Blood total mercury and fish consumption in the Korean general population in KNHANES III, 2005

Objectives

The obejective of this study was to assess the association between the blood total mercury concentration and fish consumption in the Korean general adult population using a representative sample.

Methods

We studied the blood mercury concentration in a representative sample of 1,749 Koreans who were included in the Third Korean National Health and Nutritional Examination Survey (KNHANES III) performed in 2005, and compared it with the frequency of fish consumption collected during the nutrition survey of KNHANES III.

Results

The geometric means of the blood mercury levels in female subjects (n = 890), male subjects (n = 859), and all participants (n = 1,749) representing adult Koreans aged ≥ 20 years were 3.70 μg/L [95% confidence interval (CI), 3.46-3.94 μg/L], 4.70 μg/L (95% CI, 4.38-5.02 μg/L), and 4.15 μg/L (95% CI, 3.93-4.38 μg/L), respectively. The geometric mean of the blood mercury level was significantly higher in the high-fish-consumption group (4.38 μg/L; more than once a week) than in the low-consumption group (3.71 μg/L: less than once a week), but the intergroup difference of 18% was less than that in Western countries. Among the nine listed individual types of fish and shellfish, there was a general trend for the blood mercury level to increase with the consumption frequency of squid, clam, salted seafood, and mackerel. The proportion of Korean women aged 20-49 years having blood mercury levels of at least 5.8 μg/L was 27.7% (150/542) in our study.

Conclusions

The blood mercury level in a representative sample of the Korean adult population was found to be associated with fish consumption in both men and women. However, a high consumption of fish increased the blood mercury level by only 18%.     

Cadmium monitoring in saliva and urine as indicator of smoking addiction

Cadmium is one of the many substances that may be acquired through active and passive smoking of tobacco. Saliva and urine are proposed for cadmium monitoring of non-smokers, second hand smokers, smokers and tobacco chewing appertaining to San Luis citizens without occupational exposition. Biological samples were collected by the same subjects, under strict proceeding instructions of sampling. Physical characteristics of samples were observed and checked with commercial test. Samples were analyzed using an adapted molecular fluorescence methodology with a previous extraction step. Stability of biological samples was daily studied for a period of one month. The method was successfully validated for accuracy, precision, linearity, specificity, and sensitivity. The simplicity and low coefficient of variance confirm the suitability of the method for urinary and salivary cadmium analyses. On the other side, the obtained results are in concordance with previous national epidemiological dates.     

Cadmium adsorption by oxic sediment

To understand the strong pH dependency of cadmium adsorption by oxic sediment, we investigated the surface charge of sediment particles by potentiometric titration with acid and base. Metal adsorbed by sediment can occur by complexation of metal ions with weakly acidic functional groups or by ion exchange of metal ions. A multi-site binding model, which incorporates the effect of pH, has been applied to describe the adsorption of cadmium onto sediment. The model has been used to satisfactorily predict the extent of adsorption over the pH range of 4.5–7.0.     

非饱和黏土中镉离子迁移规律的数值分析

考虑南昌-莲塘一带镉离子呈高背景或异常,而其迁移转化又是一个十分复杂的物理化学过程。论文在对南昌土质、镉离子分布调研的基础上,采用有限元法对镉离子在非饱和土中的迁移过程进行数值模拟,并与室内土柱试验成果进行对比,探讨了镉离子在非饱和土中迁移的规律,对于污染治理具有一定的参考价值。     

正长石去除镉离子的试验研究

将正长石与含镉溶液混合,分别在不同时间和不同pH值条件下反应,生成了含镉长石。水溶液中镉浓度随着反应时间的延长而降低,120h后去除率达到96%。在pH值为6的近中性条件下,长石对Cd2＋离子的去除率达到78.40%,且基本达到了平衡。XRD分析表明反应后的长石生成了含镉的硅酸盐相。XPS分析表明Cd 3d5/2的结合能为406.12eV,说明Cd2＋与长石矿物形成了较强的离子键,表明有离子交换反应的发生。长石去除水溶液中的Cd2＋既存在有吸附作用,也存在有离子交换作用,表明长石矿物具有一定的修复水体中镉离子污染的功能和效果。     

Cadmium in blood and urine after cessation of exposure.

A plant for the synthesis and packaging of cadmium oxide was operated for 32 months (1982-84) in a small chemical factory producing zinc and copper oxide. The cumulative exposure of 6 workers was from 12 to 190 days. Five years after cessation of exposure the blood cadmium levels in the exposed were, on average, 4-10 times higher than those of a reference group and the urinary cadmium levels were 1-6-times higher. In view of the long half-life of cadmium in the human body, the choice of normal reference values requires particular care since brief and sometimes forgotten exposures to cadmium may be a confounding factor to set reference values.     

Cadmium in the Rhône river

The distribution of cadmium in the Rhône river was studied using differential pulse anodic stripping voltametry with a static mercury drop electrode. For 11 potentially contaminated river stations, the Cd in true solution averaged 39 ± 23 ng kg⁻¹, adsorbed on suspended matter was 19 ± 22 ng kg⁻¹ (liquid phase) and suspended matter content was 2.4 ± 1.5 mg kg⁻¹ (solid phase), equivalent to 40 ± 24, 22 ± 24 and 38 ± 31%, respectively, of the total carried under these conditions. For sediments the mean Cd content was 0.9 ± 0.6 mg kg⁻¹. The water values are low by world standards, even though sampling was biased towards sites potentially contaminated. This could be partially due to the unusual water pH of 7.8–8.5.     

等离子光谱法测定城市污泥中总镉、总铬的方法改进

目前检测城市污泥中总镉、总铬的标准方法为<城市污水处理厂污泥检验方法>(CJ/T 221-2005),该方法样品消解时间长、酸用量大,为此改进了样品消解方法,分别采用HNO3-H2O2常压消解、HNO3-H2O2微波消解法处理污泥样品,然后采用等离子光谱法检测污泥中的总镉、总铬.与标准方法的对比试验结果表明,两种方法的相对偏差为0.8%～7.2%.改进的常压消解法的加标回收率:总镉为98.5%～105%,总铬为94.2%～95.6%;微波消解的加标回收率:总镉为104%～106%,总铬为98.5%～102%;改进方法的检出限:总镉为0.000 75 mg/L,总铬为0.002 3 mg/L.     

镉污染源水的应急处理技术研究

分析了发生突发性镉污染时镉在水体中的存在形式,考察了常规混凝、化学沉淀以及两者联用对镉污染源水的处理效果.结果表明:发生突发性镉污染时,镉在水体中主要以溶解态形式存在,所占比例＞60%;常规混凝沉淀可有效去除吸附态镉,但对溶解态镉的去除效果有限;化学沉淀法对镉有良好的去除效果,但会增加滤后水的浊度;化学沉淀与混凝联用技术可大大提高对镉的去除效果,在预调pH值至10、PAC的投加量为20 mg/L时,对镉的去除率＞97.7%,最大可处理浓度提高至0.220～0.264 mg/L.     

PAC/PS预处理对水中镉的去除及UF膜污染控制

采用粉末活性炭耦合过硫酸盐(PAC/PS)作为超滤的预处理工艺,考察其对原水中镉和天然有机物的去除效果,以及对超滤膜污染控制的影响。结果表明,对于镉超标6倍的原水水样,当PAC和PS投加量分别为30 mg/L和300μmol/L、接触时间为60 min时,UV₂₅₄、DOC和镉的去除率分别可达到91.7%、68.2%和92.7%,镉浓度可降至《生活饮用水卫生标准》(GB 5749—2006)规定的限值(5μg/L)以下;与直接超滤相比,设置PAC/PS预处理工艺后超滤膜比通量提升了50.5%,XDLVO预测模型中胶体污染物-超滤膜相互作用的总界面能降低了75.38%,超滤膜污染减轻。     

Whole blood selenium content in healthy adults in the Czech Republic

Over a 5-year period, from 1996 to 2001, blood selenium levels were recorded in a set of 2414 healthy blood donors (1781 men and 633 women; 880 smokers and 1534 nonsmokers) living in four selected areas of the Czech Republic. About 100 blood samples per year and region were analyzed using the HGA method. The internal and external quality controls of this method were performed throughout the duration of the study. In general, blood selenium concentrations (81.9 and 106.7 microg/l for median and 90th percentile, respectively) did not reach optimum values; in approximately 10% of the population sample, values lower than 60 microg/l were detected. Nonetheless, the values obtained increased significantly, with median concentrations of 73.2 microg/l in 1996 and 91.5 microg/l in 2001. The percentage of subjects with a whole blood selenium level of less than 60 microg/l also decreased from nearly 20% in 1996 to 0.2% in 2001. No substantial regional or gender-related differences were observed, but significantly lower blood selenium levels were found in smokers as opposed to nonsmokers. Although mild selenium deficiency continues to be observed, the data presented do not indicate extremely low selenium levels in the population sample.     

血必净对严重脓毒症患者血管内皮细胞相关促炎因子和凝血因子的影响

目的 探讨血必净注射液对严重脓毒症患者血管内皮细胞相关促炎症因子和凝血因子的影响.方法 将52例严重脓毒症患者随机分为常规治疗组(A组)与血必净治疗组(B组).在相同的常规治疗基础上,B组给予血必净注射液100 ml加入0.9%氯化钠100 ml中静脉滴注,每天1次,持续7 d.A组则给予同等量的0.9%氯化钠作为对照.A、B两组患者治疗前及治疗后第3、7天分别抽血检测血清内血管内皮细胞(VEC)相关促炎症因子和凝血因子水平.促炎症因子包括血管细胞黏附分子(VCAM-1)和细胞间黏附分子(ICAM-1).凝血因子包括一氧化氮(NO)、抗凝血酶Ⅲ(AT-Ⅲ)、血栓调节蛋白(TM)、组织纤溶酶原激活物(TPA)、VWF因子(VWF)、纤溶酶原激活物抑制物(PAI-1);并统计两组患者的28 d病死率.结果 B组患者28 d的病死率为32.1%(9/28),低于A组的62.5%(15/24),差异有统计学意义(P<0.05).治疗第7天B组患者VEC诱导的促炎症因子VCAM-1和ICAM-1明显低于A组;VEC诱导的抗凝(NO、AT-Ⅲ、TM)和促纤溶物质(TPA)、促凝(VWF)和纤溶抑制因子(PAI-1)都明显高于A组(P<0.05).结论 血必净注射液能够改善严重脓毒症患者的病情,降低病死率,其机制可能与其稳定血管内皮细胞,改善严重炎症反应和凝血功能紊乱有关.     

Heavy metals in maternal and cord blood

Heavy metal concentrations have been determined in maternal and cord blood samples collected from mothers in the age group 20-25 years with full-term neonates (37-40 weeks). The concentrations of Pb, Cd, Cu and Zn were found to be low in cord blood as compared to mother's blood and the ratio between cord blood and maternal blood for the respective elements was found to be approximately 0.80, 0.86, 0.47 and 0.40. On the other hand, the concentrations of Fe and Mg in the mother's blood were found to be lower than those in the cord blood. Prenatal exposure to lead in Mumbai, though low (5.1 microg/dl), is approximately 2-3 times higher than that observed in Canada or Italy. A strong correlation (r = 0.79) between the maternal and cord blood lead levels has been observed during the present study.     

Elevated blood selenium levels in the Brazilian Amazon

Contaminated fish poses a difficult challenge throughout the world, on the one hand, fish is a very nutritious food source, while on the other hand it accumulates many toxic substances, including mercury (Hg). As part of our efforts in the Brazilian Amazon to maximize nutritional input from fish consumption, a dietary mainstay, and minimize toxic risk, we have been studying the role of selenium (Se), an essential element, that may influence the distribution of Hg in the body and influence Hg neurotoxicity. Se, which is naturally present in the soil, is ingested through consumption of various foods, notably fish, mammals and certain plants. The objectives of the present study were: (i) evaluate whole blood Se (B-Se) and Hg (B-Hg); (ii) characterize B-Se variations with respect to socio-demographic and dietary variables; and (iii) examine the relation between B-Se and B-Hg. A total of 236 persons from six riparian communities of the Tapajós River Basin, a tributary of the Amazon, participated in this study. Whole blood Se and Hg were measured and interview administered questionnaires were used to obtain data on socio-demographic variable, smoking and drinking habits, and fish and fruit consumption. The results show that B-Se are in the upper normal range (median=284.3 microg/L, range=142.1-2029.3 microg/L). No individuals presented B-Se deficiency, but 9 participants from the same extended family had relatively high B-Se levels, potentially a threat to their health. B-Se varied between communities, was significantly higher among alcohol drinkers and farmers, but not associated with age, sex or tobacco consumption. A significant positive relation between B-Se and B-Hg was noted, independently of the overall fish consumption. B-Se increased with consumption of Peacock bass (Cichla sp.), a piscivorous fish species, and coconut pulp (Cocos nucifera L.). The B-Se intercommunity variations may reflect geographic differences in local soil Se levels as well as traditional land use practices in the different ecosystems of the Tapajós River Basin. In this population with relatively high exposure to Hg, Se may play an important role. Further studies should examine, in this region, the sources of Se, its transmission through the terrestrial and aquatic ecosystem and its role with respect to human health.     

pp'DDE contamination of the blood and diet in central European populations

In this study, the actual risk of DDT pollution to two European human populations was assessed by analysing DDT residues in the diet, which is the main route of pollution for man, and in the blood and placenta, which are components affecting organs and new generations, respectively. The Gdańsk region was selected as representative of areas subjected to a recent DDT ban in Europe, while a rural area in Western Germany was considered representative of European regions where DDT use and production ceased many years ago. The results of three food series of food sampling carried out with market basket methods during 2003 showed that pp'DDE, which is by far the main constituent of DDT residues, was present in foods of animal origin and in cereals at rather high concentrations in both countries, and that a risk for human health cannot be excluded. The total daily intake was higher in Poland than in Germany, and agrees with the finding that body tissues, on the average, are more polluted in donors from Poland than those from Germany.     

A follow-up comparison of blood lead levels between foreign and native workers of battery manufacturing in Taiwan

Foreign workers employed in industries in Taiwan have been found at elevated risk of injuries. Less well known is whether the elevated risk persists in chemical exposure such as lead exposure at battery manufacturing. A cohort of 70 Thai workers and 55 native workers employed at a battery plant were followed up, after an education of job safety, from 2000 until 2002. This study compared the change of blood lead levels (BLLs) between these two groups of workers. With informed consent, BLLs were measured annually for participants and compared. The average baseline BLLs were approximately at similarly high levels between Thai workers and native workers with means +/- standard deviations of 36.9 +/- 16.4 and 36.2 +/- 12.4 microg/dl, respectively (p = 0.79). At the end of 2002, the average concentration was higher in Thai workers than in native workers. Using mixed models, Thai workers had an average of 5.95 microg/dl increase in BLLs over native workers during the 3-year study. Further measurements revealed that the average BLL for workers in the assembly department was 3.57 +/- 1.83 microg/dl in excess, compared with workers in the plate engineering department. Thai workers were more likely to drink alcohol but less likely to wear gloves at work and wash hands before meals. The BLL disparities between Thai workers and native workers can partly be explained by differences in risk-taking behaviors. Higher BLLs in Thai workers suggest the need of language appropriate health education to improve their personal hygiene. Workplace smoking ceasing program may be needed both in Thai and native workers.     

Nonlinear associations between blood lead in children, age of child, and quantity of soil lead in metropolitan New Orleans

Previous studies identified a curvilinear association between aggregated blood lead (BL) and soil lead (SL) data in New Orleans census tracts. In this study we investigate the relationships between SL (mg/kg), age of child, and BL (μg/dL) of 55,551 children in 280 census tracts in metropolitan New Orleans, 2000 to 2005. Analyses include random effects regression models predicting BL levels of children (μg/dL) and random effects logistic regression models predicting the odds of BL in children exceeding 15, 10, 7, 5, and 3 μg/dL as a function of age and SL exposure. Economic benefits of SL reduction scenarios are estimated. A unit raise in median SL^0.5 significantly increases the BL level in children (b = 0.214 p = < 0.01), and a unit change in Age^0.5 significantly increases child BL (b = 0.401, p = < 0.01). A unit change in Age^0.5 increases the odds of a child BL exceeding 10 μg/dL by a multiplicative factor of 1.23 (95% CI 1.21 to 1.25), and a unit (mg/kg) addition of SL increases the odds of child BL > 10 μg/dL by a factor of 1.13 (95% CI 1.12 to 1.14). Extrapolating from regression results, we find that a shift in SL regulatory standard from 400 to 100 mg/kg provides each child with an economic benefit ranging from $4710 to $12,624 ($US 2000). Children's BL is a curvilinear function of both age and level of exposure to neighborhood SL. Therefore, a change in SL regulatory standard from 400 to 100 mg/kg provides children with substantial economic benefit.     

Changing blood lead levels and DNA damage (comet assay) among immigrant women in Taiwan

Background

International marriage has had a rapid growth in recent years in Taiwan. However, little is known about the blood lead levels and DNA damage levels among immigrant women from resource-limited countries.

Objective

This study (a) explored differences between immigrant women and native women in demographic characteristics, blood lead levels, and DNA damage levels, and (b) identified risk factors that are associated with blood lead concentrations and DNA damage levels after immigration.

Methods

We used a structured questionnaire to collect data on socio-demographic status from (a) 71 immigrant women who had resettled in 2006 in Taichung, Taiwan and (b) 83 native women who live in the same area. Each study participant provided blood samples for lead and metal measurements, complete blood count examination, and the comet assay to measure degree of DNA damage.

Results

Immigrant women had higher mean blood lead concentration (2.23 ± 1.63 vs. 1.63 ± 1.00 μg/dl; p = 0.04) and lower mean blood zinc level (6.22 ± 2.22 vs. 6.89 ± 2.44 mg/l; p = 0.07) than native women. Resettlement time was a determinant to decrease blood lead and DNA damage levels among immigrants in Taiwan. Multiple linear regression analysis confirmed a statistically significant association between blood lead level and DNA damage, while zinc had a protective effect.

Conclusions

Public health agencies should focus on primary prevention and providing screening programs for this vulnerable population. An immigrant women's cohort should been established to follow-up and improve for elevated lead exposure families.