微波消解——原子荧光光谱法测定滇重楼中砷汞含量

目的:建立硝酸微波消解-双道原子荧光光谱法测定滇重楼中的砷汞含量.方法:本方法需要样品0.3g,浓硝酸2.0mL,加水至8mL消解,定容至25mL,用原子荧光光谱仪测定As、Hg.结果:本法在汞浓度为0μg/L～1.0μg/L、砷浓度为0μg/L～10μg/L范围内有良好的线性关系,相关系数rHg=0.9988,r As=0.9997,检出限为Hg:0.007mg/kg,As:0.005 mg/kg;回收率为Hg:83％,As:94％.结论:由于所用试剂量大大减少,空白值低,结果准确可靠,适合日常批量检测.     

氢化物发生-原子荧光光谱法同时测定尿中砷和汞

目的建立氢化物发生-原子荧光光谱法同时测定尿中砷和汞[1]的方法。方法尿样经微波消解消化处理后,用氢化物发生双通道原子荧光光谱法同时测定尿中砷和汞的浓度。结果本方法中砷和汞的浓度分别在(0.00-100.0)μg/L和(0.00-80.0)μg/L的范围内有良好的线性关系,相关系数分别为r As=0.999 5和r Hg=0.999 2,方法检出限分别为As:0.28μg/L、Hg:0.045μg/L,相对标准偏差分别为0.44%~1.82%、1.11%~2.36%,回收率分别在95.50%~99.52%和94.70%~102.0%之间。结论用该法同时测定尿中砷和汞是准确可靠、操作简便、快捷、可行的,适合职业体检等大批量样本的检测分析。     

双道原子荧光光谱法同时测定福建宁德大黄鱼中砷和汞

目的:建立大黄鱼中砷汞的微波消解氢化物原子荧光光谱同时测定方法。方法:样品经微波消解,在硫脲—抗坏血酸—盐酸体系中,用硼氢化钾作还原剂,采用氢化物原子荧光光谱法同时测定。结果:砷浓度在0~20μg/L的范围内线性良好,相关系数r=0.9997,方法检出限为0.057μg/L,样品检出限5.7μg/kg,相对标准偏差0.88%~2.38%,回收率95.6%~98.6%;汞浓度在0~2.0μg/L的范围内线性良好,相关系数r=0.9999,方法检出限为0.004μg/L,样品检出限0.4μg/kg,相对标准偏差0.91%~1.58%,回收率92.0%~96.0%。结论:方法灵敏度高,准确度好,精密度高,干扰少,简便适用,适合大黄鱼中砷汞的同时测定。     

氢化物发生ICP-AES与原子荧光光谱法测定化妆品砷汞含量比较

目的通过对比氢化物发生ICP-AES和原子荧光光谱法测定化妆品中砷和汞的含量,从而为化妆品中砷汞的测定提供可靠的方法。方法分别采用氢化物发生ICP-AES和氢化物原子荧光光谱法测定化妆品中砷和汞的含量。结果氢化物发生ICP-AES测定As、Hg的检出限为0.25μg/L、0.80μg/L;RSD(n=7)为1.15%、1.26%,加标回收率为100.60%~100.90%、100.30%~99.84%;原子荧光光谱法测定As、Hg的检出限为0.041μg/L、0.041μg/L;RSD(n=7)为1.96%、2.10%,加标回收率为97.90%~101.60%、98.70%~104.80%。结论两者测量的准确度和精密度都能符合要求,若只需测定砷汞,且含量低时,推荐采用原子荧光光谱法;氢化物发生ICP-AES可同时测定多种可生成氢化物的金属元素,适合大批量样品分析。     

微波消解-原子荧光法同时测定化妆品砷和汞含量

目的建立微波消解和氢化物发生-双道原子荧光光谱法同时测定化妆品中砷和汞。方法化妆品样品采用微波消解技术消解,优化仪器条件,选择负高压270 V,砷和汞空心阴极灯电流分别为80 mA和20 mA,用氢化物发生-双道原子荧光光谱法同时测定化妆品中砷和汞,并比较同时测定和分别测定化妆品中砷和汞含量的差异。结果在本实验条件下,砷的线性范围为0～20.00μg/L,相关系数为0.999 0,检出限为0.075μg/L,精密度为0.70%～3.84%,回收率为97.60%～99.52%;汞的线性范围为0～4.00μg/L,相关系数为0.999 4,检出限为0.030μg/L,精密度为0.72%～2.74%,回收率为91.00%～99.30%。氢化物发生-双道原子荧光光谱法同时测定和分别测定化妆品中砷和汞的含量差异均无统计学意义(P0.05)。结论采用本方法同时测定化妆品中砷和汞,精密度、准确度较好,检出限能满足分析要求,操作简单,可提高日常检测效率。     

微波消解—双道原子荧光光谱法同时测定水产品中砷和汞

目的:建立微波消解—原子荧光光谱法同时测定水产品中砷和汞的方法。方法:采用微波消解方法,双道原子荧光光谱法同时测定水产品中砷和汞的含量。结果:砷与汞的线性范围分别为0.04~200μg/L,0.01~100μg/L;相关系数分别为r=0.9998,r=0.9999;砷回收率为95.7%~98.4%,相对标准偏差为1.75%~3.41%,检出限为0.04μg/L;汞回收率为92.5%~97.9%,相对标准偏差为1.77%~2.77%,检出限为0.01μg/L。结论:微波消解—双道原子荧光光谱法测定水产品中砷和汞,方法灵敏度高,操作简便快速,结果准确可靠。     

微波消解-氢化物发生原子荧光光谱法测定茶叶中的总砷含量

目的建立微波消解-氢化物发生原子荧光光谱法,用于茶叶中总砷含量的测定。方法样品中加入硝酸进行微波消解,用氢化物发生原子荧光光谱法测定茶叶中的总砷含量。结果在最佳消解条件和检测条件下,该方法具有很好的灵敏度,总砷浓度在0~20.0μg/L范围内线性关系良好,相关系数r=0.999 9,检出限为0.04 mg/kg,方法回收率为97.5%~102.5%,RSD为1.3%。结论实验表明,该方法操作简单,精密度好,回收率高,是测定茶叶中总砷含量的可靠方法。     

微波消解-氢化物发生-原子荧光光谱法测定中药材中的痕量汞

目的:建立微波消解-氢化物发生-原子荧光光谱法测定中药材中痕量汞的方法。方法:用微波消解法对几种常用中药材样品进行前处理,用氢化物发生-原子荧光光谱法测定其中痕量汞。结果:微波消解过程中,消解试剂选择硝酸+双氧水,且按3∶1比例混合时消化效果最佳,汞在浓度为0μg/L~4μg/L范围内线性关系良好,相关系数r=0.9999,方法检出限为0.014μg/L,测定汞1.0μg/ml标准溶液相对标准偏差为1.99%,测定国家一级标准物质人发(GBW09101)相对标准偏差为3.37%,且测定结果与标准含量一致。结论:该方法测定中药材中的痕量汞简便快速,准确灵敏,易于推广。     

微波消解—原子荧光光谱法测定富硒精米中硒

目的建立微波消解—氢化物发生原子荧光光谱法测定富硒精米中硒的方法。方法富硒精米样品经微波消解后,用氢化物原子荧光光谱法测定富硒精米中硒的浓度。结果本法在硒浓度为0～10μg/L范围有良好的线性关系,相关系数r=0.9997,检出限为0.002 mg/kg;相对偏差为0.57%～2.7%;回收率为99.8%～101.0%。结论该方法具有简便、快速、灵敏度高等优点,适合日常批量检测。     

微波消解-原子荧光法测定食品中总砷

目的建立应用微波消解-原子荧光法快速、准确地测定食品中总砷的方法。方法采用微波消解法对食品样品进行前处理,氢化物发生原子荧光法测定食品样品中总砷。结果砷的质量浓度在0~10μg/L范围内与原子荧光强度呈良好的线性关系,相关系数为0.999 4,方法检出限为0.006 mg/kg,回收率为96.1%~104.9%。结论本方法能简便、准确地测定食品中总砷。     

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.     

The occurrence of antimicrobial substances in toilet,sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference.To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02?μg·L^?1 to a maximum of 79?mg·L^?1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.     

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.     

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.     

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.     

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.