汞接触与汞毒性反应关系

本文报道了某厂自1978～1987年在60余个汞作业点23494次汞蒸气浓度测定,结合316名接触汞的工人历年健康监护结果,证实汞接触水平与尿汞含量之间,以及神衰征候群、汞毒性细小震颤,口腔炎和精神症状与接触水平和持续接触时间之间均有接触反应关系。汞接触水平低于0.01mg/m~(?),接触10年无一例中毒病例发生,神衰征候群为20%;接触水平0.01～0.03mg/m~3,接触5年,汞中毒为2.0%(1/50),神衰征候群为49.2%(31/6(?));接触水平超过0.03mg/m~3,接触5年,汞中毒为18.2%(4/22),神衰症候群为81%(17/21).     

金属汞危害的职业流行病学研究

应用职业流行病学方法,讨论汞接触与汞危害关系,对现行汞标准进行评价。调查接汞者1220(女工776)名,对照组944(女工592)名。汞接触水平均0.1mg/m~3内,所见症状与接汞水平、尿汞、工龄与年龄有关;女工的神经系统症状发生较男工为甚。空气汞、尿汞与中毒症状间存在剂量反应关系;空气汞与尿汞值之比约1:1.67,尿汞水平在0.05mg/L以下时,接汞水平相当于0.03mg/m~3,在此汞接触水平下,连续接触10年,汞中毒发生率为1.9％。提示以保护97％接汞人群不发生中毒为水准,建议汞的卫生标准由0.01mg/m~3修订为0.03mg/m~3。     

金属汞对作业女工月经的影响

本文对776名接触汞和592名对照女工的月经变化进行了职业流行病学调查,结果表明:长期低浓度接触汞的女工引起月经的主要变化是痛经,汞接触水平在0.03mg/m~3以上时,随汞接触浓度的增高,痛经发生率亦随之递增,呈明显的剂量反应关系;汞接触水平超过0.06mg/m~3时,月经经量减少发生率明显高于对照组(P<0.05)。一般汞接触水平在0.06mg/m~3以下时,月经的周期、经期和经量的变化不显著。     

车间金属汞卫生标准修订值的研究

根据前报道的汞的职业接触评定及剂量反应关系研究结果,进而推算,保护99％以上的作业人群,接触汞30年不发生汞中毒的水准,车间空气汞的最高容许浓度,可修订为0.03mg/m~3,这是从职业卫生研究提出的初步意见,还要考虑经济与技术的可行性,费用效益分析,以及长期反复的实践验证结果才能修订好职业毒物的卫生标准。对照欧美汞的职业卫生标准值TLV—TWA为0.05mg/m~3。长期使用并未见明显增多的汞中毒病例,可以作为借鉴。     

32例慢性轻度汞中毒临床分析

慢性汞中毒的临床表现,公认为神经精神障碍、汞中毒性震颤、口腔炎三大特征。随着工业的发展,医疗技术水平的提高,临床上对汞中毒也发现了新的情况,如近年来有的文献报道,证明汞对肾脏有损害。本文对32例汞中毒患者临床资料的分析,与上述文献报道有符合之处。另发现心电图异常率比较高,特予报道。资料 32例患者均系汞矿工人。空气中汞蒸气浓度为0.08～0.183mg/m~3。均为男性。年龄     

三硝基甲苯作业现场劳动卫生学调查

调查结果表明,工人正常生产的车间空气中TNT浓度,多数均超过MAC(1.0mg/m~3).TNT接触工人主要表现为神衰综合征,红细胞SOD水平升高,GSH-PX和血清铜兰蛋白水平下降。为此,我们认为TNT中毒机理与体内脂质过氧化有密切关系,建议对TNT接触者可用上述指标做进一步观察。     

车间金属汞卫生标准的研究

本文报道了四个地区五个体温计和/或日光灯管生产工厂(1979-1988)汞作业点18539次汞蒸气浓度的测定,和227名连续接汞十年的工人进行动态健康监护的结果,证实汞接触水平与尿汞量之间,以及神衰症候群、汞毒性细     

浅论车间空气中金属汞的卫生标准

全国约有金属汞作业4000个,接汞人数约十万,女工占30～50％。全国1979—1981年普查,汞中毒患病率为2.43％,汞吸收检出率为7.87％,接汞水平超过金属汞卫生标准0.01mg/m~3约5倍。 在生产条件下,金属汞主要以汞蒸气的形式经呼吸道吸入人体。对汞中毒的机理仍不清     

煤烟型氟中毒地区室内空气氟卫生标准的研究

根据煤烟型氟中毒地区环境流行病学调查和氟化物的毒理学研究结果,提出我国煤烟型氟中毒地区的室内空气氟卫生标准值为:室内空气氟日平均和一次最大容许浓度分别0.01mg/m~3与0.03mg/m~3。     

作业地带空气中汞蒸气含量的卫生标准

作者根据多年来临床观察、统计分析以及大量动物实验的结果,认为空气中汞蒸气含量的卫生标准应制订一个比容许峰值(0.01mg/m~8)更低的平均最高容许浓度(MAK_D),其主要论据如下。1.各种不同汞作业人员(710名)的临床检查:在平均浓度为0.02～0.03mg/m~8的汞作用下,有35.5%(±2.49)的人出现植物神经衰弱综合征。除记忆力减退、情绪不稳定、睡眠障碍等一般主诉外,尚有不同程度的体征,如震颤,持久性红色皮肤划痕征,甲状腺肿大和机能亢进,吸~(181)碘率增高,嗅觉机能状态改变,肌肉作业能力降低,尿汞增高,血红蛋白含量和红细胞计数偏低,血清间接胆红素略高。这些改变随着接触汞的持续时间延长而加重。部分病例早期     

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.     

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.     

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.     

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.