二氧化氯消毒饮用水的研究进展

二氧化氯(ClO)2作为一种新型杀菌消毒剂,在饮用水消毒方面的应用越来越广泛。随着饮用水消毒用二氧化氯产品的种类不断增加,二氧化氯消毒剂应用于饮用水消毒的安全性也日益受到人们的关注。目前,国内外对二氧化氯消毒饮水开展了广泛研究,发现其在消毒过程中同样会生成一些消毒副产物,对人体健康可能会存在潜在危害。该文就饮用水应用二氧化氯消毒的研究进展进行了综述,同时,提出了应用中需要关注的问题。     

饮用水中二氧化氯及其消毒副产物分析方法研究进展

随着二氧化氯在饮用水消毒中应用的日益广泛,关于二氧化氯及其消毒副产物分析方法的研究也逐步深入。本文就饮用水中二氧化氯及其主要消毒副产物(亚氯酸盐和氯酸盐)的分析方法作一概述。     

二氧化氯消毒在生活饮用水消毒中的应用

人类生活离不开水,饮用水是人类生存必不可少的条件.如今的饮用水大多都是从自然淡水中提炼而来的,需要经过一定的净化之后才能饮用.随着经济发展和社会进步,如今的饮用水消毒处理逐渐由传统的投放固态消毒剂向利用二氧化氯（CLO2）消毒转变.本文针对二氧化氯的化学特点,对其消毒特点和消毒效果进行了探讨,也分析了利用二氧化氯消毒需要注意的问题.     

肇庆市农村饮用水次氯酸钠、二氧化氯和漂白粉消毒效果及影响因素分析

目的 了解肇庆市农村饮用水次氯酸钠、二氧化氯和漂白粉3种消毒方式的消毒效果,并探讨其影响因素。方法 2016—2020年在全市农村地区抽取218家采取消毒的供水单位,采集出厂水和末梢水,检测消毒剂、微生物指标和浑浊度。结果 共监测经消毒处理的水样2 028份,次氯酸钠、二氧化氯、漂白粉消毒的饮用水菌落总数合格率分别为97.66%、 86.57%和86.94%,总大肠菌群合格率分别为94.16%、 86.14%和60.82%,微生物指标合格率分别为93.82%、83.19%和57.89%。不同消毒方式的水样菌落总数、总大肠菌群及微生物指标合格率差异均有统计学意义（P值均<0.05）。结论 肇庆市农村饮用水次氯酸钠消毒的水样微生物指标合格率最高,其次为二氧化氯消毒的水样。次氯酸钠消毒效果受消毒剂余量和卫生许可情况影响,二氧化氯消毒受消毒剂余量、浑浊度、消毒剂设备使用情况影响,漂白粉消毒受消毒剂余量、浑浊度、水样类型影响。配套完善净化消毒设施,规范农村供水净化消毒规程,做好管网维护,加强卫生监督,有助于提升农村供水水质。     

二氧化氯消毒饮用水最佳投入量的探讨

目的:了解二氧化氯消毒生活饮用水的最佳投放量及其相关影响,以及二氧化氯消毒副产物亚氯酸盐的残留情况.方法:选择不同水体水样作为研究对象,分别测定消毒前浑浊度、pH、耗氧量、细菌总数和大肠菌群.按9种不同用量投入二氧化氯后分别测定细菌总数、大肠菌群及二氧化氯和亚氯酸盐残留量.结果:对不同水体其耗氧量不同,所消耗的二氧化氯不同.当耗氧量＜1.0mg/L时,二氧化氯投入量为0.25mg/L可达到国家生活饮用水卫生标准,ClO2残留量＜0.2mg/L;当耗氧量＞1.0mg/L时,二氧化氯投入量＞0.5mg/L,ClO2-残留量＞0.3mg/L.结论:对污染较严重的水源,不宜使用二氧化氯作为消毒剂,其残留的ClO2-含量大大超过WHO所规定的0.2mg/L的标准.我国制定二氧化氯消毒饮用水的卫生标准时要特别注意二氧化氯投放量及亚氯酸盐残留量的限量标准问题.     

二氧化氯和漂白粉消毒对农村集中式供水微生物学安全性影响比较

目的比较二氧化氯和漂白粉消毒对农村饮用水微生物学安全性的影响。方法于2009—2012年对四川省农村集中式供水工程抽样并进行水质监测,对水样的微生物学及相关消毒剂余量指标合格率进行比较。结果 2009—2012年分别监测了2 094、2 083、2 993、2 979个工程。各年份监测的仅消毒和完全处理供水工程中,各种消毒剂处理的饮用水均为菌落总数合格率最高,大肠埃希菌或耐热大肠菌群其次,总大肠菌群最低。仅消毒和完全处理供水工程中,各年份各种消毒剂处理饮用水的微生物学指标合格率在总体上差异均有统计学意义(P0.05)。两两比较结果显示,仅消毒供水工程中,与漂白粉相比,二氧化氯消毒饮用水的微生物学和消毒剂余量指标合格率较高(P0.001);完全处理供水工程中,与漂白粉相比,二氧化氯消毒饮用水的2009—2011年大肠埃希菌或耐热大肠菌群、2010—2012年总大肠菌群合格率较高(P0.008),2009年总大肠菌群和2010年菌落总数合格率较低(P0.001),且消毒剂余量指标合格率均较高(P0.05)。结论二氧化氯消毒饮用水的微生物学质量较好,今后应加强对用漂白粉消毒的农村集中式供水工程的监测和管理。     

二氧化氯应用于农村水厂水质消毒的研究

为探讨化学法二氧化氯发生器对农村水厂饮用水消毒的应用前景，作者对ＣｌＯ２消毒水质效果进行了调查。结果表明：该方法ＣｌＯ２发生量稳定，消毒效果好，产生氯化副产物少，制水成本适中，适宜于农村水厂的水质消毒。     

四川省农村饮用水复合二氧化氯消毒效果分析

目的 了解四川省农村地区饮用水复合二氧化氯消毒实施效果,为饮用水卫生监测工作提供科学依据。 方法 根据《生活饮用水卫生标准》(GB 5749-2006)对四川省2014-2016年农村地区采用复合二氧化氯消毒的822份监测水样微生物、消毒及消毒副产物指标进行评价和分析。 结果 监测水样总大肠菌群和菌落总数合格率分别为87.7%和82.4%。总大肠菌群合格率在供水规模(χ²=23.872,P<0.001)和水源类型(χ²=7.679,P=0.022)上差异有统计学意义,大型工程合格率高于小型,深井合格率高于水库、江河溪水;菌落总数合格率在水源类型(χ²=22.572,P<0.001)上差异有统计学意义,江河溪水合格率高于深井、水库;二氧化氯合格率为85.8%,在供水规模(χ²=9.603,P=0.002)间比较差异有统计学意义,大型工程合格率高于小型;消毒副产物亚氯酸盐和氯酸盐合格率分别为99.0%和99.3%。 结论 四川省农村地区采用复合二氧化氯消毒饮用水消毒效果较好,但未能达到较理想的状态,需进一步查找具体原因,提高农村饮用水水样的微生物指标合格率。     

二氧化氢消毒饮用水最佳投入量的探讨

目的 :了解二氧化氯消毒生活饮用水的最佳投放量及其相关影响 ,以及二氧化氯消毒副产物亚氯酸盐的残留情况。方法 :选择不同水体水样作为研究对象 ,分别测定消毒前浑浊度、 p H、耗氧量、细菌总数和大肠菌群。按 9种不同用量投入二氧化氯后分别测定细菌总数、大肠菌群及二氧化氯和亚氯酸盐残留量。结果 :对不同水体其耗氧量不同 ,所消耗的二氧化氯不同。当耗氧量 <1.0 m g/ L 时 ,二氧化氯投入量为 0 .2 5 m g/ L 可达到国家生活饮用水卫生标准 ,Cl O2 - 残留量 <0 .2 mg/ L ;当耗氧量 >1.0 mg/ L时 ,二氧化氯投入量 >0 .5 m g/ L ,Cl O2 - 残留量 >0 .3m g/ L。结论 :对污染较严重的水源 ,不宜使用二氧化氯作为消毒剂 ,其残留的 Cl O2 - 含量大大超过 WHO所规定的 0 .2 mg/ L 的标准。我国制定二氧化氯消毒饮用水的卫生标准时要特别注意二氧化氯投放量及亚氯酸盐残留量的限量标准问题     

浙江省农村饮用水消毒效果及影响因素研究

目的分析浙江省农村饮用水消毒效果及影响因素,为控制农村饮用水微生物污染及预防介水传染病的发生提供依据。方法采用分层随机抽样方法抽取浙江省879家农村饮用水供水厂,采集2017年农村饮用水水样5 299份,按照GB 5749—2006 《生活饮用水卫生标准》评价饮用水的消毒效果,采用Logistic回归模型分析农村饮用水消毒效果的影响因素。结果浙江省农村水厂处理工艺以常规处理为主,540家占61.43%;水源以地表水为主,771家占87.71%。经过消毒处理的水样4 458份,占84.13%。消毒剂余量总合格率为86.05%;其中二氧化氯消毒水样占22.32%,消毒剂余量合格率为100.00%。Logistic回归分析结果显示,水厂规模、消毒剂余量是否合格、消毒设备使用频率、是否消毒、水源水浑浊度和水期是消毒效果的影响因素(P0.05)。是否消毒、消毒剂余量是否合格、消毒设备使用频率和水源水浑浊度是出厂水消毒效果的影响因素(P0.05);是否消毒、消毒剂余量是否合格、消毒设备使用频率、水源水浑浊度和水厂规模是末梢水消毒效果的影响因素(P0.05)。消毒剂余量是否合格、消毒设备使用频率、水源水浑浊度和水厂规模是地表水消毒效果的影响因素(P0.05);消毒剂余量是否合格、消毒设备使用频率、水源水浑浊度和pH值是地下水消毒效果的影响因素(P0.05)。结论浙江省农村饮用水消毒效果受原水水质、水厂规模和水处理工艺等多种因素的影响。水厂在制水和输配水过程中应完善消毒工艺,加强水厂管理,规范消毒以进一步控制微生物的超标风险。     

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.