空气中钼及其化合物的火焰原子吸收测定方法研究

目的：建立空气中钼及其化合物的原子吸收光谱测定方法。方法：用滤料（微孔滤膜）采集空气样品，经高氯酸-硝酸消化后，用乙炔-空气火焰原子吸收直接测定。结果：方法的检出限为0．1μg／ml，最低检出浓度为0．033mg／m^3，精密度为1．1％-2．1％，加标回收率为99．3％-100．8％，与现行国家标准方法ICP测定结果比对无明显差异，采样效率可达100％，曲线的线性范围在0-50μg／ml之间，样品采集后室温下至少可稳定14d。在生产现场和使用现场可能共存物在该法测定条件下均无干扰。结论：该方法适用于工作场所现场监测。     

原子吸收法测定动物骨粉中锶含量的研究

目的：建立空气-乙炔火焰原子吸收测定动物骨粉中锶含量。方法：采用高压消解法对样品进行前处理，并以氧化镧作为抗干扰剂，采用空气-乙炔火焰原子吸收富燃火焰测定锶含量。结果：高压消解法前处理骨粉消化完全，待测元素不易损失，选用浓度为8g／L氧化镧可基本消除样品中共存元素的干扰。锶含量在0—4．0μg／ml浓度范围内，回归方程为Y=0．018X＋0．0016，r=0．9990，具有良好的线性关系；方法的检出限为0．04μg／ml，相对标准偏差为4．1％-7．4％，方法回收率在90％-104％，对两种国家标准物质进行测定，测定值均与标示值相吻合。结论：方法精密准确可靠，可满足正常来样检测的需要，便于推广。     

水中砷的石墨炉原子吸收测定法

目的：建立测定水中砷的新方法。方法：用钯作掩蔽剂，石墨炉原子吸收法直接测定水样中砷。仪器的工作条件：波长193．7nm；狭缝1．3nm；灯电流12．0mA；干燥80－140℃，40s,灰化1100－1200℃，20s；原子化2300℃，5s，除残2600℃，4s。结果：线性范围10－20μg/L，加标后砷浓度为50μg/L和150μg/L的样品液，平均加标回收率在100．7％和103．6％，灵敏度可达10μg/L，标准曲线随机作6次重复测定，相关系数为0．9954－0．9997，最低检出限为5μg/L，石墨管为普通非涂层条件下，饮用水中金属离子不干扰试验，0．2％铝也不干扰测定。结论：石墨炉原子吸收法可用于测定水中砷，对较清洁水样可直接测定。     

石墨炉原子吸收光谱法测定饮用水中的铝

目的：建立一种新的石墨炉原子吸收光谱法测定饮用水中铝。方法：以K2Cr2O7-乙酰丙酮为基体改进剂，优选干燥、灰仡、原子化条件，建立工作曲线，对样品进行测定。结果：水样浓度在0—70μg／L时，方法的线性关系好。相关系数r=0．9996，检出限为1．7μg／L，加标回收率90．5％-106．5％，相对标准偏差（RDS）=4．0％。结论：该方法提高了测定铝的灵敏度，改善了实验重现性，为测定饮用水中微量铝提供了一种新方法。     

火焰原子发射法测定血清、尿及饮用水中微量锂

本文作者建立了测定正常人血清、尿及饮用水中微量锂含量的火焰原子发射法。采用脉冲定量方式,空气——乙炔流速比为5.3:1——5.6:1时,发射强度稳定。基体中常见无机离子和有机物不干扰测定。方法线性范围0—20ppb,0.23ng/ml锂产生发射强度为0.0044。11次空白值变异小于3%,三水平加标回收率分别为:血清85—107%,尿91—110%。饮用水96—109%。本法简单、快速、适合血清、尿及饮用水中微量锂的测定。     

火焰原子吸收法直接测定饮用水中钾和钠

火焰原子吸收法直接测定饮用水中钾和钠魏蓉金志玉钾、钠的测定，以往采用重量、容量、比色法，分析步骤繁杂，后用火焰光度法，灵敏度高于化学法，但需用化学分离法除去干扰物。笔者采用乙炔－空气火焰原子吸收光谱法连续测定钾、钠，加入铯盐电离抑制剂消除钾、钠的相互...     

火焰原子吸收法对滤膜中锡及化合物的测定

目的建立以盐酸消化体系用火焰原子吸收法测定工作场所空气中锡及化合物的方法。方法将微孔滤膜在浓盐酸条件下消化,火焰原子吸收法测定锡浓度。结果锡浓度在0μg/ml~160μg/ml时线性关系良好,相关系数为0.999 3,方法检出限为0.32μg/ml。低、中、高不同浓度锡标准溶液的回收率分别为99.0%、102.0%、99.2%,相对标准偏差均5.0%。结论本方法灵敏度高、干扰少、简便、快速、准确,适用于工作场所空气中锡及化合物的测定。     

溶剂萃取氧化亚氮－乙炔火焰原子吸收法测定水中痕量铝

溶剂萃取氧化亚氮－乙炔火焰原子吸收法测定水中痕量铝张晓光，李红，张潮常用测铝方法有分光光度法、石墨炉法、空气－乙炔火焰法等，这些方法操作繁琐，灵敏度低，石墨炉法氯化物容易升华（１）。我们采用铝与８－羟基喹啉螯合、ＭＩＢＫ萃取，氧化亚氮－乙炔火焰原子吸...     

原子吸收光谱法直接测定白酒中锡的含量

在乙炔－空气火焰中测定白酒中的锡，试样中无需加入试剂，直接在原子吸收光谱仪上测定结果。在所选浓度范围内线性关系良好，回收率９８．３％～１０２．４％，变异系数２．２％～３．９％。     

水中痕量铅、镉的在线螯合树脂富集火焰原子吸收测定法

目的探讨天然水体中痕量铅、镉的测定方法。方法利用蠕动泵与火焰原子吸收的提升作用,让试液先通过树脂柱再进入火焰,调节试液酸度为pH=5．7,使试液中痕量的铅、镉富集在树脂柱上,然后让1．5mol／LHNO3溶液通过树脂柱,将铅、镉以6．0ml／min快速洗脱并喷入火焰中,记录瞬时峰高。结果在线螯合树脂富集火焰原子吸收法测定水中铅、镉的检出限分别为0．500、0．02μg／L,比单纯火焰原子吸收法检出限(均为10．0μg／L)分别降低2—3个数量级,相对标准偏差分别为2．3％,1．7％,精密度好于石墨炉法,回收率为94％-104．4％。结论该方法适合对天然水体中痕量铅、镉的火焰法快速测定。     

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.