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Khan NU, Khan FU, Farina M, Merla A. RF energy harvesters for wireless sensors, state of the art, future prospects and challenges: a review. Phys Eng Sci Med 2024; 47:385-401. [PMID: 38231358 PMCID: PMC11166779 DOI: 10.1007/s13246-024-01382-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 01/01/2024] [Indexed: 01/18/2024]
Abstract
The power consumption of portable gadgets, implantable medical devices (IMDs) and wireless sensor nodes (WSNs) has reduced significantly with the ongoing progression in low-power electronics and the swift advancement in nano and microfabrication. Energy harvesting techniques that extract and convert ambient energy into electrical power have been favored to operate such low-power devices as an alternative to batteries. Due to the expanded availability of radio frequency (RF) energy residue in the surroundings, radio frequency energy harvesters (RFEHs) for low-power devices have garnered notable attention in recent times. This work establishes a review study of RFEHs developed for the utilization of low-power devices. From the modest single band to the complex multiband circuitry, the work reviews state of the art of required circuitry for RFEH that contains a receiving antenna, impedance matching circuit, and an AC-DC rectifier. Furthermore, the advantages and disadvantages associated with various circuit architectures are comprehensively discussed. Moreover, the reported receiving antenna, impedance matching circuit, and an AC-DC rectifier are also compared to draw conclusions towards their implementations in RFEHs for sensors and biomedical devices applications.
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Affiliation(s)
- Nasir Ullah Khan
- Department of Engineering and Geology, Università degli Studi "G. d'Annunzio" Chieti - Pescara, Pescara, 65127, Italy.
| | - Farid Ullah Khan
- Department of Mechatronics Engineering, University of Engineering and Technology, Peshawar, Peshawar, 25000, Pakistan
| | - Marco Farina
- Department of Information Engineering, Università Politecnica delle Marche, Ancona, 60131, Italy
| | - Arcangelo Merla
- Department of Engineering and Geology, Università degli Studi "G. d'Annunzio" Chieti - Pescara, Pescara, 65127, Italy
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2
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McKenzie RJ, Iskra S, Knipe P. Assessment of radio frequency fields in the 2.45 GHz band produced by smart home devices. Bioelectromagnetics 2024; 45:184-192. [PMID: 38014861 DOI: 10.1002/bem.22492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 08/02/2023] [Accepted: 11/03/2023] [Indexed: 11/29/2023]
Abstract
This paper describes the assessment of the electromagnetic fields produced by consumer "smart" devices used to control and monitor everyday equipment and appliances in a modern "smart" home. The assessment is based on the careful measurement of fields produced by a range of such devices in a laboratory environment configured to operate in a condition simulating high user activity. All devices included in this study operate in the 2.4 GHz band utilizing either Wi-Fi or Bluetooth connectivity. Overall results indicate very low levels of electromagnetic fields for all IoT smart devices in terms of human exposure safety standards (typically much less than 1%) with very low duty cycles (also less than 1%) resulting in even lower time-averaged exposure levels. These low levels of exposure, along with rapid reduction of levels with distance from the devices, suggests that the cumulative effect of multiple devices in a "smart" home are not significant.
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Affiliation(s)
- Raymond J McKenzie
- School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, Victoria, Australia
| | - Steve Iskra
- School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, Victoria, Australia
- Global Networks and Technology, Telstra Corporation Ltd., Melbourne, Australia
| | - Phillip Knipe
- School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, Victoria, Australia
- Total Radiation Solutions, Perth, Australia
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3
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Arribas E, Escobar I, Martinez-Plaza A, Ramirez-Vazquez R. Comments on "Wi-Fi technology and human health impact: a brief review of current knowledge" published in the June 2022 issue of Archives. Arh Hig Rada Toksikol 2022; 73:241-243. [PMID: 36226820 PMCID: PMC9837531 DOI: 10.2478/aiht-2022-73-3671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Enrique Arribas
- University of Castilla-La Mancha Faculty of Computer Science Engineering, Applied Physics Department, Albacete, Spain
| | - Isabel Escobar
- University of Castilla-La Mancha Faculty of Computer Science Engineering, Applied Physics Department, Albacete, Spain
| | - Antonio Martinez-Plaza
- University of Castilla-La Mancha School of Industrial Engineering, Mathematics Department, Albacete, Spain
| | - Raquel Ramirez-Vazquez
- University of Castilla-La Mancha Faculty of Computer Science Engineering, Applied Physics Department, Albacete, Spain
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Wi-Fi technology and human health impact: a brief review of current knowledge. ARHIV ZA HIGIJENU RADA I TOKSIKOLOGIJU 2022; 73:94-106. [PMID: 35792772 PMCID: PMC9287836 DOI: 10.2478/aiht-2022-73-3402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 06/01/2022] [Indexed: 01/05/2023]
Abstract
An enormous increase in the application of wireless communication in recent decades has intensified research into consequent increase in human exposure to electromagnetic (EM) radiofrequency (RF) radiation fields and potential health effects, especially in school children and teenagers, and this paper gives a snap overview of current findings and recommendations of international expert bodies, with the emphasis on exposure from Wi-Fi technology indoor devices. Our analysis includes over 100 in vitro, animal, epidemiological, and exposure assessment studies (of which 37 in vivo and 30 covering Wi-Fi technologies). Only a small portion of published research papers refers to the “real” health impact of Wi-Fi technologies on children, because they are simply not available. Results from animal studies are rarely fully transferable to humans. As highly controlled laboratory exposure experiments do not reflect real physical interaction between RF radiation fields with biological tissue, dosimetry methods, protocols, and instrumentation need constant improvement. Several studies repeatedly confirmed thermal effect of RF field interaction with human tissue, but non-thermal effects remain dubious and unconfirmed.
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Zeleke BM, Brzozek C, Bhatt CR, Abramson MJ, Freudenstein F, Croft RJ, Wiedemann P, Benke G. Wi-fi related radiofrequency electromagnetic fields (RF-EMF): a pilot experimental study of personal exposure and risk perception. JOURNAL OF ENVIRONMENTAL HEALTH SCIENCE & ENGINEERING 2021; 19:671-680. [PMID: 34150266 PMCID: PMC8172712 DOI: 10.1007/s40201-021-00636-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 02/15/2021] [Indexed: 06/12/2023]
Abstract
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.
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Affiliation(s)
- Berihun M. Zeleke
- Centre for Population Health Research on Electromagnetic Energy (PRESEE), School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC 3004 Australia
| | - Christopher Brzozek
- Centre for Population Health Research on Electromagnetic Energy (PRESEE), School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC 3004 Australia
| | - Chhavi R. Bhatt
- Centre for Population Health Research on Electromagnetic Energy (PRESEE), School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC 3004 Australia
- Assessment and Advice Section, Radiation Health Services Branch, Australian Radiation Protection and Nuclear Safety Agency, 619 Lower Plenty Road, Yallambie, 3085 Australia
| | - Michael J. Abramson
- Centre for Population Health Research on Electromagnetic Energy (PRESEE), School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC 3004 Australia
| | - Frederik Freudenstein
- Centre for Population Health Research on Electromagnetic Energy (PRESEE), School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC 3004 Australia
- Australian Centre for Electromagnetic Bioeffects Research, Illawarra Health and Medical Research Institute, School of Psychology, University of Wollongong, Northfields Ave, Wollongong, NSW 2522 Australia
- Department of Risk Communication, German Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589 Berlin, Germany
| | - Rodney J. Croft
- Centre for Population Health Research on Electromagnetic Energy (PRESEE), School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC 3004 Australia
- Australian Centre for Electromagnetic Bioeffects Research, Illawarra Health and Medical Research Institute, School of Psychology, University of Wollongong, Northfields Ave, Wollongong, NSW 2522 Australia
| | - Peter Wiedemann
- Centre for Population Health Research on Electromagnetic Energy (PRESEE), School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC 3004 Australia
- Australian Centre for Electromagnetic Bioeffects Research, Illawarra Health and Medical Research Institute, School of Psychology, University of Wollongong, Northfields Ave, Wollongong, NSW 2522 Australia
| | - Geza Benke
- Centre for Population Health Research on Electromagnetic Energy (PRESEE), School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC 3004 Australia
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Kljajic D, Djuric N. Comparative analysis of EMF monitoring campaigns in the campus area of the University of Novi Sad. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:14735-14750. [PMID: 32052328 DOI: 10.1007/s11356-020-08008-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 02/05/2020] [Indexed: 06/10/2023]
Abstract
Following an increasing number of artificial electromagnetic field (EMF) sources in human surrounding, a number of research studies have been devoted to the issue of environmental EMF pollution. A particular attention has been attributed to the highly sensitive EMF zones, where people can stay for a longer period of time, which, among others, includes university campuses. Thus, the modern approach of long-term EMF monitoring has been established, carrying out cumulative field strength measurements at locations that are most visited by student population and university staff. The goal was to establish periodic and systematic EMF investigation over such highly sensitive areas, through a standardized procedure for EMF monitoring. In this paper, details about two EMF monitoring campaigns over the University of Novi Sad campus were presented, performing comparative analysis of their results. The obtained results revealed the increase (up to four times) of the cumulative field strength values, as well as the general population exposure, at specific locations. Between these two campaigns, the emergence of the new base station, as well as numerous Wi-Fi networks, was noticed in the campus. Consequently, the highest field strength values were acquired at two locations, most directly exposed to the main beams of base station's antennas, although all obtained values were at least five times lower than the minimal reference levels prescribed by the Serbian legislation. Even though such results are acceptable, the future monitoring campaigns should be planned, particularly since the installation of new EMF sources are expected in the campus of the University of Novi Sad.
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Affiliation(s)
- Dragan Kljajic
- Faculty of Technical Sciences, University of Novi Sad, Trg D. Obradovica 6, Novi Sad, 21000, Serbia.
| | - Nikola Djuric
- Faculty of Technical Sciences, University of Novi Sad, Trg D. Obradovica 6, Novi Sad, 21000, Serbia
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Massardier-Pilonchery A, Nerrière E, Croidieu S, Ndagijimana F, Gaudaire F, Martinsons C, Noé N, Hours M. Assessment of Personal Occupational Exposure to Radiofrequency Electromagnetic Fields in Libraries and Media Libraries, Using Calibrated On-Body Exposimeters. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16122087. [PMID: 31200442 PMCID: PMC6616949 DOI: 10.3390/ijerph16122087] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 05/30/2019] [Accepted: 06/01/2019] [Indexed: 12/23/2022]
Abstract
Background and Objectives: With the spread of Wifi networks, safety concerns have arisen, with complaints of somatic disorders, notably in traditional libraries and media libraries. The aim of the present study was to describe the conditions and levels of exposure to radiofrequency electromagnetic fields in the real-life occupational conditions of those working in traditional libraries and media libraries. Methods: Dynamic measurements, using an exposimeter, were taken in 20 radiofrequency bands from 88 to 5850 MHz. The activity of 28 library workers was analyzed on a space-time budget. An audit of exposure sources and static measurements enabled the work-places to be mapped. Results: In seven libraries, 78,858 samples were taken over the 20 radiofrequency bands from 88 to 5850 MHz. Exposure was described for 28 working days. The median total field was 0.071 V/m (10th percentile: 0.022 V/m, 90th percentile: 0.534 V/m) and for Wifi the median field was 0.005 V/m (10th percentile: 0.005 V/m, 90th percentile: 0.028 V/m). Median individual exposure to Wifi frequency waves ranged from 0.005 to 0.040 V/m. Conclusions: Overall, the occupational exposure in this sector was close to the exposure in the general population. Peaks were due to the use of walkie-talkies by security staff. Exposure due to external sources depended on geographic location. Exposure in this occupation is well below the general occupational exposure levels, notably as regards Wifi.
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Affiliation(s)
- Amelie Massardier-Pilonchery
- Université de Lyon, Université Claude Bernard Lyon1, Ifsttar, UMRESTTE, UMR T_9405, 8 avenue Rockefeller 69373 Lyon, France.
- Centre Hospitalier Lyon Sud, Hospices Civils de Lyon, 69495 Pierre Bénite, France.
| | - Elena Nerrière
- Université de Lyon, Université Claude Bernard Lyon1, Ifsttar, UMRESTTE, UMR T_9405, 8 avenue Rockefeller 69373 Lyon, France.
| | - Sophie Croidieu
- Service de médecine préventive de la Ville Lyon, 69006 Lyon, France.
| | | | - François Gaudaire
- Division Eclairage et Champs Electromagnétiques, Centre Scientifique et Technique du Bâtiment, 24 rue Joseph Fourier, 38400 Saint Martin d'Hères, France.
| | - Christophe Martinsons
- Division Eclairage et Champs Electromagnétiques, Centre Scientifique et Technique du Bâtiment, 24 rue Joseph Fourier, 38400 Saint Martin d'Hères, France.
| | - Nicolas Noé
- Division Eclairage et Champs Electromagnétiques, Centre Scientifique et Technique du Bâtiment, 11 rue Henri Picherit, 44300 Nantes, France.
| | - Martine Hours
- Université de Lyon, Université Claude Bernard Lyon1, Ifsttar, UMRESTTE, UMR T_9405, 8 avenue Rockefeller 69373 Lyon, France.
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Chiaramello E, Bonato M, Fiocchi S, Tognola G, Parazzini M, Ravazzani P, Wiart J. Radio Frequency Electromagnetic Fields Exposure Assessment in Indoor Environments: A Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:E955. [PMID: 30884917 PMCID: PMC6466609 DOI: 10.3390/ijerph16060955] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 03/05/2019] [Accepted: 03/14/2019] [Indexed: 12/24/2022]
Abstract
Exposure to radiofrequency (RF) electromagnetic fields (EMFs) in indoor environments depends on both outdoor sources such as radio, television and mobile phone antennas and indoor sources, such as mobile phones and wireless communications applications. Establishing the levels of exposure could be challenging due to differences in the approaches used in different studies. The goal of this study is to present an overview of the last ten years research efforts about RF EMF exposure in indoor environments, considering different RF-EMF sources found to cause exposure in indoor environments, different indoor environments and different approaches used to assess the exposure. The highest maximum mean levels of the exposure considering the whole RF-EMF frequency band was found in offices (1.14 V/m) and in public transports (0.97 V/m), while the lowest levels of exposure were observed in homes and apartments, with mean values in the range 0.13⁻0.43 V/m. The contribution of different RF-EMF sources to the total level of exposure was found to show slightly different patterns among the indoor environments, but this finding has to be considered as a time-dependent picture of the continuous evolving exposure to RF-EMF.
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Affiliation(s)
- Emma Chiaramello
- Istituto di Elettronica e di Ingegneria dell'Informazione e delle Telecomunicazioni IEIIT CNR, 20133 Milano, Italy.
| | - Marta Bonato
- Istituto di Elettronica e di Ingegneria dell'Informazione e delle Telecomunicazioni IEIIT CNR, 20133 Milano, Italy.
- Dipartimento di Elettronica, Informazione e Bioingegneria DEIB, Politecnico di Milano, 20133 Milano, Italy.
| | - Serena Fiocchi
- Istituto di Elettronica e di Ingegneria dell'Informazione e delle Telecomunicazioni IEIIT CNR, 20133 Milano, Italy.
| | - Gabriella Tognola
- Istituto di Elettronica e di Ingegneria dell'Informazione e delle Telecomunicazioni IEIIT CNR, 20133 Milano, Italy.
| | - Marta Parazzini
- Istituto di Elettronica e di Ingegneria dell'Informazione e delle Telecomunicazioni IEIIT CNR, 20133 Milano, Italy.
| | - Paolo Ravazzani
- Istituto di Elettronica e di Ingegneria dell'Informazione e delle Telecomunicazioni IEIIT CNR, 20133 Milano, Italy.
| | - Joe Wiart
- Télécom ParisTech, LTCI University Paris Saclay, Chair C2M, 75013 Paris, France.
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Zeleke BM, Brzozek C, Bhatt CR, Abramson MJ, Croft RJ, Freudenstein F, Wiedemann P, Benke G. Personal Exposure to Radio Frequency Electromagnetic Fields among Australian Adults. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:ijerph15102234. [PMID: 30321997 PMCID: PMC6211035 DOI: 10.3390/ijerph15102234] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 10/03/2018] [Accepted: 10/08/2018] [Indexed: 11/16/2022]
Abstract
The measurement of personal exposure to radiofrequency electromagnetic fields (RF-EMFs) is important for epidemiological studies. RF-EMF exposure can be measured using personal exposimeters that register RF-EMFs over a wide range of frequency bands. This study aimed to measure and describe personal RF-EMF exposure levels from a wide range of frequency bands. Measurements were recorded from 63 participants over an average of 27.4 (±4.5) hours. RF-EMF exposure levels were computed for each frequency band, as well as from downlink (RF from mobile phone base station), uplink (RF from mobile phone handsets), broadcast, and Wi-Fi. Participants had a mean (±SD) age of 36.9 ± 12.5 years; 66.7% were women; and almost all (98.2%) from urban areas. A Wi-Fi router at home was reported by 61 participants (96.8%), with 38 (61.2%) having a Wi-Fi enabled smart TV. Overall, 26 (41.3%) participants had noticed the existence of a mobile phone base station in their neighborhood. On average, participants estimated the distance between the base station and their usual residence to be about 500 m. The median personal RF-EMF exposure was 208 mV/m. Downlink contributed 40.4% of the total RF-EMF exposure, followed by broadcast (22.4%), uplink (17.3%), and Wi-Fi (15.9%). RF-EMF exposure levels on weekdays were higher than weekends (p < 0.05). Downlink and broadcast are the main contributors to total RF-EMF personal exposure. Personal RF-EMF exposure levels vary according to day of the week and time of day.
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Affiliation(s)
- Berihun M Zeleke
- Centre for Population Health Research on Electromagnetic Energy (PRESEE), School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia.
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, 553 St Kilda Road, Melbourne, VIC 3004, Australia.
| | - Christopher Brzozek
- Centre for Population Health Research on Electromagnetic Energy (PRESEE), School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia.
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, 553 St Kilda Road, Melbourne, VIC 3004, Australia.
| | - Chhavi Raj Bhatt
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, 553 St Kilda Road, Melbourne, VIC 3004, Australia.
- Monash University Endocrine Surgery Unit, Alfred Hospital, 55 Commercial Rd, Melbourne, VIC 3004, Australia.
- Monash Emergency Service, Monash Health, Dandenong Hospital, 135 David Street, Melbourne, VIC 3175, Australia.
| | - Michael J Abramson
- Centre for Population Health Research on Electromagnetic Energy (PRESEE), School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia.
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, 553 St Kilda Road, Melbourne, VIC 3004, Australia.
| | - Rodney J Croft
- Australian Centre for Electromagnetic Bioeffects Research, Illawarra Health and Medical Research Institute, School of Psychology, University of Wollongong, Northfields Ave, Wollongong, NSW 2522, Australia.
| | - Frederik Freudenstein
- Australian Centre for Electromagnetic Bioeffects Research, Illawarra Health and Medical Research Institute, School of Psychology, University of Wollongong, Northfields Ave, Wollongong, NSW 2522, Australia.
| | - Peter Wiedemann
- Australian Centre for Electromagnetic Bioeffects Research, Illawarra Health and Medical Research Institute, School of Psychology, University of Wollongong, Northfields Ave, Wollongong, NSW 2522, Australia.
| | - Geza Benke
- Centre for Population Health Research on Electromagnetic Energy (PRESEE), School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia.
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, 553 St Kilda Road, Melbourne, VIC 3004, Australia.
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Hedendahl LK, Carlberg M, Koppel T, Hardell L. Measurements of Radiofrequency Radiation with a Body-Borne Exposimeter in Swedish Schools with Wi-Fi. Front Public Health 2017; 5:279. [PMID: 29214149 PMCID: PMC5703119 DOI: 10.3389/fpubh.2017.00279] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 09/29/2017] [Indexed: 12/23/2022] Open
Abstract
Introduction Wireless access to the Internet is now commonly used in schools. Many schools give each student their own laptop and utilize the laptops and wireless fidelity (Wi-Fi) connection for educational purposes. Most children also bring their own mobile phones to school. Since children are obliged by law to attend school, a safe environment is important. Lately, it has been discussed if radiofrequency (RF) radiation can have long-term adverse effects on children’s health. Method This study conducted exposimetric measurements in schools to assess RF emissions in the classroom by measuring the teachers’ RF exposure in order to approximate the children’s exposure. Teachers in grades 7–12 carried a body-borne exposimeter, EME-Spy 200, in school during 1–4 days of work. The exposimeter can measure 20 different frequency bands from 87 to 5,850 MHz. Results Eighteen teachers from seven schools participated. The mean exposure to RF radiation ranged from 1.1 to 66.1 µW/m2. The highest mean level, 396.6 µW/m2, occurred during 5 min of a lesson when the teacher let the students stream and watch YouTube videos. Maximum peaks went up to 82,857 µW/m2 from mobile phone uplink. Discussion Our measurements are in line with recent exposure studies in schools in other countries. The exposure levels varied between the different Wi-Fi systems, and if the students were allowed to use their own smartphones on the school’s Wi-Fi network or if they were connected to GSM/3G/4G base stations outside the school. An access point over the teacher’s head gave higher exposure compared with a school with a wired Internet connection for the teacher in the classroom. All values were far below International Commission on Non-Ionizing Radiation Protection’s reference values, but most mean levels measured were above the precautionary target level of 3–6 µW/m2 as proposed by the Bioinitiative Report. The length of time wireless devices are used is an essential determinant in overall exposure. Measures to minimize children’s exposure to RF radiation in school would include preferring wired connections, allowing laptops, tablets and mobile phones only in flight mode and deactivating Wi-Fi access points, when not used for learning purposes.
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Affiliation(s)
| | - Michael Carlberg
- Department of Oncology, Faculty of Medicine and Health, University Hospital, Örebro, Sweden
| | - Tarmo Koppel
- Department of Work Environment and Safety, Tallinn University of Technology, Tallinn, Estonia
| | - Lennart Hardell
- Department of Oncology, Faculty of Medicine and Health, University Hospital, Örebro, Sweden
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Bhatt CR, Abramson MJ, Benke G. Wi-Fi radiation exposures to children in kindergartens and schools - results should lessen parental concerns. Aust N Z J Public Health 2017; 41:647-648. [PMID: 28749542 DOI: 10.1111/1753-6405.12706] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
- Chhavi Raj Bhatt
- Centre for Population Health Research on Electromagnetic Energy (PRESEE), School of Public Health and Preventive Medicine, Monash University, Victoria
| | - Michael J Abramson
- Centre for Population Health Research on Electromagnetic Energy (PRESEE), School of Public Health and Preventive Medicine, Monash University, Victoria
| | - Geza Benke
- Centre for Population Health Research on Electromagnetic Energy (PRESEE), School of Public Health and Preventive Medicine, Monash University, Victoria
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