Non-Ionizing Radiation Protection Research Articles

Pregled razlika između preporuka iz 1998. i 2020. godine za ograničavanje izloženosti elektromagnetnim poljima

One of the most important documents defining recommendations for limiting exposure to almost inevitable electromagnetic radiation was released in 1998 by International Commission on Non-Ionizing Radiation Protection (ICNIRP). This document is "Guidelines for Limiting Exposure to Time-varying Electric, Magnetic and Electromagnetic Fields (up to 300 GHz)". However, the growing knowledge about the electromagnetic field (EMF)-tissue interaction and appearance of innovative telecommunication technologies, raised the need for the improvement of these Guidelines. Thus, the ICNIRP published the latest version of its recommendations in 2020. The purpose of this paper is to briefly present some important differences between the ICNIRP 1998 and 2020 Guidelines and to enlighten their reflection on national EMF legislation.

Examining EMF Time Series Using Prediction Algorithms With R

In this study, electric field strength ( E) levels of high-voltage lines were measured monthly in Sütlüce (38°N, 41°E), Muş, Turkey, between 2014 and 2018, and the obtained 60 monthly mean values were used as time series (TS) to forecast next 12 months by using conventional statistical and deep learning (DL) algorithms. In addition to the conventional statistical and DL algorithms developed for R, advanced algorithms, such as long short-term memory (LSTM) and recurrent neural network (RNN) derivative, were also used in the prediction process. We applied a cross-validation technique to the electromagnetic field (EMF) data set obtained in a period of 60 months. Thus, multiple algorithm performances were compared for the same data set. In addition, the electrical field values measured in the Sütlüce neighborhood were found to exceed the International Commission on Non-Ionizing Radiation Protection (ICNIRP) values.

Are Nonprescription Sunglasses in Ethiopian Market Protective for Ultraviolet Radiation?

BackgroundNonprescription sunglasses are available in bulk from authorized and unauthorized vendors. Sunglasses should follow the minimum requirements to sufficiently protect the eyes. In this study, we found that a significant proportion of nonprescription sunglasses available at authorized and unauthorized sources were not protective of ultraviolet radiation.PurposeProtection from harmful ultraviolet radiation with sunglasses minimizes or avoids ocular complications. In developing countries like Ethiopia, sunglasses are imported without regulation. Sunglasses are distributed to the market without regulatory tests for potential causes of ocular complications. The purpose of this study was to determine commercially available nonprescription sunglasses’ ultraviolet radiation protection level.MethodsA total of 74 pairs of nonprescription sunglasses were collected from different parts of the country and tested for ultraviolet radiation protection using ultraviolet detector (anti-radiation UV sun detector, China) instrument. Brand, lens color and average of three readings of ultraviolet radiation protection were recorded. The International Commission on Non-Ionizing Radiation Protection standard followed. Data were entered and analyzed by using SPSS version 20. Descriptive and analytical statistics were performed.ResultsOf the total 74 different pairs of nonprescription sunglasses, 47.3% (35) were obtained from authorized sources and 86.5% (p=0.23) were brand tagged. Only 73.0% (p=0.81) of nonprescription sunglasses were in accordance with the standards and protective to ultraviolet radiation, while the remaining 27.0% (p=0.59) were failed to block the harmful ultraviolet radiation. Upon one sample t-test, the mean ultraviolet radiation protection level of commercially available sunglasses was 392.77 (t-value= −7681.54, p<0.001).ConclusionSignificant proportions of nonprescription sunglasses available from vendors were not protective of ultraviolet radiation and performed below the expected international standards. Reassurance is mandatory before dispensed to users irrespective of source.

ASSESSMENT OF RADIOFREQUENCY RADIATION WITHIN THE VICINITY OF SOME GSM BASE STATIONS IN GHANA: A FOLLOW-UP.

A follow-up of radiofrequency (RF) electromagnetic radiation safety survey at public access points had been carried out in 46 towns on 76 Global Systems for Mobile Communications and Universal Mobile Telecommunication System cell sites in two major cities in Ghana. The core objective was to determine the RF field levels in residential areas, schools and marketplaces and compare the measured results with the guidelines set by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Measurements were made with calibrated log-periodic antenna coupled with a spectrum analyzer. The results obtained varied from 0.0008 to 182mW m -2, which generally shows compliance with the ICNIRP reference levels. The highest value was 1.39 % of the reference.

ASSESSING THE RISK ASSOCIATED WITH SIMULTANEOUS EXPOSURE TO MOBILE COMMUNICATION SIGNALS WITHIN 900–2500 MHZ IN NIGERIA

In this study, the total exposure due to signals within GSM 900, GSM 1800, CDMA-1900 and 3G-2100 frequency bands at 200 m from the foot of 120, 100 and 80 base station masts in the Nigerian cities of Lagos, Ibadan and Abuja, respectively, was assessed. A calibrated hand-held spectrum analyser was used to measure the level of power (in dBm) of each signal within the mobile frequency bands. The exposure quotient associated with the combine electric field strengths from the various frequency bands in each city was estimated. The maximum value of total electric field strength at each point in Lagos, Ibadan and Abuja was 0.83V/m, 0.53V/m and 1.63V/m, respectively. This study shows that the exposure quotient due to the simultaneous exposure to the four bands of mobile communication signals in each city is far less than one, as recommend by International Commission on Non-Ionizing Radiation Protection.

ASSESSING THE COMPLIANCE OF ELECTROMAGNETIC FIELDS RADIATED BY BASE STATIONS AND WIFI ACCESS POINTS WITH INTERNATIONAL GUIDELINES ON UNIVERSITY CAMPUS.

This paper presents a series of electromagnetic field measurements performed on the campus of Ferdowsi University of Mashhad in order to assess the compliance of radiation levels of cellular base stations and WiFi access points with international guidelines. A calibrated, broadband and isotropic probe is used and recommendations of International Telecommunication Union (ITU) are followed up throughout measurements. More than 300 outdoor and indoor locations have been systematically chosen for measurements. The recorded data are post-processed and compared with the guideline of International Commission on Non-Ionizing Radiation Protection (ICNIRP). Measured power densities of WiFi access points are low and do not exceed 1% of the level allowed by ICNIRP. For cellular base stations, measured power density is usually low outdoors, but reaches up to 16% of the allowed radiation level in publicly accessible indoor locations. Comprehensive exposure assessment, as recommended by ITU, has been performed to estimate the maximum possible radiation of one indoor base station. It is concluded that precautionary actions have to be taken by university authorities to limit the presence of students in close proximity to specific indoor antennas. Moreover, comprehensive exposure assessment is more likely necessary for indoor base stations whereas such assessment is not usually required outdoors.

Inter-individual variations in electric fields induced in the brain by exposure to uniform magnetic fields at 50 Hz

The International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines and the Institute of Electrical and Electronics Engineers (IEEE) standard establish safety limits for human exposure to electromagnetic fields. At low frequencies, only a limited number of computational body models or simplified geometrical shapes are used to relate the internal induced electric fields and the external magnetic fields. As a consequence, both standard/guidelines derive the exposure reference levels for the external magnetic field without considering the variability between individuals. Here we provide quantitative data on the variation of the maximum electric field strengths induced in the brain of 118 individuals when exposed to uniform magnetic fields at 50 Hz. We found that individual characteristics, such as age and skull volume, as well as incident magnetic field direction, have a systematic effect on the peak electric field values. Older individuals show higher induced electric field strengths, possibly due to age-related anatomical changes in brain. Peak electric field strengths are found to increase for larger skull volumes, as well as for incident magnetic fields directed along the lateral direction. Moreover, the maximum electric fields provided by the anatomical models used by ICNIRP for deriving exposure limits are considerably higher than those obtained here. On the contrary, the IEEE elliptical exposure model produces a weaker peak electric field strength. Our findings are useful for the revision and harmonization of the current exposure standard and guidelines. The present investigation reduces the dosimetric uncertainty of the induced electric field among different anatomical induction models. The obtained results can be used as a basis for the selection of appropriate reduction factors when deriving exposure reference levels for human protection to low-frequency electromagnetic exposure.

Safety Evaluation of Medical Implants in the Human Body for a Wireless Power Transfer System in an Electric Vehicle

One of the important safety aspects regarding electromagnetic fields is their coupling with medical implants in the human body. In this article, an adult model (Ella), with different medical implants, was exposed to a leaked magnetic field from a wireless power transfer (WPT) system in an electric vehicle, operating at a frequency of 85 kHz, with transferred powers of 3.7, 7.7, 11, and 22 kW. The induced electric field (E-field) in the human model, standing close to the vehicle and sitting inside the vehicle, was evaluated with a prosthetic hip implant, an interlocking nail implant, an InterStim neurostimulator implant, a traditional pacemaker implant, and a leadless pacemaker implant. The results indicated that medical implants influenced the maximum magnitude of the induced E-field and its distribution inside the body. A notable enhancement in the E-field was observed around the implants. In worst-case scenarios, the effects of implant shape and size were investigated. The highest induced E-field (12.68 V/m) was observed with the interlocking nail of length 340 mm for standing posture, which exceeded the prescribed limit of 11.5 V/m in the International Commission on Non-Ionizing Radiation Protection guidelines. The presence of a medical implant in the body likely limits the transferred power of the WPT system, depending on the implant type, size, location, and the body posture.

Factors Influencing the Distribution of Maximum Specific Absorption Rates in Far Field Human Exposure Scenarios

The biological and health effects of electromagnetic fields are a current concern. With the aim of evaluating these effects, it is essential to estimate the levels of human exposure to various types of electromagnetic sources within different environments. These assessments could be performed by determining the current density distributions inside organs or tissues, by modeling the different mechanisms of electromagnetic exposure or even by modelling the development of effects in living beings. Everything should be done while considering various exposure scenarios. In this paper, we have determined, through simulations employing CST Suite Studio software, the specific absorption rates (SARs) values for a human body, averaged from the values for different 10 grams of tissue in different areas of the body, in the case of its exposure to an electromagnetic field generated by a source placed in the far field domain, where the human body is located in an empty room inside a building. We have used our previously tested 3D human body model that has the geometry of an elliptical cylinder. The simulated SAR values have been also compared with the reference levels accepted by the International Commission on Non-Ionizing Radiation Protection and IEEE Standards for Safety Levels for both public and professional exposure.

Effect of Protective Measures on Eye Exposure to Solar Ultraviolet Radiation.

In this study, ocular biologically effective exposure to solar ultraviolet radiation (UVBE) is investigated with six kinds of sun protective measures (spectacle lenses, sunglasses, cap, bonnet, straw hat and under parasol). Ocular UV exposure measurements were performed on manikins during the summer period in Shenyang city (41.64° N, 123.50° E, 66m a.s.l.), China. The measurements include the ocular UV exposure of an unprotected eye and the ambient UV as a control concurrently. Based on the relative spectral weighting factors of the International Commission on Non-Ionizing Radiation Protection (ICNIRP), the ocular biologically effective UV is calculated and compared with the 8-h exposure limits of ICNIRP (30Jm-2 ). The UV index (UVI) of the measurement days is 0-8, and the 8-h (8:00-16:00 China Standard Time, CST) cumulated UVBE of the unprotected eye is 452.0Jm-2 . The 8-h cumulated UVBE of the eye with spectacle lenses, sunglasses, cap, bonnet, straw hat and under parasol are 364.2, 69.1, 51.4, 49.0, 56.8 and 110.2Jm-2 , respectively. Importantly, it should be noted that the eye could be exposed to risk despite protective measures. The 8-h cumulated UVBE of the eye with protection is ca 1.6-15.1 times the exposure limit, respectively. As indicated in the present study, during summer months, high exposure to the sun for more than 30min without eye protection and more than 1h with eye protection is not advisable. The protection measures could effectively reduce the UVBE reaching the eye, yet there is still a high degree of risk when compared with the ICNIRP 8-h exposure limits.

3D Modelling and simulation analysis of electric field under HV overhead line using improved optimisation method

This study proposes a three-dimensional (3D) quasi-static modelling of the electric field produced by high voltage (HV) overhead power lines using charge simulation method combined with intelligent optimisation algorithms, such as particle swarm optimisation, genetic algorithm and grey Wolf optimiser (GWO), to find the optimal values of parameters for an accurate calculation. Results show that the GWO works better than other algorithms. Several parameters affecting the electric field have been studied; it is observed that taking into account the effect of the exact catenary curve of the power line conductors is much more interesting particularly at the mid-span level where the electric field becomes very significant. According to these values, the limits set by the International Commission on Non-Ionising Radiation Protection guidelines for electric field strength are met for occupational and public exposure. The simulation results are compared with those obtained by the 3D Integration method, a fairly good agreement is found. To confirm the performance and effectiveness of the proposed method, the results obtained are also verified with measurement values available in the literature, a good similarity is achieved.

Optimal Phase Arrangements of Underground Transmission Lines Installed by Metropolitan Electricity Authority of Thailand

This paper investigates the magnetic field generated by underground transmission lines, which are practically installed by Metropolitan Electricity Authority (MEA) of Thailand. Specifically, various phase arrangements for duck bank (4×6) and pipe-jacking (21 ducts) of the MEA underground transmission lines were analyzed and simulated by analytical approach based on Biot-Savart Law using MATLAB program. To assure the accuracy of the simulated results, they were compared to the measured results under the same conditions where the test cite was at the tunnel link between Lad-Phrao and Vibhavadi substations, about 8 km, and the tunnel depth was at 15 m from the ground surface. In addition, the magnetic field was simulated from the measured RMS current, recorded every 30 seconds for 16 hrs. By aforementioned setting conditions, the optimal phase arrangements of MEA underground transmission lines in terms of minimized magnetic field for duck bank (4×6) and pipe-jacking (21 ducts) were proposed. Finally, from the simulated results, it shows that the magnetic field generated by underground transmission lines with proposed optimal phase arrangement techniques is not greater than the maximum exposure limits given by the World Health Organization and International Commission on Non-Ionizing Radiation Protection.

Assessment of Levels of Occupational Exposure to UV-A and UV-C Radiation among Shielded Metal Arc Welders in Accra, Ghana

This study attempted to quantify the irradiance levels of ultraviolet A (UV-A) and ultraviolet C (UV-C) from the shielded metal arc welding (SMAW) process to welders in Accra, Ghana. Exposures were assessed via measurements, observations, and interviews. The assessments were done based on safe exposure levels prescribed by recognized international organizations such as the International Commission on Non-Ionizing Radiation Protection (ICNIRP) and the American Conference of Governmental Industrial Hygienists (ACGIH). Results from the measured UV-C irradiance levels E UV-C ranged between 0.16 ± 0.08 W/m 2 and 10.46 ± 1.96 W/m 2 with its corresponding permissible exposure duration t max‑UV‑C per day ranging from 5.74 s to 367.35 s. The measured UV-A irradiance levels E UV‑A ranged from 0.88 ± 0.03 W/m 2 to 23.72 ± 6.66 W/m 2 with its corresponding permissible exposure duration t max‑UV‑A per day ranging from 421.59 s to 11,363.64 s. The obtained effective irradiance E eff has a range of 2.08 W/m 2 to 28.79 W/m 2 with the range of permissible exposure duration t max per day of 1.04 s to 14.40 s. It was found that the total exposure time of the welders exceeded the permissible exposure durations and that the safety practices among the welders were unsatisfactory.

Design of Low-SAR Mobile Phone Antenna: Theory and Applications

This article focuses on the design of a low specific absorption rate (SAR) mobile phone antennas. First, the interaction mechanism of the radiation fields of mobile phone antennas with nearby human tissues is analyzed by using boundary conditions of electromagnetics. The relations between SAR and the electric field are constructed. Then, a concept of reverse current is proposed to decrease the electric field radiated by the antenna at the air-tissue interface and, consequently, reduce the SAR of human tissues. Finally, a metal-rimmed mobile phone antenna is designed according to the proposed theory. The ground clearance of the designed antenna is 2 mm. Their measured normalized peak head and body SAR values are lower than 1.0 W/kg, much less than the SAR safety limit of 1.6 W/kg according to the guidelines of IEEE and FCC or 2.0 W/kg according to the guidelines of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The measured -6 dB impedance bandwidths are 830-1040 and 1670-2730 MHz, respectively. The measured efficiencies are higher than -5 dB at the lower band and -4 dB at the higher band. The measured results prove that the proposed theory can provide guidance for the design of low-SAR mobile phone antennas.

Design of an Integrated Platform for Mapping Residential Exposure to Rf-Emf Sources.

Nowadays, information and communication technologies (mobile phones, connected objects) strongly occupy our daily life. The increasing use of these technologies and the complexity of network infrastructures raise issues about radiofrequency electromagnetic fields (Rf-Emf) exposure. Most previous studies have assessed individual exposure to Rf-Emf, and the next level is to assess populational exposure. In our study, we designed a statistical tool for Rf-Emf populational exposure assessment and mapping. This tool integrates geographic databases and surrogate models to characterize spatiotemporal exposure from outdoor sources, indoor sources, and mobile phones. A case study was conducted on a 100 × 100 m grid covering the 14th district of Paris to illustrate the functionalities of the tool. Whole-body specific absorption rate (SAR) values are 2.7 times higher than those for the whole brain. The mapping of whole-body and whole-brain SAR values shows a dichotomy between built-up and non-built-up areas, with the former displaying higher values. Maximum SAR values do not exceed 3.5 and 3.9 mW/kg for the whole body and the whole brain, respectively, thus they are significantly below International Commission on Non-Ionizing Radiation Protection (ICNIRP) recommendations. Indoor sources are the main contributor to populational exposure, followed by outdoor sources and mobile phones, which generally represents less than 1% of total exposure.

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

BackgroundThe 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. AimsThe 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. ResultsWe 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. ConclusionIn 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.

Extremely Low-Frequency Magnetic Fields Exposure Measurement during Lessons in Elementary Schools.

Schools are an important place for children’s exposure to electromagnetic fields, which may cause adverse health effects. To better understand environmental extremely low-frequency magnetic fields (ELF-MFs) exposure among elementary school students, we measured numeric values of ELF-MFs in five classrooms at four schools during digital learning class hours. The measurement of ELF-MFs was taken with an EMDEX II field analyzer. Specifically, we examined the level of exposure to ELF-MFs for each student’s seating position in the classroom. The results showed that ELF-MFs exposure levels were lower than those in the International Commission on Non-Ionizing Radiation Protection guidelines; however, there were significant differences in the level of magnetic field exposure at each school and at each student’s seat. The exposure to ELF-MFs at students’ seat positions was mostly caused by electrical appliances, electronic wiring, and distribution boxes, but the exposure level decreased as the distance increased. Therefore, it is important to design safe and appropriate environments for digital learning in schools, such as proper seating arrangements, to avoid ELF-MFs exposure to students as much as possible. Future studies should measure ELF-MFs levels in other areas and investigate the effects of exposure to ELF-MFs during school hours on children’s health.

Health risks from radiofrequency radiation, including 5G, should be assessed by experts with no conflicts of interest.

The fifth generation, 5G, of radiofrequency (RF) radiation is about to be implemented globally without investigating the risks to human health and the environment. This has created debate among concerned individuals in numerous countries. In an appeal to the European Union (EU) in September 2017, currently endorsed by >390 scientists and medical doctors, a moratorium on 5G deployment was requested until proper scientific evaluation of potential negative consequences has been conducted. This request has not been acknowledged by the EU. The evaluation of RF radiation health risks from 5G technology is ignored in a report by a government expert group in Switzerland and a recent publication from The International Commission on Non-Ionizing Radiation Protection. Conflicts of interest and ties to the industry seem to have contributed to the biased reports. The lack of proper unbiased risk evaluation of the 5G technology places populations at risk. Furthermore, there seems to be a cartel of individuals monopolizing evaluation committees, thus reinforcing the no-risk paradigm. We believe that this activity should qualify as scientific misconduct.

RF-EMF EXPOSURE LEVELS IN SENSITIVE LAND USE IN GREECE: EDUCATIONAL UNITS CENSUS IN THE MUNICIPALITY OF KORYDALLOS.

The growing popularity of mobile phones and the expansion of network infrastructure in Greece have raised concerns about the possible negative health effects on sensitive groups, such as children, from exposure to long-term radiofrequency electromagnetic fields (RF-EMFs). The objective of this study is to estimate mean RF-EMF exposure levels of primary and secondary education schools located in the municipality of Korydallos, Athens, Greece. We performed measurements to all the schools units ($n=62$) in the region in order to calculate the mean value for RF-EMF exposure in the range of 27 MHz-3 GHz, which covers the whole spectrum of RF-EMF sources. At the $97.5\%$ of schools found in Korydallos region, the exposure level is at least 2200 times below the Greek exposure limits. The exposure levels in the locations tested are both below $60\%$ of the highest limit set by the International Commission on Non-Ionizing Radiation Protection regarding school exposures.

Effect of Loudspeakers on the In Situ Electric Field in a Driver Body Model Exposed to an Electric Vehicle Wireless Power Transfer System

This study computationally evaluates the effect of loudspeakers on the in situ electric field in a driver body model exposed to the magnetic field from a wireless power transfer (WPT) system in an electric vehicle (EV), one with a body made of carbon fiber reinforced plastic (CFRP) and the other made with aluminum. A quasi-static two-step approach was applied to compute the in situ electric field. The computational results showed that the magnetic field distribution generated by the WPT is significantly altered around the loudspeakers, and shows obvious discontinuity and local enhancement. The maximum spatial-average magnetic field strength in the driver’s body was increased by 11% in the CFRP vehicle. It was 2.25 times larger than the reference levels (RL) prescribed in the International Commission of Non-Ionizing Radiation Protection (ICNIRP) guidelines in 2010. In addition, we found that the in situ electric field computed by the line- and volume-averaging methods were stable if the top 0.1% voxels are excluded. The maximum value was well below the basic restriction (BR) of the ICNIRP guidelines. Nevertheless, the presence of the loudspeaker led to increments in the electric field strength in parts of the human body, suggesting the potential influence of permissible transmitting power in the WPT system. The maximum electric field strength in the thigh and buttock with the woofer, increased by 27% in the CFRP vehicle. The arm value was up to 3 times higher than that obtained without the tweeter in the aluminum vehicle. Moreover, this study found that the maximum electric field strength depended on the location of the loudspeaker with respect to the WPT system and the separation from the driver model. Therefore, the loudspeaker should be considered when evaluating the maximum in situ electric field strength in the vehicle body design stage.