Fetuses are a high-risk group for methylmercury (MeHg) exposure. The main objective of this study was to compare the characteristic profiles of total mercury (THg), inorganic mercury (IHg), MeHg, and selenium in plasma and red blood cells (RBCs) between maternal and cord blood at parturition collected from a group of Japanese women. Furthermore, correlations of THg in RBCs, which is a biomarker of MeHg, and THg in plasma, which is an IHg exposure biomarker, were examined in maternal and cord blood. Fifty-five pairs of maternal and cord blood samples obtained at parturition were collected from pregnant women in Fukuoka, Japan. THg in RBCs and plasma were significant correlated between maternal and cord blood. THg in RBCs was 13.9 ng/mL for cord and 9.16 ng/mL for maternal blood, with a cord:maternal RBCs ratio for THg of 1.58, suggesting that MeHg is actively transferred from the mother to the fetus via the placenta. THg in plasma showed a positive correlation with THg in RBCs for maternal and cord blood. This result suggests that measuring THg in plasma can overestimate the exposure level to IHg in fish-eating populations. The percentages of IHg in cord plasma and RBCs were 31% and 1.7%, respectively, and those in maternal plasma and RBCs were 46% and 5.9%, respectively. These results suggest that cord blood is rich in MeHg and can easily transfer to the fetal brain. Selenium in cord plasma was 67 ng/mL and that in maternal plasma was 97 ng/mL, with a cord:maternal plasma ratio for Se of 0.69, suggesting that the protective effects of Se against MeHg toxicity in fetuses may be weaker than those expected in adult mothers.

胎儿是甲基汞（MeHg）暴露的高危人群。这项研究的主要目的是比较母体和脐带血在分娩时收集的血浆和红细胞（RBC）中总汞（THg），无机汞（IHg），MeHg和硒的特征曲线日本妇女。此外，在母血和脐带血中检查了作为MeHg生物标志物的RBC中THg与作为IHg暴露生物标志物的血浆中THg的相关性。从日本福冈的孕妇那里收集了五十五对分娩时获得的母体和脐带血样本。红细胞和血浆中的THg与母体和脐带血之间显着相关。脐带血红细胞的THg为13.9 ng / mL，母体血液血的THg为9.16 ng / mL，脐带与母体血红细胞的THg之比为1.58，提示MeHg是通过胎盘从母亲主动转移到胎儿的。血浆中的THg与产妇和脐带血的RBC中的THg呈正相关。该结果表明，测量血浆中的THg可能会高估鱼类食用人群中IHg的暴露水平。脐带血浆和红细胞中的IHg百分比分别为31％和1.7％，而孕产血浆和红细胞中的IHg分别为46％和5.9％。这些结果表明脐带血中富含MeHg，可以轻松转移到胎儿大脑。脐带血浆中的硒为67 ng / mL，母体血浆中的硒为97 ng / mL，脐带：母体血浆中硒的比率为0.69，这表明硒对胎儿对MeHg毒性的保护作用可能弱于预期在成年母亲中。