人体发汞值与汞摄入量关系的探讨

根据对１２１０份发汞测得的结果认为发汞值属正偏态分布，但可以通过对数变换成为对数正态分布进行统计分析。发汞值与日均汞摄入量有关，监测发汞值可以推算人体环境汞暴露的水平，并提出了推算的方法。     

Partitioning of cadmium and lead within seston of coastal marine Waters of the Western Bay of Fundy,Canada

Seston samples were collected at 42 surface stations located in the Quoddy Region, New Brunswick, Canada. In an attempt to separate ecologically important components, the seston samples were divided into two size fractions: 20 to 64 m and 0.7 to 20 m. Particulate organic carbon, particulate aluminum, chlorophyll a, particulate cadmium, and particulate lead concentrations were determined for both size fractions. Cadmium was found to be associated almost entirely with the organic detrital component of the seston, for both size fractions. In contrast, lead was associated with several seston components. For the 20 to 64 m size fraction, lead was partitioned between the organic detrital and suspended clay aggregate components of the seston. Within the 0.7 to 20 m fraction, lead was partitioned, in descending order of importance, between the organic detrital, suspended clay aggregate, and phytoplankton components. These partitioning characteristics of the two metals were used to predict accumulation trends of cadmium and lead in the calanoid copepod species which form the primary consumer level of the marine food web of the Quoddy Region.     

松原地区居民汞暴露途径的初步研究

研究分析了松原地区居民发汞含量水平,及市售鱼类、罐装鱼类、肉类、鸡蛋等食品中的汞含量。结果表明,27.26%的受检居民发汞含量超过美国EPA最新制定的标准,表明该调查地区居民具有潜在的汞暴露风险;常食鱼人群的发汞含量显著高于不常食鱼人群的发汞含量,存在显著差异(P<0.01),头发中的汞含量与食鱼量有显著的正相关关系(r=0.243,P<0.05),这说明头发中的汞含量随着食鱼量的增加而增加;不同的饮水来源、食肉的频率、饮用牛奶的习惯对发汞含量没有显著影响;常吃鸡蛋人群的发汞含量显著低于不常吃鸡蛋人群的发汞含量;食鱼是该地区人群汞暴露风险的最主要途径。     

松花江汞污染治理后沿江渔民发汞调查

调查结果表明，沿江渔民发汞均值为２．２５μｇ／ｇ，与对照点相比差异显著（Ｐ＜０．０１），其中扶余一松江段渔民发汞均值２．５４μｇ／ｇ，高于其他各江段；３０～４０岁年龄组渔民发汞值超过正常值者占４５％，比其他各年龄组多；在调查的１１９５人中有２５名发汞值超过１０μｇ／ｇ，其中１８人发甲基汞含量超过５μｇ／ｇ。     

Organochlorine residues in shearwaters from the approaches to the Bay of Fundy,Canada

Organochlorine residues were sought in 26 specimens of Greater Shearwater (Puffinus gravis) and Sooty Shearwater (P. griseus) collected in August, 1974 from the southeastern approaches to the Bay of Fundy. Residue levels of DDTs, PCBs, dieldrin, oxychlorodane, mirex and HCB in depot fat, liver, and muscle are reported. HCB was present at the same order of magnitude in both species; all other contaminants were significantly higher inP. gravis than inP. griseus. Levels of all compounds except mirex and HCB were higher in the depot fat of femaleP. gravis than in males.     

人发中痕量汞的冷原子荧光测定法

目的 探讨冷原子荧光法在测定人发汞时的工作条件。方法 发样经洗涤烘干后在管式炉内（750±50）℃燃烧5min,吸收液中的汞被SnCl2还原后于253.7 nm用冷原子荧光法测定。结果 以3g/L SnCl2为还原剂,线性范围0.04-2.0μg/L,r=0.9999,检出限为0.05μg/L,相对标准偏差为2.5％,平均回收率在90.0％～110.0％。结论 冷原子荧光法可用于人发痕量汞的测定。     

Mercury in hair and in fish consumed by Riparian women of the Rio Negro,Amazon, Brazil

This work puts the risks and benefits of a mercury acquisition through a fish-dominated diet in the context of the other endemic health problems in the Amazon. Fish consumption rate was assessed after determining mercury concentrations in the most consumed fish and in hair of women at fertile age (15 to 45 years of age), living in remote localities of the Rio Negro basin (not impacted by gold mining). Fish-meals were consumed once a day (7.1%) but in most cases (78.6 %) at least twice a day with an estimated mean fish consumption rate of 170.5 g (range 23 to 293 g). The fish-species most preferred were Tucunarés (Cichla spp), Pacus (Mylossoma aureum and Myleus micans), Piranhas (Sarrasalmus spp), Cará (Satanoperca jurupari), Jaraquí (Semaprochilodus taeniurus). The mean Hg concentration in these species varies widely (38 to 592 ng g(- 1)) but 27% of samples had Hg concentrations above 500 ng g(- 1), and only 7% were above 1000 ng g(- 1). The hair-Hg concentrations ranged from 6.5 to 32.6 microg g(- 1) with 82% of them having concentrations above 10 microg g(- 1) (w.w.) hair. Hair-Hg concentrations were positively correlated with women's age (r=0.4500; P=0.0111). Clinical evaluation did not detected symptoms (paraparesis, tremor, numbness of limbs, sensory disturbances) compatible with Minamata disease, but there was a high (71%) incidence of clinical history of malaria. Fish is an abundant natural resource, rich in essential nutrients and important to the diet of 'ribeirinhos' of Brazilian Amazonia. We hypothesize that lack of basic medical care in these communities outweighs risk of naturally occurring fish-MMHg. Therefore food habits based on fish consumption is part of a successful strategy for survival and should be considered as a health asset.     

Mercury accumulation in relation to size and age of Atlantic herring (Clupea harengus harengus) from the southwestern Bay of Fundy,Canada

Measured muscle and whole fish total mercury concentrations showed significant positive correlations with age, weight and length, in order of decreasing correlation. Within herring age classes, however, muscle and whole fish mercury concentrations showed significant negative correlations with weight and length due to a growth dilution effect in 1- and 2-year-old herring, but demonstrated positive correlations with weight and length in 3- to 5-year-old fish. A bioenergetics-based pollutant accumulation model was used to describe total mercury accumulation for the commercially valuable Atlantic herring aged 3 to 5 years with the predicted values falling within one standard deviation of the measured annual body burdens.     

Mercury levels and fish consumption practices in women of child-bearing age in the Florida Panhandle

The southeastern United States, and in particular the coastal areas along the Gulf of Mexico (Gulf Coast) in Florida, experience some of the highest levels of mercury deposition in the country. Although the State of Florida's coastal border is among the longest in the United States, and the State has issued fish consumption advisories due to mercury on multiple fish species, few data have been systematically collected to assess mercury levels in the human population of the state or to assess the efficacy of the consumption advisories. Because of the generally high rate of seafood consumption among coastal populations, the human population in the Florida Panhandle, near Pensacola, FL is potentially exposed to elevated levels of mercury. In the present study, we analyzed hair mercury levels in women of child-bearing age (16-49 years) who had resided near Pensacola, FL for at least 1 year. We also surveyed the fish consumption practices of the cohort and evaluated awareness of the Florida Fish Consumption Advisory. Hair mercury levels were significantly higher in women who consumed fish within the 30 days prior to sampling (p<0.05) and in those women who were unaware of the consumption advisory (p<0.05). Only 31% of the women reported knowledge of the consumption advisory and pregnant women exhibited lower awareness of the advisory than non-pregnant women. The data suggest that public health interventions such as education and fish advisories have not reached the majority of women in the counties surrounding Pensacola who are most at risk from consumption of fish with high levels of mercury.     

Assessment of methylmercury exposure in Wisconsin

Between January 2004 and June 2005 the Wisconsin Department of Health and Family Services recruited more than 2000 adults for a methylmercury (MeHg) exposure assessment study. Study participants, including 978 men and 1050 women who ranged in age from 18 to 92 years, completed a fish consumption and advisory awareness survey and provided hair samples for mercury analysis. Fish intake estimates ranged from 0 to 60 meals/month (mean 7.7). Hair mercury levels ranged from 0.012 to 15.2 microg/g and were positively correlated with monthly fish meals. Despite reporting similar fish consumption rates, men tended to have higher hair mercury levels than women. Mercury levels exceeded 1 microg/g in 29% of the men and 13% of the women and increased with age. Approximately, half of the study volunteers were licensed anglers and 77% were familiar with Wisconsin's sportfish consumption advisory. Among consumers of sport-caught fish, 37% of the men and 18% of the women had a hair mercury concentration above 1 microg/g. These findings suggest that exposure to MeHg is widespread and that men may be a previously unrecognized high risk population.     

Mercury exposures and symptoms in smelting workers of artisanal mercury mines in Wuchuan, Guizhou, China

Mercury exposures to smelting workers of artisanal mercury mines in Wuchuan, Guizhou, China were evaluated by urine and hair mercury survey. The mean urinary mercury (U-Hg), hair total mercury (T-Hg), and hair methyl mercury (Me-Hg) for smelting workers was 1060 microg/g creatinine (microg/g Cr), 69.3 and 2.32 microg/g, respectively. The results were significantly higher than that of control group, which is 1.30 microg/g Cr, 0.78 and 0.65 microg/g, correspondingly. The average urinary beta2-microglobulin (beta2-MG) was 248 microg/g Cr for the exposed group contrasting to 73.5 microg/g Cr for the control group and the data showed a serious adverse effect on renal system for the smelting workers. The workers were exposed to mercury vapor through inhalation, and the exposure route of Me-Hg may be through intake of polluted diet. The results indicate that age, alcohol drinking, and smoking are not crucial factors controlling the urine and hair mercury levels for the exposed and the control group. Clinical symptoms including finger and eyelid tremor, gingivitis, and typical dark-line on gums were observed in six workers. This study indicated that the smelting workers in Wuchuan were seriously exposed to mercury vapor.     

海产品中痕量汞的微波消解—冷原子吸收测定法

目的建立用微波消解一冷原子吸收法测定海产品中的痕量汞的方法。方法海产品样品经过微波消解后,其中的汞被氧化为离子状态的汞,利用冷原子吸收测汞仪对样品进行测定。结果汞浓度在0～3.00μg/L的范围内具有较好的线性,相关系数达到0.9999,方法检出限为0.015μg/L,且对国家一级标准物质贻贝(GBW08571)的验证结果与标准值吻合,回收率为92%～105%,样品测定相对标准偏差为4.5%。结论微波消解—冷原子吸收法灵敏度高,操作简单快捷,结果可靠,适合于测定海产品中的痕量汞。     

Ranking the contributions of commercial fish and shellfish varieties to mercury exposure in the United States: Implications for risk communication

Fish and shellfish have important nutritional benefits, and US per capita seafood consumption has increased substantially since 2002. Recent research has reinforced concerns about adverse effects of methylmercury exposure, suggesting that methylmercury doses associated with typical US rates of fish consumption may pose measurable risks, with no threshold. These converging trends create a need to improve risk communication about fish consumption and mercury. The analysis performed here identifies the relative importance of different fish and shellfish as sources of mercury in the US seafood supply and proposes improved consumer advice, so that the public can benefit from fish consumption while minimizing mercury exposure. I have quantified contributions to total mercury in the US seafood supply by 51 different varieties of fish and shellfish, then ranked and sorted the 51 varieties in terms of relative impact. Except for swordfish, most fish with the highest mercury levels are relatively minor contributors to total inputs. Tuna (canned light, canned albacore and fresh/frozen varieties) accounts for 37.4 percent of total mercury inputs, while two-thirds of the seafood supply and nine of the 11 most heavily consumed fish and shellfish are low or very low in mercury. Substantial improvement in risk communication about mercury in fish and seafood is needed; in particular, several population subsets need better guidance to base their seafood choices more explicitly on mercury content. I have sorted the 51 seafood varieties into six categories based on mercury levels, as a framework for improving risk communication in this regard.     

Characterisation of protracted low-level exposure to uranium in the workplace: A comparison of two approaches

Retrospective estimates of internal doses received by workers in the nuclear industry following intake of radionuclides, based on bioassay data, are a benchmark method in epidemiological studies. Nonetheless, full information relative to thousands of people included in an epidemiological cohort is rarely available, thus implying difficulties to estimate exposure precisely. To evaluate the cumulative exposure to uranium in a cohort of the AREVA NC Pierrelatte plant workers, we compared the epidemiological Job Exposure Matrix (JEM) method with the dosimetric method based on biological monitoring of exposure for 30 workers randomly selected within the cohort. A moderate to strong correlation was observed between the estimators resulting from the two approaches, thereby validating the JEM as a tool that can be used to characterise cumulative exposure to uranium in the cohort. In addition, this study showed that the JEM is a valuable complement to the interpretation of bioassy, (1) in providing information on exposure periods as well as on physical and chemical form of the radionuclides and (2) in compensating for the lack of exposure data regarding the very earliest periods. Combining the two methods may improve the precision in reconstructing cumulative exposure for epidemiological studies.     

Fate and Transport of Mercury in Environmental Media and Human Exposure

Mercury is emitted to the atmosphere from various natural and anthropogenic sources, and degrades with difficulty in the environment. Mercury exists as various species, mainly elemental (Hg⁰) and divalent (Hg²⁺) mercury depending on its oxidation states in air and water. Mercury emitted to the atmosphere can be deposited into aqueous environments by wet and dry depositions, and some can be re-emitted into the atmosphere. The deposited mercury species, mainly Hg²⁺, can react with various organic compounds in water and sediment by biotic reactions mediated by sulfur-reducing bacteria, and abiotic reactions mediated by sunlight photolysis, resulting in conversion into organic mercury such as methylmercury (MeHg). MeHg can be bioaccumulated through the food web in the ecosystem, finally exposing humans who consume fish. For a better understanding of how humans are exposed to mercury in the environment, this review paper summarizes the mechanisms of emission, fate and transport, speciation chemistry, bioaccumulation, levels of contamination in environmental media, and finally exposure assessment of humans.     

两种模型在铅膳食长期暴露评估中的运用研究

目的 比较观测个体均值(observed individual means,OIM)模型与贝塔二项-正态分布(betabinomial-normal,BBN)模型结果及其在铅膳食长期暴露评估中的运用.方法 利用2002年中国居民营养与健康状况调查中24 h膳食回顾法收集的消费量数据、2000-2006年污染物监测数据及2005-2006年海关出口农产品监测数据.OIM模型通过计算调查期间个体食物的平均消费量与污染物平均浓度匹配相乘,计算每日暴露量,而BBN模型通过调整个体内变异,保留个体间变异构建长期膳食暴露量.以铅污染数据为实例,对两模型结果进行比较.结果 OIM模型高端百分位数值均大于BBN模型,OIM模型全人目第25～99.9百分位数(P25～P99 9)的摄入量为1.167 ～7.313 μg·kg-1·d-1,BBN为1.193 ～5.729 μg·kg-1·d-1.各组OIM模型与BBN模型结果中位数较为接近,两模型全人群摄入量分别为1.543和1.579 μg· kg-1·d-1.结论 在膳食长期暴露评估中,OIM模型分析结果比BBN模型在高端百分位数部分更具保守性.     

Total mercury levels in hair, toenail, and urine among women free from occupational exposure and their relations to renal tubular function

To investigate the relations among total mercury levels in hair, toenail, and urine, together with potential effects of methylmercury intake on renal tubular function, we determined their levels, and urinary N-acetyl-beta-D-glucosaminidase activity (NAG) and alpha1-microglobulin (AMG) in 59 women free from occupational exposures, and estimated daily mercury intakes from fish and other seafood using a food frequency questionnaire. Mercury levels (mean+/-SD) in the women were 1.51+/-0.91 microg/g in hair, 0.59+/-0.32 microg/g in toenail, and 0.86+/-0.66 microg/g creatinine in urine; and, there were positive correlations among them (P<0.001). The daily mercury intake of 9.15+/-7.84 microg/day was significantly correlated with total mercury levels in hair, toenail, and urine (r=0.551, 0.537, and 0.604, P<0.001). Among the women, the NAG and AMG were positively correlated with both the daily mercury intake and mercury levels in hair, toenail, and urine (P<0.01); and, these relations were almost similar when using multiple regression analysis to adjust for possible confounders such as urinary cadmium (0.47+/-0.28 microg/g creatinine) and smoking status. In conclusion, mercury resulting from fish consumption can explain total mercury levels in hair, toenail, and urine to some degree (about 30%), partly through the degradation into the inorganic form, and it may confound the renal tubular effect of other nephrotoxic agents. Also, the following equation may be applicable to the population neither with dental amalgam fillings nor with occupational exposures: [hair mercury (microg/g)]=2.44x[toenail mercury (microg/g)].     

Mercury and polychlorinated biphenyls in Asian market fish: A response to results from mercury biomonitoring in New York City

In 2004, the New York City (NYC) Health and Nutrition Examination Survey measured the highest blood mercury levels in Asian and foreign-born Chinese demographic groups. Fish consumption was the strongest predictor of exposure. The survey did not inquire about consumption of individual species, and subsequent visits to fish markets serving the Asian community suggested that many popular species lack contaminant data. Our objective was to supplement existing information on contaminants in commercial fish by collecting data on species present in markets serving the Asian community.We measured total mercury and the sum of 101 polychlorinated biphenyl (PCB) congeners in 282 individual specimens of 19 species or products from retail fish markets in Chinese neighborhoods in NYC. Species were selected based on their volume in the market, and an absence or insufficiency of national data on mercury levels. PCBs were measured because they are also contaminants of concern. All measurements were made on a wet weight basis on whole fillets (with skin) or products (drained of liquid). Mean mercury levels ranged from below the limit of detection (0.004 μg/g) in tilapia to 0.229 μg/g in tilefish. The highest mercury level (1.150 μg/g) was measured in a tilefish specimen, and mercury levels in tilefish increased with the specimen size. Mean PCB levels ranged from 1 ng/g in red snapper to 98 ng/g in buffalo carp. The highest PCB levels were measured in a buffalo carp (469 ng/g) and a yellow croaker (495 ng/g). Species-specific differences in PCB levels accounted for only 6.3% of total variability, in contrast with 39.2% for mercury.Although we did not measure high mean mercury levels in the species we sampled, frequent consumption of fish with low to moderate levels can also elevate blood mercury. The data we collected can be used to guide fish consumption in Asian communities. However, risk-benefit trade-offs also need to be considered.     

Correlations between mercury concentrations in umbilical cord tissue and other biomarkers of fetal exposure to methylmercury in the Japanese population

Methylmercury (MeHg) is one of the most risky substances to affect humans through fish consumption, and the fetus is known to be in the most susceptible group. Our objective in this study is to examine the relationships of total mercury (THg) and MeHg concentrations between umbilical cord tissue and other tissues as biomarkers of fetal exposure to MeHg in the Japanese population. In total, 116 paired samples were collected in three Japanese districts, the Tsushima Islands, Fukuoka City, and Katsushika ward of metropolitan Tokyo. THg was measured for hair and THg and MeHg were measured in cord tissues, maternal blood, and cord blood. The relationships among tissues in Hg concentrations were similar among districts. Therefore, we analyzed the relationships using all the samples. More than 90% of Hg in cord tissue, cord blood, and maternal blood was MeHg. THg and MeHg in cord blood was about two times higher than in maternal blood. A strong correlation was found between THg and MeHg in cord tissue. The cord tissue THg and MeHg showed a strong correlation with cord blood Hg, which is recognized as the best biomarker for fetal exposure to MeHg. The findings of this study indicate the significance of cord tissue THg and MeHg as biomarkers for fetal exposure to MeHg at parturition.