Bioelectromagnetics最新文献

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.

Short-dipole diode sensors loaded with highly resistive lines are commonly used to measure the time-averaged square of the high-frequency electromagnetic field amplitude directly. Their precision, simplicity, broadband, high dynamic range capability, and minimal scattering make them ideal for application in the near-field of sources, particularly for demonstrating compliance with exposure limits. However, the usage of these sensors to cover multiple orders of magnitude of field amplitude requires signal-specific linearization of the sensor response. Traditionally, linearization had been performed for each signal or modulation by measurement and, more recently, by simulations based on a calibrated sensor model. These approaches have become prohibitively expensive with the launch of the fifth generation of mobile communication (5G), which added thousands of diverse and complex modulation schemes. In response to these challenges, we first developed an innovative approach to accelerate sensor model simulations with an enhancement of accuracy, which allows us to subsequently establish a data set comprising a large number of probe parameters and signal characteristic configurations. Subsequently, a physics-informed neural network (PINN) was trained with readily accessible signal characteristics to obtain on-the-fly linearization parameters with acceptable uncertainties across the relevant dynamic range. In contrast to traditional artificial intelligence (AI) models that predominantly rely on pattern recognition from precomputed data, our approach ensures that the model captures the intrinsic relationships and system dynamics inherent to the physical phenomena under study. Our AI-based approach achieves an error below 0.4 dB at peak specific absorption rate (SAR) values of up to $��>��200��{��\text{W kg}��}^{�-�1�}�$. In addition, AI accelerates the determination of linearization parameters by a factor $��>�$ 34,000$��\times �$

The introduction of 5G networks has raised public concerns about potential changes in environmental electromagnetic field (EMF) exposure. This study analyzes continuous monitoring data collected over 2 years (August 2022–October 2024) from 13 frequency-selective monitoring sensors located in Greece's five largest cities. Focusing on the 3.6 GHz band, we evaluated trends and weekly variations in EMF levels. Results indicated a gradual increase in EMF exposure at 3.6 GHz, driven by the growing penetration of 5G infrastructure and devices. Notably, this band exhibited higher maximum-to-median power density ratios compared to other frequency bands, attributable to active antenna systems' characteristics and traffic variations. Applying the ICNIRP 2020 guidelines, we found that 30-min averaged values significantly reduced these variations. All measured EMF levels, including maximum values, remained well below Greek and international safety limits. These findings, especially the increasing trend identified for the EMF levels, underscore the importance of continuous monitoring networks for assessing EMF exposure to existing and emerging telecommunications networks and ensuring compliance with safety standards.