舟山地区新生儿及其母亲的汞暴露现状与影响因素

目的调查舟山地区新生儿及其母亲的汞暴露现状。方法2004年8至9月,采用整群法选取舟山市定海区第三人民医院产科出生的408名足月新生儿及其母亲,并随访新生儿的神经行为发育情况,直至1岁。抽查舟山市定海区菜市场出售的14种（每种5份）鱼类水产品的汞含量。结果新生儿脐带血汞的几何均值为27．81nmol／L,母亲发汞的几何均值为1246．56μg／kg,新生儿脐带血汞和母亲发汞有明显的相关性。新生儿脐带血汞的影响因素为母亲吃鱼次数、在舟山地区居住时间和父亲吸烟,母亲发汞的影响因素为吃鱼次数和在舟山地区居住时间,吃鱼次数与新生儿脐带血汞和母亲发汞呈显著正相关。所抽查鱼类水产品的汞平均含量在低浓度范围内,但不同种类水产品的汞含量波动较大,2份带鱼和2份鳗鱼鱼干的汞含量达到中等浓度水平。结论舟山地区新生儿及其母亲的汞暴露水平有一定潜在危险性,食鱼是舟山地区人群汞暴露的主要来源。

Status and influencing factors of mercury exposure in neonates and their mothers in Zhoushan

OBJECTIVE: To investigate the status of mercury exposure of neonates and their mothers in Zhoushan City, and analyze the related influencing factors. METHODS: From Aug to Sep, 2004, 408 neonate-mother pairs were cluster sampled at the Third People's Hospital in Dinghai region, Zhoushan City, and a further investigation for the neurobehavioral development of these children was followed up in a year. The contains of mercury of 14 kinds of fish, 5 pieces of each kind bought in markets of Dinghai region were detected. RESULTS: The geometric mean of cord-blood Hg was 27.81 nmol/L (5.58 microg/L), while that of hair Hg of mothers was 1246.56 microg/kg. 69.9% of pregnant women had surpassed the RfD (reference dose, 0.1 microg/kg/day) for Hg intake. There was a strong correlation between hair and cord blood Hg levels (r = 0.821). The factors influencing cord-blood Hg levels were fish dinners, dwelling time, and fathers smoking or not, while those of hair Hg were fish dinners and dwelling time. The correlation between fish dinners and the cord blood Hg as well as hair Hg were of significance (r = 0.539, 0.481 respectively), the Hg levels were higher in more fish dinners (H = 119.805, 94.384 respectively). The mean fish Hg level at Dinghai region was low (< 0.1 mg/kg), and no samples were higher than 0.5 mg/L. Two samples of cutlassfish and dried eel contained higher Hg than the others, belonging to a middle level (0.1-0.5 mg/kg). CONCLUSIONS: Hg levels in neonates and pregnant women were generally below those considered hazardous, but the safety margin was narrow for some women and supporting efforts should be made to reduce mercury exposure. The main resource of Hg was from eating fish, and it is necessary to investigate the Hg levels in large samples, as to developing the fish advisories for susceptible people.