Exposure to radiofrequency electromagnetic fields: Comparison of exposimeters with a novel body-worn distributed meter

A comprehensive review of 5G NR RF-EMF exposure assessment technologies: fundamentals, advancements, challenges, niches, and implications

This review offers a detailed examination of the current landscape of radio frequency (RF) electromagnetic field (EMF) assessment tools, ranging from spectrum analyzers and broadband field meters to area monitors and custom-built devices. The discussion encompasses both standardized and non-standardized measurement protocols, shedding light on the various methods employed in this domain. Furthermore, the review highlights the prevalent use of mobile apps for characterizing 5G-NR radio network data. A growing need for low-cost measurement devices is observed, commonly referred to as "sensors" or "sensor nodes," that are capable of enduring diverse environmental conditions. These sensors play a crucial role in both microenvironmental surveys and individual exposures, enabling stationary, mobile, and personal exposure assessments based on body-worn sensors, across wider geographical areas. This review revealed a notable need for cost-effective and long-lasting sensors, whether for individual exposure assessments, mobile (vehicle-integrated) measurements, or incorporation into distributed sensor networks. However, there is a lack of comprehensive information on existing custom-developed RF-EMF measurement tools, especially in terms of measuring uncertainty. Additionally, there is a need for real-time, fast-sampling solutions to understand the highly irregular temporal variations EMF distribution in next-generation networks. Given the diversity of tools and methods, a comprehensive comparison is crucial to determine the necessary statistical tools for aggregating the available measurement data.

Is the sustainability of exposure to non-ionizing electromagnetic radiation possible?

Technological advances imply an increase in artificially generating sources of electromagnetic fields (EMF), therefore, resulting in a permanent exposure of people and the environment (electromagnetic pollution). Inconsistent results have been published considering the evaluated health effects. The purpose of this study was to review scientific literature on EMF to provide a global and retrospective perspective, on the association between human exposure to non-ionizing radiation (NIR, mainly radiofrequency-EMF) and health and environmental effects. Studies on the health effects of 5G radiation exposure have not yet been performed with sufficient statistical power, as the exposure time is still relatively short and also the latency and intensity of exposure to 5G. The safety standards only consider thermal effects, do not contemplate non-thermal effects. We consider relevant to communicate this knowledge to the general public to improve education in this field, and to healthcare professionals to prevent diseases that may result from RF-EMF exposures.

Evaluating radiofrequency electromagnetic field exposure in confined spaces: a systematic review of recent studies and future directions

This study reviews recent research on Radiofrequency Electromagnetic Field (RF-EMF) exposure in confined environments, focusing on methodologies and parameters. Studies typically evaluate RF-EMF exposure using an electric field and specific absorption rate but fail to consider temperature rise in the tissues in confined environments. The study highlights the investigation of RF-EMF exposure in subterranean environments such as subways, tunnels and mines. Future research should evaluate the exposure of communication devices in such environments, considering the surrounding environment. Such studies will aid in understanding the risks and developing effective mitigation strategies to protect workers and the general public.

The effects of radiofrequency electromagnetic fields exposure on tinnitus, migraine and non-specific symptoms in the general and working population: A systematic review and meta-analysis on human observational studies

BACKGROUND

Applications emitting radiofrequency electromagnetic fields (RF-EMF; 100 kHz to 300 GHz) are widely used for communication (e.g. mobile phones), in medicine (diathermy) and in industry (RF heaters).

OBJECTIVES

The objective is to systematically review the effects of longer-term or repeated local and whole human body radiofrequency electromagnetic field (RF-EMF) exposure on the occurrence of symptoms. Primary hypotheses were tinnitus, migraine and headaches in relation to RF-EMF exposure of the brain, sleep disturbances and composite symptom scores in relation to whole-body RF-EMF exposure.

METHODS

Eligibility criteria: We included case-control and prospective cohort studies in the general population or workers estimating local or whole-body RF-EMF exposure for at least one week.

INFORMATION SOURCES

We conducted a systematic literature search in various databases including Web of Science and Medline. Risk of bias: We used the Risk of Bias (RoB) tool developed by OHAT adapted to the topic of this review.

SYNTHESIS OF RESULTS

We synthesized studies using random effects meta-analysis.

RESULTS

Included studies: We included 13 papers from eight distinct cohort and one case-control studies with a total of 486,558 participants conducted exclusively in Europe. Tinnitus is addressed in three papers, migraine in one, headaches in six, sleep disturbances in five, and composite symptom scores in five papers. Only one study addressed occupational exposure.

SYNTHESIS OF RESULTS

For all five priority hypotheses, available research suggests that RF-EMF exposure below guideline values does not cause symptoms, but the evidence is very uncertain. The very low certainty evidence is due the low number of studies, possible risk of bias in some studies, inconsistencies, indirectness, and imprecision. In terms of non-priority hypotheses numerous exposure-outcome combinations were addressed in the 13 eligible papers without indication for an association related to a specific symptom or exposure source.

DISCUSSION

Limitations of evidence: This review topic includes various challenges related to confounding control and exposure assessment. Many of these aspects are inherently present and not easy to be solved in future research. Since near-field exposure from wireless communication devices is related to lifestyle, a particular challenge is to differentiate between potential biophysical effects and other potential effects from extensive use of wireless communication devices that may compete with healthy behaviour such as sleeping or physical activity. Future research needs novel and innovative methods to differentiate between these two hypothetical mechanisms.

INTERPRETATION

This is currently the best available evidence to underpin safety of RF-EMF. There is no indication that RF-EMF below guideline values causes symptoms. However, inherent limitations of the research results in substantial uncertainty.

OTHER

Funding: This review was partially funded by the WHO radioprotection programme.

REGISTRATION

The protocol for this review has been registered in Prospero (reg no CRD42021239432) and published in Environment International (Röösli et al., 2021).

Comparison of ambient radiofrequency electromagnetic field (RF-EMF) levels in outdoor areas and public transport in Switzerland in 2014 and 2021

Mobile communication technology has evolved rapidly over the last ten years with a drastic increase in wireless data traffic and the deployment of new telecommunication technologies. The aim of this study was to evaluate the ambient radiofrequency electromagnetic field (RF-EMF) levels and temporal changes in various microenvironments in Switzerland in 2014 and 2021. We measured the ambient RF-EMF levels in V/m in the same 49 outdoor areas and in public transport in 2014 and 2021 using portable RF-EMF exposure meters carried in a backpack. The areas were selected to represent some typical types of microenvironments (e.g. urban city centres, suburban and rural areas). We calculated the summary statistics (mean, percentiles) in mW/m2 and converted back to V/m for each microenvironment. We evaluated the distribution and the variability of the ambient RF-EMF levels per microenvironment types in 2021. Finally, we compared the ambient RF-EMF mean levels in 2014 and 2021 using multilevel regression modelling. In outdoor areas, the average ambient RF-EMF mean levels per microenvironment in 2021 ranged from 0.19 V/m in rural areas to 0.43 V/m in industrial areas (overall mean: 0.27 V/m). In public transports, the mean levels were 0.27 V/m in buses, 0.33 V/m in trains and 0.36 V/m in trams. In 2021, mean levels across all outdoor areas were -0.022 V/m lower (95% confidence interval: -0.072, 0.030) than in 2014. Results from our comprehensive measurement study across Switzerland suggest that RF-EMF levels in public places have not significantly changed between 2014 and 2021 despite an 18-fold increase in mobile data transmission during that period. The absence of temporal changes may be owed to the shift to newer mobile communication technologies, which are more efficient.

Measurement studies of personal exposure to radiofrequency electromagnetic fields: A systematic review

The last 25 years have seen an increase in the number of radiofrequency sources with the global adoption of smartphones as primary connectivity devices. The objective of this work was to review and evaluate the measured studies of personal exposure to Radiofrequency Electromagnetic Fields (RF-RMF) and meet the basic quality criteria eligible for inclusion in this Review, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, following the eligibility criteria of the PECO (Population, Exposure, Comparator, and Outcome) methodology, and the instrument for critical reading Critical Appraisal Skills Programme Español (CASPe). We systematically reviewed the works published between January 1, 1998, and December 31, 2021, yielding 56 publications. Of the different types of studies in which personal exposure to RF-EMF has been measured with two measurement methodologies can be highlighted: Personal measurements with volunteers and Personal measurements with a trained researcher (touring a specific area, one or several microenvironments, an entire city, walking or in some means of transport). Personal exposimeters were used in 83% of the studies. The lowest mean was measured in Egypt with a value of 0.00100 μW/m² (1.00 nW/m²) in 2007 and the highest mean was measured in Belgium with a value of 285000 μW/m² (0.285 W/m²) in 2019. The results of our study confirm that RF-EMF exposure levels are well below the maximum levels established by the ICNIRP guidelines.

Instruments to measure environmental and personal radiofrequency-electromagnetic field exposures: an update

Modern human populations are exposed to anthropogenic sources of radiofrequency-electromagnetic fields (RF-EMFs), primarily to telecommunication and broadcasting technologies. As a result, ongoing concerns from some members of the public have arisen regarding potential health effects following RF-EMF exposures. In order to monitor human RF-EMF exposures and investigate potential health effects, an objective assessment of RF-EMF exposures is necessary. Accurate dosimetry is essential for any investigation of potential associations between RF-EMF exposure and health effects in human populations. This review updates state-of-the-art knowledge of currently available RF-EMF exposure assessment tools applicable in human epidemiological studies. These tools cater for assessing RF-EMF exposures in human environments; through mobile phone-based tools or other standalone tools. RF-EMF exposure assessment has been significantly improved through the application of some of these tools in recent years.

Three Quarters of a Century of Research on RF Exposure Assessment and Dosimetry-What Have We Learned?

This commentary, by three authors with an aggregate experience of more than a century in technology and health and safety studies concerning radiofrequency (RF) energy, asks what has been learned over the past 75 years of research on radiofrequency and health, focusing on technologies for exposure assessment and dosimetry. Research programs on health and safety of RF exposure began in the 1950s, initially motivated by occupational health concerns for military personnel, and later to address public concerns about exposures to RF energy from environmental sources and near-field exposures from RF transmitting devices such as mobile phones that are used near the body. While this research largely focused on the biological effects of RF energy, it also led to important improvements in exposure assessment and dosimetry. This work in the aggregate has made RF energy one of the best studied potential technological hazards and represents a productive response by large numbers of scientists and engineers, working in many countries and supported by diverse funding agencies, to the ever rapidly evolving uses of the electromagnetic spectrum. This review comments on present needs of the field, which include raising the quality of dosimetry in many RF bioeffects studies and developing improved exposure/dosimetric techniques for the higher microwave frequencies to be used by forthcoming communications technologies. At present, however, the major uncertainties in dosimetric modeling/exposure assessment are likely to be related to the inherent variability in real-world exposures, rather than imprecision in measurement technologies.