35,060 research outputs found

    Longitudinal study of exposure to radio frequencies at population scale

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    International audienceEvaluating exposure to radio frequencies (RF) at population-scale is important for conducting sound epidemiological studies about possible health impact of RF radiations. Numerous studies reported population exposure to RF radiations used in wireless telecommunication technologies, but used very small population samples. In this context, the real exposure of the population at scale remains poorly understood. Here, to the best of our knowledge, we report the largest crowd-based measurement of population exposure to RF produced by cellular antennas, Wi-Fi access points, and Bluetooth devices for 254,410 unique users in 13 countries from January 2017 to December 2020. First, we present methods to assess the population exposure to RF radiations using smartphone measurements obtained using the ElectroSmart Android app. Then, we use these methods to evaluate and characterize the evolution of RF exposure. We show that total exposure has been multiplied by 2.3 in the four-year period considered, with Wi-Fi as the largest contributor. The cellular exposure levels are orders of magnitude lower than regulation limits and are not correlated to national regulation policies. The population tends to be more exposed at home; for half of the study subjects, personal Wi-Fi routers and Bluetooth devices contributed to more than 50% of their total exposure. In this work, we showcase how crowdsource-based data allow large-scale and long-term assessment of population exposure to RF radiations

    Assessment of Indoor-Outdoor Wi-Fi Radiation on Human Body and its Precise SAR Measurement

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    There has been a lot of awareness concern about the health hazards of RF electromagnetic radiation on the human body, the radiofrequency electromagnetic field (RF-EMF) exposure assessment needs attention. This paper reports experimentally measured electromagnetic radiation emission from public place Wi-Fi devices. Indoor and outdoor measurements are done at different geographic locations in India. For the indoor assessment, the experiment was carried out in the national physical laboratory (NPL) New Delhi for 1-4 antennas Wi-Fi routers at a distance of 0-10-meter range are taken into consideration. The power density and electrical intensity were measured using a spectrum analyzer with isotropic E-field probe TSEMF-B1. For the outdoor measurements, four different Delhi metro stations Wi-fi devices at a distance of 20-meter range towards the train coach and below the Wi-fi routers have been considered. In this experiment, we used an instrument is Narda NBM-550 E-field probe for electric field and radiated power density estimation. In addition, the human whole body 3D model has been simulated in a free space environment, the measured outcome of indoor-outdoor electromagnetic radiation and specific absorption rate (SAR) is compared with the ICNIRP, FCC guideline limits at 2.45-5.87 GHz and precise SAR has been evaluated

    Assessment of Indoor-Outdoor Wi-Fi Radiation on Human Body and its Precise SAR Measurement

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    744-751There has been a lot of awareness concern about the health hazards of RF electromagnetic radiation on the human body, the radiofrequency electromagnetic field (RF-EMF) exposure assessment needs attention. This paper reports experimentally measured electromagnetic radiation emission from public place Wi-Fi devices. Indoor and outdoor measurements are done at different geographic locations in India. For the indoor assessment, the experiment was carried out in the national physical laboratory (NPL) New Delhi for 1-4 antennas Wi-Fi routers at a distance of 0-10-meter range are taken into consideration. The power density and electrical intensity were measured using a spectrum analyzer with isotropic E-field probe TSEMFB1. For the outdoor measurements, four different Delhi metro stations Wi-fi devices at a distance of 20-meter range towards the train coach and below the Wi-fi routers have been considered. In this experiment, we used an instrument is Narda NBM-550 E-field probe for electric field and radiated power density estimation. In addition, the human whole body 3D model has been simulated in a free space environment, the measured outcome of indoor-outdoor electromagnetic radiation and specific absorption rate (SAR) is compared with the ICNIRP, FCC guideline limits at 2.45-5.87 GHz and precise SAR has been evaluated

    Evaluation of electromagnetic interference and exposure assessment from s-Health solutions based on Wi-Fi devices

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    In the last decade the number of wireless devices operating at the frequency band of 2.4GHz has increased in several settings, such as healthcare, occupational, and household. In this work, the emissions fromWi-Fi transceivers applicable to context aware scenarios are analyzed in terms of potential interference and assessment on exposure guideline compliance. Near field measurement results as well as deterministic simulation results on realistic indoor environments are presented, providing insight on the interaction between theWi-Fi transceiver and implantable/body area network devices as well as other transceivers operating within an indoor environment, exhibiting topological and morphological complexity. By following approaches (near field estimation/deterministic estimation), colocated body situations as well as large indoor emissions can be determined.The results show in general compliance with exposure levels and the impact of overall network deployment, which can be optimized in order to reduce overall interference levels while maximizing system performance.This work has been funded by the contract CA12/00038 of Technical Support Research of the Health Strategic Action, under the National Plan R&D&I 2008–2011 References

    Wi-Fi i ljudsko zdravlje

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    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.Značajan porast uporabe bežične RF komunikacije u posljednjim desetljećima te s tim povezane izloženosti ljudi umjetno stvorenom neionizirajućem zračenju (RF polja), koje prije nije postojalo na Zemlji, tema su velikog broja istraživanja mogućih utjecaja tih zračenja na okoliš i zdravlje ljudi, osobito djece i mladih, kako bi se utvrdile činjenice o međudjelovanju RF polja s genskim materijalom živih bića. U ovom radu dan je pregled aktualnih istraživanja i preporuka međunarodnih stručnih tijela. Poseban naglasak dan je na mogući utjecaj radiofrekvencijskoga zračenja na mlade odnosno na školsku djecu koja su mu tijekom školovanja svakodnevno dodatno izložena tijekom e-škole korištenjem najmodernijih Wi-Fi tehnologijskih rješenja za komunikaciju u obrazovanju

    Evaluation of Electromagnetic Interference and Exposure Assessment from s-Health Solutions Based on Wi-Fi Devices

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    Procedure for assessment of general public exposure from Wlan in offices and in wireless sensor network testbed

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    A fast and accurate measurement procedure to determine experimentally wireless local area network (WLAN) radiofrequency (RF) exposure and to test compliance with international guidelines for the general public is proposed. This is the first paper where all optimal settings for the measurement equipment (sweep time, resolution bandwidth, etc.) are investigated, selected, and validated. The exposure to WLAN access points is determined for 222 locations with 7 WLAN networks present in office environments. The WLAN exposure is also characterized for the first time in a wireless sensor lab environment (WiLab) at IBBT-Ghent University in Belgium. Average background exposure to WLAN (WiLab off) is 0.12 V m(-1), with a 95(th) percentile of 0.90 V m(-1). With the WiLab in operation, average exposure increases to 1.9 V m(-1), with a 95(th) percentile of 4.7 V m(-1). All values are well below the International Commission on Non Ionizing Radiation Protection guidelines of 61 V m(-1) in the 2.4 GHz band (at least 9.1 times for distances of more than 1 m from the access points) but a significant increase of exposure is possible in WiLabs due to high duty cycles. By applying the proposed measurement method a relevant reduction in measurement time is obtained. Health Phys. 98(4):628-638; 201

    Architectural Indoor Analysis: A Holistic Approach to Understand the Relation of Higher Education Classrooms and Academic Performance

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    The influence of learning space on users has been broadly accepted and tested. However, the literature has focused on single factor research, instead of holistic approaches. Additionally, lower educational levels have been the focus of interest, while higher education is moving towards multi-method teaching. This paper focuses on how learning spaces for different purposes (practice and lecture rooms) may influence academic performance from a holistic approach of learning physical environment perception. For this, the iPEP scale (Indoor physical environment perception) is used and validated through Cronbach Alpha and Exploratory Factorial Analysis. Then, multiple linear regression is conducted. The results indicate that iPEP measures near to 63 percent of the construct, which is structured in six factors. Moreover, linear regression analyses support previous literature concerning the influence of learning physical environment on academic performance (R2 = 0.154). The differences obtained between practice and lecture room in terms of predictor variables bring to the light the need to diagnose learning environments before designing changes in educational buildings. This research provides a self-reported way to measure indoor environments, as well as evidence concerning the modern university, which desires to combine several teaching methods
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