Development of rapid and sensitive bioassay methods to contribute to actinide internal exposure medical response

• Project/Area Number: 22K12384
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 63020:Radiation influence-related
• Research Institution: National Institutes for Quantum Science and Technology
• Principal Investigator: 楊 国勝 国立研究開発法人量子科学技術研究開発機構, 放射線医学研究所 計測・線量評価部, 主任研究員 (10801227)
• Co-Investigator(Kenkyū-buntansha): 金 ウンジュ 国立研究開発法人量子科学技術研究開発機構, 放射線医学研究所 計測・線量評価部, 主幹研究員 (10370876) ; 鄭 建 国立研究開発法人量子科学技術研究開発機構, 放射線医学研究所 福島再生支援研究部, 上席研究員 (30370878)
• Project Period (FY): 2022-04-01 – 2025-03-31
• Project Status: Granted (Fiscal Year 2022)
• Budget Amount: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2024: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2023: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2022: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
• Keywords: Actinides / Bioassay / Radiation emergency / Dose assessment / ICP-MS/MS / Cell gas / アクチニド / バイオアッセイ / 被ばく医療 / 質量分析法

Outline of Research at the Start

東電福島第一原発廃炉作業及び日本原燃再処理施設の稼働の本格化に伴い、放射線作業員のアクチニド内部被ばく事故リスクの増加が懸念されており、効果的・効率的な内部被ばく線量評価手法の開発は急務である。そこで、本研究では、プルトニウム(Pu)を含むアクチニド核種による内部被ばく事故に備え、血液、尿及び便を対象に、迅速かつ高感度の質量分析アクチニド・バイオアッセイ手法の開発を目的とする。本研究での成果は、既存の放射能測定法を最適化することに加え、開発した質量分析法との併用により、被ばく医療対応の実効性向上と体内除染剤の機序解明などの新たな研究分野の開拓に寄与できる。

Outline of Annual Research Achievements

Synthesized faecal sample was used for actinide analytical method development in feces, with the purpose of rapid emergency response on potential radiological/nuclear accidents. High recoveries (>80%) for Np, Pu, and Am/Cm have been obtained after ashing, borate fusion, CaF2 coprecipitation, and chromatographic purification. To increase the signal intensity of actinides in ICP-MS/MS analysis, 7.5 mL/min He has be introduced into the collision/reaction cell, along with the application of APEX-Q/ACM introduction system＋x type lens. The developed method was validated by participating in the annual intercomparison organized by PROCORAD, France.

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

As expectation, bioassay method for the measurement of actinides in faecal sample was developed based on the rapid and sensitive ICP-MS/MS analysis after chemical separation and purification.
The related paper is being prepared and will be submitted in 2023.
In order to communicate with other researchers and obtain the latest information, we also participated in several domestic and international conferences.

Strategy for Future Research Activity

Since the concentrations of actinides in the blood was relatively high just after internal exposure and before decorporation. It is critical to collect and measure blood samples during this short period for the dose assessment to provide critical information for medical treatment. A novel procedure should be established. After the development of bioassay method for the measurement of actinides in faecal sample, the development of bioassay method for the measurement of actinides in blood sample will be performed in this year.

Research Products

• [Journal Article] Rapid measurement of actinides in urine by mass and alpha spectrometric methods (2023)
  • Author(s): Guosheng Yang; Jian Zheng; Munehiko Kowatari; Eunjoo Kim; Osamu Kurihara
  • Journal Title: Radiation Protection Dosimetry Volume: - Issue: 15-16 Pages: 1994-1999
  • DOI: 10.1093/rpd/ncad005
  • Peer Reviewed
• [Journal Article] The new QST bioassay laboratory in Chiba Japan (2022)
  • Author(s): Guosheng Yang; Kotaro Tani; Munehiko Kowatari; Yuki Tamakuma; Masayuki Naito; Eunjoo Kim; Osamu Kurihara
  • Journal Title: Radiation Protection Dosimetry Volume: - Issue: 15-16 Pages: 2020-2024
  • DOI: 10.1093/rpd/ncac198
  • Peer Reviewed
• [Presentation] Rapid analysis of Sr-90 in small volume of urine by ICP-MS/MS after chromatographic purification (2022)
  • Author(s): Yang, G., Kim, E., Zheng, J., Kowatari, M., Kurihara, O.
  • Organizer: International Youth Nuclear Congress IYNC2022, Koriyama, Japan.
  • Int'l Joint Research
• [Presentation] Rapid fecal and urinary bioassay for the measurement of multiple actinide isotopes (2022)
  • Author(s): Yang, G., Kim, E., Zheng, J., Kowatari, M., Kurihara, O.
  • Organizer: 2022 ARADOS-KREDOS Joint Annual Meeting, Soul, Korea
  • Int'l Joint Research
• [Presentation] Recent advancement in bioassay at QST (2022)
  • Author(s): Yang, G., Kim, E., Zheng, J., Seno, H., Kowatari, M., Kurihara, O.
  • Organizer: 日本放射化学会第66回討論会、東京都
• [Presentation] Development of a new bioassay laboratory at QST (2022)
  • Author(s): Yang, G., Tamakuma, Y., Naito, M., Seno, H., Tani, K, Kim, E., Kowatari, M., Kurihara, O.
  • Organizer: International Conference on Individual Monitoring of Ionising Radiation (IM2022) and Neutron and Ion Dosimetry Symposium (NEUDOS-14), KRAKOW POLAND (online)
  • Int'l Joint Research
• [Presentation] Rapid measurement of actinides in urine by mass and alpha spectrometric methods (2022)
  • Author(s): Yang, G., Kim, E., Zheng, J., Seno, H., Kowatari, M., Kurihara, O.
  • Organizer: International Conference on Individual Monitoring of Ionising Radiation (IM2022) and Neutron and Ion Dosimetry Symposium (NEUDOS-14), KRAKOW POLAND (online)
  • Int'l Joint Research