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Radiation and Children’s Heath: Separating Fact From Fiction. Mitsuyoshi Urashima MD, PhD, MPH Associate Professor, Jikei University School of Medicine http://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. Fukushima 3/11 ~ 4/5 131I: ~150PBq 137Cs: ~ 12PBq.
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Radiation and Children’s Heath: Separating Fact From Fiction Mitsuyoshi Urashima MD, PhD, MPH Associate Professor, Jikei University School of Medicine http://dr-urashima.jp
核戦争防止国際医師会議:1985年ノーベル平和賞核戦争防止国際医師会議:1985年ノーベル平和賞
Fukushima 3/11 ~ 4/5 131I: ~150PBq 137Cs: ~ 12PBq Chernobyl 131I: ~1760PBq 137Cs: ~ 86PBq 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, damnedlies, and statistics. “
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 Effective dose (実行線量):Sv, mSv, mSv 吸収線量: dose (D): Gy(= Sv) 1Ci=3.7×10 Bq=37GBq 10 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 irradiation 137 131 Cs I
131 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 Half life = 8 days 137 Cs : 100Bq/kg (=litter) = 100 x 0.013 = 1.3 microSv x 100 days = 130 microSv Image Half life = 30 years
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 喫煙リスク
Agenda • Basics a. Mechanisms of harm by irradiation b. Bias in epidemiological studies II. Lesson learned from Chernobyl a. Thyroid cancer b. Leukemia c. other cancer d. congenital defects III. Social psychology
Ecological study Exposure Outcome Case Control Study Confounders Cohort Study Bias
Agenda • Basics a. Mechanisms of harm by irradiation b. Bias in epidemiological studies II. Lesson learned from Chernobyl a. Thyroid cancer b. Leukemia c. other cancer d. congenital defects III. Social psychology
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)。
Agenda • Basics a. Mechanisms of harm by irradiation b. Bias in epidemiological studies II. Lesson learned from Chernobyl a. Thyroid cancer b. Leukemia c. other cancer d. congenital defects III. Social psychology
Agenda • Basics a. Mechanisms of harm by irradiation b. Bias in epidemiological studies II. Lesson learned from Chernobyl a. Thyroid cancer b. Leukemia c. other cancer d. congenital defects III. Social psychology
Agenda • Basics a. Mechanisms of harm by irradiation b. Bias in epidemiological studies II. Lesson learned from Chernobyl a. Thyroid cancer b. Leukemia c. other cancer d. congenital defects III. Social psychology
Agenda • Basics a. Mechanisms of harm by irradiation b. Bias in epidemiological studies II. Lesson learned from Chernobyl a. Thyroid cancer b. Leukemia c. other cancer d. congenital defects III. Social psychology
Analysis of Situation A series of Earthquakes Nuclear Power Point Accident Tsunami Huge number Of causalities > 20,000 Explosion Continuous Leakage Evacuation 131I 137Cs Loss of Families Loss of Work Loss of Properties Earth Water External Exp. Destruction of The communities Food Water Internal Exp. Settlement Human Economy
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 Contamination In food supply And water Broadcast
Audience rate = 14% 2011/3/24 (Thur) 8 – 9 PM
Risk communication Demonstrate Chernobyl as scientific evidence Increase of thyroid cancer in children No significant increase of cancer in adults No 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
Change in Value of People Family, Friends, Community Money, Business Shock Panic We have only the way for recovery. Positive thinking
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 life and gave us a chance to change dramatically.
Agenda • Basics a. Mechanisms of harm by irradiation b. Bias in epidemiological studies II. Lesson learned from Chernobyl a. Thyroid cancer b. Leukemia c. other cancer d. congenital defects III. Social psychology