Microsoft PowerPoint - 検討チーム甲状腺測定work b2-sent

小児甲状腺被ばく線量について

（独）放射線医学総合研究所

REMAT 医療室

立崎英夫

原子力災害対策本部、

原子力安全委員会による

小児甲状腺簡易測定

小児甲状腺簡易測定結果

甲状腺被ばく線量推定

国際連合原子放射線の影響に関する科学委員会

United Nations Scientific Committee on the Effects of Atomic Radiation

Sources, effects and risks of ionizing radiation

UNSCEAR 2013 Report

Volume I, SCIENTIFIC ANNEX A: Levels and effects of radiation exposure due to

the nuclear accident after the 2011 great east-Japan earthquake and tsunami

C92. より

The highest district-average doses to the thyroid were to individuals in the cities of Iwaki and Fukushima. The highest district-average absorbed dose to the thyroid was estimated to have been 52 mGy for a 1-year-old infant living in Iwaki City, with approximately one third of this due to inhalation and two thirds to ingestion. The contribution of inhalation to the absorbed dose to the thyroid was higher in districts with the higher deposition density of radionuclides on soil. Within each district, there was also a marked spatial

variability in the concentration of 131_{I in air and the estimates of the absorbed dose to the}

thyroid of an individual from inhalation could be up to about two to three times higher or lower in some locations within districts than the average dose for the district.

(United Nations Scientific Committee on the Effects of Atomic Radiation, Sources, effects and risks of ionizing radiation, UNSCEAR 2013 Report, Volume I, SCIENTIFIC ANNEX A: Levels and effects of radiation exposure due to the nuclear accident after the 2011 great east-Japan earthquake and tsunami, Appendix C, 2013)

（仮訳）_{C92 より；} 最高の地区平均甲状腺線量は、いわき市と福島市の個人に対するものであった。最高の 地区平均甲状腺吸収線量はいわき市に住む1歳児に対する52 mGy であった。このうちお よそ_{1/3は吸入により、2/3は経口摂取による。（中略）それぞれの地区内で空気中の}131_I濃 度の明らかな場所による変化もあり、吸入からのある人の甲状腺の吸収線量推定は、地 区内のある場所では、地区平均線量に対して、高い場合およそ 2-3倍から低い場合1/2-1/3倍でありえる。

甲状腺被ばく線量推定－国連科学委員会

甲状腺被ばく線量推定－国連科学委員会

(United Nations Scientific Committee on the Effects of Atomic Radiation, Sources, effects and risks of ionizing radiation, UNSCEAR 2013 Report, Volume I, SCIENTIFIC ANNEX A: Levels and effects of radiation exposure due to the nuclear accident after the 2011 great east-Japan earthquake and tsunami, Appendix C, 2013) 8

C98. より

The estimates of settlement-average absorbed doses to the thyroid of a 1-year-old infant are shown in table C12. The settlement-average absorbed doses to the thyroid of 1-year-old infants before and during the evacuations were estimated to be up to about 50 mGy for those evacuated by 15 March 2011 and up to about 70 mGy for those evacuated at later times. These doses were principally from inhalation during the passage of the

airborne radioactive material through the affected areas in the early days of the accident and from ingestion over the subsequent period. The absorbed doses to the thyroid for the first year for the 1-year-old infants who were evacuated ranged from 15 up to about 80 mGy.

(United Nations Scientific Committee on the Effects of Atomic Radiation, Sources, effects and risks of ionizing radiation, UNSCEAR 2013 Report, Volume I, SCIENTIFIC ANNEX A: Levels and effects of radiation exposure due to the nuclear accident after the 2011 great east-Japan earthquake and tsunami, Appendix C, 2013)

（仮訳）C98 より； 地域ごとの_{1歳児に対する平均甲状腺吸収線量を表C12に示す。避難前と避難中の地域} ごとの_{1歳児に対する平均甲状腺吸収線量は、2011年3月15日までに避難した者は約} 50m Gyまで、それより後に避難した者は約70 mGyまで、と推定される。これらの線量は、 主として事故初期に空気中を流れる放射性物質の当該地区の通過の際の吸入、及びそ れ以降の期間の経口摂取による。 避難したグループの、最初の1年間の1歳児に対する 甲状腺吸収線量は、_{15から80 mGy の範囲にわたる。}

甲状腺被ばく線量推定－国連科学委員会

(United Nations Scientific Committee on the Effects of Atomic Radiation, Sources, effects and risks of ionizing radiation, UNSCEAR 2013 Report, Volume I, SCIENTIFIC ANNEX A: Levels and effects of radiation exposure due to the nuclear accident after the 2011 great east-Japan earthquake and tsunami, Appendix C, 2013) 10