Monitoring of Low-Level Mercury Exposure in Utero

我们采集了鹿儿岛县约300对母婴的血液样本。知情同意是从母亲那里获得的。产后3~4天采母血。分娩后立即从脐静脉取脐血样。大岛市医院(N=193)和鹿儿岛大学医学院医院(N=90)母亲的母亲红细胞中总汞的几何平均数分别为43.7和16.8 ppb。前者和后者的脐带血样本几何均数分别为58.9和24.6 ppb。大岛市母亲和胎儿体内的汞含量大约是鹿儿岛市的两倍。正如Suzuki等人1976年报告的那样，这种差异可能归因于鱼类消费的地区差异。女性胎儿(N=90)的平均汞含量为60.8 ppb，高于男性(N=103)的52.6 ppb。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含量为143.9 ppb。该病例的头发汞含量估计为25ppm。有22个胎儿的脐带血汞水平超过100ppb(最高为205.5 ppb)。母亲和胎儿的汞水平与鱼的摄入量呈正相关。脐带血和母血之间的比例与母体水平呈负相关。有趣的是，脐带血汞水平与胎盘重量之间存在负相关。有必要进行进一步的研究，以阐明这一观察到的机制。我们的研究表明，在鹿儿岛偏远岛屿分娩的婴儿在宫内暴露在相对较高水平的汞中，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.