Monitoring of Low-Level Mercury Exposure in Utero

我们收集了鹿儿岛县约300对母胎的血液样本。知情同意书来自母亲。在分娩后3-4天期间采集母体血液样品。分娩后立即从脐静脉采集脐带血样本。在大岛市立医院（N=193）和鹿儿岛大学医学院医院（N=90）的母亲中，母体红细胞中总汞的几何平均值分别为43.7和16.8 ppb。脐带血样本的几何平均值分别为58.9和24.6ppb。母亲和胎儿体内的汞含量在大岛市比鹿儿岛市高出约两倍。如Suzuki et al.in 1976所报告，这种差异可能是由于鱼类消费的地区差异。女性胎儿（N=90）的平均汞含量为60.8ppb，高于男性（N=103）的平均汞含量52.6ppb。有9位母亲的红细胞汞含量超过100 ppb。母体红细胞的最高汞水平为143.9 ppb。该病例的头发汞含量估计为25 ppm。有22个胎儿的脐带血汞含量超过100 ppb（最高; 205.5 ppb）。母亲和胎儿体内的汞含量与鱼类摄入量呈正相关。脐血与母血水平比值与母血水平呈负相关。有趣的是脐带血汞水平和胎盘重量之间呈负相关。进一步的调查是必要的，以阐明在这一观察所涉及的机制。我们的研究表明，在鹿儿岛偏远岛屿出生的婴儿在子宫内暴露于相对较高的汞暴露水平，敦促对这一主题进行进一步调查。

We collected blood samples from about 300 maternofetal pairs in Kagoshima Prefecture. Informed consent was taken from mothers. Maternal blood samples were taken during 3-4 days after delivery. / Cord blood samples were obtainted from umbilical veins immediately after delivery. Geometric means of total mercury in maternal RBCs were 43.7 and 16.8 ppb for the mothers in Ohshima Municipal Hospital (N=193) and Kagoshima University Medical School Hospital (N=90), respectively. Geomwtric means in cord blood samples were 58.9 and 24.6 ppb in the former and the latter hospitals, respectively. The mercury levels in mothers and their fetuses were about tow-fold higher in Ohshima than in Kagoshima City. The difference may be attributable to the area differences of fish consumption, as report by Suzuki et al.in 1976. The average mercury level in female fetuses (N=90) was 60.8ppb and was higher than that in males (N=103), which was 52.6 ppb. There were nine mothers whose RBC mercury levels exceeded 100 ppb. The highest mercury levels of maternal RBCs was 143.9 ppb. The estimated hair mercury level for this case was 25 ppm. There were 22 fetuses whose cord blood mercury levels exceeded 100 ppb (the highest ; 205.5 ppb). The mercury levels in mothers and fetuses were positively correlated to fish consumption. The rations between cord blood and maternal blood levels were inversely correlated to maternal levles. Of interest was an inverse correlation between cord blood mercury levels and placental weights. Further investigations are necessary to elucidate the mechanisms involved in this observation. Our study, which showed that babies delivered in remote islands in Kagoshima are exposed to relativery high levels of mercury exposure in utero, urges further investigation in this topics.