Andreas Christ, Adrian Aeschbacher, Bernadetta Tarigan, Ninad Chitnis, Arya Fallahi, Sven Kühn, Myles Capstick, Niels Kuster
{"title":"Human Skin Model From 15 GHz to 110 GHz","authors":"Andreas Christ, Adrian Aeschbacher, Bernadetta Tarigan, Ninad Chitnis, Arya Fallahi, Sven Kühn, Myles Capstick, Niels Kuster","doi":"10.1002/bem.70025","DOIUrl":"https://doi.org/10.1002/bem.70025","url":null,"abstract":"<p>Compliance testing of wireless devices with absorbed power density (APD) limits requires body models that conservatively reproduce the absorption characteristics of human skin. Previous studies indicate that impedance-matching effects are caused by the stratum corneum (SC) layer. The objective of this study is to develop a single macroscopic dielectric model reproducing absorption of electromagnetic fields by the skin up to 110 GHz. The reflection coefficient of the skin of human volunteers was measured at frequencies of 15 to 43 GHz with open waveguide probes, complementing previous data from 45 to 110 GHz. The measurements were made at various regions of the body. The statistical analysis of the results shows that the reflection coefficient in dB follows normal distribution in regions with thin SC, which permits the development of a conservative skin model. In regions with thick SC, for example, the palms, the reflection coefficient is not normally distributed because the thickness of the SC depends on the mechanical stress the hands are exposed to. The measured data allow the derivation of dispersive two-layer models representing absorption and reflection at the skin surface with known uncertainty. The models can be used to conservatively demonstrate compliance with the APD limits of wireless devices in any of the 5G and 6G bands.</p>","PeriodicalId":8956,"journal":{"name":"Bioelectromagnetics","volume":"46 7","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/bem.70025","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jingtian Xi, Sven Kühn, Cosimo Fortunato, Erdem Ofli, Niels Kuster
{"title":"Evaluation of Exposure Assessment Methods and Procedures for Induction Hobs","authors":"Jingtian Xi, Sven Kühn, Cosimo Fortunato, Erdem Ofli, Niels Kuster","doi":"10.1002/bem.70024","DOIUrl":"https://doi.org/10.1002/bem.70024","url":null,"abstract":"<p>Induction hobs generate strong alternating magnetic fields to heat pots by inducing eddy currents. These fields are the strongest close to the bottom of the cookware, but stray fields at large distances can still be substantial. In general, these are higher than the reference levels defined by international electromagnetic exposure safety guidelines (ICNIRP 1998; ICNIRP 2010; IEEE 2019). That the reference levels are exceeded does not imply that the basic restrictions are also violated. In this study, we assess the exposures caused by the latest generation of induction hobs by applying the advanced instrumentation and different methods that include the procedures developed by the International Electrotechnical Commission (IEC) for household appliances (IEC 62233) (IEC International Electrotechnical Commission 2005), the 4-tier approach developed for inductive wireless power transfer systems (IEC 63184) (IEC International Electrotechnical Commission 2021), and their derivatives. First, methods for determining the maximum exposure configuration were assessed. Then, the 3D distribution of the incident magnetic field was sampled with a scanning system and analyzed, and the contact currents assessed. Lastly, numerical dosimetric evaluations were performed in anatomical models to determine the maximum fields induced by the measured incident fields directly or by a representative coil model converted from the measured fields. The study's findings reveal significant variations in exposure across different induction hobs, with differences of up to a factor of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>></mo>\u0000 </mrow>\u0000 <annotation> $gt $</annotation>\u0000 </semantics></math> 20 (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>></mo>\u0000 </mrow>\u0000 <annotation> $gt $</annotation>\u0000 </semantics></math> 26 dB) as a function of power, coil size, and proximity to the coil. This suggests that low-exposure hobs can be designed without compromising cooking performance. Furthermore, the study strengthens the conclusions of previous studies that IEC 62233 (IEC International Electrotechnical Commission 2005) may underestimate the exposure for persons standing next to the hob by up to a factor of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>></mo>\u0000 </mrow>\u0000 <annotation> $gt $</annotation>\u0000 </semantics></math> 30—based on testing according to the exposure limits from (ICNIRP 1998; IEEE 2019)—and thus does not ensure safety. A dosimetric analysis, the most accurate method, would be relatively costly. Alternative approaches derived from (IEC International Electrotechnical Commission, 2021) that are affordable and not overly conservative are discussed. Bioelectromagnetics. 00:","PeriodicalId":8956,"journal":{"name":"Bioelectromagnetics","volume":"46 7","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/bem.70024","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145181618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Adam Verrender, Jacob Manley, Nikkeah K. Wallace, Sarah P. Loughran, Rodney J. Croft
{"title":"Looking for Biomarkers Which May Explain Idiopathic Environmental Intolerance Attributed to Electromagnetic Fields (IEI-EMF): Does RF-EMF Exposure Influence Salivary Cortisol Response?","authors":"Adam Verrender, Jacob Manley, Nikkeah K. Wallace, Sarah P. Loughran, Rodney J. Croft","doi":"10.1002/bem.70021","DOIUrl":"https://doi.org/10.1002/bem.70021","url":null,"abstract":"<p>In order to understand Idiopathic Environmental Intolerance attributed to Electromagnetic Fields (IEI-EMF), it has been argued that it is crucial to test for effects of radiofrequency electromagnetic fields (RF-EMF) on biomarkers, given that they can be more objective than symptom reports. While no clear evidence links RF-EMF exposure to biomarker changes, research remains limited and largely speculative due to the lack of known bioeffect mechanisms. However, there is in vitro evidence that cortisol is affected by heating, which, as RF-EMF causes heating, raises the possibility that RF-EMF exposure may increase cortisol via thermally mediated processes. If cortisol is affected by RF-EMF exposure, it may form part of a broader aetiology of IEI-EMF, where RF-EMF-induced physiological (cortisol) inputs first generate somatic sensations, which are then fostered by expectancy or learning-based processes to generate symptoms. However, studies investigating whether RF-EMF exposure influences cortisol have reported inconsistent, but mostly null results, and many suffer from methodological issues. The current study was designed with several methodological improvements to determine whether RF-EMF affects cortisol. Seventy-two participants completed a randomized, double-blind, counterbalanced provocation study where they were exposed to both active (2 W/kg peak SAR<sub>10g</sub> in head) and sham RF-EMF (0 W/kg peak SAR<sub>10g</sub> in head). Despite implementing several methodological improvements, the current study failed to find an effect of RF-EMF exposure on salivary cortisol concentration. This study provides a valuable direction for future research and stresses the importance of establishing and testing theoretically plausible interactions between low-level RF-EMF exposure, the human body, and IEI-EMF symptoms.</p>","PeriodicalId":8956,"journal":{"name":"Bioelectromagnetics","volume":"46 6","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/bem.70021","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144998759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kenneth Deprez, Bram Stroobandt, Adriana Fernandes Veludo, Zsuzsanna Vecsei, Peter Pal Necz, Piotr Politański, Leen Verloock, Kinga Polanska, György Thuróczy, Martin Röösli, David Plets, Wout Joseph
{"title":"5G RF EMF Spectral Exposure Assessment in Four European Countries","authors":"Kenneth Deprez, Bram Stroobandt, Adriana Fernandes Veludo, Zsuzsanna Vecsei, Peter Pal Necz, Piotr Politański, Leen Verloock, Kinga Polanska, György Thuróczy, Martin Röösli, David Plets, Wout Joseph","doi":"10.1002/bem.70019","DOIUrl":"https://doi.org/10.1002/bem.70019","url":null,"abstract":"<p>This study assesses the exposure to 5G radio frequency electromagnetic fields (RF EMF) across four European countries. Spot measurements were conducted indoor and outdoor in both public spaces and educational institutions, encompassing urban and rural environments. In total, 146 measurements were performed in 2023, divided over Belgium (47), Switzerland (38), Hungary (30) and Poland (31). At 34.9% of all measurement locations a 5G connection to 3.6 GHz was established. The average cumulative incident power density (<i>S</i><sub>avg</sub>) and maximum cumulative incident power density (<i>S</i><sub>max</sub>) were determined, for both “background” exposure (no 5G user equipment; No UE) and worst-case exposure (maximum downlink with 5G user equipment; Max DL). Furthermore, 3.6 GHz 5G-specific average <i>S</i><sub>avg,5G</sub> and maximum <i>S</i><sub>max,</sub><sub>5G</sub> incident power density are considered as well. For the No UE scenario, the highest <i>S</i><sub>max</sub> is 17.6 mW/m<sup>2</sup>, while for the Max DL, the highest <i>S</i><sub>max</sub> is 23.3 mW/m<sup>2</sup>. Both values are well within the ICNIRP guidelines. The highest <i>S</i><sub>max,</sub><sub>5G</sub> measured over all countries and scenarios was 10.4 mW/m<sup>2</sup>, which is 3.2% of the frequency-specific ICNIRP guidelines. Additionally, a comparison was made between big cities, secondary cities, and villages for all four countries. The ratio of power density measured in rural areas was significantly lower than in urban areas (−4.8 to −10.4 dB). Under LOS conditions, the average incident power density was 2.3 mW/m<sup>2</sup>, whereas under NLOS conditions, the average incident power density decreases to 0.9 mW/m<sup>2</sup>. Furthermore, the relative variation increases under NLOS scenarios. Lastly, an analysis was performed regarding the power density in educational institutions compared to all other measurement locations, both indoors and outdoors for the different city types. The measured incident power density is not extensively lower in or around schools compared to public places, neither in the big cities, secondary cities, or the villages.</p>","PeriodicalId":8956,"journal":{"name":"Bioelectromagnetics","volume":"46 6","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/bem.70019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144869794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ninad Chitnis, Fariba Karimi, Sven Kühn, Arya Fallahi, Andreas Christ, Niels Kuster
{"title":"Traceable Assessment of the Absorbed Power Density of Body Mounted Devices at Frequencies Above 10 GHz","authors":"Ninad Chitnis, Fariba Karimi, Sven Kühn, Arya Fallahi, Andreas Christ, Niels Kuster","doi":"10.1002/bem.70018","DOIUrl":"https://doi.org/10.1002/bem.70018","url":null,"abstract":"<p>In this study, a comprehensive approach for the experimental assessment of the absorbed power density (APD) is developed. The method includes several novel components: (i) a specialized probe, (ii) a composite phantom, (iii) a reconstruction technique, (iv) a calibration method, and (v) a validation process. The described solution has been developed for the frequency range from 24 to 30 GHz, but can be extended to all frequency bands between 10 and 45 GHz. A novel composite phantom emulates the reflection and transmission coefficients of human skin for propagating and evanescent modes, while its increased penetration depth, in comparison to dermis tissue, enables the measurement of the induced electromagnetic fields (EMFs) with a new miniaturized dosimetric broadband probe. The implementation has a wide dynamic range and sufficient spatial resolution to use it for type approval of mobile devices. Its probe is calibrated with low uncertainty in a novel, traceable setup. A set of reference antennas with known numerical target values for the APD has been compiled to validate the measurement system. The validation demonstrates that the deviation is within the expanded uncertainty of 1.6 dB for pAPD and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mo><</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> $lt $</annotation>\u0000 </semantics></math> 1.5 dB for psAPD.</p>","PeriodicalId":8956,"journal":{"name":"Bioelectromagnetics","volume":"46 6","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/bem.70018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jody C. Cantu, Ibtissam Echchgadda, Joseph W. Butterworth, Jason A. Payne, Leland R. Johnson, David A. Freeman, Weston C. Williams, Brad W. Hoff, Robert J. Thomas, William P. Roach, Bennett L. Ibey