Childhood urine mercury excretion: dental amalgam and fish consumption as exposure factors

The authors investigated the effect of amalgam fillings and fish consumption on urine mercury level (UHg), in children aged 4-8 years old inclusive. Using a sample of 60 children, we found that children with amalgam fillings had significantly higher UHg levels than children without amalgams (geometric mean=1.412microg Hg/g versus 0.436 microg Hg/g, respectively, P = 0.0001). Subjects with reported higher fish consumption also had significantly higher UHgs (P = 0.004). Univariate analyses provide evidence of an association between elevated UHg level and young age (P = 0.009), short height (P = 0.024), and low weight (P = 0.049) in children with amalgam chewing surfaces. We also found a negative correlation between urine mercury and age (-0.378), height (-0.418), and weight (-0.391). A multiple logistic regression model shows that the presence of amalgam fillings leads to increased odds of high UHg in children (OR=47.18), even after adjusting for high fish consumption (OR=8.66) and height (OR=11.36).     

Temporal variation of blood and hair mercury levels in pregnancy in relation to fish consumption history in a population living along the St. Lawrence River

Fish consumption from the Great Lakes and the St. Lawrence River has been decreasing over the last years due to advisories and increased awareness of the presence of several contaminants. Methylmercury (MeHg), a well-established neurotoxicant even at low levels of exposure, bioaccumulates to differing degrees in various fish species and can have serious adverse effects on the development and functioning of the human central nervous system, especially during prenatal exposure. Most studies on MeHg exposure have focussed on high-level consumers from local fish sources, although mercury (Hg) is also present in fresh, frozen, and canned market fish. Moreover, little information exists on the temporal variation of blood and hair Hg in pregnant women, particularly in populations with low levels of Hg. The aim of the present study was to characterize the temporal variation of Hg during pregnancy and to investigate the relation between fish consumption from various sources prior to and during pregnancy and maternal cord blood and mother's hair Hg levels. We recruited 159 pregnant women from Southwest Quebec through two prenatal clinics of the Quebec Public Health System. All women completed two detailed questionnaires concerning their fish consumption (species and frequency) prior to and during pregnancy. The women also provided blood samples for all three trimesters of pregnancy and hair samples after delivery of up to 9 cm in length. Blood and hair Hg levels were analyzed by cold-vapor atomic-absorption and -fluorescence spectrometry methods, respectively. Results showed that maternal blood and hair Hg levels decreased significantly between the second and third trimesters of pregnancy. However, cord blood Hg was significantly higher than maternal blood at birth. Maternal hair was correlated with Hg blood concentration and was highly predictive of the organic fraction in cord blood. A strong dose relation was observed between the frequency of fish consumption before and during pregnancy and Hg exposure in mothers and newborns. Fish consumption prior to and during pregnancy explained 26% and 20% of cord blood Hg variance, respectively. For this population, detailed multivariate analyses showed that during pregnancy market fish (fresh, canned, and frozen) were more important sources of Hg exposure than were fish from the St. Lawrence River. These results should be taken into account for future advisories and intervention strategies, which should consider Hg levels in different species from all sources in order to maximize the nutritional input from fish and minimize the toxic risk.     

Hair mercury levels versus freshwater fish consumption in household members of Swedish angling societies

Hair mercury levels were determined in 143 individuals from households of members in angling societies in an area of Sweden with many lakes that have freshwater fish with relatively high mercury levels. Thus, the individuals had a potentially high intake of methyl mercury. The mean mercury concentration of pike and perch was approximately 0.7 microg/g. One-third of the subjects consumed these freshwater fish at least once a week. As could be expected, there was a clear increase in hair Hg with reported freshwater fish consumption (P < 0.001). The median mercury level in hair was 0.9 microg Hg/g for the whole group, and for those who reported consumption of freshwater fish at least once a week it was 1.8 microg/g. The highest hair mercury level was 18.5 microg/g, in a man who consumed pike and perch several times per week. Men had higher hair Hg than women, also when stratified for fish consumption. This was verified in 32 couples, of which the man and woman consumed the same fish and reported the same consumption. The median hair mercury level in these 32 couples was 1.3 microg/g for men and 0.8 microg/g for women (P = 0.002). About half of the subjects had hair mercury exceeding 1 microg/g, corresponding to the reference dose (RfD) of 0.1 microg of mercury per kilogram body weight set by the US Environmental Protection Agency. Although the RfD applies to all populations, the most at-risk group at these levels is pregnant women. There were only 2 women (of 12) of fertile age with hair mercury above 1 microg/g. In Sweden pregnant women are advised not to eat perch and pike at all during pregnancy. Since fish is rich in many important nutrients, it is unsatisfactory that fish consumption must be restricted, and thus there is a need to reduce mercury levels in fish.     

微波消解-双道原子荧光光谱法同时测定化妆品中的砷和汞

目的建立原子荧光光谱法同时测定化妆品中的砷和汞的方法。方法采用微波消解预处理样品和原子荧光光谱法同时测定化妆品中的砷和汞的含量。结果检出限：砷0.073ug/L,汞0.012ug/L。线性范围：砷0～32ug/L,相关系数为0.9999。汞0～3.2ug/L,相关系数为0.9996。砷、汞相对标准偏差分别为2.01%～1.28%、3.27%～1.44%。回收率分别为96.4%、94.9%。结论微波消解-双道原子荧光光谱法同时测定化妆品中的砷和汞具有操作简便、快速、检出限低、灵敏度高、结果准确等优点,适合于化妆品中砷和汞的同时测定。     

Levels of Total Mercury in Marine Organisms from Adriatic Sea,Italy

The presence of total mercury in fish, crustacean and cephalopod from Adriatic Sea, was investigated. The highest concentrations were observed in decreasing order in: Norway lobster (0.97 ± 0.24 mg/kg; mean ± SE), European hake (0.59 ± 0.14 mg/kg), red mullet (0.48 ± 0.09 mg/kg), blue whiting (0.38 ± 0.09 mg/kg), Atlantic mackerel (0.36 ± 0.08 mg/kg) and European flying squid (0.25 ± 0.03 mg/kg). A significant difference (p < 0.01) was found between the levels of total mercury in Norway lobster and those detected in all other species. The 25% of all samples exceeded the maximum limit fixed by Commission Regulation (EC) No 1881/2006. The results show that fish and fishery products can exceed the maximum levels and stress the need of more information for consumers in particular for people that eat large amount of fish.     

基于AVR单片机的数字式耳温测量仪的设计

电子体温计的应用在医院已经逐渐普及,但产品市场良莠不齐。作者根据医院的使用要求,设计了一套基于AVR单片机的数字式耳温测量仪。该仪器经测试,其稳定性、准确性良好,能满足医院使用要求。     

微波消解-冷原子荧光光谱法测定螃蟹中汞的含量

目的使用冷原子荧光光谱法测定水产品中汞的含量,并调查苏州地产螃蟹中汞污染状况。方珐在微波消解条件、负高压和灯电流、载气流量、屏蔽气流量、溶液酸度、硼氢化钾浓度等影响汞测定因素下进行试验并予以优化;采集太湖、阳澄湖和池塘3个水系中养殖的螃蟹进行汞测定。结果该方法检出限为0．0016ug／L,相对标准偏差为3．6％,样品加标回收率为89．0％～108．9％;太湖螃蟹汞含量最高,为0．23mg／kg。结论该法简便、快速、灵敏度高、稳定性好、回收率高,可用于水产品中汞的检测。     

某体温计厂汞作业工人健康状况分析

[目的]调查某体温计厂汞作业职工的健康状况。[方法]检测某体温计厂工作场所空气中汞浓度,并对147名汞作业工人进行职业健康检查。[结果]部分工作场所空气中汞浓度超过国家职业卫生标准,重汞作业岗位的封头、制坯下、涨真空岗位的采样点汞蒸气浓度超过国家职业卫生标准;48名汞作业工人具有类神经征,检出率32．65％（48／147）,28人具有口腔．牙龈炎,检出率19．05％（28／147）,122名汞作业工人尿汞超标,尿汞平均值为（129．83±82．14）肚∥g肌酐。[结论]该体温计厂汞作业环境汞蒸气超标,怍业工人慢性汞中毒症状和体征检出率较高,企业必须采取有效的职业病防治措施,保护工人的健康。     

严重铅汞中毒病例报告

目的了解某患者因服用2种仙丹1月余所致疾病原因,为临床治疗提供科学依据。方法采用催化极谱法、冷原子吸收分光光度法,对仙丹及患者血液、尿液进行分析。结果灰色仙丹含铅(以氧化铅计)质量百分比为23.00%,黄色仙丹含汞(以氧化汞计)质量百分比为18.00%;患者停服仙丹37 d后,血铅0.06 mg/L,尿铅0.24 mg/L;血汞0.013mg/L,尿汞0.180 mg/L。对患者进行驱铅、汞及对症支持治疗,康复治疗后,其血液、尿液铅、汞达到正常值,恢复健康,已上岗正常工作。结论根据患者血液、尿液中铅、汞检测结果,确认该患者所患疾病为严重铅、汞中毒引起。     

职业接触汞女工胎盘微量元素含量及其对子代影响的研究

本文通过收集职业性接触汞蒸气女工和对照组在分娩时的母体血、脐带血、胎盘和乳汁生物样品,应用原子吸收光谱法测定其汞含量以及胎盘Pb、Mn、Cd、Zn、Fe、Mg、Ca和Se微量元素含量,并随访观察两组子代的生长发育情况。研究结果表明,接触组乳汁、母体血、脐带血和胎盘汞含量均显著高于对照组,表明职业性接汞可使女工体内汞负荷增加,且金属汞易经胎盘转运和乳汁分泌。两组胎盘10种微量元素含量无明显差异。对两组儿童在出生时、生后三个月和生后六个月的随访,其双顶径、身长、体重和胸围没有发现明显差异,表明现有职业性接汞水平对儿童生长发育无明显影响。