氢化物发生-原子荧光法同时测定尿中砷和汞

目的：建立同时测定尿中砷和汞的氢化物发生－原子荧光法。方法：采用硝酸－高氯酸消化法。结果：砷和汞的线性检测范围分别为0－100μg/L和0－80μg/L。方法检出限分别为0．36μg/L和0．048μg/L，样品加标加收率砷为87．5％－101．0％，汞为92．0％－105．7％。结论：本法具有基体干扰小，灵敏度高、检出限低、线性范围宽、操作简便、快捷、结果准确可靠的优点，适合职业人群尿砷、汞的检测分析。     

食品中砷和汞的微波消解——原子荧光光谱测定法

目的建立微波消解原子荧光法同时测定食品中砷和汞的方法。方法采用微波消解处理样品。原子荧光法测定,并进行消解条件、精密度、回收率等试验。结果砷的检出限为0．50μg／L,汞的检出限为0．04μg／L。砷在0～100μg／L相关系数为0．9996;汞在0—50μg/L相关系数为0．9995;砷和汞的回收率,其范围分别为砷98．4％～104．1％,汞97．O％一104．3％。结论微波密闭消解样品,消化过程节约试剂,防止试样中待测元素的损失,干扰少,适用于食品中砷和汞的测定。     

连续测定化妆品中微量汞、砷、铅的方法研究

目的：建立一种快速消解法消化样品并能连续测定化妆品中汞、砷、铅的方法。方法：应用微波消解法消化样品，氢化物-原子荧光光谱法连续测定化妆品同一试样中汞、砷、铅。结果：在经过优化的实验条件下。汞、砷、铅的检出限分别为0．005、0．08、0．2μg／L；本方法取样0．5g，稀释62．5倍，汞、砷、铅的最低检测浓度分别为0．6、10．0、30．6μg／kg，测定化妆品中汞、砷、铅的荧光强度与其浓度的线性范围分别为0-2．5、0-50和0-50μg/L。得到3种元素的回收率在90％-102％之间，相对标准偏差小于或等于2％，方法操作更为简便、快速、准确、灵敏度高。结论：化妆品中微量汞、砷、铅可以用微波消解-氢化物原子荧光光谱法连续测定。     

双道原子荧光法测定涉水塑料管材浸泡液中的砷和锑

目的探讨同时测定涉水塑料管材浸泡液中砷、锑的方法，以提高工作效率。方法采用氢化物发生-原子荧光法进行测定。砷、锑灯电流均为60mA，负高压280V，介质酸度8％，硼氢化钾浓度1．0％。结果砷在0～80μg/L范围内线性良好，相关系数0．9995，检出限0．074μg/L，相对标准偏差1．43％～3．14％，回收率94．7％～100．5％；锑在0～40μg/L范围内线性良好，相关系数0．9996，检出限0．17μg/L，相对标准偏差1．34％～2．75％，回收率91．3％-107．0％。结论此法适用于涉水塑料管材中砷和锑的同时测定。     

保健食品中铅、砷、汞微波消解前处理方法的研究

目的 应用微波消解前处理测定保健食品中铅、砷、汞的含量。方法 用微波溶样系统对保健食品进行消解，消解过的样品可用于石墨炉的原子吸收光谱仪和原子荧光光谱仪同时测定保健食品中的铅、砷、汞的含量。结果 本方法测定铅、砷、汞的检出限分别0．28μg／kg、0．007mg／kg和0．10μg/kg；回收率分别为88．5％～106．0％、85．0％～106．0％、和88．2％～96．7％；测定线性范围分别为0～100．0 ng／ml、0～200．0,ng／ml和0～60．0μg／L。结论 该方法简便、快速，灵敏度、精密度、准确度较好，适合保健食品的快速消解及微量金属污染物的定量分析。     

同时测定保健食品中微量铅和汞的方法研究

目的：建立一种快速消解并同时测定保健食品中微量铅和汞的方法。方法：采用微波消解样品，氢化物发生原子吸收光谱法同时测定保健食品中的微量铅和汞。结果：方法简便、快速、准确，灵敏度高，方法检出限铅和汞分别为0．10μg/L、0．35μg/L，平均加收率铅和汞分别为94．2％、103．9％，对铅含量为10．0μg/L，汞含量为10．0μg/L的样品连续测定8次的相对标准偏差分别为2．29％、3．61％。结论：保健食品中的微量铅和汞可以用氢化物原子吸收法同时测定。     

氢化物原子荧光光度法同时测定食品中砷和汞

目的探讨原子荧光光度法同时测定食品中砷和汞的方法,研究酸度、硼氢化钾浓度、负高压、灯电流以及原子化器高度等因素对测定的影响。方法氢化物原子荧光光度法。结果在最佳测试条件下,砷、汞的检出限分别为0．04μg／L,0．02μg／L;样品的加标回收率砷为89．2％～95．7％,汞为97．1％～106．3％。结论在最佳测试条件下样品可以经过一次消化后,同时测定食品中砷和汞,且方法快速简便,准确。     

氢化物发生—原子荧光法测定保健食品中的砷

本文采用硝酸-高氯酸处理样品，以氢化物发生-原子荧光光谱法测定保健食品中砷的含量，方法的检出限为0.1μg/L，在0-120μg/L范围内线性相关系数为0.9996，样品加标回收率为88%-102%,相对标准偏差为3.9%-7.4%。     

大米中砷和汞的微波消解-原子荧光光谱测定法

目的建立双道原子荧光光谱法同时测定大米中的砷和汞的方法。方法采用微波消解法处理大米样品,以原子荧光光谱法同时测定其中的砷和汞。结果砷和汞的检出限分别为0.004 4、0.039μg/L;砷、汞标准溶液分别在1.0～20.0和0.10～1.20μg/L范围内线性良好,其相关系数分别为0.999 5、0.999 2;精密度RSD:测定含2.0μg/L砷和0.4μg/L汞的混合标准溶液的RSD分别为2.12%、4.59%。样品加标回收率:砷92.2%～96.8%,汞90.3%～92.1%。结论该方法灵敏度、准确度高,操作方便快速,具有较低的检出限,能满足同时测定大米中砷和汞含量的测定工作。     

尿中砷和汞的原子荧光分光光度同时测定法

目的探讨应用AFS-930型双道原子荧光光度计，同时进行尿中砷和汞的测定方法。方法采用高压消解器对样品进行消解，用硫脲-抗坏血酸混合剂处理样品，并以氢氧化钾和硼氢化钾为还原剂，上机测定尿中砷和汞。结果砷、汞回收率均大于95％，相对标准偏差小于3％，砷、汞的检出限分别为：As0．35μg／L，Hg0．060μg／L。结论该方法灵敏度高，检出限低，线性范围宽，操作简便，回收率高，是测定职业人群尿中砷、汞的可靠方法。     

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.