Radiation and Children’s Heath:Separating Fact From Fiction

Mitsuyoshi Urashima MD, PhD, MPHAssociate Professor, Jikei University School of Medicinehttp://dr-urashima.jp

核戦争防止国際医師会議： 1985 年ノーベル平和賞

圧力制御室

Chernobyl 131I: ~1760PBq 137Cs: ~ 86PBq

Fukushima 3/11 ~ 4/5 131I: ~150PBq 137Cs: ~ 12PBq

Global Release of Atmospheric Nuclear Weapon Testing 131I: ~675,000PBq 137Cs: ~ 948PBq

330microSv/hr

270microSv/hr

255microSv/hr

Mark Twain

"There are three kinds of lies: lies, damned lies, and statistics. “

External irradiation

Effective dose ( 実行線量）： Sv, mSv, Sv吸収線量 : dose (D): Gy (= Sv)

1Ci ＝ 3.7×10 Bq ＝ 37GBq 10

Effective dose ( 実行線量） : 全身影響を表わす量　　　　　　　　　　　　　　　　　　　組織毎の係数をかけるEquivalent dose ( 等価線量） : 放射線の種類によって異なる　　　　　　　　　　　　　　　　　　　X 線やベータ線、ガンマ線は１、

中性子線は５～２０、アルファ線は２０

イメージとしては、１ｋｇの放射線を放っている物質が放射線を出し終わるまでの、放射線の総量

Internal irradiation131

I137Cs

I : 100Bq/kg (=litter) = 100 x 0.022 = 2.2 microSv x 100 days = 220 microSv

* X 0.016 の係数を使う場合もある

131

Cs : 100Bq/kg (=litter) = 100 x 0.013 = 1.3 microSv x 100 days = 130 microSv

137

Image

Half life = 8 days

Half life = 30 years

Deterministic Effects

骨髄被曝線量 (Gy)

骨髄移植（＋） 骨髄移植（－）

患者数 皮膚・腸管傷害による死亡

GVH反応による死亡

生存者

患者数 皮膚・腸管傷害による死亡

GVH反応による死亡

生存者

< 6.5 4 0 3 1 5 0 0 5

6.5 – 9.0 3 2* 0 1 4 3 0 1

9.0 < 6 5 1 0 5 5 0 0

合計 13 7 4 2 14 8 0 6

Stochastic Effects

被曝量 (mGy) 癌発症リスク

0.5 正常範囲内

0.5 ~ 5 0.04% 上昇

5 ~ 50 0.04% ~0.4%上昇

50~100 0.4~0.8% 上昇

100 ~ 250 0.8~2%上昇

250~700 2~5.6%上昇

喫煙リスク 受動喫煙　　　 x 2 =100% 上昇通常喫煙　　　 x 10 　 =900% 上昇ヘビー　　　　　 x 20 　 = 1900% 上昇

検査時年齢

グループ I事故後に妊娠・出

産

グループ II事故時妊娠中

グループ III事故時既に小児

男児 女児 男児 女児 男児 女児8 0/67 0/759 0/651 0/66710 0/138

30/128

711 0/152

30/154

70/156 0/149 0/28 0/26

12 0/897 0/858 0/501 0/406 0/333 1/34513 0/305 0/302 0/437 1/437 1/989 6/90614 0/164 0/159 2/144

98/146

015 3/133

99/131

916 0/579 2/75717 1/93 0/100合計 0/482

60/464

60/125

80/115

17/481

024/49

10

Stochastic Effects

AgendaI. Basics a. Mechanisms of harm by irradiation b. Bias in epidemiological studiesII. Lesson learned from Chernobyl a. Thyroid cancer b. Leukemia c. other cancer d. congenital defectsIII. Social psychology

Bias

Ecological study

Case Control Study

Cohort Study

Exposure Outcome

Confounders

AgendaI. Basics a. Mechanisms of harm by irradiation b. Bias in epidemiological studiesII. Lesson learned from Chernobyl a. Thyroid cancer b. Leukemia c. other cancer d. congenital defectsIII. Social psychology

被爆量（ Gy） 平均被爆量(Gy)

甲状腺がん /全体（人）

オッヅ比 (95%信頼区間 )

0.00 - 0.24 0.11 9/6357 1

0.25 - 0.74 0.44 9/3521 2.31 (0.91 – 5.88)

0.75 – 1.49 1.07 10/1591 6.25 (2.56 – 15.6)

1.50 – 2.99 2.06 8/944 8.97 (3.99 – 23.7)

3.00 – 47.63 6.48 9/699 15.3 (5.88 – 40.0)

• 男性の過剰相対リスク = 2.21 (95% 信頼区間 0.40 – 13.80)/Gy• 女性の過剰相対リスク = 16.57 (95% 信頼区間 1.08 – 1651)/Gy• • 女性の方が被爆した際、甲状腺がんになるリスクは高い（しかし

統計学的有意差は無かった）。• • 0~4 歳児の過剰相対リスク = 9.08 (95% 信頼区間 1.33 – 84.8)/Gy• 5~9 歳児の過剰相対リスク = 7.00 (95% 信頼区間 1.76 – 33.04)/Gy• 10~18 歳児の過剰相対リスク = 3.39 (95% 信頼区間 0.68 – 19.68)/Gy• • 年齢が小さい小児が被爆した際、甲状腺がんになるリスクは高い

（しかし統計学的有意差は無かった）。

因子 甲状腺がん /PY 過剰相対リスク（ 95％信頼区間） 相乗効果

性別 0.40男 28/35,240 1.20 (0.03 – 6.74)女 37/37,764 2.66 (0.46 – 12.49)

事故時年齢 0.400 ~ 4 歳 18/21,236 7.43 (1.67 – )

4 ~ 12 歳 31/34,941 1.57 (-0.02 – 8.51)12 ~ 18 歳 16/16,827 0.69 (-0.04 – 6.31)

検査時年齢 0.71<22 歳 16/26,440 2.08 (0.10 –13.65)

22 ~ 30 歳 25/34,374 1.83 (0.01 – 11.97)30 ~ 40 歳 24/12,190 0.74 (0.06 – 4.95)

事故時住所 0.005チェルノブイリ 42/38,746 5.20 (-0.001 – 1.27)

キエフ 11/34,374 1.22 (-0.02 – 12.59)ジトミル 12/20,816 0.08 (1.45 – 21.40)

事故以降住所 0.008チェルノブイリ 39/37,988 4.07 (0.95 – 16.80)

キエフ 15/14,710 2.70 (0.27 – 27.52)ジトミル 11/20,254 0.06 (-0.02 – 1.08)

ヨウ素剤予防内服 0.56いいえ 50/51,674 2.11 (0.36 – 9.28)はい 12/18,154 1.03 (0.08 – 9.84)

びまん性甲状腺腫 0.89いいえ 45/45,122 1.78 (0.33 – 6.41)はい 20/15,882 2.07 (0.03 – 28.4)

サイログロブリン ng/mL 0.92<15 20/30,854 1.58 (0.32 – 13.77)

15 ~ 30 21/20,687 1.89 (0.18 – 12.21)31 ~ 643 21/16,108 2.58 (0.16 – 34.73)

AgendaI. Basics a. Mechanisms of harm by irradiation b. Bias in epidemiological studiesII. Lesson learned from Chernobyl a. Thyroid cancer b. Leukemia c. other cancer d. congenital defectsIII. Social psychology

AgendaI. Basics a. Mechanisms of harm by irradiation b. Bias in epidemiological studiesII. Lesson learned from Chernobyl a. Thyroid cancer b. Leukemia c. other cancer d. congenital defectsIII. Social psychology

AgendaI. Basics a. Mechanisms of harm by irradiation b. Bias in epidemiological studiesII. Lesson learned from Chernobyl a. Thyroid cancer b. Leukemia c. other cancer d. congenital defectsIII. Social psychology

AgendaI. Basics a. Mechanisms of harm by irradiation b. Bias in epidemiological studiesII. Lesson learned from Chernobyl a. Thyroid cancer b. Leukemia c. other cancer d. congenital defectsIII. Social psychology

Tsunami

A series of EarthquakesNuclear Power Point Accident

Explosion Continuous Leakage

Destruction ofThe communities

Huge numberOf causalities > 20,000

Loss of FamiliesLoss of WorkLoss of Properties

Evacuation

Settlement

131I137Cs

EarthWater

FoodWater

Human

Internal Exp.

External Exp.

Economy

Analysis of Situation

Risk Communication by Government

This level of irradiation has no hazardous effects on health for now.

People think: That’s means some problems later, cancer, congenital anomalies, infertility?

This level of irradiation in water and food has no hazardous effects on health if you do not take long term. However, if you can avoid taking, please do so. But if you can’t, it’s OK. Doesn’t matter.

People think: This must be quite danger.

Earthquake

ContaminationIn food supplyAnd water

Broadcast

Audience rate = 14%2011/3/24 (Thur) 8 – 9 PM

Risk communication

Demonstrate Chernobyl as scientific evidence

Increase of thyroid cancer in childrenNo significant increase of cancer in adultsNo significant increase in congenital anomalies

What we need to do is protecting children.

1. People outside the area of disaster do not have to worry about yourself.

2. We should have sympathy to the causalities with serious anxiety as if they are our family or friends.

3. If the society be confused and depressed, the situation will be much more worsened. So, we should seek more positive side of things.

Try to keep unequivocal attitude to wipe out anxiety and suspicion of the people in their hard time

Shock

Panic

Positive thinking

Change in Value of People

Family, Friends, Community

Money, Business

We have only the way for recovery.

1. Power of Media Many e-mails and phone calls

I felt the atmosphere of Japanese society had been changed totally after that.

2. Dynamic changes of behavior in such a short period. Go home earlier.

　　 People seek behavior: Do the right things, Justice.

3. Things have both negative and positive side.

Crisis made us notice what is the most important in lifeand gave us a chance to change dramatically.

AgendaI. Basics a. Mechanisms of harm by irradiation b. Bias in epidemiological studiesII. Lesson learned from Chernobyl a. Thyroid cancer b. Leukemia c. other cancer d. congenital defectsIII. Social psychology

@ high risk

1. Women and mothers

2. Older adults

3. Evacuees and those with a high degree of exposure to the disaster

Depression

Anxiety

Somatization

Chronic distress

Distrust of politics

A variety of chronic stressors

Invisible stress coming from radiation

Uncertainty of future disease

Economic and political turmoil

Low life satisfaction

Depression

FemaleOlder age

Occupation

Relocation history

Chronic stressors

Negative life events

Mastery/Controllability

Family problem

RegionContamination level

Family history of leukemia

Anxiety

Female

Occupation

Relocation history

Chronic stressors

Negative life events

Mastery/Controllability

Family problem

RegionContamination level

Family history of leukemia

Older age

Somatization

Female

Occupation

Relocation history

Chronic stressors

Negative life events

Mastery/

Controllability

Family problem

RegionContamination level

Family history of leukemia

Older age