‘In our experiment, with a short [Wi-Fi & DECT cordless phone] exposure of 10 minutes, EMF effects on HRV were found even though the power flux density was only 0.000275% of the ICNIRP limit…’
This study aims to evaluate the effect of radio-frequency electromagnetic fields (RF-EMF) on heart rate variability (HRV) in adults within a modern office environment. The frequencies used were 1.8 GHz (DECT) and 2.45 GHz (Wi-Fi), with an exposure time of 10 minutes. HRV parameters such as SDNN, RMSSD, LF, and HF were recorded from 60 adults across three runs, totaling 154 recordings. Significant changes were observed in the SDNN parameter, indicating that HRV is a suitable method to detect the effects of RF-EMF on humans under certain conditions. Future studies should consider prolonged exposure and new frequencies like 5G to provide a better description of RF-EMF effects in office environments.
Authors: Sanda Dale, Romulus Reiz, Sorin Popa, Andreea Ardelean-Dale, Julian Keller, Jens Uwe Geier
Publication Date: June 2024
Introduction
The increasing prevalence of radio-frequency electromagnetic fields (RF-EMF) in modern office environments due to devices such as Wi-Fi routers and DECT phones has raised concerns about potential health impacts. This study investigates whether heart rate variability (HRV) can be an effective method to assess these impacts.
Background
Overview of RF-EMF
RF-EMF is a type of non-ionizing radiation used in various wireless communication technologies. With the rapid proliferation of such devices in office environments, there is a growing interest in understanding the biological effects of RF-EMF exposure.
Heart Rate Variability (HRV)
HRV refers to the variation in time intervals between heartbeats. It is a non-invasive marker of autonomic nervous system activity and can reflect the body’s stress levels. HRV parameters such as SDNN (standard deviation of NN intervals), RMSSD (root mean square of successive differences), LF (low-frequency power), and HF (high-frequency power) are commonly used to measure autonomic regulation.
Materials and Methods
Study Design
This single-blinded provocation study was conducted in a controlled laboratory environment. Participants were exposed to RF-EMF at frequencies of 1.8 GHz (DECT) and 2.45 GHz (Wi-Fi) while their HRV parameters were recorded. The study involved 60 adults tested across three separate runs, totaling 154 recordings.
Participants
Participants were recruited from the University of Oradea and surrounding areas. Inclusion criteria required participants to be over 18 years old. They were asked to refrain from smoking or consuming caffeinated beverages two hours before the experiment.
Experimental Procedure
Participants were exposed to RF-EMF in a relaxed sitting position with a 5-lead ECG Holter monitoring their cardiac functions. The exposure protocol included three phases: 10 minutes of no exposure (OFF1), 10 minutes of exposure (ON), and another 10 minutes of no exposure (OFF2).
Technical Setup
The experiments were conducted in a room with minimal background RF exposure. Commercially available wireless equipment was used to simulate office environments. The power flux density during exposure was approximately 16,000 µW/m².
HRV Measurements
HRV parameters were recorded using a BTL-08 ECG Holter device. Parameters measured included SDNN, RMSSD, LF, and HF.
Statistical Analysis
A repeated measures ANOVA was used to analyze the data. Statistical significance was considered at p < 0.05.
Results
Main Findings
The study found significant effects of RF-EMF exposure on HRV parameters, particularly SDNN. A decrease in SDNN was observed during exposure phases, indicating increased stress levels. The patterns of HRV response were consistent across all three runs of the experiment.
Run 1 Results
In the first run, significant decreases in SDNN, RMSSD, LF, and HF were observed from the no exposure phase (OFF1) to the exposure phase (ON).
Run 2 Results
In the second run, a significant increase in SDNN was observed from the exposure phase (ON) to the post-exposure phase (OFF2).
Run 3 Results
In the third run, a significant decrease in SDNN from OFF1 to ON and a significant increase from ON to OFF2 were recorded.
Influence of Cofactors
The study also examined the influence of cofactors such as smoking, coffee consumption, and medication use. It was found that these factors did not significantly alter the response to RF-EMF exposure, suggesting that the observed effects on HRV were primarily due to RF-EMF.
Discussion
Interpretation of Results
The consistent decrease in HRV parameters during RF-EMF exposure suggests that such exposure may induce stress in humans. This finding is significant considering the widespread use of RF-EMF emitting devices in modern office environments.
Comparison with Other Studies
Previous studies have shown mixed results regarding the effects of RF-EMF on HRV. Some studies have found significant effects, while others have not. This study contributes to the growing body of evidence suggesting that RF-EMF exposure can affect autonomic regulation.
Implications for Office Environments
Given the potential health impacts of RF-EMF exposure, it is crucial to consider these findings in the context of workplace safety. Prolonged exposure to RF-EMF in office environments may have cumulative effects on stress levels and overall health.
Recommendations for Future Research
Future studies should investigate the long-term effects of RF-EMF exposure and include a broader range of frequencies, including 5G. Additionally, exploring the effects of varying exposure durations and intensities can provide a more comprehensive understanding of the health impacts of RF-EMF.
Conclusion
This study demonstrates that HRV is a suitable method for detecting the effects of RF-EMF on humans in a modern office environment. The significant changes observed in HRV parameters during exposure highlight the need for further research and potential reconsideration of safety guidelines for RF-EMF exposure in workplace settings.
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