Journal of Environmental Health Sciences (한국환경보건학회지)

Korean Society of Environmental Health (한국환경보건학회)
권호 표지

Difference in Methylmercury Exposure to Fetus and Breast-feeding Offspring: A Mini-Review

  • Sakamoto Mineshi (Department of Epidemiology, National Institute for Minamata Disease) ;
  • Murata Katsuyuki (Department of Environmental Health Sciences, Akita University School of Medicine) ;
  • Nakai Kunihiko (Department of Environmental Health Sciences, Tohoku University Graduate School of Medicine) ;
  • Satoh Hiroshi (Department of Environmental Health Sciences, Tohoku University Graduate School of Medicine)
  • Published : 2005.06.01
Download PDF
⟨ Previous Next ⟩

Abstract

The purpose of this paper was to concisely review the practical changes in MeHg concentrations in fetus and offspring throughout gestation and suckling from our recent animal and human studies. In the animal study, adult female rats were given a diet containing 5ug/g Hg (as MeHg) for 8 weeks. Then they were mated and subsequently given the same diet throughout gestation and suckling. On embryonic days 18, 20, 22 and at parturition, the concentrations of Hg in the brains of fetus were approximately 1.5-2.0 times higher than those in the mothers. However, during the suckling period Hg concentrations in the brain rapidly declined to about 1/10 of that during late pregnancy. Hg concentrations in blood also decreased rapidly after birth. In human study, Hg concentrations in red blood cells (RBC-Hg) in 16 pairs of maternal and umbilical cord blood samples were compared at birth and 3 months of age after parturition. RBC-Hg in the umbilical cords was about 1.6 times higher than those in the mothers at parturition. However, all the infants showed declines in Hg concentrations throughout the breast-feeding period. RBC-Hg at 3 months of age was about half that at birth. Both the animal and human studies indicated that MeHg exposure to the fetus might be especially high but it dramatically decreases during the suckling period. Therefore, close attention should be paid to the gestation rather than the breast-feeding period to avoid the risk of MeHg to human infants.

Keywords

References

  1. Akagi, H., Grandjean, P., Takizawa, Y. and Weihe, P. : Methylmercury dose estimation from umbilical cord concentrations in patients with Minamata disease. Environ Res., 77(2), 98-103, 1998 https://doi.org/10.1006/enrs.1997.3822
  2. Amin-Zaki, L., Elhassani, S., Majeed, M.A., Clarkson, T.W., Doherty, R.A. and Greenwood, M. : Intra-uterine methylmercury poisoning in Iraq. Pediatrics, 54, 587-595, 1974
  3. Amin-zaki, L., Majeed, M.A., Greenwood, M.R., Elhassani, S.B., Clarkson, T.W.R. and Doherry, A. : Methylmercury poisoning in the Iraqi suckling infant: a longitudinal study over five years. J. Appl. Exp. Toxicol., 1, 210-214, 1981 https://doi.org/10.1002/jat.2550010405
  4. Ashner, M. and Clarkson, T.W. : Diatribution of mercury 203 in pregnant rats and their fetuses following systematic infusion with thiolcontaining amino acids and glutathione during late gestation. Teratology, 38, 145-155, 1988 https://doi.org/10.1002/tera.1420380207
  5. Cernichiari, E., Brewer, R., Myers, G.J., Marsh, D.O., Lapham, L.W., Cox, C., Shamlaye, C.F., Berlin, M., Davidson, P.W. and Clarkson, T.W. : Monitoring methylmercury during pregnancy: maternal hair predicts fetal brain exposure. Neurotoxicology, 16, 705-710, 1995
  6. Choi, B.H. : The effects of methylmercury on the developing brain. Prog. Neurobiol., 321, 447-470, 1989
  7. Clarkson, T.W. and Strain, J.J. : Nutritional factors may modify the toxic action of methyl mercury in fish-eating populations. J Nutr., 133, 1539-1543, 2003
  8. Eto, K., Yasutake, A., Miyamoto, K., Tokunaga, H. and Otsuka, Y. : Chronic effects of methylmercury in rats. II. Pathological aspects. Tohoku J. Exp. Med., 182, 197-205, 1997 https://doi.org/10.1620/tjem.182.197
  9. Furst, A. : Can nutrition affect chemical toxicity? Int. J. Toxicol., 21, 419-424, 2002 https://doi.org/10.1080/10915810290096649
  10. Galster, W.A. : Mercury in Alaskan Eskimo mothers and infants. Environ. Health Perspect. 15, 135- 140, 1976 https://doi.org/10.2307/3428396
  11. Grandjean, P., Jorgensen, P.J. and Weihe, P. : Human milk as a source of methylmercury exposure in infants. Environ. Health Perspect., 102, 74- 77, 1994 https://doi.org/10.1289/ehp.9410274
  12. Hansen, J.C., Tarp, U. and Bohm, J. : Prenatal exposure to methylmercury among Greenlandic polar Inuits. Arch. Environ. Health, 45, 355-358, 1990 https://doi.org/10.1080/00039896.1990.10118754
  13. Kajiwara, Y., Yasutake, A., Adachi, T. and Hirayama, K. : Methylmercury transport across the placenta via neutral amino acid carrier. Arch. Toxicol., 70, 310-314, 1996 https://doi.org/10.1007/s002040050279
  14. Kershaw, T.G., Clarkson, T.W. and Dhahir, P.H. : The relationship between blood levels and dose of methylmercury in man. Arch. Environ. Health, 35, 28-36, 1980 https://doi.org/10.1080/00039896.1980.10667458
  15. Kosta, L., Byrne, A.R. and Dermelj, M. : Trace elements in some human milk samples by radiochemical neutron activated analysis. Sci. Total Environ., 29, 261-268, 1982 https://doi.org/10.1016/0048-9697(83)90095-5
  16. Kunz, C., Rodriguez-Palmero, M., Koletzko, B. and Jensen, R. : Nutritional and biochemical properties of human milk, Part 1: General aspects, proteins, and carbohydrates. Clin. Perinatol., 26, 307-333, 1999
  17. Newland, M.C. and Reile, P.A. : Blood and brain mercury levels after chronic gestational exposure to methylmercury in rats. Toxicol. Sci., 50, 101-116, 1999
  18. Nunes, J. and Ferreira, S. : Possible mercury intoxication of newborns via breast milk. Front. Fetl. Health, 2, 18-20, 2000
  19. Oddy, W.H. : Breastfeeding protects against illness and infection in infants and children. Breastfeed Rev., 9, 11-18, 2001
  20. Oliveira, R.B., Malm, O. and Guimaraes, J.R.D. : Distribution of methylmercury and inorganic mercury in neonate hamsters dosed with methylmercury during fetal life. Environ. Res. Section A, 86, 73-79, 2001 https://doi.org/10.1006/enrs.2001.4220
  21. Oskarsson, A., Hallen, I.P. and Sundberg, J. : Exposure to toxic elements via breast milk. Analyst., 120, 765-770, 1995 https://doi.org/10.1039/an9952000765
  22. Oskarsson, A., Schts, A., Skerfving, S., Hallën, I.P., Ohlin, B. and Lagerkvist, B.J. : Total and inorganic mercury in breast milk and blood in relation to fish consumption and amalgam fillings in lactating women. Arch. Environ. Health, 51, 234-241, 1996 https://doi.org/10.1080/00039896.1996.9936021
  23. Pan, H.S., Sakamoto, M., Oliveira, R.B., Liu, X.J., Kakita, A. and Futatsuka, M. : Changes in methylmercury accumulation in the brain of rat offspring throughout gestation and suckling. Toxicol. Environ. Chem., 86, 161-168, 2004
  24. Rice, D.C. and Barone, S. : Critical periods of vulnerability for developing nervous system: evidence from human and animal models. Environ. Health Perspect., 108, 511-533, 2000 https://doi.org/10.2307/3454543
  25. Sakamoto, M., Kakita, A., Wakabayashi, K., Nakano, A., Takahashi, H. and Akagi, H. : Evaluation of changes in methylmercury accumulation in the developing rat brain and its effects: a study with consecutive and moderate dose exposure through gestation and lactation periods. Brain Res., 949, 51-59, 2002a https://doi.org/10.1016/S0006-8993(02)02964-5
  26. Sakamoto, M., Kubota, M., Matsumoto, S., Nakano, A. and Akagi, H. : Declining risk of methylmercury exposure to infants during lactation. Environ. Res., 90, 185-189, 2002b https://doi.org/10.1016/S0013-9351(02)00011-7
  27. Sakamoto, M., Nakano, A., Akagi, H., Kitano, T. and Futatuka, M. : Difference by sex and age of mercury concentration in red blood cells. Jpn. J. Hyg. 48, 911-919, 1993a https://doi.org/10.1265/jjh.48.911
  28. Sakamoto, M., Nakano, A., Kajiwara, Y., Naruse, I. and Fujisaki, T. : Effects of methylmercury in postnatal developing rats. Environ. Res., 61, 43-50, 1993b https://doi.org/10.1006/enrs.1993.1048
  29. Sandborgh-Englund, G., Ask, K., Belfrage, E. and Ekstrand, J. : Mercury exposure in utero and during infancy. J. Toxicol. Environ. Health, 63, 317-320, 2001 https://doi.org/10.1080/15287390152103634
  30. Skerfving, S. : Mercury in women exposed to methylmercury through fish consumption, and in their newborn babies and breast milk. Bull. Environ. Contam. Toxicol., 41, 475-482, 1988 https://doi.org/10.1007/BF02020989
  31. Sundberg, J., Jonsson, S., Karlsson, M.O. and Oskarsson, A. : Lactation exposure and neonatal kinetics of methylmercury and inorganic mercury in mice. Toxicol. Appl. Pharmacol., 154, 160-169, 1999 https://doi.org/10.1006/taap.1998.8566
  32. Sundberg, J., Oskarsson, A. and Albanus, L. : Methylmercury exposure during lactation: milk concentration and tissue uptake of mercury in the neonate rats. Bull. Environ. Contam. Toxicol., 46, 255-262, 1991 https://doi.org/10.1007/BF01691946
  33. Suzuki, T., Takemoto, T., Shimano, H., Miyama, Y., Katsunuma, H. and Kagawa, Y. : Mercury content in the blood in relation to dietary habit of the women without any occupational exposure to mercury. Ind. Health, 9, 1-8, 1971 https://doi.org/10.2486/indhealth.9.1
  34. Svensson, B.G., Schüllts, A., Nilsson, A., Akesson, I., Åkesson, B. and Skerfvong, S. : Fish as a source of exposure to mercury and selenium. Sci. Total Environ., 126, 61-74, 1992 https://doi.org/10.1016/0048-9697(92)90484-A
  35. Swedish Expert Group : Mercury in fish: A toxicological- epidemiologic evaluation of risks. Nord Hygienisk Tidskrift, Suppl. 4. Stockholm, Sweden, 1971
  36. Takeuchi, T. : Pathology of Minamata disease, with special reference to its pathogenesis. Acta Pathol. Jpn., 32(Suppl. 1), 73-99, 1982
  37. World Health Organization (Eds.) : IPCS. Environmental Health Criteria 101. Methylmercury. World Health Organization, Geneva, 1990
  38. Yoshida, M., Watanabe, C., Satoh, H., Kishimoto, T. and Yamamura, Y. : Milk transfer and tissue uptake of mercury in suckling offspring after exposure of lactating maternal guinea pigs to inorganic or methylmercury. Arch. Toxicol., 68, 174-178, 1994 https://doi.org/10.1007/s002040050051