Four Cases of Abnormal Neuropsychological Findings in Children with High Blood Methylmercury Concentrations

Annals of Occupational and Environmental Medicine

Young-Seoub Hong³  Dae-Seon Kim²  Seung-Do Yu²  Seong-Hwan Kim⁴  Jong-Kuk Kim⁵  Yu-Mi Kim¹  Jae-Ho Yu⁶  Ji-Hyun Jung⁷  Byoung-Gwon Kim³ 

[1] Department of Preventive Medicine, College of Medicine, Dong-A University, Busan, South Korea

[2] Department of Environmental Health Research, National Institute of Environmental Research(NIER), Incheon, South Korea

[3] Heavy Metal Exposure Environmental Health Center, Dong-A University, Busan, South Korea

[4] Department of Psychiary, College of Medicine, Dong-A University, Busan, South Korea

[5] Department of Neurology, College of Medicine, Dong-A University, Busan, South Korea

[6] Department of Pediatrics, College of Medicine, Dong-A University, Busan, South Korea

[7] Department of Occupational and Environmental Medicine, Dong-A University Medical Center, Busan, South Korea

关键词: Fish consumption;    Neuropsychological findings;    Methylmercury;   

Others  :  791029
DOI  :  10.1186/2052-4374-25-18

 received in 2012-11-06, accepted in 2013-06-24,  发布年份 2013

【 摘 要 】

Background

Methylmercury (MeHg) easily crosses the blood–brain barrier and accumulates in the brain. Accumulated MeHg will cause neurological symptoms. We report four pediatric cases of neuropsychological findings with high blood MeHg concentrations.

Case presentation

Four children were admitted for follow-up study because their total mercury (THg) concentration in the blood was found to be high during a national survey. Case 1 was a 9-year-old female with a 16.6 μg/ℓ blood THg concentration in the survey. During admission, the blood THg, hair THg, and blood MeHg concentration(mercury indices) were 21.4 μg/ℓ, 7.2 μg/g, and 20.1 μg/ℓ, respectively. In our neuropsychological examination, cognitive impairment and attention deficit were observed. Her diet included fish intake 2–3 times per week, and she had been diagnosed with epilepsy at 3 years of age. Case 2 was a 12-year-old male with blood THg of 15.4 μg/ℓ in the survey and the mercury indices were 12.7 μg/ℓ, 5.7 μg/g, and 11.8 μg/ℓ, respectively, on admission. He was also observed to have attention-deficit/hyperactivity disorder. Case 3 was a 10-year-old male child with blood THg of 17.4 μg/ℓ in the survey, and the mercury indices on admission were 21.6 μg/ℓ, 7.5 μg/g and 21.5 μg/ℓ, respectively. In his case, mild attention deficit was observed. Case 4 was a 9-year-old male with blood THg of 20.6 μg/ℓ in the survey and the mercury indices were 18.9 μg/ℓ, 8.3 μg/g, and 14.4 μg/ℓ, respectively, on admission. Mild attention difficulty was observed.

Conclusion

We suggest that fish consumption may be the main source of MeHg exposure, and that MeHg may have been the cause of the neuropsychological deficits in these cases.

【 授权许可】

   
2013 Hong et al.; licensee BioMed Central Ltd.

【 参考文献 】

• [1]Harada Y, Miyamoto Y, Nonaka I, Ohta S, Ninomiya T: Electroencephalographic studies of Minamata disease in children. Dev Med Child Neurol 1968, 10(2):257-258.
• [2]Cox C, Clarkson TW, Marsh DO, Amin-Zaki L, Tikriti S, Myers GG: Dose–response analysis of infants prenatally exposed to methyl mercury: an application of a single compartment model to single-strand hair analysis. Environ Res 1989, 49(2):318-332.
• [3]WHO: Guidence for identifying populations at risk from mercury exposure. Geneva: WHO; 2008.
• [4]Grandjean P, Weihe P, White RF, Debes F, Araki S, Yokoyama K, Murata K, Sorensen N, Dahl R, Jorgensen PJ: Cognitive deficit in 7-year-old children with prenatal exposure to methylmercury. Neurotoxicol Teratol 1997, 19(6):417-428.
• [5]Myers GJ, Davidson PW, Shamlaye CF, Axtell CD, Cernichiari E, Choisy O, Choi A, Cox C, Clarkson TW: Effects of prenatal methylmercury exposure from a high fish diet on developmental milestones in the Seychelles Child Development Study. Neurotoxicology 1997, 18(3):819-829.
• [6]Crump KS, Kjellstrom T, Shipp AM, Silvers A, Stewart A: Influence of prenatal mercury exposure upon scholastic and psychological test performance: benchmark analysis of a New Zealand cohort. Risk Anal 1998, 18(6):701-713.
• [7]Seo HJ, Myung YS, Jung HJ, Kim MJ, Seo YR, Park KA, Park CS, Park JS, Park JS: Case reports : a case of acute lung injury and acute generalized exanthematous pustulosis induced by inhalation of mercury vapor. Korean J Asthma Allergy Clin Immunol 2012, 32(4):259-263.
• [8]Becker K, Kaus S, Krause C, Lepom P, Schulz C, Seiwert M, Seifert B: German Environmental Survey 1998 (GerES III): environmental pollutants in blood of the German population. Int J Hyg Environ Health 2002, 205(4):297-308.
• [9]Hughes WL: A physicochemical rationale for the biological activity of mercury and its compounds. Ann N Y Acad Sci 1957, 65(5):454-460.
• [10]Castoldi AF, Coccini T, Ceccatelli S, Manzo L: Neurotoxicity and molecular effects of methylmercury. Brain Res Bull 2001, 55(2):197-203.
• [11]Clarkson TW: Mercury: major issues in environmental health. Environ Health Perspect 1993, 100:31-38.
• [12]Caldwell KL, Mortensen ME, Jones RL, Caudill SP, Osterloh JD: Total blood mercury concentrations in the U.S. population: 1999–2006. Int J Hyg Environ Health 2009, 212(6):588-598.
• [13]Schulz C, Angerer J, Ewers U, Heudorf U, Wilhelm M, Human Biomonitoring Commission of the German Federal Environment Agency: Revised and new reference values for environmental pollutants in urine or blood of children in Germany derived from the German environmental survey on children 2003–2006 (GerES IV). Int J Hyg Environ Health 2009, 212(6):637-647.
• [14]Klaassen CD: Casarett and Doull’s Toxicology - The Basic Science of Poisons. 5th edition. Blacklick, Ohio, U.S.A: McGraw-Hill; 1996.
• [15]Grandjean P, Murata K, Budtz-Jorgensen E, Weihe P: Cardiac autonomic activity in methylmercury neurotoxicity: 14-year follow-up of a Faroese birth cohort. J Pediatr 2004, 144(2):169-176.
• [16]Thurston SW, Bovet P, Myers GJ, Davidson PW, Georger LA, Shamlaye C, Clarkson TW: Does prenatal methylmercury exposure from fish consumption affect blood pressure in childhood? Neurotoxicology 2007, 28(5):924-930.
• [17]Park HS, Lim HS, Huh BY, Hahn HG, Hwang YS, Moon HR, Hong KE: A case report of a fatal mercury poisoning. J Korean Acad Fam Med 1991, 12(5):66-71. (Korean)
• [18]Kim CW, Kim YW, Chae CH, Son JS, Park SH, Koh JC, Kim DS: The effects of the frequency of fish consumption on the blood mercury levels in Koreans. Korean J Occup Environ Med 2010, 22(2):114-121. (Korean)
• [19]SaKon J: Health effects of mercury exposure through fish. Yeungnam Univ J Med 2011, 28(2):105-115. (Korean)