Elucidation of the mechanism of mercury isotopic fractionation in the environment

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H03623
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 64010:Environmental load and risk assessment-related
• Research Institution: Gakushuin University
• Principal Investigator: Ohno Takeshi 学習院大学, 理学部, 教授 (40452007)
• Co-Investigator(Kenkyū-buntansha): 深海 雄介 学習院大学, 理学部, 助教 (10754418) ; 伊地知 雄太 東京大学, 大学院理学系研究科(理学部), 特任研究員 (10911258)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 水銀 / 同位体 / 同位体分別 / MIF

Outline of Final Research Achievements

Mercury is a toxic element to the human body, and its contamination on a global scale is a growing problem. Mass independent isotopic fractionation (MIF) of mercury has attracted attention as a research method for analyzing the source of mercury contamination. However, the mechanism of mercury MIF in nature has not been well understood. In this study, the mechanism of mercury isotope fractionation in nature suggests that in the aqueous environment, the OH radicals generated during photoreduction and the nuclear spins of mercury odd isotopes affect the reaction rate of mercury odd isotopes. It was also suggested that in the atmosphere, mercury even isotope MIF is caused by the photo-redox reaction of mercury, and that the even isotope selective reaction may be caused by certain UV wavelengths.

Free Research Field

環境地球化学

Academic Significance and Societal Importance of the Research Achievements

水銀は人体に有害であり、揮発しやすい化学的性質により、世界的に汚染が広がるため問題となっている。また、水銀は生物に濃縮し、食物連鎖を通して大型魚に濃縮し、人体に影響を与えることが懸念されており、人への暴露経路となる大気・水圏における水銀循環の理解は、人への影響を低減していくために重要な研究課題である。本研究では、水銀の質量に依存しない同位体組成の変動に注目し、水銀の汚染源を同位体の比率から調べるための研究手法を開発した。