About NIMD

Our organization, departments, staff and researchers

Mineshi Sakamoto

The research group I work for : Risk Assessment Group

Specialty: Environmental Epidemiology, Toxicological Neuroethology
I have been primarily engaged in research on the fetal effects of methylmercury for over 30 years.
In an epidemiological study of fetuses, which have the highest sensitivity to methylmercury, I found that boys were more vulnerable to methylmercury contamination than girls, and that excess deaths of boys due to stillbirths and miscarriages reduced the ratio of male to female births in Minamata City. I also published a paper showing that methylmercury is actively transferred via the placenta, accumulating in fetal blood and brain at higher concentrations than in the mother, and that it is less likely to be transferred from breast milk. These findings were adopted as the scientific evidence for the 2005 Ministry of Health, Labour and Welfare (MHLW) decision on "Precautions for Seafood Consumption by Pregnant Women in Consideration of Possible Effects on the Fetus.” On the other hand, based on the fact that fish contains docosahexaenoic acid (DHA), which is beneficial to the fetal brain, the American Chemical Society Science News featured the recommendation that pregnant women should eat small fish rich in DHA and low in mercury to help protect their children's brains.
Currently, I am working diligently to investigate a new aspect of Minamata disease: the elevated selenium concentration in Minamata disease patients and the role of selenium in the pathogenesis of the disease, which remained a mystery for many years. In 2017, I received the Presidential Award of the National Personnel Authority (individual category) in recognition of my contributions to Minamata disease research, as well as my international contributions to solving numerous mercury contamination problems overseas in response to urgent requests from the World Health Organization (WHO) and others.

Overseas surveys and investigations:
Field surveys at the request of WHO (Kyrgyzstan, Cambodia, Indonesia, Mongolia); cooperation for investigation of mercury pollution due to a factory fire in Hanoi, Vietnam
Cooperation to JICA (Philippines, Brazil, Bangladesh); international joint studies (Brazil, China, USA, Canada, Slovenia, Spain, Philippines, Italy, Vietnam, Mongolia)

Research subjects and areas of work (principal roles only)

Study on the coexistence of mercury and selenium in Minamata disease and the effects of methylmercury on fetuses and infants

Main research achievements
Externally-funded research(principal roles only)
Main career history, academic history, academic degrees, awards, etc.

Doctor of Medicine

Academic affiliations: Japanese Society for Hygiene, Japan Society for Biomedical Research on Trace Elements

  • 2018-2020:Visiting Professor, Tohoku University Graduate School of Medicine
  • 2017:The 29th Presidential Award of the National Personnel Authority (individual category)
  • 2017-:Part-time Lecturer, Mie University Graduate School of Medicine and Faculty of Medicine
  • 2017-:Part-time Lecturer, Kumamoto University Graduate School of Pharmaceutical Sciences
  • 2017-:Visiting Research Fellow, Kagoshima University Graduate School of Medical and Dental Sciences
  • 2014-2016:Visiting Professor, Federal University of Western Pará Brazil
  • 2014-2019:Visiting Professor, Prefectural University of Kumamoto
  • 2014-:Editorial Board Member: Environ Res
  • 2013-:Visiting Associate Professor, Kumamoto University Graduate School of Medical Sciences
  • 2007-2018:Executive Committee Member, International Conference on Mercury as a Global Pollutant
  • 2005-2007:Editorial Board Member, Japanese Society for Hygiene
  • 2005-:Councilor, Japanese Society for Hygiene