The Association between Exposure to Heavy Metals during Pre-/Neonatal Periods and Neurodevelopment - Analysis of Milk Teeth

• Project/Area Number: 18K10048
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 58020:Hygiene and public health-related: including laboratory approach
• Research Institution: Kochi University
• Principal Investigator: Yasumitsu-Lovell Kahoko 高知大学, 医学部, 特任助教 (60598522)
• Co-Investigator(Kenkyū-buntansha): 滿田 直美 高知大学, 医学部, 特任助教 (30611389) ; 菅沼 成文 高知大学, 教育研究部医療学系連携医学部門, 教授 (50313747) ; 栄徳 勝光 高知大学, 教育研究部医療学系連携医学部門, 講師 (50552733) ; 西脇 芳典 高知大学, 教育研究部人文社会科学系教育学部門, 教授 (50632585)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2020: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2019: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2018: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
• Keywords: 重金属曝露 / 乳歯 / 小児 / 精神神経発達 / 蛍光X線

Outline of Final Research Achievements

Although previous studies on the measurement of deciduous milk teeth using liquid chromatography inductively coupled plasma mass spectrometry (LC-ICP-MS) have increased in recent years, there are no previous studies on similar measurement methods to this study using X-ray fluorescence. We conducted studies utilizing optical microscopy, manipulated electron microscopy (SEM), and X-ray (polycapillary-focused and KB mirror-focused) measurements. The X-ray measurements were carried out at the KEK, High Energy Accelerator Research Organization. Characteristic concentrations of some heavy metals such as P, Ca, Ni, Zn, Hg, Pb, Sr, Cu, Cr and Mn were identified. Neonatal lines, which is essential for estimating the timing of exposure, were also confirmed.

Academic Significance and Societal Importance of the Research Achievements

Our method to measure heavy metal distribution using X-ray fluorescence seems to be applicable to estimate exposure timing during critical developmental windows, perinatal and early childhood periods when individuals are most susceptible to chemical exposures as well as to pursue repeatability.

Research Products

• [Presentation] Synchrotron Radiation X-Ray Fluorescence Analysis (SR-XRF) of Heavy Metal Accumulation in Deciduous Teeth (2019)
  • Author(s): Kahoko Yasumitsu-Lovell, Yoshinori Nishiwaki, Tetsuya Yamamoto, Masamitsu Eitoku, Naomi Mitsuda, Narufumi Suganuma
  • Organizer: the 18th International Conference of the Pacific Basin Consortium For Environment and Health. 16-19 Septembber, 2019. Kyoto, Japan
  • Int'l Joint Research
• [Presentation] 発達障害メカニズム解明のための乳歯の放射光蛍光X線イメージング分析 (2019)
  • Author(s): the 18th International Conference of the Pacific Basin Consortium For Environment and Health. 16-19 Septembber, 2019. Kyoto, Japan
  • Organizer: 第５５回X線分析討論会（福島県福島市 コラッセふくしま）～Ｘ線分析を通して福島の復興を考える～