Effects of dioxin exposure on fetal brain development and infant neurodevelopment after birth

2016 Fiscal Year Final Research Report

• Project/Area Number: 25305024
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 海外学術
• Research Field: Hygiene and public health
• Research Institution: Kanazawa Medical University
• Principal Investigator: NISHIJO Muneko 金沢医科大学, 医学部, 教授 (40198461)
• Co-Investigator(Kenkyū-buntansha): 森河 裕子 金沢医科大学, 看護学部, 教授 (20210156)
• Co-Investigator(Renkei-kenkyūsha): NISHIJO Hisao 富山大学, 医学(系)研究科(大学院), 教授 (00189284)
• Research Collaborator: Pham Ngoc Thao ベトナム軍医科大学 ; Nghiem Thi Thuy Giang ベトナム軍医科大学 ; Pham The Tai ベトナム軍医科大学 ; Phoung Van Luong ベトナム軍医科大学 ; Tran Hai Anh ベトナム軍医科大学 ; Tran Ngoc Nghi ベトナム厚生省
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: ダイオキシン / 母乳 / 臍帯血 / 新生児脳波 / 性ホルモン / 脳神経発達 / ベトナム

Outline of Final Research Achievements

To investigate effects of prenatal dioxin exposure on neurodevelopment of offspring, we performed measurements of testosterone (TS) in umbilical cord blood and neonatal EEG at birth and neurodevelopmental tests at 6 months, 2 years, and 3 years of age in offsprings living in exposed areas around former American air base. In girl, TS in cord blood were inversely correlated with total Toxicity Equivalency Quantity (TEQ), and in boys, TS levels in high TCDD group (TCDD >= 5.5 pg) were significantly lower compared with low TCDD group (TCDD < 5.5). In boys, EEG power at 4-7 Hz of electrode O was correlated with total TEQ, but in girls, EEG power at 2-3 Hz of electrode C inversely correlated with total TEQ. At 2 years of age, toddlers who showed delay of language development were significantly more frequent in high TCDD boys. In mothers with high TCDD in breast milk, female offspring was more frequent, suggesting endocrine disrupture effects on gender ratio at birth in high TCDD group.

Free Research Field

環境保健