砷化合物致人表皮癌A431细胞的毒性及氧化应激和砷代谢研究

目的探讨不同砷化合物致人表皮癌细胞(A431)的细胞毒性及氧化应激和砷代谢的情况。方法培养的A431细胞分别暴露于0.05～50.0μmol/L一甲基亚胂酸(MMAⅢ),0.05～200.0μmol/L三氧化二砷(As2O3,As3+),0.5～500.0μmol/L砷酸氢二纳(As5+)和二甲基胂酸钠(DMAⅤ)24 h,应用四甲基偶氮唑盐(MTT)法测定细胞生存率;检测砷化物对丙二醛(MDA)含量、超氧化物歧化酶(SOD)活力的影响;以流式细胞仪检测细胞内活性氧(ROS);以原子荧光分析方法检测细胞内外不同形态砷含量。结果在一定剂量范围的MMAⅢ(≥5.0μmol/L)、As2O(3≥200.0μmol/L)、砷酸氢二钠(0.5,≥200.0μmol/L)和二甲基胂酸钠(500.0μmol/L)能够显著降低A431的细胞生存率(P<0.05,P<0.01),而在低剂量时,四种砷化物能显著促进A431细胞增殖(P<0.05,P<0.01)。与对照组相比,50.0μmol/L MMAⅢ组,50.0、250.0μmol/LAs2O3组,0.5μmol/L砷酸氢二钠组MDA含量均显著升高(P<0.05,P<0.01),而250.0μmol/L砷酸氢二钠和5.0～250.0μmol/L二甲基胂酸钠组MDA含量均显著降低(P<0.05,P<0.01)。与对照组相比,0.5、50.0μmol/L MMAⅢ组,5.0～250.0μmol/L砷酸氢二钠组和0.5～500.0μmol/L二甲基胂酸钠组的SOD活力显著升高(P<0.05,P<0.01)。细胞内活性氧含量依次为0.5μmol/L MMAⅢ>50.0μmol/L As2O3>100.0μmol/L砷酸氢二钠>100.0μmol/L二甲基胂酸钠。低剂量As2O3、砷酸氢二钠组细胞内砷甲基化率高于高剂量组,且As2O3组甲基化率高于砷酸氢二钠。结论在本实验条件下,不同砷化物在低剂量促进A431细胞增殖,高剂量抑制增殖,可能与A431细胞的氧化应激和砷代谢有关。     

桂东南某河流铊污染后人群铊暴露状况初步调查

目的了解桂东南某河流铊污染3年后沿岸某村井水、土壤、地产食用农产品以及居民重金属铊含量水平,评估当地居民健康风险。方法于2016年,选择2013年发生铊污染事件的某河流沿岸某村作为污染区,选择该河流污染段上游沿岸的1个自然村作为对照区。采集井水、土壤、地产食用农产品及(18～75)岁常住居民尿液样品,采用电感耦合等离子体质谱仪(ICP-MS)测定井水、土壤、食物及尿液铊含量水平。结果污染区井水铊含量(M=0.290μg/L)高于对照区(未检出),差异有统计学意义(z=-6.51,P<0.01),污染区井水铊合格率(24.6%)低于对照区(100.0%),差异有统计学意义(χ~2=42.48,P<0.01);污染区土壤铊含量(M=0.755 mg/kg)高于对照区(M=0.595 mg/kg),差异有统计学意义(z=-2.02,P<0.05);污染区食物铊含量(M=1.861μg/kg)高于对照区(M=0.250μg/kg),差异有统计学意义(z=-4.14,P<0.01);污染区人群尿铊含量(G=0.70μg/g肌酐)与对照区(G=0.67μg/g肌酐)相比差异无统计学意义(F=1.18,P>0.05)。结论污染区人群存在一定水平的铊暴露,但人群尿铊水平与对照区人群水平相当。     

重金属污染重点地区土壤及食物砷含量调查

目的了解广西环境重金属污染重点地区土壤及食物砷含量水平。方法于2014—2016年,在广西3个重金属污染重点防控区选择污染较严重的4个行政村作为污染区,同时选择3个行政村作为对照区,采集279件土壤样品和1 374件当地产食物样品,测定土壤砷含量、大米无机砷含量及食物总砷含量,并进行评价。结果污染区和对照区土壤砷合格率分别为19.7%和91.7%。污染区农田、菜地土壤砷含量的中位数分别为29.2 mg/kg(范围为2.2~847.0 mg/kg)和46.8 mg/kg(范围为2.5~379.7 mg/kg),对照区农田、菜地土壤砷含量的中位数分别为11.5 mg/kg(范围为3.2~91.5 mg/kg)和13.8 mg/kg(范围为2.5~160.0 mg/kg)。污染区土壤砷含量高于对照区,合格率低于对照区,差异均有统计学意义(P0.01)。污染区食物砷合格率97.4%,对照区食物砷均合格。以污染区大米的砷含量最高,合格率为94.6%。结论污染区土壤砷污染较严重,由此造成的食物砷污染对人体健康存在潜在影响。     

刁江沿岸土壤重金属污染状况及土地的合理利用模式

目的了解刁江沿岸土壤重金属污染区分布,寻求安全的污染区土地利用模式。方法于2003年在刁江沿岸设置了12个采样断面,采样分析土壤中重金属含量,分析了污染区大米、玉米和桑叶中的重金属(As,Pb,Cd、Zn)含量。结果土壤中的主要污染物为As(19.6～7441mg/kg)、Pb(53.4～1823mg/kg)、Cd(0.35～39.2mg/kg)、Zn(110～4199mg/kg)等,污染区范围与洪水淹没区一致。污染耕地上产出的大米中Cd和Pb含量超过国家食品卫生标准,尤其是大米中Cd的含量超标4.9倍,Pb超标0.905倍;玉米中Pb、Cd和Zn的含量分别超标1.345倍,0.56倍和0.598倍。结论受上游矿山开发影响,刁江沿岸土壤重金属污染十分严重,建议将污染区耕地划定为食用农作物禁止种植区,在污染区开展种桑养蚕试验,将严重尾砂覆盖污染区作为尾砂库并进行植被恢复与重建。     

砷的毒性与生物学功能

砷 (Arsenic) ,元素符合 As,原子序数 33,其最外层电子结构是 4s2 、 4p3,因此砷可表现出多种价态 ,最常见的是- 3、 3和 5价。在生物中较为重要的砷化合物除以无机砷如砷酸和亚砷酸及其盐的形成存在外 ,还以甲基胂酸CH3As O32 -、二甲基次胂酸 (CH3) 2 As O2 2 -、三甲基胂氧(CH3) 3As O、一甲基胂 CH3As H2 、二甲基胂 (CH3) 2 As H和三甲基胂 (CH3) 3As等有机砷的形式存在 ,在整个生物循环中 ,又以含甲基的砷化合物最为重要的。砷在地壳中的丰度为 (1.7～ 1.8) m g/kg,广泛存在于岩石、土壤和水中。我国早在四千多年前就将雄…     

大米中总砷与无机砷含量检测与结果分析

目的建立大米中无机砷的常规检测方法,监测大米中总砷与无机砷含量。方法用电感耦合等离子体质谱法测定大米中总砷含量,液相原子荧光法测定大米中无机砷含量。分层随机采集赣榆区市售大米样品进行砷含量检测。结果总砷在0.50～50.0μg/L范围内线性关系良好(r=1.000),方法检出限为2.5μg/kg,定量限为7.5μg/kg,加标回收率为85.0%～110.0%,相对标准偏差(RSDs)为3.7%～6.8%。无机砷在2.00～20.0μg/L范围内线性关系良好(r值均0.998),检出限为0.02mg/kg,定量限为0.05mg/kg,加标回收率为91.2%～107.0%,RSDs为4.4%～6.8%。采集20份市售大米样品进行检测,总砷含量为0.04～0.23mg/kg,平均(0.132±0.052)mg/kg;无机砷含量为0.01～0.16mg/kg,平均(0.082±0.025)mg/kg。检出无机砷样品中,无机砷含量占总砷的43.6%～89.1%,平均(62.4±9.6)%。市售大米As(Ⅲ)、As(Ⅴ)检出率分别为95.0%、5.0%,通过大米摄入无机砷的量远远低于人可耐受摄入量。结论赣榆区大米中无机砷多以As(Ⅲ)存在,对人体健康的风险处于较低水平。     

HPLC-ICPMS测定海鱼中六种砷形态方法探讨

采用1%硝酸微波萃取进行提取,梯度洗脱的方式对六种砷形态(As B、As C、AsⅢ、As V、MMA、DMA)进行分离,HPLC-ICPMS(液相色谱-电感耦合等离子体质谱)测定海鱼中六种砷形态。对影响液相分离的各条件进行优化,得出六种砷形态的线性范围为1.0μg~200μg/L,相关系数r=0.999 6~1.000 0,检出限依次为As C:0.21μg/L、As B:0.21μg/L、DMA:0.14μg/L、MMA:0.12μg/L、AsⅢ:0.23μg/L、As V:0.21μg/L。加标回收率为82.2%~97.5%,相对标准偏差为0.8%~8.6%,该方法 12 min内能分离六种砷形态,前处理步骤简单,适用于海鱼中砷形态的测定。     

内蒙古巴彦淖尔地区环境中砷的分布特征

目的了解巴彦淖尔地区环境中砷的分布特征。方法于2008—2009年对内蒙古巴彦淖尔市临河区(A区)、五原县乃日乡(B乡)等地区的地下水、土壤和植物采样共812件;并从山东招远金矿附近(D区)相应采集了72件环境样品,自山西大营村(F村,地砷病重病区)和巴彦淖尔东升庙矿区附近(E区)分别采集了8件地下水样品,检测所有样品砷及相关元素的含量。结果巴彦淖尔地区水中砷含量超标率为58.9%～100%;土壤中砷含量均值(大于12mg/kg)高于中国土壤均值(9.2mg/kg)和D区土壤样品砷均值。该地区439件植物样品砷含量差异较大(0.01～6.04mg/kg),部分农作物和蔬菜类样品砷含量高于野生植物。水中砷的分布趋势和铁、锰大致相反,土壤中砷分布与铁、锰一致。结论巴彦淖尔地区地下水、土壤和植物样本砷含量较高。     

山西省某地环境汞污染对女性生殖健康影响

目的通过流行病学调查,分析山西省某地区环境中汞污染状况及对当地女性居民生殖健康影响。方法用原子荧光光谱法测定当地大气、水、粮食和居民尿中汞含量;通过问卷调查方法获得女性人群基本健康资料和生殖健康情况。结果污染区空气中汞含量为(0.11±0.01)μg/m3,明显高于对照区(P0.05);污染区小米、玉米中汞含量分别为(0.013±0.006),(0.006±0.003)mg/kg,明显高于对照区(P0.05);污染区女性尿汞含量为(1.06±1.23)μg/L,明显高于对照区(P0.05);污染区女性月经异常检出率和妊娠结局异常率明显高于对照区女性(P0.05);污染区女性妊娠合并高血压和新生儿死亡率明显高于对照区(P0.05)。结论污染区环境(主要是空气、土壤和农作物)存在汞污染;污染区女性居民体内汞负荷增高;汞对污染区女性生殖健康有一定影响。     

污灌玉米中10种元素的测定及营养评价

摘要:目的　研究污染灌溉区玉米中10种元素铬（Cr）、镍（Ni）、铜（Cu）、锌（Zn）、硒（As）、砷（Se）、钼（Mo）、镉（Cd）、汞（Hg）、铅（Pb）含量的变化,并对其进行营养评价。方法　采自对照区和A、B两处污染区的玉米籽粒,经前处理之后,采用微波消解-电感耦合等离子体质谱法（ICP-MS）测定其中的10种元素含量并计算必需元素的INQ值。结果　污灌A区的玉米中Cr、Zn、Mo、Cd、Hg、Pb含量高于对照区（P＜0.05）,污灌B区的玉米中Zn、Mo、Cd、Hg、Pb含量高于对照区（P＜0.05）;两处污灌区重金属Cd、Hg、Pb含量均超国标最高限值;对照区玉米中As、Se的INQ＜1,污灌B区玉米中As的INQ＜1,其余INQ＞1。结论　污水灌溉导致玉米中一些元素含量改变,有毒重金属Cd、Hg、Pb含量超标;对照区玉米As、Se含量偏低,不能满足人体需求。     

Calcium intake in the elderly: validation of a dietary questionnaire

Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly.     

Self-reported health problems among Swedish miners one year after unemployment

Unemployment is considered to be a public health concern sincedeterioration in the health of the unemployed is often anticipated.However, for some groups, such as miners, unemployment mightimprove health due to a cessation of potentially harmful occupationalexposures. This study evaluates the health of 79 miners in oneSwedish iron-ore mine, and 226 age-matched controls from thegeneral population, during one year after the closure of themine. The participants received a questionnaire regarding medicalhistory and subjective symptoms at the beginning of the studyperiod, and after one year. Statistically significant negativeeffects on self-reported health attributable to unemploymentwere not found, although neuropsychiatric symptoms were morecommon among the unemployed miners. The miners reported a statisticallysignificant improvement in grip force (p=0.031). They had asignificantly higher prevalence of symptoms associated withmining related exposures when compared with the population controls;pain in the upper extremities [relative risk (RR)=2.27, 95%confidence interval (Cl)=1.44–3.59), back pain (RR=1.84;Cl=1.237–2.75), vasospastic disease of the fingers (RR=2.05;Cl=1.18–3.57) and obstructive respiratory symptoms (attacksof dyspnea and wheezing: RR=3.67; Cl=1.167–11.6).     

Excès de cas humains et animaux de tularémie en France au cours de l’hiver 2007–2008 : émergence ou phénomène isolé ?

Context

Tularemia is a zoonosis affecting humans and hares in France. We describe the results of surveillance in both species, in 2007 and 2008.

Methods

Human tularemia cases are mandatorily notifiable in France since 2003. In hares, surveillance relies on volunteer hunter associations in all districts of the country. Data from mandatory reports and volunteer surveillance in 2007/2008 were analyzed and compared with previous results.

Results

In 2007/2008, 144 cases were reported in humans and 117 cases in hares. This was a 100% increase compared to previous years. Human cases differed from those of previous years only by the frequency of contact with breeding animals. Human cases without any documented risk exposure were also more frequent.

Conclusion

An increase of tularemia cases occurred in 2007/2008 in both species. Complementary studies are needed to identify the species reservoir in France to understand the causes of this peak of cases.     

深圳公立医院管理体制改革制度设计

深圳公立医院管理体制改革实行政事分开、管办分开,在理事会架构下按法定机构模式组建市医管中心,落实公立医院运营管理自主权.作者从当前公立医院管理体制的弊端入手,介绍了深圳市进行公立医院管理体制改革的基本思路及改革方案设计的主要举措,深入剖析了的改革方案的特点,并对改革效果进行了预测.     

Effects of nitrogen dioxide on red blood cells of rats: Changes in components of red cell membranes during in vivo exposure to NO2

Red cell membranes, prepared from red blood cells of rats exposed to 4, 10, or 20 ppm nitrogen dioxide (NO₂) for 1 to 10 days, were examined for evidence of changes in membrane components. Appreciable changes were not found in contents of phospholipid and cholesterol during exposure to 10 ppm NO₂. By contrast, protein content altered with the time of exposure. Moreover, changes in protein composition were observed by employing sodium dodecyl sulfate — polyacrylamide gel electrophoresis. Twenty-four-hour exposure to NO₂ at the concentration above 10 ppm resulted in a marked increase in the percentage of lysophosphatidylethanolamine (LysoPE) to the total phospholipids. The prolonged exposure to 10 ppm NO₂ gave rise to a further increase in LysoPE, whereas the percentage of phosphatidylethanolamine (PE) showed a gradual decrease. A 1-day exposure to 4.0 ppm NO₂ also caused an increase in sialic acid content and decreases in those of PE and hexose. In addition to contents of these components the percentage of LysoPE increased 5 days after exposure and the elevated values were maintained up to the end of exposure period. These results demonstrate that red blood cells in circulation exhibit different membrane properties in terms of lipid and carbohydrate composition during 10 days of exposure to 4.0 ppm NO₂.     

Occupational health hazards in mining: an overview

This review article outlines the physical, chemical, biological, ergonomic and psychosocial occupational health hazards of mining and associated metallurgical processes. Mining remains an important industrial sector in many parts of the world and although substantial progress has been made in the control of occupational health hazards, there remains room for further risk reduction. This applies particularly to traumatic injury hazards, ergonomic hazards and noise. Vigilance is also required to ensure exposures to coal dust and crystalline silica remain effectively controlled.     

Manufacture and use of nanomaterials: current status in the UK and global trends

This paper provides an overview of the production and use of nanomaterials (NMs), particularly in the UK. Currently, relatively few companies in the UK are identifiable as NM manufacturers, the main emphasis being the bulk markets in metals and metal oxides, and some niche markets such as carbon nanotubes and quantum dots. NM manufacturing in the UK does not reflect the global emphasis on fullerenes, nanotubes and fibres. Some assumptions have been made about the types of NM that are likely to be imported into the UK, which currently include fullerenes, modified fullerenes and other carbon-based NMs including nanotubes. Many university departments, spin-offs and private companies have developed processes for the manufacture of NMs but may only be producing small quantities for research and development (R&D) purposes. However, some have the potential to scale up to produce large quantities. The nanotechnology industry in the UK has strong R&D backup from universities and related institutions. This review has covered R&D trends at such institutions, and appropriate information has been added to a searchable database. While several companies are including NMs in their products, only a few (e.g. manufacturers of paints, coatings, cosmetics, catalysts, polymer composites) are using nanoparticles (NPs) in any significant quantities. However, this situation is likely to change rapidly. There is a need to collect more information about exposure to NPs in both manufacturing and user scenarios. As the market grows, and as manufacturers switch from the micro- to the nanoscale, the potential for exposure will increase. More research is required to quantify any risks to workers and consumers.     

Investigating clusters in the workplace and beyond

Clusters of disease are common and occur in the workplace and in the general community. They often arouse considerable concern among the population. Investigations have sometimes lead to exciting new knowledge, but in general the investigation of clusters is difficult and often unrewarding, especially for community clusters. In the workplace, investigations are more likely to find associations and even new causes, but still many clusters remain enigmatic. Despite this, there are many reasons for investigating clusters, including allaying community concern and identifying uncontrolled exposures. A structure for investigating clusters in the workplace is suggested.