碳与硝酸铵联合基体改进剂石墨炉AAS法测定高盐样品铅

目的:建立低温原子化测定铅的方法。方法:在平台石墨管中加入碳粉,结合硝酸铵做基体改进剂,用相对较低的原子化温度测定高盐样品铅含量。结果:该法线性范围为0.00μg/L～8.00μg/L,相关系数(r)0.999,方法加标回收率为94.4%～105.3%,RSD(%)为0.92%～4.1%,检出限为5.0μg/L。结论:该法灵敏度高,检出限低,精密度好,背景吸收小,准确度可靠。用于酱油和尿液铅含量的测定,结果满意。     

微波消解-石墨炉原子吸收光谱法测定土壤中铅和镉

[目的]建立微波消解-石墨炉原子吸收光谱测定土壤中铅和镉的分析方法。[方法]土壤样品研磨过100目筛,用硝酸-氢氟酸-过氧化氢混合消解液微波消解后,石墨炉原子吸收光谱测定。[结果]铅浓度为5.0~40.0μg/L、镉浓度为0.20~2.00μg/L时,石墨炉原子吸收光谱测定土壤中铅和镉的方法线性良好,相关系数均为0.9999。铅和镉的方法定量检出限分别为5.0、0.040mg/kg。加标回收率为90.0%~110.0%,相对标准偏差为4.1%~6.9%,标样的测定结果在不确定度范围内。[结论]该方法简便、快速,基体干扰少,结果准确,适用于土壤中铅、镉含量的测定。     

石墨炉原子吸收法测定微量血铅的测量不确定度分析

[目的]建立微量全血中铅的测量不确定度分析的模式。[方法]用石墨炉原子吸收法测定。[结果]血样中铅浓度为61.1μg/L时扩展不确定度为1.9μg/L。[结论]该方法可用于全血中铅的测定。     

石墨炉原子吸收法测定酱油中铅

目的:建立酱油中微量铅的测定方法。方法:利用混合酸对样品进行消化处理,磷酸二氢铵作为基体改进剂,石墨炉原子吸收光谱法测定。结果:在实验条件下,方法线性范围为0~80μg/L,相关系数在0.9980以上,方法的检出限为1.8μg/kg,定量限为5.6μg/kg,测定样品的相对标准偏差在0.83%~2.48%之间,回收率在91.0%~98.0%之间。结论:方法简单、快速、准确,可用于快速测定酱油中的铅。     

石墨炉原子吸收光谱法直接测定尿中铅浓度研究

目的建立直接测定尿中铅浓度的石墨炉原子吸收光谱法。方法用5 g/L的磷酸二氢铵作为基体改进剂,采用塞曼扣除背景,石墨炉原子吸收光谱法直接测定尿液中铅的浓度。结果该方法线性范围0～50μg/L,相关系数0.999 0,检出限0.84μg/L,回收率90.0%～98.9%。结论该法背景干扰低,稳定性好,测定结果准确可靠,方法简单,适合大批量样品的检测。     

石墨炉原子吸收法直接测定酱油中的铅

目的：建立一种石墨炉原子吸收法直接测定酱油中铅的方法。方法：以氯化钯和硝酸铵为基体改进剂,酱油样品经稀释后直接用石墨炉原子吸收法测定。结果：氯化钯和硝酸铵基体改进剂的使用,可将灰化温度提高到1 000℃,降低氯化钠对测定结果的影响。线性范围为0～80μg/L,相关系数在0.9980以上,方法的检出限为1.7μg/kg,定量限为5.6μg/kg,测定样品的相对标准偏差在1.5%～3.3%之间,回收率在89.5%～108.0%之间。结论：采用氯化钯和硝酸铵为基体改进剂,用石墨炉原子吸收法直接测定酱油中的铅,是测定酱油中铅的一种简便、快速、准确的方法。     

氢化物原子荧光光谱法测定水中铅

[目的]研究氢化物发生—原子荧光光谱法测定水中铅的方法。[方法]对AFS-930双道原子荧光光度计的工作条件及实验条件进行选择。[结果]在选定的最佳测定条件下,标准曲线线性范围为0~50μg/L。30μg/L铅标准液相对标准偏差为1.23%,检出限0.26μg/L,回收率93.2%~97.6%。[结论]该方法测定水中铅,成本低,操作简便,灵敏度高,检出限低,结果准确可靠。     

尿铅、镉的石墨炉原子吸收光谱测定方法研究

[目的]研究石墨炉原子吸收光谱法测定尿中铅、镉的方法。[方法]用石墨炉原子吸收光谱法以标准加入法模式对氯化钯等3种基体改进剂和石墨炉参数进行了优化选择,建立了用一套经同样处理的样品测定尿中铅、镉含量的方法。[结果]在所选实验条件下,铅的线性范围为0—60μg/L,加标回收率为96．81％～101．06％,检测限为0．0028μg/L,精密度相对标准偏差为0．97％～3．24％。镉的线性范围为0～3μg/L,回收率为99．02％～100．34％,检测限为0．0022μg/L,精密度测定相对标准偏差为0．68％-3．05％。[结论]建立的方法具有准确、稳定、灵敏、经济、简便等优点,能够满足铅和镉接触人群的健康监护和铅、镉中毒的诊断、治疗和疗效评价。     

直接测定尿中铅的石墨炉原子吸收光谱法

[目的]改进尿中铅的石墨炉原子吸收光谱法。[方法]尿样加基体改进剂后，通过优化仪器实验条件，直接进样测定尿中铅。[结果]尿铅浓度在0～120μg／L范围内呈良好的线性关系，相关系数r=0．9996，最低检出限为0．016μg／L，相对标准偏差小于3．08％，回收率为97．6％～103．2％。[结论]该方法简便、快速、灵敏度高、精密度好、结果准确，适用于直接测定尿中铅。     

炉内消化石墨炉原子吸收法直接测定酱油中铅

目的建立酱油中铅的石墨炉原子吸收直接测定法。方法采用钯和抗坏血酸作基体改进剂,炉内消化塞曼扣背景石墨炉原子吸收法(GFAAS)直接测定酱油中铅。对干燥温度、灰化温度和原子化度进行了优化选择,消除了酱油中氯化钠产生的高背景干扰。结果方法的检出限为0.10μg/L。定量限为3.3μg/kg。相对标准偏差为2.29%～3.77%(n=8);回收率为94.0%～108.0%。结论该方法简便、快速、准确、灵敏度高、干扰少,适用于酱油中铅的测定。     

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.     

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.     

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.     

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.