Effects of electromagnetic fields on the immune systems of occupationally exposed humans and mice

The authors examined immunological disorders in 6 individuals who had been exposed occupationally to environmental electromagnetic fields. Comparable effects on mice exposed in a similar environment were also investigated. The human subjects had worked 8 hr/day for 5 yr in a laboratory located above electrical transformers and high-tension cables, and in which there were low-frequency electromagnetic fields of 0.2-6.6 microtesla (microT). The 6 control subjects (matched for socioeconomic parameters, sex, and age) had worked away from the immediate vicinity of transformers and high-tension cables. The authors found statistically significantly lower total lymphocyte, CD4, and CD3 counts, and significantly increased natural killer (NK) cells, in exposed subjects vs. controls. Six months after exposure had ceased, total lymphocyte counts had increased, as had CD4, CD3, and CD19 counts (+13%, +28%, +22%, and +17%, respectively), and NK cell counts were decreased by 26% (not significant) in the same human subjects. In the second part of this study, 12 Swiss male mice housed in cages were exposed in the same room in which the human subjects had been exposed (i.e., 5-microT, 50-Hz magnetic field) for 109 days; 12 additional mice were used as unexposed controls. The total lymphocyte, leukocyte, polymorphonuclear neutrophil, CD4, and NK counts of the exposed mice at 109 days were significantly lower than those of controls. In addition, plasma glucose levels (at 30 days) and amylase activity (at 109 days) were significantly lower, whereas plasma sodium and chloride levels were significantly elevated at 109 days. Results from this study suggest that chronic exposure to a 0.2-6.6-microT magnetic field can lead to decreased immunological parameters (total lymphocytes and CD4 counts) in both humans and mice. The increase in some values once exposure was terminated suggests a causal relationship with exposure to electromagnetic fields, as do the changes in mice, particularly the changes in total lymphocyte and CD4 counts.     

模式生物酵母对电磁场的生物学反应

随着家用电器的普及和电力工业及通讯事业的迅速发展，人类生活环境中的电磁场强度成倍增加，业已成为一种新的环境污染因素。虽然流行病学调查显示，电磁辐射可能与神经系统、免疫系统和血液系统等病变有关，但在动物、组织、细胞和分子等水平的研究结果很不一致，目前还无法对电磁辐射与健康的关系作出定论。我们认为，为深入了解电磁辐射对健康的影响，首先必须阐明电磁场诱发的生物学效应及其作用机制。     

工频电磁场对人体免疫功能的作用

目的　探讨工频电磁场对人体免疫功能的影响。方法　检测２５ 例长期工作在３ ×１０５ Ｖ超高压环境中的工作人员与５ 例正常对照者的外周血Ｔ 淋巴细胞分泌白细胞介素２（ＩＬ２） 活性,白细胞介素２ 受体（ＩＬ２Ｒ） 表达;单核／ 巨噬细胞抗体依赖的细胞介导的细胞毒（ＡＤＣＣ） 效应,白细胞介素１５（ＩＬ１５） 活性;血清中ＩｇＧ、ＩｇＡ、ＩｇＭ 的水平。结果　（１） 观察组ＩＬ２ 活性为（３６２ ±７８） Ｕ／ｍｌ,明显高于对照组［（２５４ ±６７）Ｕ／ｍｌ］ ,差异有显著性（ Ｐ ＜ ０ ．０５） 。（２） 观察组ＩＬ２Ｒ 表达比率为２８ ．４ ％ ±３ ．２ ％ ,对照组为２２ ．８ ％ ±１０ ．７ ％ ,差异无显著性（ Ｐ ＞ ０ ．０５） 。（３） 观察组单核／ 巨噬细胞ＡＤＣＣ 效应及ＩＬ１５ 分泌水平均有增强或增高的趋势,但差异无显著性（ Ｐ ＞ ０ ．０５） 。（４） 观察组血清中ＩｇＧ 水平为（１０ ．３７ ±１ ．２８）ｇ／Ｌ,明显高于对照组［（８ ．８９ ±１ ．８８）ｇ／Ｌ］ ,差异有显著性（ Ｐ ＜ ０ ．０５） ,而血清中ＩｇＡ、Ｉｇ Ｍ 水平与对照组比较,差异无显著性（ Ｐ ＞ ０ ．０５） 。结论　长期工作在工频电磁场环境中人员的Ｔ     

系统地研究电磁场生物学效应合理地管理电磁环境

<中华劳动卫生职业病杂志>对我国电磁场生物学效应研究、电磁场健康危险度评价和电磁环境管理领域十分重视,第五次刊发了生物电磁学重点号.本期重点号不仅介绍了本研究领域骨干单位浙江大学、第三军医大学、第四军医大学、军事医学科学院、华东师范大学和苏州大学等的工作,而且,国家电网公司及其电力科学研究院也撰文分析了国际上工频电磁场的暴露限值和高压输变电设施的电磁场暴露现状,并以"建绿色电网创和谐家园"为题论述了电力部门在工频电磁环境保护方面所做的努力,充分说明电磁场的公共卫生问题已引起全社会的重视.同时,为增进对电磁场超敏问题的了解,特邀请国际上该领域的研究权威奥地利的NorbertLeitgeb教授撰写了专门的文章.     

Occupational exposure to high frequency electromagnetic fields and its effect on human immune parameters

The present study recorded a considerable excess of recommended exposure limits in the vicinity of shortwave diathermy devices used for medical treatment of patients. Different kinds of field probes were used to measure electric and magnetic field strength and the whole body exposure of medical personnel operating shortwave, decimeter wave and microwave units was calculated. To investigate the influence of chronic exposure on the immune system of operators, blood was sampled from physiotherapists working at the above mentioned devices. Eighteen exposed and thirteen control persons, matched by sex and age, were examined. Total leucocyte and lymphocyte counts were performed and leucocytic subpopulations determined by flow cytometry and monoclonal antibodies against surface antigens. In addition, to quantify subpopulations of immunocompetent cells, the activity of lymphocytes was measured. Lymphocytes were stimulated by mitogen phytohemagglutinin and their proliferation measured by a flow cytometric method. No statistically significant differences between the control and exposed persons were found. In both study groups all immune parameters were within normal ranges.     

Assessment of potential effects of the electromagnetic fields of mobile phones on hearing

Background

One of the goals of this study was to learn the coverage, safety and logistics of a mass vaccination campaign against typhoid fever in children and adults using locally produced typhoid Vi polysaccharide (PS) and group A meningococcal PS vaccines in southern China.

Methods

The vaccination campaign targeted 118,588 persons in Hechi, Guangxi Province, aged between 5 to 60 years, in 2003. The study area was divided into 107 geographic clusters, which were randomly allocated to receive one of the single-dose parenteral vaccines. All aspects regarding vaccination logistics, feasibility and safety were documented and systematically recorded. Results of the logistics, feasibility and safety are reported.

Results

The campaign lasted 5 weeks and the overall vaccination coverage was 78%. On average, the 30 vaccine teams gave immunizations on 23 days. Vaccine rates were higher in those aged ≤ 15 years (90%) than in adolescents and young adults (70%). Planned mop-up activities increased the coverage by 17%. The overall vaccine wastage was 11%. The cold chain was maintained and documented. 66 individuals reported of adverse events out of all vaccinees, where fever (21%), malaise (19%) and local redness (19%) were the major symptoms; no life-threatening event occurred. Three needle-sharp events were reported.

Conclusion

The mass immunization proved feasible and safe, and vaccine coverage was high. Emphasis should be placed on: injection safety measures, community involvement and incorporation of mop-up strategies into any vaccination campaign. School-based and all-age Vi mass immunizations programs are potentially important public health strategies for prevention of typhoid fever in high-risk populations in southern China.     

Assessment of potential effects of the electromagnetic fields of mobile phones on hearing

Background  

Mobile phones have become indispensable as communication tools; however, to date there is only a limited knowledge about interaction between electromagnetic fields (EMF) emitted by mobile phones and auditory function. The aim of the study was to assess potential changes in hearing function as a consequence of exposure to low-intensity EMF's produced by mobile phones at frequencies of 900 and 1800 MHz.     

社会心理因素与交通环境对行人分心的联合影响

目的  基于联合行为模型检验社会心理因素和交通环境对使用手机、与同行人员交谈、吃喝东西/吸烟3类行人分心的联合影响。方法  采用多阶段随机抽样法抽取长沙市20个十字交叉路口作为研究现场,综合使用视频拍摄和现场问卷调查收集行人分心、社会心理因素和交通环境等数据。参照联合行为模型,从行人对不同分心的态度、主观规范、个人能动性和分心习惯等社会心理因素角度设计调查问卷。采用结构方程模型检验社会心理因素和交通环境对行人分心的联合影响。结果  研究者共邀请到1 974名行人参与问卷调查,其中有效问卷1 741份(手机使用问卷600份、与同行人员交谈问卷660份、吃喝东西/吸烟问卷481份)。个人态度、主观规范、个人能动性、意图、分心习惯和交通环境因素共同解释行人手机使用、与同行人员交谈和吃喝/吸烟分心变异的22%、18%和23%。个人能动性、主观规范、个人态度是手机使用分心的主要解释因子,其间接效应分别为0.126、0.110和0.102(均有P＜0.05);分心习惯是与同行人员交谈、吃喝东西/吸烟分心的主要解释因子,其总效应分别为0.158和0.250(均有P＜0.05)。交通环境对3类行人分心的影响均无统计学意义。结论  社会心理因素和交通环境共同影响手机使用、与同行人员交谈和吃喝东西/吸烟3类行人分心的发生,不同分心的主要解释因子存在差异。未来应针对不同行人分心的主要解释因子,综合采用教育、立法和工程干预以减少行人分心。     

仿生脉冲电磁场骨质疏松治疗系统的研制

介绍了仿生脉冲电磁场(BEMFs)治疗骨质疏松的原理,根据骨骼压电特性而模拟人体运动状态下骨骼产生的生物物理刺激信号,以人体最易发生骨质疏松的脊柱和股骨及周围骨骼肌作为治疗靶器官,通过床垫式人体形治疗器产生的BEMFS进行治疗。从硬件和软件2方面介绍了Union-2000型骨质疏松治疗系统的研制,主要技术特点,通过临床试验结果验证其疗效,并对结果进行了探讨。     

电磁辐射对神经、内分泌和免疫系统的影响

近年来研究电磁波效应文章非常多，现仅将神经系统、内分泌系统和免疫系统受电磁辐射的影响作一介绍。     

Biological effects of nonionizing radiation: low frequency electromagnetic fields

This article reviews various studies on effects of electric and magnetic fields of extremely low frequencies on human health and gives an overview of residential and occupational exposure to different sources, currently established exposure limitations, and protection measures. Throughout the evolution biological systems adapted to natural electric and magnetic fields. Only hundred years ago human exposure to radiation was limited to electric and magnetic fields arising either from extraterrestrial or terrestrial sources, yet both natural. For the past fifty years there has been large growth of artificial sources of electric and magnetic fields, especially with frequencies of 50 and 60 Hz (power generating and distribution systems). The concern about long-term exposure to artificial fields and possible adverse effects on human health has been entirely justified and led to numerous intensive epidemiological and laboratory studies. Results of several epidemiological studies confirm the connection between exposure to electric and magnetic fields of extremely low frequencies (up to 300 Hz) and increased risk of leukemia and brain tumor in children and adults. In addition, the risk of breast cancer in occupationally exposed population has increased. Laboratory studies on animal models, in vitro systems, and human volunteers did not confirm this connection. There is a growing interest in investigation of other possible adverse health effects such as neurodegenerative diseases (Alzheimer's disease and other forms of dementia, amyotrophic lateral sclerosis), cardiovascular disorders (arrhythmias and acute myocardial infarction), psychiatric disorders, and electrosensitivity.     

The effects of physical exercise on the immune system

Physical exercise has numerous effects on the human body, including the immune system. After strenuous exercise, athletes pass through a period of impaired immune resistance. During this period, athletes are theoretically more susceptible to upper respiratory tract infections, although a causal relation has never been demonstrated. Moderate exercise seems to have a beneficial effect on the immune function, which could protect against upper respiratory tract infections. Exercise has effects on both the humoral and the cellular immune system. Doping products, except glucocorticoids, only have modest effects on the immune system, although erythropoietin may, in rare cases, cause severe side-effects. Glutamine and vitamin C could, hypothetically, prevent the negative effects of strenuous exercise on the immune function, but further studies are needed to demonstrate and explain these effects.     

Exposure-dependent effects of ethanol on the innate immune system.

Extensive evidence indicates that ethanol (alcohol) has immunomodulatory properties. Many of its effects on innate immune response are dose dependent, with acute or moderate use associated with attenuated inflammatory responses, and heavy ethanol consumption linked with augmentation of inflammation. Ethanol may modify innate immunity via functional alterations of the cells of the innate immune system. Mounting evidence indicates that ethanol can diversely affect antigen recognition and intracellular signaling events, which include activation of mitogen activated protein kinases, and NFkappaB, mediated by Toll-like receptors, leading to altered inflammatory responses. The mechanism(s) underlying these changes may involve dose-dependent effects of ethanol on the fluidity of cell membrane, resulting in interference with the timely assembly or disassembly of lipid rafts. Ethanol could also modify cell activation by specific interactions with cell membrane molecules.