher than the thresholdthan the threshold

incorrect repair takes incorrect repair takes place regardless of place regardless of repair capacity of the repair capacity of the cellscells

biological effect biological effect occurs even at very occurs even at very low doseslow doses

Effective Dose LimitEffective Dose Limit（（ PublicPublic））

11ｍｍ Sv/yearSv/year

ICRP recommendations (Publication 103), pp99 (Table 6), 2007ICRP recommendations (Publication 103), pp99 (Table 6), 2007

100100ｍｍ Sv/Sv/５５ yearsyears not exceed 50mSv in any single year additional restrictions apply to the

pregnant women

Effective Dose LimitEffective Dose Limit（（ OccupationalOccupational））


Detriment-adjusted nominal risk coefficients after Detriment-adjusted nominal risk coefficients after exposure to radiation at low dose rateexposure to radiation at low dose rate

Exposed populationExposed population CancerCancer Heritable effectsHeritable effects TotalTotal

Whole populationWhole population 5.5 x 105.5 x 10-2-2/Sv/Sv 0.2 x 100.2 x 10-2-2/Sv/Sv 5.7 x 105.7 x 10-2-2/Sv/Sv

Adult workersAdult workers 4.1 x 104.1 x 10-2-2/Sv/Sv 0.1 x 100.1 x 10-2-2/Sv/Sv 4.2 x 104.2 x 10-2-2/Sv/Sv


リスクの比較（人口 10万人あたりの年間死亡者概数）

全死因 848.5放射線発がん

（放射線業務従事者）4.1

がん 255.1 水難事故 0.70

心疾患 135.4 インフルエンザ 0.55

脳血管疾患 103.9 他殺 0.52

喫煙発がん（現状） 80.0 自然災害 0.10

喫煙発がん（ 1000円） 30.0 HIV 0.04

自殺 23.9 食中毒 0.004

交通事故 9.1 落雷 0.002

放射線発がん（一般公衆）

5.5BSE感染牛による

クロイツフェルトヤコブ病0.0009

いろいろな事項についての 10万人あたりの年間死亡数、体質研究会、 http://www.taishitsu.or.jp/risk/risk2006.htmlリスクのモノサシ、中谷内一也、 NHKブックス

Brenner et al., PNAS 100, 13761-137661, 2003Brenner et al., PNAS 100, 13761-137661, 2003

Cancer risks of atomic bomb survivorsCancer risks of atomic bomb survivorsEstimated excess relative risk (+/- 1SE) of mortality (1950-1997) from solid Estimated excess relative risk (+/- 1SE) of mortality (1950-1997) from solid cancers among groups of survivors who were exposed to low doses cancers among groups of survivors who were exposed to low doses (<500mSv) of radiation(<500mSv) of radiation

ａａ linear non-threshold (LNT)linear non-threshold (LNT)ｂｂ downwardly curvingdownwardly curvingｃｃ upwardly curvingupwardly curvingｄｄ thresholdthresholdｅｅ hormetichormetic

Radiation risks down to very low dosesRadiation risks down to very low dosesAll of these possible extrapolations could be consistent with higher-dose All of these possible extrapolations could be consistent with higher-dose epidemiological dataepidemiological data

Brenner et al., PNAS 100, 13761-137661, 2003Brenner et al., PNAS 100, 13761-137661, 2003

Lobrich and Jeggo, Nature Rev Cancer 7:Lobrich and Jeggo, Nature Rev Cancer 7: 861861--869869, , 20072007

Encounters with radiation and risk Encounters with radiation and risk estimationestimation

from Madurai to Nagercoil, Tamilnadu, Indiafrom Madurai to Nagercoil, Tamilnadu, India

Tirunelveri District, Tamilnadu, India

Chinnavilai in Manavalakurichi Town Panchayath, Kanyakumari District, Tamilnadu, IndiaChinnavilai in Manavalakurichi Town Panchayath, Kanyakumari District, Tamilnadu, India

St.Joseph’s Primary School, Chinnavilai, Kanyakumari District, Tamilnadu, IndiaSt.Joseph’s Primary School, Chinnavilai, Kanyakumari District, Tamilnadu, India

Kudankulam Nuclear Power Project, Tirunelveli district, Tamiunadu, IndiaKudankulam Nuclear Power Project, Tirunelveli district, Tamiunadu, India

World Nuclear Association, February 2009World Nuclear Association, February 2009

ReactorReactor StateState TypeType Mwe net, eachMwe net, each Commercial Commercial operationoperation

Tarapur 1&2Tarapur 1&2 MaharashtraMaharashtra BWRBWR 150150 19691969

Kaiga 1&2Kaiga 1&2 KarnatakaKarnataka PHWRPHWR 202202 1999-20001999-2000

Kaiga 3Kaiga 3 KarnatakaKarnataka PHWRPHWR 202202 20072007

Kakrapar 1&2Kakrapar 1&2 GujaratGujarat PHWRPHWR 202202 1993-19951993-1995

Kalpakkam 1&2Kalpakkam 1&2 Tamil NaduTamil Nadu PHWRPHWR 202202 1984-19861984-1986

Narora 1&2Narora 1&2 Uttar PradeshUttar Pradesh PHWRPHWR 202202 1991-19921991-1992

Rawatbhata 1Rawatbhata 1 RajasthanRajasthan PHWRPHWR 9090 19731973

Rawatbhata 2Rawatbhata 2 RajasthanRajasthan PHWRPHWR 187187 19811981

Rawatbhata 3&4Rawatbhata 3&4 RajasthanRajasthan PHWRPHWR 202202 1999-20001999-2000

Tarapur 3&4Tarapur 3&4 MaharashtraMaharashtra PHWRPHWR 490490 2005-20062005-2006

17 reactors operating17 reactors operating 3,7793,779

Kaiga 4Kaiga 4 KarnatakaKarnataka PHWRPHWR 202202 20092009

Rawatbhata 5&6Rawatbhata 5&6 RajasthanRajasthan PHWRPHWR 202202 20092009

Kudankulam 1&2Kudankulam 1&2 Tamil NaduTamil Nadu PWR (VVER)PWR (VVER) 950950 Sep-Dec 2009Sep-Dec 2009

KalpakkamKalpakkam Tamil NaduTamil Nadu FBRFBR 470470 20112011

9 reactors under construction9 reactors under construction 2,9762,976

Nuclear Power Plant in IndiaNuclear Power Plant in India

Annual terrestrial radiation doses in the worldAnnual terrestrial radiation doses in the world

http://www.taishitsu.or.jp/genshiryoku/gen-1/1-ko-shizen-2.htmlhttp://www.taishitsu.or.jp/genshiryoku/gen-1/1-ko-shizen-2.html

AreaArea MeanMean (mGy/year)(mGy/year)

MaximumMaximum (mGy/year)(mGy/year)

Ramsar, IranRamsar, Iran 10.210.2 260260

Guarapari, BrazilGuarapari, Brazil 5.55.5 3535

Kerala, IndiaKerala, India 3.83.8 3535

Yangiang, ChinaYangiang, China 3.53.5 5.45.4

World AverageWorld Average 0.500.50

JapanJapan 0.430.43 1.261.26

Jiang T et al., J Radiat Res 41S:Jiang T et al., J Radiat Res 41S: 6363--6868, , 20002000

Increase in unstable-type chromosome aberrations in Increase in unstable-type chromosome aberrations in inhabitants of high background radiation areas in Chinainhabitants of high background radiation areas in China

Relative risk for cancer in high background radiation Relative risk for cancer in high background radiation areas in China during 1979-1995areas in China during 1979-1995

Tao Z et al., J Radiat Res 41S:Tao Z et al., J Radiat Res 41S: 3131--4141, , 20002000

VariableVariable LowLow MediumMedium HighHigh SubtotalSubtotal

Follow-up Follow-up periodperiod

1979-861979-86 1.10 (0.86-1.10 (0.86-1.42)1.42)

1.02 (0.79-1.02 (0.79-1.32)1.32)

0.98 (0.75-0.98 (0.75-1.29)1.29)

1.04 (0.85-1.04 (0.85-1.28)1.28)

1987-951987-95 1.04 (0.83-1.04 (0.83-1.30)1.30)

0.98 (0.78-0.98 (0.78-1.22)1.22)

0.86 (0.68-0.86 (0.68-1.10)1.10)

0.96 (0.80-0.96 (0.80-1.15)1.15)

SexSex

MaleMale 1.02 (0.83-1.02 (0.83-1.26)1.26)

1.09 (0.89-1.09 (0.89-1.34)1.34)

0.93 (0.74-0.93 (0.74-1.16)1.16)

1.02 (0.86-1.02 (0.86-1.20)1.20)

FemaleFemale 1.14 (0.87-1.14 (0.87-1.51)1.51)

0.82 (0.61-0.82 (0.61-1.11)1.11)

0.89 (0.65-0.89 (0.65-1.21)1.21)

0.95 (0.76-0.95 (0.76-1.20)1.20)

AgeAge

0-590-59 0.99 (0.80-0.99 (0.80-1.24)1.24)

0.98 (0.79-0.98 (0.79-1.22)1.22)

0.90 (0.71-0.90 (0.71-1.13)1.13)

0.96 (0.80-0.96 (0.80-1.15)1.15)

60+60+ 1.18 (0.91-1.18 (0.91-1.53)1.53)

1.02 (0.78-1.02 (0.78-1.32)1.32)

0.94 (0.71-0.94 (0.71-1.25)1.25)

1.05 (0.85-1.05 (0.85-1.29)1.29)

Boffetta P et al., Am J Epidemiol 165:Boffetta P et al., Am J Epidemiol 165: 3636--4343, , 20062006

Kaplan-Meier curve for total cancer incidence by Kaplan-Meier curve for total cancer incidence by frequency of chromosomal aberrations in central Europe frequency of chromosomal aberrations in central Europe during 1978-2002during 1978-2002

Nagercoil, Tamilnadu, IndiaNagercoil, Tamilnadu, India

Meals with Chapati (Meals with Chapati (चपा�ती�चपा�ती�)) Meals with Chapati (Meals with Chapati (चपा�ती�चपा�ती�))

Vegetable Uthappam (Vegetable Uthappam (தோ��சை�தோ��சை�, Dosa), Dosa) Sambar Ghee Idly (Sambar Ghee Idly (இட்லிஇட்லி) )

No direct evidence from in vitro and in vivo studyNo direct evidence from in vitro and in vivo study

The lower limit of cancer risk at doses around The lower limit of cancer risk at doses around 100mSv from epidemiological study100mSv from epidemiological study

Increased chromosome aberrations but no elevation Increased chromosome aberrations but no elevation of cancer risk in high background radiation areas of cancer risk in high background radiation areas

Uncertainty on health effects at low dosesUncertainty on health effects at low doses

●　チェルノブイリ

ウクライナ

ゴメリ州　●

ベラルーシ共和国

●　クリンシー（ブリヤンスク州）

ロシア連邦

●　チェルノブイリ

ウクライナ

ゴメリ州　●

ベラルーシ

●　クリンシー（ブリヤンスク州）

ロシア連邦

Chernobyl

チェルノブイリ原子力発電所事故

19861986年年 44 月月 2626日に発生。日に発生。原子炉内の多量の放射性物質が大気中に放出。原子炉内の多量の放射性物質が大気中に放出。現在のウクライナ、ベラルーシ共和国及びロシア現在のウクライナ、ベラルーシ共和国及びロシア連邦に及ぶ地域が汚染。連邦に及ぶ地域が汚染。

急性放射線障害による死者は急性放射線障害による死者は 2828名。名。 20042004年までの間に年までの間に 1919名ががんで死亡。被ばく名ががんで死亡。被ばくとの因果関係は不明。との因果関係は不明。

周辺地区において小児甲状腺がんが有意に増加。周辺地区において小児甲状腺がんが有意に増加。

朝日新聞　 2006年 4月 27日

チェルノブイリ原子力発電所事故によるがん死のリスク

対象人口

平均被ばく線量

がんの種類

期間 *

自然発がん死事故による発がん死

発生数発生率発生数発生率寄与率

事故処理作業者

1986-1987

200,000

100mSv

固形がん生涯 415,000 21 2,000 1 5

白血病生涯 800 0.4 200 0.1 20

初期 40 0.02 150 0.08 79

避難住民半径 30km

135,000

10mSv

固形がん　

生涯215,000 16 150 0.1 0.1

白血病生涯 500 0.3 10 0.01 2

初期 65 0.05 5 0.004 7

高度汚染地区住民

270,000

50mSv

固形がん生涯 43,500 16 1,500 0.5 3

白血病生涯 1,000 0.3 100 0.04 9

初期 130 0.05 60 0.02 32

その他の汚染地区 **

住民

6,800,000

7mSv

固形がん生涯 800,000 16 4,600 0.05 0.6

白血病生涯 24,000 0.03 370 0.01 1.5

初期 3,300 0.05 190 0.003 5.5*生涯： 95年、初期： 10年　　　 **Cs-137>37kBq/m3

Cardis et al. 1996

3,960 4,970

チェルノブイリ原子力発電所事故によるがん発生死

対象人口平均被ばく線量事故による発がん死

発生数寄与率

事故処理作業者避難住民

高度汚染地区住民600,000 66mSv 4,000 3.5

事故処理作業者避難住民

高度汚染地区住民その他の地区住民

～ 6,000,000 14mSv 9,000 0.9

ヨーロッパ全土～ 570,000,000 0.5mSv 16,000 0.01

International Agency for Research on Cancer/WHO, 2006

5.6人 /10万人 /mSv

放射線作業者

BMJ 2005;331;77-

解析対象集団　 15ヶ国　 407,391人

平均個人累積線量　 19.4mSv

A cumulative dose of A cumulative dose of 100mSv100mSv would lead to would lead to 9.7%9.7% increased mortality from cancers excluding leukaemia.increased mortality from cancers excluding leukaemia.

The corresponding figure is The corresponding figure is 19%19% for mortality from for mortality from leukaemia excluding CLL.leukaemia excluding CLL.

1-2%1-2% of deaths from cancer among workers in this cohort of deaths from cancer among workers in this cohort may be attributable to radiation.may be attributable to radiation.

喫煙・アルコール摂取量と累積線量の関係

2000.12　放射線影響協会

Because of the uncertainty on health effects at low Because of the uncertainty on health effects at low doses, the Commission judges that doses, the Commission judges that it is not appropriateit is not appropriate, , for the purposes of public health planning, to calculate for the purposes of public health planning, to calculate the hypothetical number of cases of cancer or heritable the hypothetical number of cases of cancer or heritable disease that might be associated with disease that might be associated with very small very small radiation dosesradiation doses received by received by large numbers of peoplelarge numbers of people over over very long periods of timevery long periods of time..

ICRP recommendations (Publication 103), pp51(paragraph 66), 2007ICRP recommendations (Publication 103), pp51(paragraph 66), 2007

Radiation effect is observed in non-irradiated cellsRadiation effect is observed in non-irradiated cells Bystander-effect / Non-Targeted effectBystander-effect / Non-Targeted effect

Survived cells mutate after cell divisionsSurvived cells mutate after cell divisions Genetic instability / Delayed responsesGenetic instability / Delayed responses

Unrepairable DNA damage exists by very low dosesUnrepairable DNA damage exists by very low doses Low-dose hypersensitivityLow-dose hypersensitivity

Uncertainty on health effects at low dosesUncertainty on health effects at low dosesmysterious biological responsesmysterious biological responses

The bystander effect of radiationThe bystander effect of radiation

Damage signals may be transmitted from irradiated to non-irradiated cells in a Damage signals may be transmitted from irradiated to non-irradiated cells in a population, leading to the occurrence of biological effects that receive no population, leading to the occurrence of biological effects that receive no radiation exposure.radiation exposure.

irradiated cellsirradiated cells non-irradiated cellsnon-irradiated cells

damage signalsdamage signals

biological effectbiological effect

Gap Junctional Intercellular CommunicationGap Junctional Intercellular CommunicationExtracellular Soluble FactorsExtracellular Soluble Factors

Gene expressionsGene expressionsGenetic effectsGenetic effects - DNA damage, cell killing, - DNA damage, cell killing, mutation, transformation mutation, transformation

The bystander effect of low LET radiationThe bystander effect of low LET radiationTechnical approachesTechnical approaches

AuthorsAuthors Radiation sourceRadiation source MethodMethod

Mothersill & Seymour Mothersill & Seymour

1997-1997-6060Co Co γγ-irradiation-irradiation

medium transfermedium transfer

Balajee et al. 2004Balajee et al. 2004 137137Cs Cs γγ-irradiation-irradiation

Prise et al. 2003Prise et al. 2003 278eV C278eV CKK soft X-ray soft X-ray microbeammicrobeam

Yang et al. 2005Yang et al. 2005 250kVp X-ray250kVp X-ray co-cultureco-culture

Localization of phosphorylated ATM in irradiated nucleus Localization of phosphorylated ATM in irradiated nucleus

unirradiatedunirradiated 0.5 Gy0.5 Gy 1.0 Gy1.0 Gy

Confocal observation by Zeiss LSM 510 META

0

10

20

30

0.0 0.5 1.0

irradiated dose (Gy)

ph

osp

ho

ryla

ted

AT

M f

oci

/nu

cle

us

Phosphorylated ATM in bystander cellsPhosphorylated ATM in bystander cells

before medium transferbefore medium transfer

2h after medium transfer from 1Gy-irradiated cells2h after medium transfer from 1Gy-irradiated cells

Focus of phosphorylated ATM and g-H2AXFocus of phosphorylated ATM and g-H2AX

Red : phosphorylated ATMRed : phosphorylated ATMGreen : g-H2AXGreen : g-H2AX

unirradiated unirradiated cultureculture

Num

ber

o f g

a mm

a -H

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N

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c ell s

00

0.10.1

0.20.2

0.30.3

0.40.4

Induction of DNA damage in unirradiated cellsInduction of DNA damage in unirradiated cells

co-culture of co-culture of unirradiated and unirradiated and irradiated cells irradiated cells

Micronucleus formation

mitosis (telophase)

binuclear cell

micronucleus

00

5050

100100

150150

200200

250250

300300

350350

Induction of micronucleus in unirradiated cellsInduction of micronucleus in unirradiated cells

Nu m

ber

o f m

i cro

n uc l

eus

in 2

0 00

u nir r

a dia

ted

cells

Num

b er

of m

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000

u nirr

a dia

t ed

cells



co-culture in the co-culture in the presence of an presence of an

anti-oxidantanti-oxidant

00

55

99

Induction of mutation in unirradiated cellsInduction of mutation in unirradiated cells

Mut

a tio

n fr

e qu e

ncy

a t H

PR

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c us

(10

Mut

ati o

n fr

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T lo

c us

( 10-6-6

))



Irradiation set up for shielded irradiation

Mancuso M. et.al. PNAS 2008;105:12445-12450

© 2008 by The National Academy of Sciences of the USA

Radiation damage by expected scatter dose in exposed vs. bystander EGL

Mancuso M. et.al. PNAS 2008;105:12445-12450Mancuso M. et.al. PNAS 2008;105:12445-12450

© 2008 by The National Academy of Sciences of the USA

Radiation damage by expected scatter dose in exposed vs. bystander EGL. (A and B) γ-H2AX positivity in the outer EGL of SH-8.3 Gy mice at 6h postirradiation compared with undetectable staining after exposure to the scatter dose (0.1 Gy). (D and E) Increased apoptosis in EGL of SH-8.3Gy mice at 6 h postirradiation compared with very rare apoptosis after a 0.1 Gy dose. (C and F) Percentage of γ-H2AX-positive and apoptotic cells in cerebellum at 3, 4.5, 6, and 18 h post-8.3-Gy (SH) and 0.1 Gy (WB) irradiation. *, P = 0.0139; **, P = 0.0015; ***, P = 0.0001. (Scale bars, 20 μm.)

The commission recognizes that these biological factors, The commission recognizes that these biological factors, together with possible tumor-promoting effects of together with possible tumor-promoting effects of protracted irradiation, and immunological phenomena, protracted irradiation, and immunological phenomena, may influence radiation cancer risk, but may influence radiation cancer risk, but current current uncertainties on their mechanisms and tumorigenic uncertainties on their mechanisms and tumorigenic consequences of the above processes are too great for consequences of the above processes are too great for the development of practical judgments.the development of practical judgments.

ICRP recommendations (Publication 103), pp51(paragraph 67), 2007ICRP recommendations (Publication 103), pp51(paragraph 67), 2007

Debate on the Topic “Does Scientific Evidence Support a Debate on the Topic “Does Scientific Evidence Support a Change from the LNT Model for Low-Dose Radiation Risk Change from the LNT Model for Low-Dose Radiation Risk Extrapolation?”Extrapolation?”

D. Averbeck (France)D. Averbeck (France) Living cells and tissues react Living cells and tissues react

differently to radiation insults from high differently to radiation insults from high to low dose exposures.to low dose exposures.

Some protection mechanisms are Some protection mechanisms are especially active at low doses, especially active at low doses, including protection against ROS, including protection against ROS, signaling activation of DNA repair, and signaling activation of DNA repair, and elimination of damaged cells.elimination of damaged cells.

At high doses, DNA repair is fully At high doses, DNA repair is fully activated, which can be in part error-activated, which can be in part error-prone giving rise to chromosomal prone giving rise to chromosomal damage and mutations.damage and mutations.

Unirradiated preneoplastic cells Unirradiated preneoplastic cells effectively undergo apoptosis.effectively undergo apoptosis.

D. J. Brenner (USA)D. J. Brenner (USA) There is no direct evidence for There is no direct evidence for

different damage response pathways different damage response pathways at very low doses.at very low doses.

Even if there were such evidence Even if there were such evidence from in vitro studies, we would not be from in vitro studies, we would not be able to predict the consequences in able to predict the consequences in terms of low dose cancer risks in terms of low dose cancer risks in humans.humans.

We don’t know if deviations from the We don’t know if deviations from the predictions of LNT will be large or predictions of LNT will be large or small, nor even whether they will small, nor even whether they will increase or decrease the cancer risk.increase or decrease the cancer risk.

It is more than premature to be It is more than premature to be advocating changes in policy or advocating changes in policy or practice of radiation protection.practice of radiation protection.

NCRP 44NCRP 44thth Annual Meeting “Low Dose and Low Dose-Rate Radiation Effects and Models”, Annual Meeting “Low Dose and Low Dose-Rate Radiation Effects and Models”, 2008 2008

Issues that may prompt the NRC to reexamine radiation Issues that may prompt the NRC to reexamine radiation protection standardsprotection standards

Potential gender and age differences in radiation Potential gender and age differences in radiation sensitivitysensitivity

Threshold for cataracts formationThreshold for cataracts formation

Ability to identify genetic markers in people who may Ability to identify genetic markers in people who may be abnormally sensitive to radiation exposurebe abnormally sensitive to radiation exposure

Possible existence of a real or practical threshold in Possible existence of a real or practical threshold in radiation dose responseradiation dose response

U.S. Nuclear Regulatory Commission Perspective, 2008U.S. Nuclear Regulatory Commission Perspective, 2008

Report of High Level and Expert Group on European Low Dose Risk Research, Jan 2009Report of High Level and Expert Group on European Low Dose Risk Research, Jan 2009

Shape of dose responseShape of dose response- LNT (linear non-threshold)LNT (linear non-threshold)- Dose rate- Dose rate

Tissue sensitivitiesTissue sensitivities- Tissue weightning factorsTissue weightning factors

Radiation qualityRadiation quality- Radiation quality factorsRadiation quality factors

Internal emittersInternal emitters- Biokinetic modelsBiokinetic models- Dosimetric modelsDosimetric models

Individual sensitivitiesIndividual sensitivities- GeneticsGenetics- AgeAge- GenderGender- LifestyleLifestyle- Other exposuresOther exposures

Non-cancer effectsNon-cancer effects- Circulatory diseasesCirculatory diseases- Cognitive functionsCognitive functions- Lens opacitiesLens opacities

Radiation Protection SystemRadiation Protection System

Dose limitsDose limitsConstraintsConstraintsOptimisationOptimisation

Dose as surrogate for riskDose as surrogate for riskAddtivityAddtivity

Cancer and hereditary effectsCancer and hereditary effects

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The main issues where judgements are made in the current system of radiation protection. The four The main issues where judgements are made in the current system of radiation protection. The four upper boxes denote judgements that fall directly within the main ICRP dosimetric system, while the two upper boxes denote judgements that fall directly within the main ICRP dosimetric system, while the two lower boxes include issues that are at present included only to a relatively minor degree. lower boxes include issues that are at present included only to a relatively minor degree.

国際放射線保健医療研究

原爆医療研究

放射線基礎生命科学研究

『社会と個人の安全と安心確保のための技術開発と

　　　　

地球規模の教育研究拠点構築の必要性

』

• 高齢化する原爆被爆者医療高齢化する原爆被爆者医療　（進行がん、多重がん、精神心理影響）　（進行がん、多重がん、精神心理影響）• 在外被爆者・海外ヒバクシャ問題在外被爆者・海外ヒバクシャ問題

　「

被ばく医療学

」

の確立

１

２

３

Nagasaki University Global COE ProgramNagasaki University Global COE ProgramGlobal Strategic Center for Radiation Health Risk Control

Division of Radiation Biology and ProtectionDivision of Radiation Biology and ProtectionCenter for Frontier Life Sciences, Nagasaki UniversityCenter for Frontier Life Sciences, Nagasaki UniversityDomestic projectsDomestic projects

Yoshida M, Morita N, Takao H, Miura M, Hayashida R, Kaneko M, Takemoto T, Okimura YYoshida M, Morita N, Takao H, Miura M, Hayashida R, Kaneko M, Takemoto T, Okimura YIndian projects Indian projects

Selvasekarapandian S, Brahmanandhan GM, Hakkim FL, Takamura N, Suyama ASelvasekarapandian S, Brahmanandhan GM, Hakkim FL, Takamura N, Suyama A+ terrific students in Kalasalingam, Bharathiar, and Nagasaki University+ terrific students in Kalasalingam, Bharathiar, and Nagasaki University

நன்றி�நன்றி� nandrinandri

risk

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