应用原子荧光光度计测定工作场所空气中的铅

[目的]为寻找一种测定工作场所空气中的铅的实用方法。[方法]用原子荧光光度计在最佳条件下,对工作场所空气中的铅进行测定。[结果]方法对铅的检出限为1.73μg/L,最低检出浓度为0.00058mg/m3(以采集75L空气样品计),相对标准偏差为1.18%,样品消化测定的平均回收率为90.4%～108.0%。[结论]该方法操作简单,结果准确,能满足工作场所空气中铅的检测要求。     

化妆品铅的测定——双硫腙水相直接光度法

双硫腙萃取分光光度法测定化妆品铅是国家规定的标准方法,但该法重现性差,试剂需用易挥发且毒性大的氯仿及氰化钾,我们参考文献,改用吐温20作增溶剂,双硫腙水相直接光度法测定化妆品中铅,操作简便,结果满意。1 试验部分 1. 1 主要试剂与仪器     

双硫腙水相光度法测定水中微量锌的研究

目的　改进双硫腙水相光度法。方法　利用表面活性剂Tween 80对双硫腙螯合物的胶束增溶作用 ,建立了一种水相直接比色测定水中微量锌的新方法。结果　在选定的实验条件下 ,方法的线性范围为 0～ 0 5mg/L ,检测限为 0 0 3mg/L ,测定低、中、高浓度锌标准溶液的相对标准偏差分别为 9 2 %、2 9%和1 0 %。水样的低、中、高浓度加标回收率分别为 71 7%～ 110 0 %、83 5 %～ 10 5 5 %和 90 5 %～ 10 5 5 %。测定锌标准物质和盲样 ,与标准值相符。结论　通过与国标法进行试验对比 ,两法标准系列的回归直线、加标回收率、低浓度的标准偏差均无显著性差异 (P >0 0 5 ) ,但两法中 ,高浓度的标准偏差有显著性差异 (P <0 0 5 ) ,双硫腙水相光度法优于国标法     

铅对人体的危害与防治（下）

空气中铅的测定铅在自然界以Pb_s、P_bSO_4、PC_1O_2等形式存在,在厂房空气中,铅及其某些化合物常以气溶胶,即以铅烟和铅尘的形式存在。空气中铅的测定,多采用双硫腙比色法,该方法准确度高、灵敏度好,操作设备简单,便于实际应用。双硫腙比色法的原理是:双硫腙(Dithizone)在弱碱性溶液中,可与铅离子生成红色络合物——双硫腙铅、它溶于氯仿、四氯化碳、苯等有机溶剂,根据所呈红色深浅进行比色测定。双硫腙可与多种金属离了生成络合物,在pH值8.5～11时,加入氰化钾,要使大多数干扰金属离子与     

空气中铜的氢化物原子荧光测定法

目的建立氢化物原子荧光法测定空气中铅的方法.方法采集空气中铅后的滤膜经消化后,加入铁氰化钾、草酸、盐酸的混合溶液,用AFS-920双道原子荧光光度计测定.结果最佳测定条件为,盐酸浓度0.12 mol/L,铁氰化钾浓度为8g/L,草酸浓度为0.4g/L,硼氢化钾浓度为15g/L.该方法的检出限为1μg/L,相对标准偏差为2.5%,回收率为90%～95%,线性范围为10～80μg/L.结论该方法可以应用于测定空气中的微量铅,可获得满意结果.     

双硫腙比色法测定空气中铅的质量控制

目的快速准确地用双硫腙比色法测定空气中的铅含量。方法空气中铅烟、铅尘用微孔滤膜采集，硝酸溶解后，与双硫腙反应，用分光光度法比色定量。结果在该法条件下绘制标准曲线（0．0～7．0）ug/ml浓度范围内线性关系良好，变异系数1．06％～3．14％，加标回收率98．8％-102．0％。结论通过质量控制，得到准确可靠的检验结果。     

测定尿铅的双硫腙分光光度法的改进

对测定尿铅的双硫腙分光光度法进行了改进,改进后的方法操作简便,适用。并对改进前后两种测定方法的测定结果进行比较,两者差异无显著性(P>0.05)。采用改进后的尿铅双硫腙分光光度法测定西宁市95%人群尿铅含量的正常上限值为0.367μmol/L(0.076 mg/L)。     

低浓度铅作业对女工生殖机能影响的调查研究

目的研究长期暴露在低铅环境下对女工生殖机能健康状况的影响。方法用热消化双硫腙比色法测定环境中的铅,用横断面方法进行女性生殖机能的调查,用回顾性调查方法进行妊娠方面及子代发育情况的调查。结果工作场所空气铅浓度为0.035￣0.048mg/m3,接铅作业女工的月经先兆症状、痛经以及闭经的发生率显著高于对照组(P<0.05)。结论空气中低浓度铅对女工生殖机能有一定影响。     

工作场所空气中甲酸的离子色谱测定法

目的 建立工作场所空气中甲酸的硅胶管采集离子色谱测定法.方法 甲酸经硅胶管采集,20 mmol/L KOH溶液解吸,离子色谱法测定.结果 进样量25 μl,甲酸浓度在0～25.0 mg/L范围内具有良好的线性关系,方法的相对标准偏差为0.6%～1.2%,加标回收率为98%～103%,测定范围为0.8～83.3 mg/m3.结论 该方法适用于工作场所空气中甲酸的测定.     

水中铅的简易快速测定—巯基棉浓集重金属试剂法

铅是五大工业毒物之一,在中国饮水中铅的标准是0.05mg/L。双硫腙比色法是测铅的常用方法,但它不适于在野外快速简便地测铅。我们采用巯基棉吸附预处理水样,盐酸洗脱,重金属试剂显色,测定简易快速,并提高了测定饮水中铅的灵敏度,受干扰影响小。采集了42个天然水样,经测定含铅量均低于0.05mg/L, 没有超过饮水标准,而加入0.1mg/L的Pb~(++)到16个天然水样中,并用该法和标准方法测定,大多数结果两法一致,说明该法测铅的回收率较好。     

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.