A new wire patch cell for the exposure of cell cultures to electromagnetic fields at 2.45 GHz: Design and numerical characterization

Studies on the interaction between electromagnetic (EM) fields and biological systems have recently gathered further momentum due to the huge diffusion of wireless networks. In order to investigate possible effects on cultured cells of EM fields, in the frequency range typical of such a kind of communication, an in vitro exposure system has been designed and numerically characterized. The system is a Wire Patch Cell (WPC) operating at 2.45 GHz which enables the contemporary exposure of four 35 mm Petri dishes and can be inserted into a commercial incubator. Numerical dosimetry has been carried out by means of the CST Microwave Studio® simulator. Results indicate a good efficiency, in terms of Specific Absorption Rate (SAR) in the biological sample per 1 W of input power. Moreover, the homogeneity of the SAR distribution inside each Petri dish is around 70%, considered an acceptable value for such a kind of biological experimentsStudies on the interaction between electromagnetic (EM) fields and biological systems have recently gathered further momentum due to the huge diffusion of wireless networks. In order to investigate possible effects on cultured cells of EM fields, in the frequency range typical of such a kind of communication, an in vitro exposure system has been designed and numerically characterized. The system is a Wire Patch Cell (WPC) operating at 2.45 GHz which enables the contemporary exposure of four 35 mm Petri dishes and can be inserted into a commercial incubator. Numerical dosimetry has been carried out by means of the CST Microwave Studio ® simulator. Results indicate a good efficiency, in terms of Specific Absorption Rate (SAR) in the biological sample per 1 W of input power. Moreover, the homogeneity of the SAR distribution inside each Petri dish is around 70%, considered an acceptable value for such a kind of biological experiments

Guidelines for limiting exposure to electromagnetic fields (100 kHz to 300 GHz)

Radiofrequency electromagnetic fields (EMFs) are used to enable a number of modern devices, including mobile telecommunications infrastructure and phones, Wi-Fi, and Bluetooth. As radiofrequency EMFs at sufficiently high power levels can adversely affect health, ICNIRP published Guidelines in 1998 for human exposure to time-varying EMFs up to 300 GHz, which included the radiofrequency EMF spectrum. Since that time, there has been a considerable body of science further addressing the relation between radiofrequency EMFs and adverse health outcomes, as well as significant developments in the technologies that use radiofrequency EMFs. Accordingly, ICNIRP has updated the radiofrequency EMF part of the 1998 Guidelines. This document presents these revised Guidelines, which provide protection for humans from exposure to EMFs from 100 kHz to 300 GHz

Gaps in knowledge relevant to the “guidelines for limiting exposure to time-varying electric and magnetic fields (1 Hz-100 kHz)"

Sources of low-frequency fields are widely found in modern society. All wires or devices carrying or using electricity generate extremely low frequency (ELF) electric fields (EFs) and magnetic fields (MFs), but they decline rapidly with distance to the source. High magnetic flux densities are usually found in the vicinity of power lines and close to equipment using strong electrical currents, but can also be found in buildings with unbalanced return currents, or indoor transformer stations. For decades, epidemiological as well as experimental studies have addressed possible health effects of exposure to ELF-MFs. The main goal of ICNIRP is to protect people and the environment from detrimental exposure to all forms of non-ionizing radiation (NIR). To this end, ICNIRP provides advice and guidance by developing and disseminating exposure guidelines based on the available scientific research. Research in the low-frequency range began more than 40 years ago, and there is now a large body of literature available on which ICNIRP set its protection guidelines. A review of the literature has been carried out to identify possible relevant knowledge gaps, and the aim of this statement is to describe data gaps in research that would, if addressed, assist ICNIRP in further developing guidelines and setting revised recommendations on limiting exposure to electric and magnetic fields. It is articulated in two parts: the main document, which reviews the science related to LF data gaps, and the annex, which explains the methodology used to identify the data gaps

Light-emitting diodes (LEDS): Implications for safety

Since the original ICNIRP Statement was published in 2000, there have been significant improvements in the efficiency and radiance (i.e., optical radiation emission) of LEDs. The most important improvement is the development of 'white' LEDs that can be used as general lighting sources, which are more efficient than traditional lighting sources. LEDs emitting in the ultraviolet wavelength region have also become available and have made their way into consumer products. All these changes have led to a rise in concern for the safety of the optical radiation emissions from LEDs. Several in vitro and animal studies have been conducted, which indicate that blue and white LEDs can potentially cause retinal cell damage under high irradiance and lengthy exposure conditions. However, these studies cannot be directly extrapolated to normal exposure conditions for humans, and equivalent effects can also be caused by the optical radiation from other light sources under extreme exposure conditions. Acute damage to the human retina from typical exposure to blue or white LEDs has not been demonstrated. Concern for potential long-term effects, e.g. age-related macular degeneration (AMD), remains based on epidemiological studies indicating a link between high levels of exposure to sunlight and AMD. When evaluating the optical radiation safety of LEDs, it has now been established that published safety standards for lamps, not lasers, should be applied. Thus far, the only clear, acute adverse health effects from LEDs are those due to temporal light modulation (including flicker). Glare can also create visual disturbances when LED light fixtures are not properly designed. Further research is needed on potential health effects from short- and long-term exposure to new and emerging lighting technologies

Principles for non-ionizing radiation protection

In this statement, the International Commission on Non-Ionizing Radiation Protection (ICNIRP) presents its principles for protection against adverse health effects from exposure to non-ionizing radiation. These are based upon the principles for protection against ionizing radiation of the International Commission for Radiological Protection (ICRP) in order to come to a comprehensive and consistent system of protection throughout the entire electromagnetic spectrum. The statement further contains information about ICNIRP and the processes it uses in setting exposure guidelines

Ionic Channel Gating under Electromagnetic Exposure: A Stochastic Model

Researchers interested in the biological effects of electromagnetic (EM) fields are focusing their attention on the behavior of transmembrane ionicchannels and on their kinetic properties. Theoretical studies of the biochemical dynamic properties of the channels have suggested the development of a modelistic approach considering the membrane channel as a non-deterministic state machine. Its behavior is fully described by a set of states, a matrix of transition rates, and a vector for the probability of the machine to be in each single state at a certain instant. In this work astochasticmodel is developed, generating random processes where the probability for each state is an aleatory variable. The model can be applied to both voltage- and ligand-dependent channels, both unexposed and exposed to EM fields. The response of the model, for voltage-dependent channels such as K+, Na+ and Ca2+ in a voltage-clamp situation, is analyzed for sinusoidal EM fields in the ELF range. The results obtained appear more satisfactory than those presented in earlier papers using similar approaches, as this model shows the sensitivity of the channel response to both the frequency and amplitude of the EM stimulation

Analysis of the interaction between microwave fields and snail neurons by an ionic model of the membrane electrical activity

On the basis of a new ionic model of the electrophysiological behaviour of the snail neuronal membrane, the interaction mechanisms proposed in literature to justify the microwave effects on neurons have been examined. The analysis has been carried out by supposing that the electromagnetic field acts upon specific sites of the cell. The alterations of the membrane activity, obtained theoretically by changing the model parameters according to the proposed mechanisms, have been compared with the available experimental results. The analysis shows that, among the considered mechanisms, those supposing an action on the transmembrane-channel proteins or an alternation of the intracellular calcium are better supported by the theoretical-experimental agreemen

LOW-DC POWER 2-18 GHZ MONOLITHIC MATRIX AMPLIFIER

The authors present a (2 x 5) matrix amplifier with a DC power consumption as low as 200 mW with 13 dBm of RF output power (@1 dB compression point) achieving 7 dB small-signal gain (residual ripple 0.3 dB) and input and output return losses always better than -14 dB. Designed using the LN05 monolithic process of Thomson Composants Microondes (TCM), the amplifier employs ten MESFETs of 160 mum) gate width and submicron (0.5 mum) gate length, for a total chip area of 2.5 x 3.5 mm2. Broadband performance and very low power consumption make this amplifier very well suited for end-volume realisation of monolithic multiple-stage front-ends in integrated high bit-rate optical receivers