Electromagnetic Field Exposure Assessment Research Articles

Assessment of Radio Frequency Electromagnetic Field Exposure from Wi-Fi Routers in LAUTECH Campus, Ogbomoso, Nigeria

Wi-Fi routers play a crucial role in enabling internet connectivity within the academic environment. However, there are concerns that radiofrequency electromagnetic field exposure from Wi-Fi routers may be hazardous to human health. The main objective of the research is to assess the safety of RF-EMF exposure in educational environments. A total of 14 Wi-Fi routers were randomly selected and investigated across LAUTECH campus using stratified random sampling method. Measurement of the power density and the electric field strength from these routers were taken using a hand-held electrosmog, TES-593, radiofrequency meter. Measurement points were selected at various distances of 1.0, 2.0, 3.0, 4.0 and 5.0 m from the Wi-Fi routers, representing typical distances between users and routers. At each measurement point, the TES-593 meter was held 1 m above the ground at a fixed position for 30 seconds to record the E-field strength and the power density. The measured power density and the electric field strength, varied from routers to routers depending on their location and the distance of measurement from the routers. The power density recorded for all the Wi-Fi routers investigated ranged from 0.001 to 3.302 W/m2 with a mean of 0.390 W/m2. For all the Wi-Fi routers investigated. The overall exposure levels for the power density decreases with distances for all the routers. The measured electric field strength also decreases with distance ranging from 0.106 to 3.528 V/m with a mean of 0.981 V/m. The measured power densities and the electric field strengths in this research work were comparable and similar with reports from other research work from different environments including educational, residential, and urban settings. The power densities and the electric field strengths recorded were below the 10 W/m2 and 5 V/m recommended by various regulatory agencies respectively. All the Wi-Fi routers considered in this research work were within safety guidelines set by regulatory agencies for the power density and the electric field strength, thus emitting radiations at a level that are considered safe for human exposure within the academic communities. The operation of RF-EMF exposure from Wi-Fi routers in the academic environment of LAUTECH will no pose any potential health risks on staff and students of the institution. The evidence-based insights into potential health risks associated with prolonged exposure to electromagnetic fields from Wi-Fi routers in this research can guide policymakers in establishing safety regulations that will limit exposure levels. It can also inform guidelines on the optimal placement of routers, frequency of usage, and the implementation of periodic monitoring to ensure compliance with international safety standards.

Smartphone-Based Methodology Applied to Electromagnetic Field Exposure Assessment.

This study presents the measurements of exposure to electromagnetic fields, carried out comparatively following standard methods from fixed sites using a broadband meter and using a smartphone on which an App designed for this purpose has been installed. The results of two measurement campaigns carried out on the campus of the University of Alcalá over an area of 1.9 km2 are presented. To characterize the exposure, 20 fixed points were measured in the first case and 860 points along the route made with a bicycle in the last case. The results obtained indicate that there is proportionality between the two methods, making it possible to use the smartphone for comparative measurements. The presented methodology makes it possible to characterize the exposure in the area under study in four times less time than that required with the traditional methodology.

Assessment of Radio Frequency Electromagnetic Field Exposure Induced by Base Stations in Several Micro-Environments in France

Assessment of Radio Frequency Electromagnetic Field Exposure Induced by Base Stations in Several Micro-Environments in France

Numerical Assessment of Human EMF Exposure to Collocated and Distributed Massive MIMO Deployments in an Industrial Indoor Environment

This article presents a comparative numerical study of collocated and distributed massive multiple-input–multiple-output (MIMO) deployments at 3.5 GHz in an industrial indoor environment from the point of view of downlink human electromagnetic field (EMF) exposure. A collection of environmental models incorporating elements with stochastic geometry is generated, in which the EMF propagation is calculated using the ray-tracing (RT) method. To evaluate the human exposure, the finite-difference time-domain (FDTD) method is used, including a realistic human phantom and a user equipment model, into which the excitation is introduced based on the RT results. Single-user maximum ratio transmission and multiuser zero-forcing scenarios are studied. Small-scale EMF distributions in proximity to the phantom's head are assessed in FDTD and analysed for different user locations in the environment and user equipment placement with respect to the head. The massive MIMO hot-spot is characterized in terms of its size, instantaneous and time-averaged EMF enhancement, and position with respect to the head and the user equipment. The human exposure is assessed using the peak-spatial specific absorption rate averaged over 10 g, referenced to the hot-spot EMF amplitude, and compared to international guidelines. It is shown that the distributed deployment results in a more accurate and consistent EMF hot-spot around the user equipment with a higher average E-field gain, compared to the collocated deployment. In addition, the distributed configuration produced more compact hot-spots relative to the collocated one, leading to a more than tenfold average exposure reduction in a multiuser scenario.

A Generalizable Indoor Propagation Model Based on Graph Neural Networks

A surrogate model that “learns” the physics of radio wave propagation is indispensable for the efficient optimization of communication network coverages and comprehensive electromagnetic field (EMF) exposure assessments. The capability of a model to predict reasonable outputs given an input that is beyond the data with which the model is trained, namely, “generalizability”, is a fundamental challenge and a key factor for its practical deployment. In this paper, by leveraging the concept of graph neural networks (GNNs), a prediction model for indoor propagation that is “generalized” to not only transmitter positions but also new geometries is presented. We demonstrate that a geometry and a transmitter antenna can be modeled as a graph with all necessary information being included, and a GNN can acquire the knowledge of propagation physics through “learning” from these graphs. We further show that the model can be generalized to new geometry shapes, beyond the shape (square) for model training. We provide useful information on how to obtain an acceptable accuracy for different scenarios. We also discuss the potential solutions to further improve the model’s capability.

Assessment of Electromagnetic Field Exposure on European Roads: A Comprehensive In Situ Measurement Campaign.

The rapid evolution of wireless communication technologies (such as fifth-generation (5G) cellular networks) in the last years has allowed connecting different objects (from wearable electronics to vehicles) and people through communication networks, and at the same time, has led to widespread deployment of base stations. Along with this growth, questions about the potential adverse effects on human health due to electromagnetic fields (EMFs) from base station antennas have also been raised. In this paper, we focus on the assessment of EMFs in automobiles during short (between cities) and long (between countries) trips on several European roads. Comprehensive measurement campaigns were carried out in several European countries: Austria, Bulgaria, Croatia, Hungary, Italy, Slovenia, and the Republic of Serbia. The results show that the median total electric field is 0.23-0.24 V/m in Bulgaria, Croatia, Hungary, Italy, and the Republic of Serbia. In Austria and Slovenia, the median is 0.28-0.31 V/m. Austria demonstrated the highest value for the total electric field, at 17.4 V/m.

Limitations of using electro-optical probes for the measurement of the electromagnetic field emitted by the new generations of wireless communication devices

The rapid evolution of communication standards caused a paradigm shift in electromagnetic field (EMF) measurement campaigns, as exposure is more likely to take place in the proximity of the device. With the increased spatial variability of EMF exposure, electro-optical (EO) technology stands out as a promising alternative to conventional near field measurement instrumentation due to their miniature sizes and dielectric structure that does not interfere with the measured field. Motivated by the recent progress in the EO sensing technology, it is this article purpose to quantify the limitations of using a set of commercially available EO probes for measurement of EMF emitted by an IEEE 802.11ax router and a VoLTE mobile phone. To our knowledge, this is the first attempt to characterize the capabilities of this emerging sensing technology for EMF exposure assessment in real world communication situations. Present findings suggest that the sensitivity of the investigated EO probes is insufficient for measuring broadband signals at field levels that characterize state-of-the-art communication devices used by the public in common usage scenarios. This work also documents the EO probes suitability and response with respect to frequency, electric field strength and signal bandwidth.

The prospects for radiofrequency electromagnetic fields control approaches improvement under 5G wireless communication technologies introduction

5G mobile communication system networks improvement leads to scenarios for the use of electromagnetic energy in various sectors of the economy variety increase and radiofrequency electromagnetic fields (EMF) person’ exposure with expansion of the exposed by occupational and non-occupational exposure contingent including. Base station EMF distinctive feature is its complex frequency-time and spatial dynamics with constant control signals that should be taken into account in modern EMF control methods. International practice in case of cellular base stations EMF assessment uses maximal values determination: theoretical and actual levels. EMF theoretical maximal values characterize base station operation mode under highest network load, highest data traffic and time-frequency radio channel resource full usage at the maximum permitted transmission power. Actual maximum EMF levels determination approach is base stations EMF evaluation alternative principle and is based on practically achievable maximum EMF emission, stochastic nature of base station signals with taking into account. The approaches to statistical assessment of actual maximum exposure levels are becoming a priority for international practice of base station EMF assessment and control due to adaptive antenna technologies in 5G cellular networks development. This approach to realistic EMF exposure assessment is fundamentally new for Russian practice and will require methodological updating of regulatory framework as well as comprehensive researches with network operators, including approaches to selective measurement results extrapolation for implementation. Ethics. The study did not require the ethics committee conclusion.

A Monte Carlo Analysis of Actual Maximum Exposure From a 5G Millimeter-Wave Base Station Antenna for EMF Compliance Assessments.

International radio frequency (RF) electromagnetic field (EMF) exposure assessment standards and regulatory bodies have developed methods and specified requirements to assess the actual maximum RF EMF exposure from radio base stations enabling massive multiple-input multiple-output (MIMO) and beamforming. Such techniques are based on the applications of power reduction factors (PRFs), which lead to more realistic, albeit conservative, exposure assessments. In this study, the actual maximum EMF exposure and the corresponding PRFs are computed for a millimeter-wave radio base station array antenna. The computed incident power densities based on near-field and far-field approaches are derived using a Monte Carlo analysis. The results show that the actual maximum exposure is well below the theoretical maximum, and the PRFs similar to those applicable for massive MIMO radio base stations operating below 6 GHz are also applicable for millimeter-wave frequencies. Despite the very low power levels that currently characterize millimeter-wave radio base stations, using the far-field approach can also guarantee the conservativeness of the PRFs used to assess the actual maximum exposure close to the antenna.

Methodology for Electromagnetic Field Exposure Assessment of 5G Massive MIMO Antennas Accounting for Spatial Variability of Radiated Power

The technology of massive Multiple Input Multiple Output (maMIMO) antennas introduces new challenges in the Radio Frequency Electromagnetic Fields (RF EMF) exposure assessment of 5G base stations due to the aleatory changes of the radiation direction. The beamforming capabilities of the antenna modify the radiation pattern both in space and in time domain in order to adapt the electromagnetic footprint to the changes of user positions, mobility, and service requests. Recently, Base Station (BS) power monitoring counters per Angular Regions (AR) were introduced in maMIMO antenna technology for monitoring the power associated to specific angular directions. By analyzing the time averaged power reported by ARs power monitoring counters the paper proposes, making use of simulations, a methodology to quantify a statistical spatial power reduction factor (0.05 to 0.5, on the base of the assumptions adopted in this paper) to be applied in the RF EMF exposure assessment process accounting for the variability of the maMIMO antenna radiation pattern. The proposed approach enhances and completes the methodology already described in normative documents for characterizing time variations of the total radiated power. The paper is completed with a sensitivity analysis for the size of each AR with respect to the antenna beam size; the analysis shows that a good spatial resolution is achieved when the AR Region has almost the same size as the beam’s half power beam width.

Occupational electromagnetic spectrum hazards and the significance of artificial optical radiation: country report for Greece.

Background:The electromagnetic spectrum spans over an enormous range from 0 up to more than 1020 Hz in the deep ionizing region, significant exposures exist in specific occupational environments. Between the ionizing and the electromagnetic fields (EMF) part of the spectrum, the ‘optical radiation’ (OR) region has specific properties. Comparative and concise evaluation enables action prioritization.Methods:Following the transposition and implementation periods of the artificial optical radiation (AOR) and EMF European Directives, the Hellenic Ministry of Labour in collaboration with the Greek Atomic Energy Commission (EEAE) and the National Technical University of Athens, conducted thorough occupational exposure investigation in Greece. Using dedicated measuring equipment and procedures, the majority of EMF emitting installations in Greece and also AOR emitting installations including arc welding, lasers and PC monitors has been assessed.Results:Measurement results from occupational settings reveal that it is the non-coherent metal arc welding AOR that can pose even sub-second overexposures. Rare EMF overexposures are manageable and EMF concern is not justified. Maintenance procedures demand proper attention. Preliminary laser safety assessment reveals OHS gaps and potential eye and skin hazards. Blue light exposure from computer monitors is well below safety limits.Conclusions:This electromagnetic spectrum risk assessment conducted in Greece enables the justification of the real occupational hazards, in this sense: i) EMF exposure assessment has to be concentrated to maintenance procedures; ii) AOR measuring setups are challenging and standardized measurement procedures are missing, and iii) AOR overexposures from arc welding pose significant eye and skin hazards.

Towards Environmental RF-EMF Assessment of mmWave High-Node Density Complex Heterogeneous Environments.

The densification of multiple wireless communication systems that coexist nowadays, as well as the 5G new generation cellular systems advent towards the millimeter wave (mmWave) frequency range, give rise to complex context-aware scenarios with high-node density heterogeneous networks. In this work, a radiofrequency electromagnetic field (RF-EMF) exposure assessment from an empirical and modeling approach for a large, complex indoor setting with high node density and traffic is presented. For that purpose, an intensive and comprehensive in-depth RF-EMF E-field characterization study is provided in a public library study case, considering dense personal mobile communications (5G FR2 @28 GHz) and wireless 802.11ay (@60 GHz) data access services on the mmWave frequency range. By means of an enhanced in-house deterministic 3D ray launching (3D-RL) simulation tool for RF-EMF exposure assessment, different complex heterogenous scenarios of high complexity are assessed in realistic operation conditions, considering different user distributions and densities. The use of directive antennas and MIMO beamforming techniques, as well as all the corresponding features in terms of radio wave propagation, such as the body shielding effect, dispersive material properties of obstacles, the impact of the distribution of scatterers and the associated electromagnetic propagation phenomena, are considered for simulation. Discussion regarding the contribution and impact of the coexistence of multiple heterogeneous networks and services is presented, verifying compliance with the current established international regulation limits with exposure levels far below the aforementioned limits. Finally, the proposed simulation technique is validated with a complete empirical campaign of measurements, showing good agreement. In consequence, the obtained datasets and simulation estimations, along with the proposed RF-EMF simulation tool, could be a reference approach for the design, deployment and exposure assessment of the current and future wireless communication technologies on the mmWave spectrum, where massive high-node density heterogeneous networks are expected.

Assessment of Indoor-Outdoor Wi-Fi Radiation on Human Body and its Precise SAR Measurement

There has been a lot of awareness concern about the health hazards of RF electromagnetic radiation on the human body, the radiofrequency electromagnetic field (RF-EMF) exposure assessment needs attention. This paper reports experimentally measured electromagnetic radiation emission from public place Wi-Fi devices. Indoor and outdoor measurements are done at different geographic locations in India. For the indoor assessment, the experiment was carried out in the national physical laboratory (NPL) New Delhi for 1-4 antennas Wi-Fi routers at a distance of 0-10-meter range are taken into consideration. The power density and electrical intensity were measured using a spectrum analyzer with isotropic E-field probe TSEMF-B1. For the outdoor measurements, four different Delhi metro stations Wi-fi devices at a distance of 20-meter range towards the train coach and below the Wi-fi routers have been considered. In this experiment, we used an instrument is Narda NBM-550 E-field probe for electric field and radiated power density estimation. In addition, the human whole body 3D model has been simulated in a free space environment, the measured outcome of indoor-outdoor electromagnetic radiation and specific absorption rate (SAR) is compared with the ICNIRP, FCC guideline limits at 2.45-5.87 GHz and precise SAR has been evaluated.

무선 주파수 전자기장 인체영향 연구 현안

This study describes the basis of the International Commission on Non-Ionizing Radiation Protection guidelines and IEEE standards for protecting the human body from exposure to electromagnetic fields (EMF) in the radio frequency band. A brief summary of epidemiological studies that have been conducted on the health risks of long-term EMF exposure in the mobile communication frequency range are reviewed. EMF exposure assessment for epidemiological studies should incorporate mobile-device usage patterns, mobile communication uplink and downlin\k exposure analysis in real environments, age-specific human model development, and dosimetry. Trends and limitations on these topics are described.

Effect of antioxidants intake on oxidative stress among mobile phone users

The current study aimed to assess mobile phone usage intensity and evaluate potential oxidative stress exerted among mobile users then evaluate the effect of antioxidants supplement on oxidative stress status. Intervention study done on 150 students using mobile phones from both technical nursing institute and faculty of nursing, Cairo .University. Only (108) students completed to the post intervention phase. Questionnaire and assessment of electromagnetic field exposure from mobile phones was done. Malondialdyde, superoxide dismutase and catalase were measured pre and post supplementation. Mobile phones with two SIM cards, non-android mobiles and mobile phones owned by the medium users group had significant higher electromagnetic emissions. Malondialdyde was significant higher in high mobile users. Significant negative correlation between emissions from mobile phone and superoxide dismutase. After supplementation, significant improvement in superoxide dismutase and Catalase among both groups using mobiles (>5years and <5years), using one or two phones, using one or two SIM cards and in android mobile users. Moreover, Malondialdyde show significant reduction among non-android mobile users. It was concluded that exposure to low emissions from mobile phones could be fixed by dietary modification and increase antioxidant intake.

A case study on electromagnetic field assessment and uncertainty evaluation

This paper presents a radiofrequency electromagnetic field exposure assessment carried out in an observatory open for general public, where there are multiple radio and television transmitters in the surrounding area. An uncertainty evaluation is presented, considering that the main broadcast stations reduced their transmitted power to comply with the regulatory limits throughout the observatory area. A discussion is done about uncertainty of measurement result and its use or not in both precautionary measure and sanctioning process applied by regulatory authority.

Human RF-EMF Exposure Assessment Due to Access Point in Incoming 5G Indoor Scenario

The study aimed at expanding the knowledge about the assessment of radio-frequency electromagnetic fields (RF-EMF) exposure, considering the novelties introduced by the incoming 5G networks. Specifically, a possible future case of indoor exposure scenario is investigated, where the presence of a 5G access point (AP) in a room is simulated. The AP was modelled by two different indoor uniform planar array (UPA) antennas at 3.7 GHz and at 14 GHz, to evaluate how the beamforming and the higher frequency use could impact the exposure levels. Different scenarios were evaluated, considering the maximum antenna gain, two different human computational models, an adult model and a child one, and by varying the distance and the orientation between the UPA antenna and the two models head. All the simulations were conducted using the Sim4Life platform and in particular the exposure levels were expressed by the specific absorption rate averaged on 10 g of tissue (SAR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10g</sub> ), which was analyzed for the skin and for some specific tissues. The work underlined that the highest SAR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10g</sub> values were obtained in the head area for all scenarios, with the skin SAR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10g</sub> highest peaks when the UPA is placed laterally to the human model (195.73 mW/kg and 223.29 mW/kg for the adult and child model, respectively, for 100 mW input power). Furthermore, the work permitted to highlight that the SAR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10g</sub> exposure levels are slightly higher for the child model, compared to the adult one and that the distance between the UPA antenna and the human models could greatly lower the SAR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10g</sub> levels. At last, it was found that the SAR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10g</sub> exposure levels obtained with the UPA antenna at 14 GHz were lower than the ones at 3.7 GHz, although further investigations will be necessary.

Instrumental assessment of mobile communication base station electromagnetic field exposure

Introduction. Monitoring and ensuring safe operating conditions of modern base stations for occupational and general public exposure is relevant with the use of methods for measuring electromagnetic fields, which allow to assess the contribution of different sources to the overall level of the electromagnetic background, taking into account the dynamic features of base stations and the spectral electromagnetic characteristics. The aim of study is the levels of electromagnetic fields assessment from modern base stations using broadband and selective measurement methods, as well as the possibility of predicting the worst exposure conditions. Materials and methods. The levels of electromagnetic fields from base stations according to the LTE2600 standard were evaluated at the maximum transmission traffic (laboratory mearements) and at real variable traffic (field measurements). For broadband measurements, the power density (PD) was estimated, for selective measurements, the PD level in the LTE frequency channel (frequency-selective measurements) and the PD level of the reference signal (code-selective measurements) were evaluated. The theoretical maximum PD level was calculated from the maximum value of the reference signal. Results. When simulating the maximum intensity of data traffic, the PD level in the LTE channel was 94.51-101.39% of the calculated maximum value. According to field measurements, the values of electromagnetic field levels obtained from frequency-selective measurements in the LTE frequency channel were less than the corresponding values estimated from the results of broadband measurements, and were no more than 25% of the theoretical maximum. Conclusions. The use of selective approach and measurement methods made it possible to estimate the maximum possible contribution of a single source to the overall level of the electromagnetic background and to predict the worst conditions for human exposure.

Hygienic assessment of mobile communication base stations electromagnetic field exposure

The mobile networks base stations electromagnetic field exposure is the important subject of hygienic assessment, control, monitoring and significant concern in modern society. The Russian assessment approach needs electromagnetic field of multiple sources exposure estimation improvement by application of selective methods for the worst possible case. The general scheme for maximal electromagnetic field exposure assessment from GSM, UMTS, LTE and 5G/NR modern base stations on the basis of international approach are considered. The results of selective electromagnetic field measurements performed for actual and maximal possible exposure assessment in the vicinity of LTE base station are presented.

The problems of mobile communication electromagnetic field exposure assessment today and tomorrow

New and necessary improvements of electromagnetic exposure assessment principles and methods are considered and presented. The electromagnetic field exposure assessment is the physical basis for hygienic and biological research and needs s to consider the new technological features of emerging 5G mobile systems in addition to existing 2-4G systems. The new generation of telecommunication networks will cause significantly novel electromagnetic field exposure, in particular for time-frequency and spatial parameters. A complex exposure assessment based on refined broadband measurements seems to be the proper and necessary approach to the enhancement of Russian EMF assessment guidelines. Simple broadband EMF measurements are the common approach for present exposure assessment and cannot be used any longer as the only measure for multiple 5G sources exposure evaluation. Then again broadband measurements are the simple and practical approach for mm wave in-situ exposure assessment. Frequency-selective and code-selective measurements provide detailed EMF level distribution in separate frequency channels, telecommunication services or sources and are a promising approach for objective exposure assessment.