Bioelectromagnetics最新文献

This study evaluates radiofrequency electromagnetic field (RF-EMF) exposure in 5G networks using a dual approach that combines theoretical extrapolations and direct measurements in diverse semiurban and urban environments, specifically on the campus of the Polytechnic University of Valencia. Measurements were conducted using personal exposimeters under active traffic conditions on the 5G network, complemented by a code-selective measurement system based on an R&S TSME6 scanner. This approach enabled the calculation of maximum theoretical exposure by detailed analysis of 5G signals and the capture of key parameters such as cell ID and beam indices at 16 representative points across the campus. For precise spatial visualization, Kriging interpolation techniques in ArcGIS were employed to generate continuous exposure maps illustrating the spatial distribution of RF-EMF in the study area. The results indicate that both the extrapolated theoretical values and measured levels align with the limits recommended by the ICNIRP, even under high data demand scenarios, supporting current safety assessments of 5G infrastructure regarding electromagnetic exposure. The correlation between theoretical and instantaneous exposures validates the applied methodology and its effectiveness in assessing exposure in diverse environments. This study provides a robust framework for future research and highlights the importance of continuous monitoring to ensure public safety during the deployment of new telecommunications infrastructure in urban areas. Bioelectromagnetics. 00:00–00, 2025. © 2025 Bioelectromagnetics Society.

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 (S_avg) and maximum cumulative incident power density (S_max) 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 S_avg,5G and maximum S_max,5G incident power density are considered as well. For the No UE scenario, the highest S_max is 17.6 mW/m², while for the Max DL, the highest S_max is 23.3 mW/m². Both values are well within the ICNIRP guidelines. The highest S_max,5G measured over all countries and scenarios was 10.4 mW/m², 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/m², whereas under NLOS conditions, the average incident power density decreases to 0.9 mW/m². 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.

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 $��\; ��<��$ 1.5 dB for psAPD.

This study explored the impact of low-intensity theta burst patterned electromagnetic fields (TBEMF) on fear-related learning in the flatworm species Planaria, a simple model organism known for its regenerative properties and ability to demonstrate basic learning behaviors. Planaria were exposed to an aversive stimulus (light) in a T-maze, and changes in their behavior, including time taken to select an arm and preferred arm selections, were assessed over the course of several days. The TBEMF consisted of five pulsed bursts at 100 Hz with alternating amplitudes and an intensity of 1 μT. In the group exposed to aversive light, a significant decrease in preferred arm selections was observed (p < 0.001), indicating that the planaria successfully learned to avoid the arm associated with the aversive stimulus. However, planaria exposed to TBEMF, either before or after the light exposure phase, did not show the same behavioral adaptation, as their arm selections remained stable, indicating that no fear learning occurred. These findings suggest that TBEMF disrupts the processes involved in fear-related learning, likely by interfering with theta rhythm-dependent mechanisms that are crucial for memory encoding and retrieval. Further exploration of EMF's effects on more complex organisms could reveal additional insights into its broader applications and implications for both basic neuroscience and clinical practice. Bioelectromagnetics. 00:00–00, 2025. © 2025 Bioelectromagnetics Society.

Radiofrequency electromagnetic fields (RF-EMF) exposure is increasingly prevalent, raising concerns about potential non-thermal health effects. This systematic review synthesizes current evidence regarding RF exposure effects on cardiac activity, focusing on heart rate (HR) and heart rate variability (HRV). Studies on healthy individuals were selected based on strict methodological criteria, including experimental design, control for confounding variables, and sufficient details on exposure parameters. Articles were included if they compared healthy subjects with and without exposure and provided cardiac measurements, specific absorption rate, or exposure measurement. A total of 28 articles were analyzed. This review included studies with RF exposure ranging from 100 to 110,000 MHz and exposure durations varying from short periods to 7 nights, with most studies lasting between 5 and 50 min. Most studies demonstrated no significant effects of RF exposure on HR, regardless of the exposure system, frequency, duration, age, sex, distance, or subject position. Findings for HRV were more nuanced, with most studies indicating no significant impact on key HRV parameters. However, some position-dependent variations emerged, particularly in antenna-based studies. Additionally, our analysis suggests that RF exposure may particularly interfere with cardiac regulatory mechanisms when the cardiovascular system is challenged and required to adapt, such as during postural changes or physiological maneuvers, although there are insufficient comparable studies to validate this hypothesis. Importantly, all included studies were conducted under resting or non-stressful conditions and involved only healthy participants. Therefore, our conclusions cannot be generalized to stressed states or clinical populations. Moreover, methodological harmonization is needed to improve comparability across future studies. The main limitation of the current evidence being the heterogeneity of experimental protocols, highlighting the need for methodological standardization in future studies. To address current heterogeneity, we propose specific methodological recommendations, including systematic blinding, accurate exposure measurement and detailed exposure, to improve comparability and reproducibility in future studies. Bioelectromagnetics. 00:00–00, 2025. © 2025 Bioelectromagnetics Society.

Radiofrequency (RF) electromagnetic field spot measurements were performed in line-of-sight to 56 active 5G macro base stations across 30 publicly accessible locations in the United Kingdom (UK). Four different exposure scenarios were assessed: background (no traffic instigation), streaming videos, downlink speed test, and extrapolation of SS-RSRP decoder measurements. Power density measurements across the 420 MHz–6 GHz frequency range were also performed at each site to assess the total exposure from various RF sources in the environment. Both total RF and 5G specific power density levels were found to be well within the 1998 ICNIRP public reference levels, even when extrapolating to worst-case scenario (≤ 5%). 4G downlink was the dominant contributor to total RF exposure, with 5G contributing on average less than 10%. No statistically significant difference was observed between beamforming and non-beamforming sites. Streaming did not seem to contribute materially to exposure levels, suggesting that background measurements are a good representation of typical downlink exposure at current urban and suburban 5G sites.

The present study investigated the core body temperature (CBT) response of free-moving adult male and female Sprague Dawley rats, during and following a 3-h exposure to 1.95 GHz radiofrequency electromagnetic fields (RF-EMFs) within custom-built reverberation chambers, using temperature capsules implanted within the intraperitoneal cavity and data transmitted via radiotelemetry. Comparing RF-EMF exposures (at Whole-Body Average-Specific Absorption Rate [WBA-SAR] levels of 0.1, 0.4, and 4 W/kg) to the sham exposed condition, we identified a statistically significant peak increase in CBT after 26 min of RF-EMF exposure at 4 W/kg (+0.49°C), but not in the 0.1 or 0.4 W/kg conditions at the same timepoint. In the last 30 min of the RF-EMF exposure, temperature was significantly increased in both the 4 W/kg (0.62°C) and 0.4 W/kg (0.14°C) conditions, but not 0.1 W/kg, when compared to sham. After 20 min following cessation of exposure, post temperature was still significantly higher in the 4 W/kg condition when compared to the sham (0.37°C), but not in either 0.1 or 0.4 W/kg. Based on our findings, it is apparent that rats can effectively compensate for increased thermal loads of up to 4 W/kg as the maximum temperature rise was substantially lower than 1°C. In addition, the elevated CBT during exposure in the 4 W/kg condition was significantly reduced immediately after exposure cessation, indicating that measures of CBT following RF-EMF exposure cessation may not reflect maximum RF-EMF-mediated changes in the CBT of rats. Bioelectromagnetics. 00:00–00, 2025. © 2025 Bioelectromagnetics Society.