还原气化-原子吸收光谱法测定尿中汞的方法研究

目的 研究还原气化－原子吸收光谱法分别测定尿中总汞、无机汞和有机汞的方法。尿样中汞（汞中无机汞和经溴酸钾－溴化钾处理尿中有机汞生成的无机汞）以硼氢化钠还原生成汞原子蒸气,用原子吸收分光光度仪分别测定其总汞、无机汞和有机汞的含量。结果 该法在0－48μg/L范围内,直线回归相关系数总汞和无机汞分别为0．9992、0．9990,检测限总汞为0．028μg／L、无机汞为0．025μg／L,精密度测定相对标准偏差总汞为2．5％－4．5％、无机尔为1．1％－5．1％,加标回收率总汞测定为97．83％－98．56％、无机汞测定为95．25％－96．25％。结论 该方法对尿汞测定是一种准确、灵敏、快速、简便的分析方法。     

原子荧光法测定生活饮用水中的汞

[目的]应用AFS-2202E型双道原子荧光光度计测定生活饮用水中的汞。[方法]以1 9硝酸为载流,0.5g/L硼氢化钾为还原剂,将汞还原为原子态,以氩气为载气将汞引入原子化器,经汞空心阴极灯光源激发,产生共振荧光,荧光强度与汞浓度遵守朗伯—比耳定律,求出汞含量。[结果]汞在0.50~10.00μg/L范围内,荧光强度值与汞浓度相关系数r>0.999,汞的最低检出限DL=0.0411μg/L,RSD=1.957%,回收率88%~106%。[结论]应用原子荧光法测定生活饮用水中汞,操作简便,检出限低,重现性好,线性关系好,回收率高,适用于生活饮用水中微量汞的测定。     

流动注射-氢化物发生原子吸收光谱法测定蛋制品中的汞

[目的]通过测定蛋制品中的汞,研究了氢化物发生测定汞的最佳条件。[方法]利用流动注射氢化物发生技术与原子吸收分光光度计相结合的方法测定汞,并和国家标准冷原子吸收光谱法进行了实验比对。[结果]本法检出限为0.10μg/L,相对标准偏差在3.7%~6.1%之间,回收率范围在96.9%~104.2%之间,平均回收率为100.3%,结果令人满意。[结论]本方法简便、重现性好、准确度高、灵敏度好,适用于条件有限的基层单位。     

DMA-80直接测汞仪与冷原子吸收仪测定尿汞的对比研究

目的:使用DMA-80直接测汞仪和冷原子吸收测汞仪对尿汞的测定进行对比研究。结果:两种仪器在尿汞含量为0.0~50.0μg/L的范围内线性关系良好;直接测汞仪方法检出限为0.3μg/L,RSD为1.68%~7.99%,平均回收率为99.6%~110.0%;冷原子吸收测汞仪方法检出为0.5μg/L,RSD为0.84%~4.67%,平均回收率为108.0%~114.0%。结论:用统计软件对两种仪器测定的84组样本检测结果进行分析,差异无统计学意义。     

氢化物发生-原子荧光光谱法测定输配水材料中的汞

[目的]建立输配水材料中汞的测定方法。[方法]样品经浸泡处理后,用氢化物发生-原子荧光光谱法测定其中的汞。[结果]方法的检出限为0.01μg/L,线性范围0~5μg/L,回收率91.5%~109.0%,RSD5.05%~6.59%。[结论]本方法适合于输配水材料中汞的测定。     

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。     

湿法消解—氢化物原子荧光光谱法测定食品中无机砷

研究了以湿法消解—氢化物原子荧光光谱法测定食品中无机砷的最佳条件,在20 g/L硼氢化钾还原介质和5 g/L氢氧化钠溶液中,砷的线性范围为5.0~100μg/L,相关系数为0.9992,样品的加标回收率为94.5%~105.7%,相对标准偏差小于10%。     

石墨炉原子吸收光谱法测定全血中铍

[目的]建立石墨炉原子吸收光谱法测定全血中铍（Be）的方法。[方法]全血样用5%（v/v）硝酸脱去蛋白,经离心后取上清液进样,以0.5%（m/v）硝酸镁Mg（NO3）2作为基体改进剂,采用标准工作曲线法测定。[结果]测定方法的线性范围为0.18~5.00μg/L,相关系数（r）为0.9996,相对标准偏差（relative standard deviation,RSD）为2.7%~4.2%,检出限为0.27μg/L,加标回收率为90%~100%。[结论]该方法取样量少,消解处理简单,且快速、准确,适用于全血中铍的测定。     

健康人群尿汞本底值的调查

目的探讨不同地区非接触汞正常人群尿汞正常值.方法在上海、黑龙江、广东、四川等省市,收集非接触汞正常人群尿样共2 248例.样本采集采用随意尿,统一使用聚乙烯塑料瓶收集不少于25 ml的尿样,统一使用上海光华仪器厂生产的F732-G型测汞仪,测定方法采用尿中汞的酸性氯化亚锡还原-冷原子吸收法和尿中汞的碱性氯化亚锡还原-冷原子吸收法.并用肌酐和比重校正.采用苦味酸法测定肌酐,采用比重计测定比重.结果尿汞测定值呈偏态分布,采用对数转换成正态或近似正态分布,用几何均数表示平均水平.酸性法和碱性法2种测定方法的比较,差异无统计学意义（P=0.099）.男女间各地区比较,差异无统计学意义（P＞0.05）.尿汞正常值95%上限为≤4.25μg/L（21.22 nmol/L）,用肌酐校正后为3.724 5 μg/g Cr（18.38 mol/g Cr）,比重校正后为4.45μg/L（22.50 nmol/L）.结论建议尿汞正常参考值为≤5μg/L（25 mol/L）,肌酐校正后为≤4 μg/L Cr（20nmol/Cr）,比重校正后为≤5 μg/L（25 nmol/L）.     

石墨炉原子吸收光谱法测定尿中铝的方法研究

[目的]建立石墨炉原子吸收光谱测定尿中铝的方法。[方法]应用0.10%曲拉通-100（TritonX-100）和0.50%硝酸直接稀释样品,石墨炉原子吸收光谱法直接测定尿中铝的含量。[结果]通过试验,该方法的线性相关系数为0.999,检出限为1.02μg/L,回收率为91.8%~104.9%,相对标准偏差在3.9%~7.9%,尿样在4℃冰箱中至少可以保存14d。[结论]所建立的分析方法灵敏、简便、准确,可测定尿中铝。     

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.     

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.     

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.     

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.