Our organization, departments, staff and researchers
Megumi Yamamoto
The research group I work for : Risk Assessment
Group(Group Leader), International Contribution/Information Group
There are individual differences in the health effects of exposure to mercury
compounds. High-risk groups for methylmercury exposure include those exposed to high concentrations of
mercury and those with high sensitivity to mercury. Fetuses and infants are known to be particularly
sensitive to methylmercury because of their developing brain nervous system. Metabolic abnormalities
associated with diseases may also affect sensitivity to exposure to mercury compounds. Therefore, it is
necessary to accurately determine exposure to methylmercury and conduct an appropriate risk assessment
of health effects in these groups. Our laboratory is conducting exposure analyses in high-risk groups
for methylmercury exposure and experimental studies to elucidate factors associated with mercury
sensitivity.
Research theme - Areas of work
Reinforcing exposure assessment systems for high-risk groups for methylmercury exposure
Mercury exposure assessment and technology transfer in developing countries
Yoshino K, Yamada K, Kanaya G, Komorita T, Okamoto K, Tanaka M, Tada Y, Henmi Y, Yamamoto M. Food Web Structures and Mercury Exposure Pathway to Fish in Minamata Bay. Arch Environ Contam Toxicol. 2023 Nov;85(4):360-373. doi: 10.1007/s00244-023-01040-y. Epub 2023 Nov 2.
Oguro A, Fujiyama T, Ishihara Y, Kataoka C, Yamamoto M, Eto K, Komohara Y, Imaoka S, Sakuragi T, Tsuji M, Shibata E, Kotake Y, Yamazaki T. Maternal DHA intake in mice increased DHA metabolites in the pup brain and ameliorated MeHg-induced behavioral disorder. J Lipid Res. 2023 Nov;64(11):100458. doi: 10.1016/j.jlr.2023.100458. Epub 2023 Oct 12.
Ishitsuka K, Tsuji M, Yamamoto M, Tanaka R, Suga R, Kuwamura M, Sakuragi T, Shimono M, Kusuhara K; Japan Environment and Children’s Study Group. Association between maternal fish consumption during pregnancy and preterm births: the Japan Environment and Children's Study. Environ Health Prev Med. 2023;28:47. doi: 10.1265/ehpm.23-00084.
Nakamura M, Tatsuta N, Murata K, Nakai K, Iwata T, Otobe T, Sakamoto M, Yamamoto M, Itatani M, Miura Y, Koriyama C. Neurodevelopmental associations of prenatal and postnatal methylmercury exposure among first-grade children in the Kinan region, Japan. Environ Res. 2023 Oct 15;235:116688. doi: 10.1016/j.envres.2023.116688. Epub 2023 Jul 17.
2022
The First Exposure Assessment of Mercury Levels in Hair among Pregnant Women and Its Effects on
Birth Weight and Length in Semarang, Central Java, Indonesia. Muniroh M, Bakri S, Gumay AR,
Dewantiningrum J, Mulyono M, Hardian H, Yamamoto M,
Koriyama C. Int J Environ Res Public Health. 2022 Aug 27;19(17):10684. doi:
10.3390/ijerph191710684.
Sakamoto M, Haraguchi K, Tatsuta N, Marumoto M, Yamamoto
M, Nakamura M. Breast milk contribution to tissue mercury levels in rat pups examined
by cross-fostering at birth. Environ Res. 2022 Jan 19;208:112772. doi:
10.1016/j.envres.2022.112772.
2021
Yamamoto M, Marumoto K: Locally originated analytical
chemistry "Mercury Analytical Methods Originated in Minamata." Bunseki (In Japanese): The Japan
Society for Analytical Chemistry 2021;1: 21-22. https://www.jsac.or.jp/bunseki/pdf/bunseki2021/p21.pdf
Oguro A, Fujita K, Ishihara Y, Yamamoto M, Yamazaki T.
DHA and its metabolites have a protective role against methylmercury-induced neurotoxicity in
mouse primary neuron and SH-SY5Y cells. Int. J. Mol. Sci.2021, 22(6), 3213;
https://doi.org/10.3390/ijms22063213
Kataoka C, Yoshino K, Kashiwada S, Yamamoto M. Do
polystyrene beads contribute to accumulation of methylmercury in oysters?Arch. Environ. Contam.
Toxicol.2021 Apr 24. doi: 10.1007/s00244-021-00848-w.
Yoshino K, Yamada K, Tanaka M, Tada Y, Kanaya G, Henmi Y, Yamamoto M. Subtidal benthic communities in Minamata Bay,
Japan, approximately 30 years after mercury pollution remediation involving dredging
disturbance. Ecol. Res. 2021. https://doi.org/10.1111/1440-1703.12281
2020
David J, Muniroh M, Nandakumar A, Tsuji M, Koriyama C, Yamamoto
M. Inorganic mercury-induced MIP-2 expression is suppressed by N-acetyl-L-cysteine in
RAW264.7 macrophages. Biomed. Rep . 2020 Feb; 12 (2):39-45.
Muniroh M, Gumay AR, Indraswari DA, Bahtiar Y, Hardian H, Bakri S, Maharani N, Karlowee V,
Koriyama C, Yamamoto M. Activation of MIP-2 and MCP-5
Expression in Methylmercury-Exposed Mice and Their Suppression by N-Acetyl-L-Cysteine. Neurotox
Res.2020 Feb; 1-8.
Haraguchi K, Sakamoto M, Matsuyama A, Yamamoto M, Hung
DT, Nagasaka H, Uchida K, Ito Y, Kodamatani H, Horvat M, Chan HM, Rand M, Cirtiu CM, Kim BG,
Nielsen F, Yamakawa A, Mashyanov N, Panichev N, Panova E, Watanabe T, Kaneko N, Yoshinaga J,
Herwati RF, Suoth AE, Akagi H. Development of human hair reference material supporting the
biomonitoring of methylmercury. Anal. Sci . 2020 May; 10;36(5):561-567.
Yoshino K, Mori K, Kanaya G, Kojima S, Henmi Y, Matsuyama A, Yamamoto M. Food sources are more important than
biomagnification on mercury bioaccumulation in marine fishes.Environ. Pollut. 2020
Jul;262:113982.
Sakamoto M, Kakita A, Sakai K, Kameo S, Yamamoto M,
Nakamura M. Methylmercury exposure during the vulnerable window of the cerebrum in postnatal
developing rats. Environ Res. 2020 Sep;188:109776. doi: 10.1016/j.envres.2020.109776. Epub 2020
Jun 9.
Yamamoto M, Yanagisawa R, Sakai A, Mogi M, Shuto S,
Shudo M, Kashiwagi H, Kudo M, Nakamura M, Sakamoto M. Toxicokinetics of methylmercury in
diabetic KK-Ay mice and C57BL/6 mice. J Appl Toxicol .2020 Oct 5. doi: 10.1002/jat.4078.
2019
Yamamoto M, Motomura E, Yanagisawa R, Hoang VAT, Mogi M,
Mori T, Nakamura M, Takeya M, Eto K. Evaluation of neurobehavioral impairment in
methylmercury-treated KK-Ay mice by dynamic weight-bearing test. J Appl Toxicol. 2019
Feb;39(2):221-230.
Tsuji M, Koriyama C, Ishihara Y, Yamamoto M,
Yamamoto-Hanada K, Kanatani K, Bamai YA, Onishi K, Senju A, Araki S, Shibata E, Morokuma S,
Sanefuji M, Kitazawa H, Saito M, Umezawa M, Onoda A, Kusuhara K, Tanaka R, Kawamoto T; Japan
Environment & Children’s Study Group. Associations Between Metal Levels in Whole Blood and
IgE Concentrations in Pregnant Women Based on Data From the Japan Environment and Children's
Study. J Epidemiol. 2019 Dec 5;29(12):478-486.
2018
Tsuji M, Shibata E, Morokuma S, Tanaka R, Senju A, Araki S, Sanefuji M, Koriyama C, Yamamoto M, Ishihara Y, Kusuhara K, Kawamoto T, Japan
Environment & Children's Study Group (JECS). The association between whole blood
concentrations of heavy metals in pregnant women and premature births: The Japan Environment and
Children’s Study (JECS). Environ Res .2018 June; 166:562-569.
Jaingam W, Komorita T, Ishimatsu S, Takenaka R, Umehara A, Kobayashi J, Yamamoto M, Arizono K, Tsutsumi H. Biomagnification
Process of Total Mercury in the Macro-benthic Communities in an Enclosed Bay, Isahaya Bay,
Kyushu, Japan. Jpn. J. Environ. Toxicol. 2018 Sep 21 (1):9-20.
Jaingam W, Komorita T, Ishimatsu S, Kobayashi J, Yamamoto
M, Arizono K, Tsutsumi H. Influence of benthic biomagnification process on the total
mercury content of fish and mega-benthos in an enclosed bay. Jpn. J. Shiranuikai & Kumagawa
Reg. Stud .2018 12(1):3-14.
Sakamoto M, Tatsuta N, Izumo K, Phuong PT, Loi VD, Yamamoto
M, Nakamura M, Nakai K, Murata K. Health impacts and biomarkers of prenatal exposure
to methylmercury. Toxics .2018 Aug 3;6(3). pii: E45.
2017
Yamamoto, M., Khan, N., Muniroh, M., Motomura, E.,
Yanagisawa, R., Matsuyama, T., Vogel, C. F. Activation of IL-6 and IL-8 expressions by
methylmercury in human U937 macrophages involves RelA and p50. J. Appl. Toxicol. (2017)
May;37(5) 611-620.
Hoang, VAT., Sakamoto, M., Yamamoto, M. Mercury and
selenium levels, and their molar ratios in several species of commercial shrimp in Japan
regarding the health risk of methylmercury exposure. J. Toxicol. Sci. (2017)
42(4):509-517. https://www.jstage.jst.go.jp/article/jts/42/4/42_509/_pdf/-char/en
Hoang, VAT., Do, HTT., Agusa, T., Koriyama, C., Akiba, S., Ishibashi, Y., Sakamoto, M., Yamamoto, M. Hair mercury levels in relation to fish
consumption among Vietnamese in Hanoi. J. Toxicol. Sci. (2017) 42(5):651-662. https://www.jstage.jst.go.jp/article/jts/42/5/42_651/_pdf/-char/en
David, J., Nandakumar, A., Muniroh, M., Akiba, S., Yamamoto,
M,. Koriyama, C. Suppression of methylmercury-induced MIP-2 expression by
N-acetyl-L-cysteine in murine RAW264.7 macrophage cell line. Eur. J. Med. Res . (2017) 22(1):
45.
2016
Shao, Y., Yamamoto, M., Figeys, D., Ning, Z., Chan, H.
M. Proteome profiling reveals regional protein alteration in cerebrum of common marmoset
(Callithrix jacchus) exposed to methylmercury. Toxicology. (2016) Mar 10; 347-349:29-39.
Sakamoto, M., Murata, K., Domingo, J. L., Yamamoto, M.,
Oliveira, R. B., Kawakami, S., Nakamura, M. Implications of mercury concentrations in umbilical
cord tissue in relation to maternal hair segments as biomarkers for prenatal exposure to
methylmercury. Environ. Res . (2016) Aug;149:282-287.
Yoshimoto, K., Anh, H. T., Yamamoto, A., Koriyama, C., Ishibashi, Y., Tabata, M., Nakano, A.,
Yamamoto, M. Simple analysis of total mercury and
methylmercury in seafood using heating vaporization atomic absorption spectrometry. J. Toxicol.
Sci .(2016) 41(4):489-500. https://www.jstage.jst.go.jp/article/jts/41/4/41_489/_pdf/-char/en
Shao, Y., Yamamoto, M., Figeys, D., Ning, Z., Chan, H.
M. Proteomic Analysis of Cerebellum in Common Marmoset Exposed to Methylmercury. Toxicol. Sci.
(2015) Jul;146(1):43-51. https://academic.oup.com/toxsci/article/146/1/43/1661267
Muniroh, M., Khan, N., Koriyama, C., Akiba, S., Vogel, C. F., Yamamoto, M. Suppression of methylmercury-induced IL-6 and
MCP-1 expressions by N-acetylcysteine in U-87MG human astrocytoma cells. Life Sci. (2015)
May:134:16-21.
Sakamoto M, Yamamoto M. Health effects of mercury.
Seikatsu to Kankyo (Life and Environment): Japan Environmental Sanitation Center, May 2015,
pp16-22.
2014
Yamamoto, M., Yanagisawa, R., Motomura, E., Nakamura,
M., Sakamoto, M., Takeya, M., Eto, K. Increased methylmercury toxicity related to obesity in
diabetic KK-Ay mice.J. Appl. Toxicol. (2014) Aug;34(8):914-923.
Shiraishi, M., Hangai, M., Yamamoto, M., Sasaki, M.,
Tanabe, A., Sasaki, Y., Miyamoto, A. Alteration in MARCKS phosphorylation and expression by
methylmercury in SH-SY5Y cells and rat brain. Environ. Toxicol. Pharmacol. (2014)
May;37(3):1256-1263.
Yachiguchi, K., Sekiguchi, T., Nakano, M., Hattori, A., Yamamoto, M., Kitamura, K., Maeda, M., Tabuchi, Y., Kondo,
T., Kamauchi, H., Nakabayashi, H., Srivastav, AK., Hayakawa, K., Sakamoto, T., Suzuki, N. Effect
of inorganic mercury and methylmercury on osteoclasts and osteoblasts in the scales of the
marine teleost as a model system of bone. Zoolog. Sci.(2014) May;31(5):330-337.
Ishibashi Y, Yamamoto M. Remediation of mercury
contaminated environment by bioremediation. Metal-Biotechnology for Environmental Conservation
and Resource Recycling (In Japanese), CMC Publishing, November 2014, pp251-256.
2013
Sakamoto, M., Yasutake, A., Kakita, A., Ryufuku, M., Chan, H. M., Yamamoto, M., Oumi, S., Kobayashi, S., Watanabe, C.
Selenomethionine Protects against Neuronal Degeneration by Methylmercury in the Developing Rat
Cerebrum. Environ. Sci. Technol. (2013) Mar 19;47(6):2862-2868.
Yamazaki, T., Yamamoto, M., Ishihara, Y., Komatsu, S.,
Munetsuna, E., Onizaki, M., Ishida, A., Kawato, S., Mukuda, T. De Novo synthesized estradiol
protects against methylmercury-induced neurotoxicity in cultured rat hippocampal slices. PLoS
One. (2013) 8(2):e55559.
Sakamoto M, Yamamoto M. Mercury (methylmercury): Trace
elements in food -From essential elements to radioactive nuclides- (In Japanese). Japan Food
Hygiene Association, April 2013, pp97-107
2012
Yamamoto, M., Takeya, M., Ikeshima-Kataoka, H., Yasui,
M., Kawasaki, Y., Shiraishi, M., Majima, E., Shiraishi, S., Uezono, Y., Sasaki, M., Eto, K.
Increased expression of aquaporin-4 by methylmercury in the brain of Common Marmoset. J.
Toxicol. Sci. (2012) 37:749-763. https://www.jstage.jst.go.jp/article/jts/37/4/37_749/_pdf
Mori, N., Yamamoto, M., Tsukada, E., Yokooji, T.,
Matsumura, N., Sasaki, M., Murakami, T. Comparison of in vivo with in vitro pharmacokinetics of
mercury between methylmercury chloride and methylmercury cysteine using rats and Caco2 cells.
Arch. Environ. Contam. Toxicol. (2012) Nov;63(4):628-636.
2010
Adler, R., Barbosa, F., Domingo, J., Flegal, R., Gardner, R., Goldman, L., Nyland, J., Sakamoto,
M., Silbergeld, E., Stern, A., Wells, E., Yamamoto, M.
“Children’s exposure to mercury compounds”. (2010) World Health Organization,Geneva. http://whqlibdoc.who.int/publications/2010/9789241500456_eng.pdf
Miyamoto, K., Kuwana, T., Ando, T., Yamamoto. M.,
Nakano, A. Methylmercury Analyses in Biological Materials by Heating Vaporization Atomic
Absorption Spectrometry. J. Toxicol. Sci. (2010) vol35,217-224. https://www.jstage.jst.go.jp/article/jts/35/2/35_2_217/_pdf
Ando, T., Yamamoto, M., Tomiyasu, T., Tsuji, M., Akiba,
S. Mercury distribution in seawater of Kagoshima Bay near the active volcano, Mt. Sakurajima in
Japan. Bull. Environ. Contam. Toxicol. (2010) Apr;84(4):477-481.
Externally-funded research
FY2024-2026 JSPS Grant-in-Aid for Scientific Research (C) (Principal Investigator）
Metabolism and kinetics of methylmercury and its transfer from mother to fetus under glucose metabolism disorder
FY2022-2024 JSPS Grant-in-Aid for Scientific Research (C) (Co-Investigator）
Assessment of mercury exposure and cardiovascular disease risk in a Japanese cohort
FY2020-2022 Ministry of Health, Labour and Welfare Subsidy for Clinical Research
Projects for Work-related Diseases (Co-Investigator)
Epidemiological study of the relationship between welding fume exposure (personal and in vivo
exposure) and health effects in welders.
FY2021-2023 JSPS Grant-in-Aid for Scientific Research (C) (Principal Investigator）
Study on mother-to-fetus transfer of methylmercury under abnormal glucose metabolism
FY2016-2018 JSPS Grant-in-Aid for Scientific Research (B) (Co-Investigator）
The risk assessment and biological defense mechanism for high methylmercury exposure group eating
whale and tuna
FY2016-2019 JSPS Grant-in-Aid for Scientific Research (C) (Principal Investigator）
Modification mechanism of methylmercury toxicokinetics and toxicity under diabetic status
FY2011-2013 JSPS Grant-in-Aid for Scientific Research (C) (Co-Investigator）
Selenomethionine protects against neuronal degeneration by methylmercury in the developing rat
brain
FY2011-2013 JSPS Grant-in-Aid for Challenging Exploratory Research (Principal
Investigator）
Effect of metabolic changes related to disease on methylmercury toxicity
Main career history, academic history, academic degrees, awards,
etc.