Safety standards for human exposure to radio frequency radiation and their biological rationale

Exposure guidelines for RF radiation have been promulgated for nearly half a century. However, our understanding of biological effects of exposure to RF radiation is still evolving and more so for cellular mobile telephones and wireless personal communication devices. There are two different sets of guidelines promulgated for limiting human exposure to RF radiation, worldwide. Currently, there is a backdrop of persistent, publicly expressed lack of confidence in radio-frequency (RF) exposure standards, pertaining to the maximum permissible exposure (MPE) level of humans exposed to RF electromagnetic radiation. Much of the current effort is driven by the advent of cellular mobile telephony, which uses RF radiation in the range of 800-2,500 MHz. The setting of guidelines or standards for maximum permissible levels of exposure to RF and microwave radiation is a valid approach to managing the risk of such exposures. The existing guidelines, however, are based on results obtained from acute, short-term studies that are atypical of the RF exposures associated with the handset of cellular mobile telephones. For the first time in human history, a source of RF radiation is located right next to the head of millions of cellular mobile telephone users. Biological effects after repeated, prolonged, or lifelong exposure to RF energy emitted by these low-power wireless telecommunication devices have been investigated only during the past few years. The existing scientific results are equivocal and arguable in many respects. Consequently, there remains a widespread public concern about the adequacy of existing guidelines in safeguarding the general population against possible harm of RF radiation from cellular mobile telephones.     

Health effects: scientific research and mobile phone testing

A decade ago, a major research initiative, with orchestrated monetary and programmatic support from both industry and the government, was launched to investigate the biological effects and health implications of radio frequency (RF) radiation emitted from cellular mobile telephones. The subject remains a focus of public concern and shows no sign of relenting. There is a lack of scientific consensus on experimental studies that provide clear evidence either refuting or supporting the cancer induction or promotion potential of RF and microwave radiation from cell phones. The uncertainties persist, in part, because of the limited number and scope of studies that have been undertaken.     

Risks to children from cellular telephone radiation

Are children more vulnerable to the microwave radiation from cellular mobile telephones? It is an open question. The paucity of laboratory results should make anyone hesitate in making definitive remarks on the health and safety of mobile-phone radiation on children. On the other hand, there have been plenty of computational studies on deposition of mobile-phone radiation or the specific absorption rate (SAR) in head models of youngsters and adults.     

LED灯具光辐射安全相关标准介绍

介绍了关于LED光辐射安全的主要标准,包括国际非电离辐射防护委员会的光辐射导则、国际照明委员会、国际电工委员会、欧盟、北美的激光产品或灯和灯系统的光生物安全性标准,分析了这些标准的差异和联系。     

Human EEG and microwave radiation from cell phones

The effects of exposure to microwave radiation from cellular mobile telephones on human brain wave potentials or electroencephalograms have been studied. In particular, a large number of small, metallic electrodes typically are placed upon a subject's scalp, with electrically conducting paste or a glue-like substance to hold them in place. Low voltage signals (< 500 /spl mu/V) are amplified by the electronics in the EEG recording system. The resulting polygraphic display is then read by unaided visual inspection, followed by spectral analysis.     

Risk of human exposure to cellular mobile communication radiation

Most of our knowledge concerning the biological effects of radio frequency (RF) radiation from wireless communication devices has come out of investigations conducted using experimental animals, such as rats, mice, etc. When it comes to the impact of RF radiation on human health and safety, epidemiology can play a pivotal role because it is a study of the distribution of disease and its determinants in human populations. To examine if exposure to wireless communication radiation is involved in cancer induction and promotion, it is necessary to collect data from people with similar backgrounds, other than RF exposure     

Comparing test requirements for low-voltage circuit breakers

Low-voltage circuit protective devices include low-voltage power circuit breakers, insulated case circuit breakers, and molded case circuit breakers. Each of these circuit breaker types is used for particular applications, and is tested against standards that relate to those applications. In North America, low-voltage power circuit breakers are designed and tested in accordance with ANSI/UL standard 1066, which in turn refers to the series of applicable ANSI C37 standards. Insulated case circuit breakers and molded case circuit breakers are designed and tested in accordance with the UL standard 489. In this paper the standards are compared by means of tables. The standards for low-voltage power circuit breaker and the molded case circuit breaker have many common elements. As a consequence, either type of circuit breaker could be used for some applications. However, there are several significant performance differences that relate to the application of these circuit breakers. Specifically, the low-voltage power circuit breaker is normally applied upstream of the molded case circuit breakers     

The Standards Department and Its Relationships to the IEEE Standards Process

THE PROCESS of developing voluntary electrical standards is one of the outstanding activities of the IEEE Industry Applications Society. The resulting IEEE standards give long-lasting and widespread benefits to Society members, and this is perhaps most evident in the Society's ``Color Book' series. The Society standards activity also provides a significant service to other members of the IEEE. For instance, ten percent of all income from IEEE standards document sales in recent years has come from IAS standards [1]. This income production is ahead of the collective standards produced by any other IEEE society. (IEEE standards document sales in 1984 alone totalled $1.8 million.) As described in the IEEE Standards Manual [2], an IEEE standard represents a consensus of all interests concerned with the scope of the standard, provides a common ground for communication among those using the standard, and gives an authoritative reference to the state of technology. Each existing IEEE standard must be kept up to date by means of mandatory review at least every five years. The IEEE is accredited by the American National Standards Institute (ANSI), and IEEE standards are routinely submitted to ANSI for adoption as American National Standards.     

Influence of nonuniformity of ZnO varistors on their energyabsorption capability

A simple thermo-mechanical model is applied to evaluate the influence of the nonuniformity of ZnO varistor disks used in surge arresters on their energy handling capability. Puncture is the dominating failure mode for slightly nonuniform disks, but cracking becomes more likely as the degree of nonuniformities increases. It is shown that minimization of the chance of a failure of varistor disks at high-current pulses can be achieved by adjusting their resistivity in the upturn region of the I-V characteristic. Simulation of the behavior of varistor disks under high-current 4/10 μs pulses required by the ANSI standard tests shows that these tests provide very little information about the actual energy handling capability of the disks. This conclusion suggests that alternate test methods should be developed and included in the relevant standards     

Free-electron lasers: reliability, performance, and beam delivery

The Vanderbilt free-electron laser (FEL) is a continuously tunable source of pulsed, mid-infrared radiation. FEL applications research has been underway for a decade. Recent experimental advances in FEL ablation of soft tissue indicate the potential for FEL-based protocols in surgery and medicine. In anticipation of these medical applications, the Vanderbilt FEL is being upgraded to meet the reliability and performance standards for a medical laser. Facilities for laser surgery have been constructed and equipped and medical delivery systems are being developed for pre-clinical and clinical research     

A Method of Deriving Overall Accuracy for Single Phase Watthour Meters

The ANSI Standard equation for overall accuracy places a small amount of emphasis on light load accuracy for watthour meters. Results from a recent load research study indicated a significant amount of energy is accumulated at lighter loads where watthour meter accuracy is poorer. Perhaps the standard equation for overall accuracy is a consensus of opinions prior to utilities performing load research studies. Although small inaccuracies of watthour meters at lighter loads may seem insignificant, they become large when applied to an entire meter population. ANSI C12.1-1982 may be interpreted to mean that 20% of all energy registration occurs at light load. The results of a load research study show that watthour meters spend a great deal of time at light loads. A method was developed to establish at which loads watthour meters register energy consumption. Watthour meters spent 85% of the time and registered more than 40% of the total energy for a one year period at light loads.     

Safety standards for exposure to RF electromagnetic fields

Looking back at the past 40 years of development and forward to the new millennium, this article reviews the subject of safety standards for exposure to microwave/RF energy. The present standards are highly advanced with the use of modern dosimetry and a thorough computerized review of the literature. The bioeffects and hazards are predominantly thermal in nature and applicable standards, whether for exposure or product performance, incorporate large safety factors. These standards are the result of broad consensus among an appropriate balance of scientists, engineers, and stakeholders that results under the due process of the IEEE Standards system     

Design aspects of industrial distribution systems to limit arc flash hazard

Industrial distribution systems have been designed in the USA, considering prevalent standards, i.e., American National Standards Institute (ANSI), IEEE, National Electrical Code (NEC), Occupational Safety and Health Administration (OSHA), etc., and arc flash was not a consideration for designing electrical power systems in the industry. Functionality and economics were the important factors, and will always be so. However, the arc flash analysis and limiting the incident energy will usher a new parameter in system design. It can be demonstrated that in many current installations and new installations designed without considerations of limiting the arc flash energy, the hazard risk category exceeds the highest Class 4 personal protective equipment (PPE), i.e., an arc thermal performance exposure value (ATPV) of 40 cal/cm/sup 2/. This paper discusses typical industrial distribution systems at low-voltage and medium-voltage levels and demonstrates the impact of system design decisions and protection on the incident energy and arc flash hazard reduction.     

基于驻留时间自适应的电能表RS检测研究

针对电能表辐射抗扰度(Radiate Susceptibility,RS)试验结果不准确的问题,基于NET Framework平台,使用C#语言设计开发了电能表辐射抗扰度自动检测软件。通过RS 232串口、网口、GPIB等控制接口,将被测电能表、电能表辅助检测模块、辐射干扰模块设备等硬件设备级联,实现电能表辐射抗扰度试验,同时在有电流检测方式下实现驻留时间自动调整和匹配,无电流检测方式下通过数字图形处理的模式实现自动监测电能表故障现象,并记录视频作为回查确认备用。试验结果表明,开发的自动检测系统满足电能表相关标准和规范的要求,可大幅度提高工作效率和数据的准确程度。     

Cell phone microwaves and cognitive function in children

Are cell phones so harmful that a cautious approach of risk management especially in relation to children should be taken? Are the brains of children more susceptible to the radio frequency (RF) fields emitted by cell phones than those of adults? Some fear any disturbance to brain activity in children could lead to impaired learning ability or behavioral problems. Moreover, any lasting biochemical effects could have important consequences, especially in the young who still have years of development ahead of them. This paper report the results of test conducted to young users of cellular mobile telephones.     

Regulating radio-frequency fields in Italy

Throughout the world, there has been a move to "harmonize" exposure limits to radio-frequency (RF) energy from sources such as mobile phones, communications transmitters, radar, industrial equipment, and the like. "Harmonization," in practice, means the adoption of a consistent set of exposure limits in different nations around the world. Precautions taken in Italy are discussed, as are the Vatican radio transmitters, public controversy, health concerns, politics and the science involved.     

Health effects - effects of cell-phone radiation on lymphoma-prone mice

Discusses the incidence of lymphomas in mice following long-term exposure to pulse-modulated microwave fields similar to those used in digital cellular mobile telephones. The mice are predisposed to developing lymphomas spontaneously.     

Patents-the suit against future infringement

Can a patent owner sue a competitor who is about to bring out an infringing product? That was the question before the court in the recent case of Interdigital Technology Corp. v. OKI America Inc. and Qualcomm Inc. The case involved the burgeoning field of cellular telephones. Interdigital owned patents which it believed gave it control of all cellular telephones that would satisfy two of the industry-wide standards set by the Telecommunications Industry Association. The Interdigital case shows that a patent owner need not stand idly by while a competitor makes plans to enter the market. If the patent owner can show that the competitor has made meaningful preparations to enter the market and intends to go forward in spite of the patent owner's protest, a court will hear the issue immediately. This action can significantly shorten the time to an ultimate judgment and injunction against the competitor's activities. Moreover, in the meantime, the fact that a lawsuit is pending can substantially handicap a competitor in the market because many customers may not want to deal with a supplier that may be put out of business in the future     

Transformer Voltages, Part I: Analysis of Voltages Listed in ANSI C57, C84, and C92 Standards

The voltages listed in the American National Standards Institute (ANSI) C57 transformer standards are analyzed, tabular comparisons with those listed in the ANSI C84 and C92 preferred voltage standards are provided, and classifications for them as ``preferred,' ``non-preferred,' or ``non-standard' are recommended. Observations are included pertinent to the pattern of the tabulations which are intended to contribute to improved standardization and coordination of ANSI Committees C57, C84, and C92. Information on International Electrotechnical Committee (IEC) voltages is included in the Appendix for comparison. Finally, questions are raised in conclusion to stimulate constructive thought, and hopefully action, in the U.S. electrical industry to improve voltage standardization.