Tatsuta Nozomi, Murata Katsuyuki, Iwai-Shimada Miyuki, Yaginuma-Sakurai Kozue, Satoh Hiroshi, Nakai Kunihiko
Development and Environmental Medicine, Tohoku University Graduate School of Medicine.
Department of Environmental Health Sciences, Akita University Graduate School of Medicine.
Tohoku J Exp Med. 2017 May;242(1):1-8. doi: 10.1620/tjem.242.1.
Fish contain nutrients essential to the developing fetal brain, but they are contaminated with methylmercury. The Tohoku Study of Child Development, now underway in the Sanriku coastal area of Miyagi prefecture, Japan, follows mother-child pairs to examine the risks and benefits of fish consumption during pregnancy, especially the effects of prenatal exposures to methylmercury, selenium, and docosahexaenoic acid (DHA) on child neurodevelopment. Children aged 18 months were administered the Bayley Scales of Infant Development second edition (BSID-II) and Kyoto Scale of Psychological Development (KSPD) in 2004-2008. Complete data of cord-blood total mercury (THg), cord-plasma selenium, maternal-plasma DHA, the above test scores, and confounders for 566 mother-child pairs were available. The median cord-blood THg level was 15.7 (range, 2.7-96.1) ng/g. Since the BSID-II and KSPD scores were significantly lower in the 285 boys than in the 281 girls, analyses were conducted separately. The Psychomotor Development Index (PDI) of BSID-II was significantly correlated with cord-blood THg only in the boys, and significance of the association remained unchanged after adjusting for possible confounders; i.e., a 10-fold increase in cord-blood THg was associated with a 8.3-point decrease in the score of the PDI. Other significant correlations of THg were not seen in the boys or girls. Selenium and DHA showed no significant correlations with the BSID-II or KSPD scores in either sex. In conclusion, intrauterine methylmercury exposure may affect psychomotor development, and boys appear to be more vulnerable to the exposure than girls.
鱼类含有对胎儿大脑发育至关重要的营养物质，但它们被甲基汞污染。目前正在日本宫城县三陆沿海地区进行的东北儿童发育研究，跟踪母婴对，以研究孕期食用鱼类的风险和益处，特别是产前接触甲基汞、硒和二十二碳六烯酸（DHA）对儿童神经发育的影响。2004年至2008年，对18个月大的儿童进行了贝利婴儿发育量表第二版（BSID-II）和京都心理发育量表（KSPD）测试。获得了566对母婴的脐带血总汞（THg）、脐带血浆硒、母体血浆DHA、上述测试分数以及混杂因素的完整数据。脐带血THg水平的中位数为15.7（范围为2.7 - 96.1）纳克/克。由于285名男孩的BSID-II和KSPD分数明显低于281名女孩，因此分别进行了分析。BSID-II的心理运动发育指数（PDI）仅在男孩中与脐带血THg显著相关，在调整可能的混杂因素后，这种关联的显著性仍然不变；即脐带血THg增加10倍与PDI分数下降8.3分相关。在男孩或女孩中未发现THg的其他显著相关性。在任何性别中，硒和DHA与BSID-II或KSPD分数均无显著相关性。总之，宫内甲基汞暴露可能影响心理运动发育，而且男孩似乎比女孩更容易受到这种暴露的影响。
