Georeferencing of Personal Exposure to Radiofrequency Electromagnetic Fields from Wi-Fi in a University Area

The exposure analysis of the long-term broadband EMF monitoring in the campus area of the University of Novi Sad

Due to wide prevalence of electromagnetic field (EMF) sources in human surrounding, EMF-level measurements and corresponding exposure assessment have imposed as an important topic. With an intention to present an approach to the long-term exposure assessment in EMF RATEL network, this paper conveys a high-level statistical analysis of the high-frequency exposure data, acquired during the 5-y time period, for the case study of monitoring sensor installed in the area of the Novi Sad University campus. Time series of exposure values were averaged on a daily, weekly, and monthly basis, and their yearly comparison was performed. Results showed clear differences between the day and night hours, as well between working and weekend days. Regarding exposure values, averaged on the monthly basis, the impact of COVID-19 pandemic in 2020 and 2021 can be noticed. Finally, the highest obtained exposure values (electric field squared) were 22 times below the maximal allowable level, according to the Serbian legislation.

Electromagnetic fields regulate iron metabolism in living organisms: A review of effects and mechanism

The emergence, evolution, and spread of life on Earth have all occurred in the geomagnetic field, and its extensive biological effects on living organisms have been documented. The charged characteristics of metal ions in biological fluids determine that they are affected by electromagnetic field forces, thus affecting life activities. Iron metabolism, as one of the important metal metabolic pathways, keeps iron absorption and excretion in a relatively balanced state, and this process is precisely and completely controlled. It is worth paying attention to how the iron metabolism process of living organisms is changed when exposed to electromagnetic fields. In this paper, the processes of iron absorption, storage and excretion in animals (mammals, fish, arthropods), plants and microorganisms exposed to electromagnetic field were summarized in detail as far as possible, in order to discover the regulation of iron metabolism by electromagnetic field. Studies and data on the effects of electromagnetic field exposure on iron metabolism in organisms show that exposure profiles vary widely across species and cell lines. This process involves a variety of factors, and the complexity of the results is not only related to the magnetic flux density/operating frequency/exposure time and the heterogeneity of the observed object. A systematic review of the biological regulation of iron metabolism by electromagnetic field exposure will not only contributes to a more comprehensive understanding of its biological effects and mechanism, but also is necessary to improve human awareness of the health related risks of electromagnetic field exposure.

Effects of radiofrequency field from 5G communication on fecal microbiome and metabolome profiles in mice

With the rapid development of 5G networks, the influence of the radiofrequency field (RF) generated from 5G communication equipment on human health is drawing increasing attention in public. The study aimed at assessing the effects of long-term exposure to 4.9 GHz (one of the working frequencies of 5G communication) RF field on fecal microbiome and metabolome profiles in adult male C57BL/6 mice. The animals were divided into Sham group and radiofrequency group (RF group). For RF group, the mice were whole body exposed to 4.9 GHz RF field for three weeks, 1 h/d, at average power density (PD) of 50 W/m2. After RF exposure, the mice fecal samples were collected to detect gut microorganisms and metabolites by 16S rRNA gene sequencing and LC-MS method, respectively. The results showed that intestinal microbial compositions were altered in RF group, as evidenced by reduced microbial diversity and changed microbial community distribution. Metabolomics profiling identified 258 significantly differentially abundant metabolites in RF group, 57 of which can be classified to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Besides, functional correlation analysis showed that changes in gut microbiota genera were significantly correlated with changes in fecal metabolites. In summary, the results suggested that altered gut microbiota and metabolic profile are associated with 4.9 GHz radiofrequency exposure.

Assessment of the electromagnetic field exposure due to wireless communication technologies in two university campuses of medellin, Colombia

Exposure to radiofrequency electromagnetic fields (RF-EMFs) is considered an area of significant importance in the medical and scientific community. However, the availability of exposure data for indoor and outdoor locations in universities is limited and currently inconsiderate in Latin America. The aim of this work was to evaluate the electric field levels due to mobile telecommunication technologies and Wi-Fi to which students and faculty staff from two campuses of a higher education institution are exposed. Using a portable spectrum analyzer, we carried out 516 short-term measurements in the 800-3000 MHz frequency range at both indoor and outdoor locations. These locations were chosen to cover all areas of the assessed buildings. The electric field differences between floors and buildings are discussed. Finally, we compared the electric field levels with exposure limits. The highest electric field level measured was 13.97 V/m at the 850 MHz band. However, the average electric field values were below 2 V/m. The greatest contribution to the total electric field was due to sources using the 850 MHz and 1900 MHz bands (98%), while the contribution of the Wi-Fi network was low (1.0%). The results show that all the electric field levels measured were lower than the ICNIRP reference levels for radio-frequency exposure.

Personal exposure from free Wi-Fi hotspots in downtown Mexico City

In 2019, the Government of Mexico City implemented actions that allowed citizens to approach a free Wi-Fi hotspot, where more than 13000 points have been installed throughout the city. In this work, we present the results of the measurements of personal exposure to Radiofrequency Electromagnetic Fields carried out in Plaza de la Constitución, better known as Zócalo located in the center of Mexico City. The measurements were taken by one of the researchers while walking on a weekday morning and afternoon, in different microenvironments (on the street, on public transport: subway, at the Zócalo, and finally, at home). We also carry out spot measurements in the center of the Zócalo. Subsequently, we carried out a comparative analysis of the different microenvironments, through box plot and violin plot, and we elaborate georeferenced and interpolated maps with intensity levels through the Kriging method, using the Geographic Information System. The Kriging interpolation gives us a good visualization of the spatial distribution of RF-EMF exposure in the study area, showing the highest and lowest intensity levels. The mean values recorded at the measured points in the Zócalo were 326 μW/m2 in the 2.4- to 2.5-GHz Wi-Fi band and 2370 μW/m2 in the 5.15- to 5.85-GHz Wi-Fi band. In the case of the mean values recorded on the street, they were 119 μW/m2 in the 2.4- to 2.5-GHz frequency band and 31.8 μW/m2 in the 5.15- to 5.85-GHz frequency band, like the values recorded at home, 122 μW/m2 and 33.9 μW/m2, respectively. All values are well below the reference levels established by the International Commission on Non-Ionizing Radiation Protection.

Comment on Martin L. Pall "Millimeter (MM) wave and microwave frequency radiation produce deeply penetrating effects: the biology and the physics", Rev Environ Health, 2021

In this letter, we present some comments related to Pall's publication, in which Pall states that the electric field disappears after a few centimeters and that the magnetic field continues progressing within the studied material.

Radiofrequency Exposure Levels in Greece

Medical Physics Department (Medical School, University of Thessaly) participated in a Greek National EMF research program (EDBM34) with the scope to measure and evaluate radiofrequency (RF) exposure (27-3000 MHz) in areas of sensitive land use. A thousand (1000) measurements were carried out at two "metropolitan locations" (Athens and Thessaloniki: 624 points) and several rest urban/rural locations (376 points). SRM 3006 spectrum analyzer manufactured by Narda Safety Test Solutions was used. The broadband mean electric field in metropolitan areas was 0.41 V/m, while in the rest of Greece was 0.36 V/m. In metropolitan areas, the predominant RF source was the TV and Radio FM signals (36.2% mean contribution to the total RF exposure level). In the rest areas, the predominant source was the systems of the meteorological and military/defensive service (31.1%). The mobile sector contributed 14.9% in metropolitan areas versus 12.2% in the rest of Greece. The predominant mobile source was 900 MHz in both cases (4.5% in metropolitan areas vs. 3.3% in the rest of Greece). The total exposure from all RF sources complied with the International Commission on Non-Ionizing Radiation Protection (ICNIRP) 2020 safety guidelines [ICNIRP, 2020]. The maximum exposure level was 0.129% of the limit for the metropolitan areas vs. 0.110% for the rest of Greece. Nonremarkable differences between metropolitan areas' exposure and the rest of Greece. In most cases, new 5 G antennas will be added to the existing base stations. Thus, the total exposure may be increased, leading to higher safety distances. © 2023 Bioelectromagnetics Society.

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.

Comparison of personal exposure to Radiofrequency Electromagnetic Fields from Wi-Fi in a Spanish university over three years

In this work we present the personal exposure levels to Radiofrequency Electromagnetic Fields (RF-EMF) from Wireless Fidelity (Wi-Fi) 2.4 GHz and 5.85 GHz bands in a Spanish university, specifically, at the Faculty of Computer Science Engineering at the University of Castilla-La Mancha (Albacete, Spain). We present results from three years, 2017, 2018 and 2019 in the same study place and points; and measurements carried out in 2022 inside a classroom and inside a professor's office, with the aim to compare the measurements and verify compliance with reference levels established by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The minimum average was 0.0900 μW/m² in the 2.4 GHz Wi-Fi, in 2019, and the maximum average was 211 μW/m² in the 5.85 GHz Wi-Fi in 2017, around the building. Comparing the measurements carried out inside the classroom with students and without students, we identified that the maximum value was 278 μW/m² (classroom with students, in the 5.85 GHz Wi-Fi band) and the minimum value was 37.9 μW/m² (classroom without students, in the 5.85 GHz Wi-Fi band). Finally, comparing the results of all the measurements (average values) inside the classroom and inside a professor's office, the maximum value was 205 μW/m² (in the 5.85 GHz Wi-Fi band) inside the classroom with students, and the minimum value was 0.217 μW/m² inside a professor's office (in the 2.4 GHz Wi-Fi band). These values in no case exceed the limits established by the International Commission on Non-Ionizing Radiation Protection, 10 W/m² for general public exposure.

Measurement of personal radio frequency exposure in Japan: The Hokkaido Study on the Environment and Children's health

The opportunities for exposure to radiofrequency electromagnetic fields (RF-EMF) among children are increasing. Children's exposure to RF-EMF in Japan was recorded using a personal exposure meter (ExpoM-RF), and factors associated with the exposure examined. A total of 101 children, aged 10-15 years old, participated in the prospective birth cohort "Hokkaido study". RF-EMF data were recorded in the 700 MHz-5.8 GHz frequency range for 3 days. The recorded data were summarized into six groups of frequency bands: downlink from mobile phone base stations (DL), uplink from mobile phones to a base station (UL), Wireless Local Area Network (LAN), terrestrial digital TV broadcasting (digital TV), 2.5 GHz and 3.5 GHz Time Division Duplex (TDD), 1.9 GHz TDD, and total (the summation of power density in all measured frequency bands). A questionnaire was used to document the internet environment (at home) and mobile phone usage. Personal RF-EMF exposure in Japanese children was lower than that reported in studies in Europe. The DL signals from mobile phone base stations were the most significant contributors to total exposure, while Wireless LAN and digital TV were only higher at home. The urban residence was consistently associated with increases in the four groups of frequency bands (DL, UL, digital TV, and TDD). TDD level has several associations with mobile phone usage (calls using mobile phones, video viewing, text message service, and online game). The association between inattention/hyperactivity subscale of the Strengths and Difficulties Questionnaire (SDQ) and higher Wireless LAN exposure at nighttime was also noted. Further studies with additional data will shed light on factors involved in RF-EMF exposure among Japanese children.

Comparison of mobile phone usage and physical activity on glycemic status, body composition & lifestyle in male Saudi mobile phone users

Background

&Objectives: This study aimed to compare the effects of mobile phone usage and physical activity on HbA1c, body composition, and lifestyle among male Saudi Arabian mobile phone users.

Methods

The study was conducted in the Department of Physiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia from July 2020 to July 2021. The study sample consisted of 203 non-smoker male Saudi participants aged from 20 to 60 years who used mobile phones. Personal information was obtained through interviews using a proforma. The participants were divided into three groups according to their daily mobile phone usage: Group (1): less than 2 h, Group (2): 2–3 h, and Group (3): more than 3 h, and according to their physical activities: Group (1): sedentary, Group (2): average, and Group (3): athletes. Glycated Hemoglobin (HbA1c), Bioelectrical Impedance Analysis (BIA), and (SF) 36- items survey was performed.

Results

The mean age of 203 Saudi male adult participants was 28.0 ± 10.4 years. Mobile phone usage in the less than 2 h group was (33.5%), between 2-3 h (22.7%), and more than 3 h (43.8%) respectively. The mean age of Group (3), who used mobile phones for more than 3 h, was the lowest (23.9 ± 5.7). The results showed that HbA1C levels were almost equal in all three groups (5.8 ± 0.4, 5.7 ± 0.4, and 5.7 ± 0.3 respectively). In addition, emotional well-being and social functioning showed insignificant decreases in the more than 3 h group compared to other groups of mobile phone usage (69.3 ± 15.7, 70.9 ± 15.5, 65.2 ± 16.0, p = .091 and 82.9 ± 201, 81.2 ± 18.7, 77.6 ± 21.6, p = .267) respectively. No effect was detected between groups regarding various body compositions. Regarding physical activity classifications: the sedentary group constituted (36%) of the sample, whereas the average and athlete groups represented (53.7%) and (10.3%) of the total sample respectively. There was a significant decrease in BMI (29.6 ± 7.8, 25.3 ± 5.1,24.7 ± 5.6, p = .000), fat mass (24.7 ± 15.0, 17.1 ± 9.1, 15.3 ± 10.6, p = .000), and free fat mass (64.0 ± 10.2, 56.8 ± 8.7, 57.5 ± 8.0, p = .000) in the average and the athletic groups compared to the sedentary group. No significant difference was found in HbA1c between physical activity groups (5.8 ± 0.4, 5.7 ± 0.4, 5.7 ± 0.4, p = .218).

Conclusions

Mobile phone usage does not affect HbA1c and body composition parameters. Furthermore, we found the youngers used mobile phones longer than others. Insignificant decrease in emotional well-being and social functioning parameters of the style of life due to long mobile phone usage which needs more attention.

Base transceiver station antennae exposure and workers' health

BACKGROUND

With the rapid development of technologies related to the communications industry, human exposure to electromagnetic fields has increased during recent decades. The study aimed at investigating the effect of exposure to waves emitted from the base transceiver stations (BTS) on workers' health.

METHODS

240 workers (120 BTS maintenance workers (case group) and 120 office staff (control group)) participated in the study. In order to determine the general health conditions in two groups, along with electromagnetic waves exposure measurement, the general health questionnaire (GHQ) was completed and the data on blood parameters were assessed.

RESULTS

The mean age and job experience in the case and control groups were 34.1 ± 4.8 and 10.1 ± 6 years and 31.6 ± 5.5 and 8.8 ± 7 years, respectively. According to the GHQ results, only anxiety and insomnia subscales showed a significant difference between the two groups. The white blood cell and red blood cell counts in the case and control groups were 6715.6 ± 1591 and 7594 ± 2416, 5.3×10⁶±4.6×10⁵ and 5.05×10⁶±5.39×10⁵ per ml, respectively. Analysis of the results showed that the difference between the two groups was significant.

CONCLUSION

The results revealed that blood parameters in the BTS operators showed more changes. Thus, it can be concluded that these health impacts result from occupational exposure to BTS waves.

Physical units to report intensity of electromagnetic wave

The aim of this work is to propose a consensus to scientific community that handles personal exposimeters, which measure intensity of an electromagnetic wave (W/m²). To express the intensity of an electromagnetic wave there is a duality in the way of expressing it. Some scientists prefer to use W/m² while others use V/m, which is a unit of the electric field. There is also a duality in the name, sometimes it is called it power flux density and some other times, wave intensity. We believe that this second name is more appropriate from the point of view of physics. We suggest expressing intensity of an electromagnetic wave in W/m² instead of giving the value of their electric field which is measured in V/m. There is a quadratic relation between electric field and intensity of the wave, and it is necessary to do a mathematical operation, so in our opinion, it is preferable to use W/m² which directly gives us the value of the measured intensity. Furthermore, if the intensity is very low, it may be expressed in μW/m² and with only three significant figures, due to sensitivity of the current exposimeters used.

Wi-fi related radiofrequency electromagnetic fields (RF-EMF): a pilot experimental study of personal exposure and risk perception

The impact of providing people with an objectively measured personal radiofrequency electromagnetic fields (RF-EMF) exposure information on the risk perception of people is not well understood. We conducted an experimental study, among three groups of participants, to investigate the risk perception of people towards RF-EMF from Wi-Fi sources (ISM 2.4 GHz) by providing participants with either basic text, precautionary information, or a summary of their personal RF-EMF exposure measurement levels. Participants provided with personal RF-EMF exposure measurement information were more confident in protecting themselves from RF-EMF exposure, compared to those provided with only basic information. Nonetheless, neither the exposure perception nor the risk perception of people to Wi-Fi related RF-EMF differed by the type of information provided. The measured Wi-Fi signal levels were far below international exposure limits. Furthermore, self-rated levels of personal RF-EMF exposure perception were not associated with objectively measured RF-EMF exposure levels. Providing people with objectively measured information may help them build confidence in protecting themselves from Wi-Fi related RF-EMF exposure.

Protocol for personal RF-EMF exposure measurement studies in 5th generation telecommunication networks

BACKGROUND

The general population is exposed to Radio-Frequency Electromagnetic Fields (RF-EMFs) used by telecommunication networks. Previous studies developed methods to assess this exposure. These methods will be inadequate to accurately assess exposure in 5G technologies or other wireless technologies using adaptive antennas. This is due to the fact that 5G NR (new radio) base stations will focus actively on connected users, resulting in a high spatio-temporal variations in the RF-EMFs. This increases the measurement uncertainty in personal measurements of RF-EMF exposure. Furthermore, a user's exposure from base stations will be dependent on the amount of data usage, adding a new component to the auto-induced exposure, which is often omitted in current studies.

GOALS

The objective of this paper is to develop a general study protocol for future personal RF-EMF exposure research adapted to 5G technologies. This protocol will include the assessment of auto-induced exposure of both a user's own devices and the networks' base stations.

METHOD

This study draws from lessons learned from previous RF-EMF exposure research and current knowledge on 5G technologies, including studies simulating 5G NR base stations and measurements around 5G NR test sites.

RESULTS

To account for auto-induced exposure, an activity-based approach is introduced. In survey studies, an RF-EMF sensor is fixed on the participants' mobile device(s). Based on the measured power density, GPS data and movement and proximity sensors, different activities can be clustered and the exposure during each activity is evaluated. In microenvironmental measurements, a trained researcher performs measurements in predefined microenvironments with a mobile device equipped with the RF-EMF sensor. The mobile device is programmed to repeat a sequence of data transmission scenarios (different amounts of uplink and downlink data transmissions). Based on simulations, the amount of exposure induced in the body when the user device is at a certain location relative to the body, can be evaluated.

CONCLUSION

Our protocol addresses the main challenges to personal exposure measurement introduced by 5G NR. A systematic method to evaluate a user's auto-induced exposure is introduced.

Personal Exposure Assessment to Wi-Fi Radiofrequency Electromagnetic Fields in Mexican Microenvironments

In recent years, personal exposure to Radiofrequency Electromagnetic Fields (RF-EMF) has substantially increased, and most studies about RF-EMF with volunteers have been developed in Europe. To the best of our knowledge, this is the first study carried out in Mexico with personal exposimeters. The main objective was to measure personal exposure to RF-EMF from Wireless Fidelity or wireless Internet connection (Wi-Fi) frequency bands in Tamazunchale, San Luis Potosi, Mexico, to compare results with maximum levels permitted by international recommendations and to find if there are differences in the microenvironments subject to measurements. The study was conducted with 63 volunteers in different microenvironments: home, workplace, outside, schools, travel, and shopping. The mean minimum values registered were 146.5 μW/m² in travel from the Wi-Fi 2G band and 116.8 μW/m² at home from the Wi-Fi 5G band, and the maximum values registered were 499.7 μW/m² and 264.9 μW/m² at the workplace for the Wi-Fi 2G band and the Wi-Fi 5G band, respectively. In addition, by time period and type of day, minimum values were registered at nighttime, these values being 129.4 μW/m² and 93.9 μW/m², and maximum values were registered in the daytime, these values being 303.1 μW/m² and 168.3 μW/m² for the Wi-Fi 2G and Wi-Fi 5G bands, respectively. In no case, values exceeded limits established by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Of the study participants (n = 63), a subgroup (n = 35) answered a survey on risk perception. According to these results, the Tamazunchale (Mexico) population is worried about this situation in comparison with several European cities; however, the risk perception changes when they are informed about the results for the study.

A statistical analysis for RF-EMF exposure levels in sensitive land use: A novel study in Greek primary and secondary education schools

BACKGROUND

The increasing popularity of mobile phones and the expansion of network infrastructure in Greece have given rise to public concerns about potential adverse health effects on sensitive groups, such as children, from long-term radio-frequency (RF) electromagnetic fields (EMFs) exposure. According to Greek law the RF limit values for sensitive land use (schools, hospitals, etc) have been set to 60% of those recommended by EU standard and 70% for the general population.

AIMS

The objective of this study is to estimate mean RF-EMF exposure levels of Greek primary and secondary edu-cation schools located in urban environments.

METHODS

In selecting the minimum sample size we observed that the variance of the random variable was unknown, as there has been no similar previous study in Greece with schools as the target population. For this reason, a pilot study was conducted in 65 schools in order to estimate the standard deviation of the population and use that value to calculate the minimum sample size. Using a random machine num-ber generator contracted in R based on pseudo-random number algorithms, we obtained a sample of 492 schools in order to estimate the mean value for RF-EMF radiation sources in the 27 MHz-3GHz range in schools within urban environments in Greece.

RESULTS

We have performed the appropriate hypothesis test to get that there is sufficient evidence at the α = 0.05 level to conclude that the mean value for RF-EMF radiation sources in the 27 MHz-3GHz range, in schools within urban environments in Greece, is equal to 0.42 V/m, also a 95% confidence interval for the mean value is (0.4024, 0.4395)] with central value equal to the sample mean 0.4209.

CONCLUSION

In conclusion, the exposure level in the locations tested are both below 60% of the highest limit set by ICNIRP (International Commision on Non-Ionizing Radiation Protection) regarding sensitive land use.

Comparative Analysis of User Exposure to the Electromagnetic Radiation Emitted by the Fourth and Fifth Generations of Wi-Fi Communication Devices

A suitable metric to describe human exposure to microwaves emitted by wireless communication devices is still incomplete. By using both theoretical analysis and experimental validation (in controlled and real deployed networks), we analyze and compare the specificity of exposure due to data transmissions in different configurations of fourth and fifth generation wireless fidelity (Wi-Fi) standards in the proximity of a mobile device. Measurements made use of the capability of the amplitude probability density incorporated in a real-time spectrum analyzer, proving its agility of highlighting different user exposure profiles. The results are presented comparatively and indicate that, in Wi-Fi networks, the modulation and coding scheme (MCS) should be used together with the duty cycle for an improved exposure assessment. The present work introduces the emitted energy density per bit in describing the user's exposure to Wi-Fi signals and proves its superiority in characterizing the true levels of exposure for the IEEE 802.11n and 802.11ac standards of communication.