In Vitro Evaluation of Biological Effects on Human Keratinocytes Exposed to 900 MHz Electromagnetic Field

Summary The biological effects of electromagnetic radiation at ultra high frequency on human keratinocytes were investigated. HaCaT cell system, a spontaneously immortalized human keratinocytes cell line, was chosen as model since skin is usually exposed to electromagnetic radiation at considered frequency more than inner tissues. HaCaT cells were exposed to a pure sinusoidal field at a frequency of 900 MHz (average SAR levels ranging from 0.04 to 0.08 W/kg) in plane wave condition inside a GTEM chamber for time intervals of 18 hours at a controlled temperature of 37^∘C. Growth curves were obtained for exposed and control cells, and a reduction in the number of exposed cells in comparison to unexposed ones was found; however the number of dead cells was not significantly different in exposed and unexposed samples. In order to investigate whether the reduction in cell proliferation of exposed cells was due to the activation of a differentiative process, the expression of two hallmarks of differentiation was examined. Both keratin 1 and involucrin expression was increased in exposed in comparison to unexposed cells. These results suggest that this protocol of exposure to 900 MHz electromagnetic field can trigger a differentiation program in HaCaT cells.     

Graphical Presentation of 50/60 Hz Magnetic Field Contours as an Engineering Tool for Minimizing ELF Fields

Summary Since IARC classified ELF magnetic field as Possibly Carcinogenic to Human the fear from 50/60 Hz magnetic field exposure had been increased to the state of public “panic”. Subsequently, environment quality preservation organizations increased their pressure on their government to adopt the “precautionary principle” and to reduce the allowable ELF Magnetic Field exposure to much lower values than are recommended by ICNIRP-1998. As an example the present Environmental Ministry in Israel recommendation is to lower the ELF Field exposure to 10 mG averaged over 24 h. As a result of this stringent exposure guideline imposed by the government, electrical engineers who are involved in the deployment and installation of large and medium electrical utilities, such as overhead power lines, transformers, UPS systems, electrical public transportation, switching stations, etc., are much more aware to the need to employ special measures and methods for reducing the magnetic fields that might be emitted from such utilities. There are few computer codes that are capable of analyzing with great accuracy magnetic and electric fields surrounding single phase and three phase electrical utilities in a 3-D system. The best presentations of the analysis results are by equi-value contours depicting electric and magnetic fields. This graphical presentation is a powerful design tool that enables better deployment and installation design aided to reduce the magnetic field emissions from high-power electrical utilities. This paper describes the various types of graphical presentations available for ELF field contours, the dependent and independent variants and parameters, magnetic field animation for optimization of power line installation and routing, and finally an example that demonstrates the usefulness of the graphical presentation tools.     

Thermal Effects of Photon-Phonon Interaction on a Simple Tissue

Summary The thermal effect due to electromagnetic absorption by human tissues is investigated at different frequencies ranging from 10¹–10¹⁶ Hz. Special emphasis is being considered in the microwave band used in wireless communications of the mobile industry. The present work examines basically the thermal effect that arises as the duration of exposure to the electromagnetic radiation and its dosage is increased. Using a computer simulation, a semi-classical model is adopted, were the photon-phonon interaction is mediated by a homogenous sample of identical elements, which are naturally in harmonic modes of vibration. The phonon lifetime is also included in this work. These thermal effects decrease with frequency in conformity with experimental results. This model is then extrapolated to the individual cells of a human tissue and the possible rise in temperature is estimated.     

岩溶区桩端持力层的电磁层析探测

隐伏岩溶的存在对工程危害较大,常规钻探、物探手段对岩溶区桩端持力层勘探存在不足。本文应用电磁波层析成像技术进行桩端持力层探测分析。工程实例表明该方法行之有效,具有较高的探测精细程度,为桩端持力层的确定提供了直观而准确的依据。     

低频通信系统天线近场辐射危害研究

目的 为低频通信系统电磁辐射危害控制方法提供数据支撑。方法 基于IEEE-Std-C95.1—2005、GJB 5313A—2017以及GB 8702—2014，通过试验详细地获取不同功率和频率条件下低频通信系统天线近场综合场强值，并将工作区域划分为危险区、短时活动区和安全工作区。结果 以甚低频菱形天线为中心，40 m半径范围内为危险区，其峰值场强高于70 V/m，40~70 m半径范围内为短时活动区，70 m半径外为安全工作区。结论 甚低频天线近场电磁辐射危害试验验证和区域划分，为低频通信系统电磁辐射危害有效控制提供技术支撑。     

物理污染及其对人类的危害

本文从噪声、放射性和电磁辐射三个方面对物理性污染的来源及其危害作了详尽的阐述，指出了物理性污染的形成及其诱发疾病的常见症状，提醒人们在日常生活中注意对物理性污染的防范。     

我国1000kV特高压交流输电线路电磁环境的研究

采用CDEGS软件,对特高压交流输电线路周围的电磁环境进行了仿真研究。以正三角排列的架空线路为模型,分析了相导线对地高度、相间距离、分裂导线的根数、分裂间距、分裂导线子导线直径变化对工频电场、工频磁场、无线电干扰和可听噪声的影响,并分别比较了大雨、湿导线和晴天时特高压输电线路周围的无线电干扰和可听噪声。     

家庭电磁辐射污染及防护

本文讨论了家庭环境中电磁辐射污染的来源、对人体的危害的影响因素和在家庭环境中电磁辐射污染的防护措施.     

极低频电磁场及与铅联合作用对发光细菌Vibrio qinghaiensis发光的影响

观察了50Hz，0．1～9．6mT，10～30min的电磁场暴露及其与铅的联合作用对淡水发光细菌青海弧菌(Vibrio qinghaiensis)发光的影响．结果表明，电磁场暴露能增强发光细菌的发光，在6.4mT附近，增强作用最为强烈，在0．2～0．4mT附近，增强作用显得最为微弱，提示ELFEMFs对发光细菌的效应具有剂量“窗口”特性；Pb(0．2～1．6mgL^-1)能抑制发光细菌发光，并随着Pb剂量的增大，抑制效应愈明显，呈明显的线性负相关；电磁场与Pb合并作用，Pb并没有改变电磁场对发光细菌效应的包括剂量窗口在内的特性，但3．2～9.6mT的电磁场暴露提高了发光细菌对Pb剂量变化的敏感性．图3表3参9     

警惕室内外环境新杀手-电磁辐射污染

随着人民生活水平的提高以及社会的发展和科技进步,各类家用电器、办公自动化设备、移动通讯设备等迅速进入办公室、家庭,提高了人们的工作效率,丰富了人们的精神和物质生活.可是随之而来的是这些高科技的电器产品,在使用过程中会不同程度地产生电磁辐射,并成为继室内空气污染、放射性污染和噪音污染后的又一室内环境污染物质--"电磁辐射污染".本文将从电磁辐射污染的特性、危害、国家相关规定以及怎样防止和减少室内电磁辐射的污染等几方面进行论述.