发电与高压输变电工程的工频电磁场现状及防护

通过对典型发电与高压输变电工程工频电磁场的现场检测,阐明了发电与高压输变电工程的工频电磁场现状.在此基础上,根据科学界关于极低频电磁场对人体短期和长期效应研究的明确结论,介绍了发电与高压输变电工程的工频电磁场暴露对人体健康的影响.同时,从卫生安全的角度提出了防止和减少工频电磁场影响的综合防护措施,其中包括:慎重选址,合理设计,适当个体防护和必要的警示标识.另外,扼要地介绍了工频电磁场的有关卫生标准和测量方法.     

Effects of in vitro exposure to GSM900 electromagnetic field on human erythrocytes

High frequency electromagnetic fields (EMF) are widely used for transmitting of radio and TV signals, in wireless communications, etc. A huge number of people are exposed so the possible risk to human health from telecommunication technologies could be significant even if biological effects are slight. The study of the biological effects of RF EM radiation could contribute to better understanding of the possible health hazards. The levels of released hemoglobin serve as an indicator of hemolysis, caused by increased membrane fragility. This study was designed to investigate the alterations in hemoglobin release after in vitro exposure of human erythrocytes to GSM900 electromagnetic field. Erythrocyte suspensions with two different cell concentrations (hematocrit 20% and 40%) were exposed to EM radiation from GSM mobile phone (carrier frequency 902 MHz, 2 W output power in pulse) for 20 min in two different positions in relation to telephone antenna: Position 1 is in the centre of the major lobe of the azimuth antenna pattern and Position 2 is between major and back lobes. Alterations in hemolysis were registered 0, 10, 20, 30, 40, 50 and 60 min after the treatment. Hemolysis was determined by measuring the absorbance of hemoglobin at 413 nm in the supernatant obtained by centrifuging the suspensions. Hemolysis was expressed as hemoglobin concentration. Our data indicated decrease in the hemoglobin level in irradiated suspensions. The GSM900 EMF exposure probably stabilized erythrocyte membrane and caused reduction in the hemolysis depending on the EMF parameters, on the suspension water content (hematocrit) and on the time elapsed after irradiation.     

Study of high-frequency electromagnetic field effect on some somatic and neuro-behavioral characteristics in healthy and neurodefective mice

The effect of long-term exposure to high frequency electromagnetic field (HF EMF) on some somatic and neural characteristics was studied in neurodefective Lurcher mutant (+/Lc) and normal wild type mice (+/+). Both newborn and young adult (3 months) animals derived from two strains (C3H, B6CBA) were exposed to HF EMF (870 MHz) from 1st to 21st day or from 91st to 120th day respectively. In animals of both groups and controls we observed the development of body weight. Moreover, in the HF EMF exposed adult B6CBA animals we studied spatial learning ability, motor functions and the CNS excitability. To investigate specific energy absorption rate (SAR) in experimental animals we have done the basic 3D calculations of the electromagnetic energy distribution in the simplified model of the mouse. The HF EMF exposed animals exhibited mild differences of body weight between them and unexposed controls. The long-term exposure to HF EMF did not significantly influence the ability to learn in the Morris water maze. However, significant lower swimming speed was found in the irradiated +/Lc as well as lower motor activity of +/+ in the open field when compared to controls. No significant differences were found between HF EMF irradiated animals and controls in examination of the CNS excitability and motor functions.     

超高压输电线路电磁场影响及防治

近年来国家超高压电网的建设发展迅速,使得降低工程运行期间电磁场对环境的影响成为当前重要的研究课题.以钦州、防城港电厂送出500 kV输电线路工程为例,简要分析了工程电磁场及无线电干扰对环境的影响,提出了切实可行的环保措施,以将其带来的负面影响减轻到最低程度.     

典型220 kV交流输电线路电磁场分布

通过理论计算和实际测量,揭示220 kV输电线路下的电磁场强度分布情况.从实际测量结果来看,输电线路下电磁场强度高于环境背景值,但均低于国家标准限值.     

电磁环境工程管理与航空武器装备研制

电磁环境工程管理在航空武器装备研制生产中具有重要地位,电磁环境工程管理是要将装备研制生产时需要开展的电磁环境工程工作规范化、系统化,在研制早期开始将一系列工程工作有机的纳入装备研制的全寿命期中。     

基于存储示波器的PS/2键盘电磁截获研究

计算机键盘有用信号电磁截获的传统方法是基于宽带接收机完成的,这种方法较复杂且需要较多的设备和空间。为使键盘截获技术向小型化和实用化过渡,提出了使用基于软件无线电的解码技术及基于存储示波器全频谱远场截获。首先,基于频谱对比的方法对有用信号的频段进行初判,然后对截获的全频域信号中包含有敏感信息的频段基于软件无线电的方法进行带通滤波和解调。最后,使用一种能够精确判别按键信息的解码方法,通过预先设计的程序来实现信息的截获。实验结果表明计算机键盘有用信号电磁截获实现实用化和小型化是有一定可行性的,并且能够得到比较精确的结果。     

无线电干扰系统电磁辐射安全限值的研究

在严格遵循国家有关部门电磁辐射防护规定中的相关标准情况下,进行无线电干扰系统的实验和操作中,发现当系统长时间使用时,按照电磁辐射相关安全标准设置安全间距仍会对人体健康产生不利影响。文章根据实验数据,对电磁辐射相关安全标准进行了深入研究和探讨,在对国家安全标准探讨的基础上提出考虑电磁辐射危害时不能仅仅将人体作为点来考虑,应充分认识到人体作为等效天线的特征以及吸收功率的问题。     

电磁炉电磁辐射水平调查

采用电磁辐射分析仪PMM8053B,按照《对人体暴露于家用及类似用途电器电磁场的测量方法》（EN62233：2008）监测标准,对市场上部分电磁炉的电磁辐射水平进行监测,结果显示：电磁炉的电场强度最高达106．04V/m,磁感应强度最高达69．03μT,超过EN62233的限值规定,并使电磁炉周围的环境电磁辐射水平明显升高。建议进一步开展电磁炉电磁辐射的系统研究,制定有关环保标准和管理体制,将电磁炉纳入电磁辐射法定监管范畴。     

浅谈通讯基站电磁辐射环境影响理论预测模式

介绍了通讯基站电磁辐射环境影响评价的重要胜,在介绍电磁辐射环境标准限值的基础上,针对现有环境影响理论预测与实际监测值存在误差的情况,分析了通讯基站电磁辐射的影响因素和误差存在的原因,并对采取的理论预测模型提出优化建议,使预测结果更接近于实际值,为通讯基站电磁辐射环境影响预测及评价提供更加科学、合理的依据。