Publications_old
Journal Publications
Electromagnetic Fields Exposure Assessment in Europe Utilizing Publicly Available Data
Authors: Iakovidis, S.; Apostolidis, C.; Manassas, A.; Samaras, T.
Sensors 2022, 22, 8481. https://doi.org/10.3390/s22218481
Abstract
The ever-increasing use of wireless communication systems during the last few decades has raised concerns about the potential health effects of electromagnetic fields (EMFs) on humans. Safety limits and exposure assessment methods were developed and are regularly updated to mitigate health risks. Continuous radiofrequency EMF monitoring networks and in situ measurement campaigns provide useful information about environmental EMF levels and their variations over time and in different microenvironments. In this study, published data from the five largest monitoring networks and from two extensive in situ measurement campaigns in different European countries were gathered and processed. Median electric field values for monitoring networks across different countries lay in the interval of 0.67–1.51 V/m. The median electric field value across different microenvironments, as evaluated from in situ measurements, varied from 0.10 V/m to 1.42 V/m. The differences between networks were identified and mainly attributed to variations in population density. No significant trends in the temporal evolution of EMF levels were observed. The influences of parameters such as population density, type of microenvironment, and height of measurement on EMF levels were investigated.
An Extrapolation Approach for RF-EMF Exposure Prediction in an Urban Area using Artificial Neural Network
Authors: Chikha, W. B.; Wang, S.; Wiart, J.
IEEE Access 2023, 11, pp. 52686-52694. https://doi:10.1109/ACCESS.2023.3280125
Abstract
The prediction of the electric (E) field plays an important role in the monitoring of the radiofrequency electromagnetic field (RF-EMF) exposure induced by cellular networks. In this paper, we present an approach to extrapolate the E field in an urban area using artificial neural network. We first apply a moving average method over a sliding window to average out the EMF random fluctuations and remove the noise produced during the drive test recording of E field measurements along the route. Using public accessed datasets, i.e., cartoradio and OpenStreetMap, we then extract relevant features, including the ones that have a relation with the number of active antennas and those used by Bertoni-Walfisch propagation model. By applying the Gram-Schmidt Orthogonalization procedure, we select the best subset of the extracted features as inputs to the artificial neural network (ANN). In this work, two disjoint subsets are selected for the learning and testing phases to evaluate the performance of our proposal in the extrapolation of the E field measurements and to quantify the uncertainty generated by the proposed predictor due to the dynamicity usage of cellular networks and geolocalization inaccuracies.
A study of the long term changes in the electromagnetic environment using data from continuous monitoring sensors in Greece
Authors: Manassas, A.; Apostolidis, C.; Iakovidis, S.; Babas, D.; Samaras, T.
Scientific Reports 2023, 13, 13784.https://doi.org/10.1038/s41598-023-41034-3
Abstract
Owing to the advancement of wireless technologies, there is a strong public perception of increasing exposure to Radiofrequency (RF) electromagnetic fields (EMF). The aim of this study is to determine the evolution of EMF in the environment, and consequently, human exposure to them, over a period of about two decades, spanning from the end of 2003 until February 2022. The study is based on data collected by two non-ionizing radiation monitoring networks in Greece. The networks consist of fixed EMF sensors that register the RMS electric field value every 6 min, on a 24 h basis. We used the Seasonal–Trend decomposition method using (LOESS), known as the STL method to decompose the time series into trend, seasonal, and noise components. Additionally, since the sensors include frequency filters for separating the cellular frequencies, the recorded data were used to identify the exposure contribution by cellular networks in comparison to other EMF sources. The study indicates that RF-EMF do not explicitly decrease or increase but rather fluctuate over time. Similarly, the contribution of mobile cellular networks to the total field change over time.
Conference Publications
Traceable Absorbed Power Density Assessment System in the 28 GHz Band
Authors: Ninad Chitnis, Fariba Karimi, Arya Fallahi, Sven Kühn, and Niels Kuster
Presentation by Ninad Chitnis
BioEM 2023, 18-23/06/2023, Oxford, United Kingdom
Abstract
ICNIRP and IEEE closed a critical gap in the safety guidelines by introducing a basic dosimetric restriction above 6 GHz. These are the absorbed power density (APD) and the spatial averaged power density. In previous work by our group, a phantom and a compatible probe were developed to measure the APD in the 5G new radio frequency range 2 (NR FR2; 24–30 GHz). Here, an experimental validation procedure for the proposed phantom is detailed. The reflection coefficient was measured with sources at different distances from the phantom. Target values were obtained using the finite-difference time-domain solver in Sim4Life (ZMT Zurich MedTech AG, Switzerland). The measurements and simulations were compared on the basis of cosine similarity.
A setup based on the multi-mode solution for a rectangular waveguide radiating into a dielectric half-space was developed for calibrating the novel APD probe. The field profile of the propagating mode is obtained analytically by formulating the fields in both, the rectangular waveguide and the dielectric medium, and matching them at the intersection. The calibrated electric field is obtained by scaling the uncalibrated probe response to match the computed field profile. The results of this research validate the first APD measurement system designed for the 5G NR FR2 band (24–30 GHz).
5G mm-wave mouse exposure system based on reverberation chambers
Authors: Myles Capstick, Beyhan Kochali, Isaac Alonso Marin, and Niels Kuster
Presentation by Dr. Myles Capstick
BioEM 2023, 18-23/06/2023, Oxford, United Kingdom
Abstract
Here we describe a reverberation chamber-based millimeter-wave exposure system for mice providing three exposure levels, high, low, and sham. Each chamber has a volume of ~1 m3 and contains 3 mode stirrers and houses 12 cages and up to 48 adult mice and provides lighting and ventilation. 5G modulated signals are up converted and amplified in situ to avoid transmission losses. The exposure is computer controlled to maintain the identical exposure over the period of the experiment.
How much am I exposed? Exploring public perceptions of EMF exposure from mobile Communication technology and 5G
Authors: Sarah Link, Marie Eggeling, Ferdinand Abacioglu, and Christoph Böhmert
Presentation by Sarah Link
BioEM 2023, 18-23/06/2023, Oxford, United Kingdom
Abstract
In order to understand citizens’ reactions to the 5G roll out, their perceptions of electromagnetic fields (EMFs) exposure need to be explored. While precursor studies on 2G to 4G have investigated exposure perceptions mostly quantitatively, the present study applies a qualitative exploratory approach. To do so, 35 individual interviews and six focus groups were conducted. Participants were recruited from several locations in Germany, where 5G roll out is at different stages. Interactive tasks, particularly a sorting task and a base station siting task encouraged participants to consider their exposure perception regarding 5G. Data were analyzed using an exploratory content analysis. The sorting task indicated that ~60% of the participants feel more exposed from base stations than from mobile devices. In the siting task, most participants chose a location outside the village (16 short distance, 15 remote). Besides exposure, aesthetic aspects and reception were frequently mentioned as reasons for/against a location. After informing participants that for regular smartphone users, individual exposure increases with increasing base station distance, 53% of those initially choosing a remote site changed to a closer location. However, results are mostly in line with the literature on 2G to 4G and do not indicate a substantially different exposure perception for 5G. As with other EMF sources (e.g., power lines), siting preferences are influenced by many factors. Consequently, perceived exposure is only one factor in judgments of 5G base station locations. Further research needs to address the complexity of individual 5G assessments.
Performance Evaluation of DEVIN at a Low Sampling Frequency
Authors: Taghrid Mazloum, Serge Bories, and David Dassonville
Poster presented by Dr. Serge Bories
BioEM 2023, 18-23/06/2023, Oxford, United Kingdom
Abstract
In the context of epidemiological studies, the personal miniaturized electromagnetic (EM) exposimeter DEVIN allows collecting data from volunteers in their daily life. DEVIN allows identifying the user activities along the day as well as recording the power emitted by the mobile phone at both the cellular and WiFi frequency bands. This occurs at a certain sampling frequency. The critical challenge of DEVIN is to keep it logging data as long as possible during a whole day. It has been seen that decreasing the sampling frequency from 100 Hz to 10 Hz increases the battery autonomy from almost 6 to 11 hours. Therefore, we intend in the present work to evaluate the performance of DEVIN with a sampling frequency of 10 Hz, for two various signals types, i.e., voice over LTE (VoLTE) and data uploading signals.
Comparison of Measurement Systems on Conducting RF-EMF Drive Test Campaign in Greek Urban and Suburban environments
Authors: S. Wang, W. Ben Chikha, Y. Zhang, J. Liu, M. Christopoulou, E. Karabetsos, A. Manassas, S. Iakovidis, C. Apostolidis, D. Babas, T. Samaras, J. Wiart
Poster presented by Dr. Shanshan Wang
BioEM 2023, 18-23/06/2023, Oxford, United Kingdom
Abstract
This work presents the downlink (DL) radio-frequency (RF) electromagnetic field (EMF) exposure monitoring campaign in two cities in Greece. The measurement of RF-EMF exposure is done by drive test method, in which three measurement systems are used and compared, i.e., Tektronix RSA 306B, Narda SRM 3006, and Narda NBM 550. The drive test focuses on the DL cellular frequency bands, which are from 750 MHz to 3800 MHz, including 2G, 3G, 4G, and 5G technologies. All the E-field probes from the three measurement systems are mounted on the top of the car, while their basic units are placed inside the car. The drive test measurements cover in total 44.87 km with an average vehicle speed of 15 km/h in two types of environment: urban and suburban. The measurement results from three measurement systems are compared in terms of sweep time, considered frequency band and total electric (E) field.