Radiofrequency Electromagnetic Field Levels Research Articles

Influence of radiofrequency electromagnetic fields exposure on sleep patterns in preterm neonates

Purpose The study objective was to assess the influence of radiofrequency electromagnetic fields (RF-EMF) exposure on sleep patterns in preterm newborns. We hypothesized that an increase in RF-EMF exposure levels would alter infants’ sleep structure parameters. Materials and methods Individual, continuous measurements of RF-EMF levels were performed in 29 hospitalized preterm newborns throughout the first 21 days after birth. The last day, overnight sleep structure was recorded by polysomnography. Relationships between both chronic (three-week period) and acute (polysomnographic period) RF-EMF levels with sleep parameters were computed. Results At median levels, the main chronic effect was an increase in indeterminate sleep with RF-EMF exposure. At the highest exposure levels found in our study, an increase in RF-EMF levels increased sleep fragmentation. No significant relationship was found between acute RF-EMF levels and sleep parameters. Conclusions Despite no consolidated disruption in sleep structure, this study is the first to show that some sleep parameters seem to have a certain sensitivity to chronic – but not acute – RF-EMF exposure in preterm newborns. Further studies are needed to confirm our results and examine possible mid- to long-term, sleep-related cardiorespiratory and neurodevelopmental outcomes.

Artificial Neural Network Based Prediction of Long-Term Electric Field Strength Level Emitted by 2G/3G/4G Base Station

Accurate predictions of radio frequency electromagnetic field (RF-EMF) levels can help implement measures to reduce exposure and check regulatory compliance. Therefore, this study aims to predict the RF-EMF levels in the medium using an artificial neural network (ANN). The work was conducted at Ondokuz Mayis University, Kurupelit Campus, where the measurement location has line-of-sight to the base stations. Band selective measurements were also performed to assess the contribution of 2G/3G/4G services to the total RF-EMF level, which was found to be the highest among all services within the total band. Long-term RF-EMF measurements were carried out for 35 days within the frequencies of 100 kHz to 3 GHz. Then, an ANN model with Levenberg–Marquardt (LM) and Bayesian Regulation (BR) algorithms was proposed, which utilized inputs from real-time RF-EMF measurements. The performance of the models was assessed in terms of mean squared error (MSE) and regression performance. The average MSE and regression performances of the models were similar, with the lowest testing MSEs of 2.78 × 10−3 and 3.76 × 10−3 for LM and BR methods, respectively. The analysis of the models showed that the proposed models help to predict the RF-EMF level in the medium with up to 99% accuracy.

Exposure levels of radiofrequency electromagnetic fields from mobile base stations in Mpumalanga province, South Africa

This study assessed the radiofrequency electromagnetic fields (RF-EMF) exposure levels proximal to primary school structures in the Mpumalanga province of South Africa. A calibrated Acoustimeter was used to measure the RF EMF levels at defined distance points of 50 and 100m away from the three mobile base stations, that provide a 4G network coverage. All the measurements were obtained from three mobile stations, each from one district municipality, using 30 minutes intervals for repeated measurements. The measured peak exposure level at 50m was 887 μW/m2 and 905 μW/m2 at 100m. No statistical difference was found when comparing the measurement data obtained at 50 and 100m from the three district municipalities. However, comparison of measurements obtained at 50 and 100m for all base stations were statistically significant, p-value< .002 and p< .003 respectively. The measured RF EMF exposure levels at both distance points were below the reference levels found under International Commission for Non-ionizing Radiation Protection (ICNIRP) RF guidelines. It is therefore essential for mobile base station companies to consider proximity of residential structures when installing new base stations in the future, and regularly maintain the components of mobile base towers, especially in the current state of power load shedding in South Africa.

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

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

Exposure to Low Levels of Radiofrequency Electromagnetic Fields Emitted from Cell-phones as a Promising Treatment of Alzheimer's Disease: A Scoping Review Study.

Alzheimer's disease (AD) is one of the most significant public health concerns and tremendous economic challenges. Studies conducted over the past decades show that exposure to radiofrequency electromagnetic fields (RF-EMFs) may relieve AD symptoms. To determine if exposure to RF-EMFs emitted by cellphones affect the risk of AD. In this review, all relevant published articles reporting an association of cell phone use with AD were studied. We systematically searched international datasets to identify relevant studies. Finally, 33 studies were included in the review. Our review discusses the effects of RF-EMFs on the amyloid β (Aβ), oxidative stress, apoptosis, reactive oxygen species (ROS), neuronal death, and astrocyte responses. Moreover, the role of exposure parameters, including the type of exposure, its duration, and specific absorption rate (SAR), are discussed. Progressive factors of AD such as Aβ, myelin basic protein (MBP), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and neurofilament light polypeptide (NFL) were decreased. While tau protein showed no change, factors affecting brain activity such as glial fibrillary acidic protein (GFAP), mitogen-activated protein kinases (MAPKs), cerebral blood flow (CBF), brain temperature, and neuronal activity were increased. Exposure to low levels of RF-EMFs can reduce the risk of AD by increasing MAPK and GFAP and decreasing MBP. Considering the role of apoptosis in AD and the effect of RF-EMF on the progression of the process, this review indicates the positive effect of these exposures.

Hygienic assessment of electromagnetic fields generated by promising models of power plants

Introduction. The analyses of staff occupationally connected with maintenance and operation of plants included in the Federal Project “Development of technologies for Controlled Thermonuclear Fusion (CTF) and innovative plasma technologies” electromagnetic safety problems required full-scale measurements of the electromagnetic fields (EMF) and hygienic assessment in personnel workplaces. Materials and methods. Measurements of EMF frequency and intensity-time parameters and preliminary hygienic assessment in workplaces of Tokamaks MEFIST-0, T-11M, TUMAN-3M, FT-2, magnetic trap MK-200M were carried out. Results. The studies showed very high levels of pulsed magnetic fields (MF) (up to 433 mT), despite of official regulatory values absence, according to magnetic component effects mechanisms can be assessed as human health risk factor. Radio frequency EMF levels, despite the short-term exposure, can have the adverse effect on human health, because in all points of possible employees’ location there were exceeding the maximum permissible values (up to 170 fold). 1 Hz-1 kHz frequency range EMF electric and magnetic components amplitude-frequency characteristics peaks may be risk factor for human health too (despite the lack of this frequency range hygienic standards in Russia). Limitations. The limitations of the study are determined by the lack of generated by new CTF samples EMF frequency and intensity-time parameters objective data. Conclusion. EMF assessment in examined CTF staff work places pilot study showed that pulsed MF, radio frequency EMF, 1 Hz-1 kHz frequency range EMF both components levels reach very high values and, despite the absence of officially valid regulatory values, according to factor action mechanisms, can be risk factor for personnel health.

Radiofrequency Electromagnetic Field Levels at Workplaces of Technical Specialists of Cellular Communication

Introduction: One of the main professional groups of workers in cellular radiotelephone communication includes technical specialists who serve and ensure trouble-free operation of radio transmitters of cellular base stations (BS). Transmitting antennas and BS equipment are powerful sources of radiofrequency electromagnetic fields (RF EMFs) and one of the main adverse physical factors of the working environment for technicians. RF EMFs affect the functional state of various systems of the human body including the nervous, cardiovascular, and immune systems. The objective of our study was to assess the exposure to RF EMFs of cellular communication technical specialists and to establish occupations with the highest exposure levels. Materials and methods: Instrumental testing of energy flux density of the electromagnetic wave generated by BS receiving and transmitting equipment was carried out at service sites of cellular communication facilities by technical specialists of the industry. The time spent by technicians at workplaces with high EMF levels during the average work shift was measured. Results: The analysis of collected data showed that 28 % of energy flux density values measured at workplaces exceeded the maximum permissible level for the personnel serving radio transmitters and spending from 12 to 61 % of the work shift in the specified conditions. We established that network construction engineers, network operation engineers, power engineers, technical audit specialists, network development engineers, and mechanics were exposed to increased RF EMF levels. Conclusion: Our findings indicate the necessity to monitor and reduce occupational exposures of technical specialists of cellular communication in order to improve their working conditions and prevent, inter alia, RF EMS-related diseases.

Safety and Efficacy of amplitude-modulated radiofrequency electromagnetic fields in advanced hepatocellular carcinoma

Importance: Hepatocellular carcinoma (HCC) is the third leading cause of cancer death worldwide. Despite the recent approval of several new agents, long-term disease control remains elusive for most patients. Administration of 27.12 MHz radiofrequency (RF) electromagnetic fields (EMF) by means of a spoon-shaped antenna (TheraBionic P1 device) placed on the anterior part of the tongue results in systemic delivery of low and safe levels of RF EMF from head to toe. Objective: To report treatment outcomes and adverse events associated with treatment with the TheraBionic P1 device in comparison to suitable historical placebo and actively treated controls. Design: Pooled case series with comparison to historical controls. Participants: Patients with advanced HCC receiving this treatment, 18 real-world patients and 41 patients from a previously reported phase II study. Historical controls from previously conducted clinical trials. Interventions: Three hours daily treatment with the TheraBionic P1 device compared with standard of care as received by historical controls in the previously conducted trials. Main outcomes and measures: Overall survival (OS), time to progression, response rate, and adverse events in the combined pooled patients and in appropriate subgroups comparable to the historical control groups. Results: In the pooled treatment group, median OS of patients with Child-Pugh A disease (n = 32) was 10.36 (95% CI 5.42–14.07) months, 4.44 (95% CI 1.64–7.13) months for patients with Child-Pugh B disease (n = 25), and 1.99 (95% CI 0.76–3.22) months for patients with Child-Pugh C disease (n = 2). Median OS for Child-Pugh A patients was 2.62 (33.9%) months longer than the 7.74 months OS of comparable historical controls (p = 0.036). The 4.73 (95% CI 1.18–8.28) months median OS for Child-Pugh B patients receiving TheraBionic P1 device as first line therapy is slightly higher than the 4.6 months median OS of historical controls receiving Sorafenib as first line therapy. Only grade 1 mucositis and fatigue were reported by patients using the device, even among Child-Pugh B and C patients. No patients discontinued treatment because of adverse events. Conclusions and Relevance: Treatment of advanced HCC with the TheraBionic P1 device is well tolerated, even in patients with severely impaired liver function, and results in improved overall survival compared to historical controls without any significant adverse events, even after many years of continuous treatment. This treatment modality appears to be well suited for patients who have failed or are intolerant to currently approved therapies.

Exposure assessment of radio frequency electromagnetic field levels in hospitals of Samsun Province, Turkey.

With the increase in the use of different types of electronic systems used inside and outside the hospital, the electromagnetic medium in the hospital has changed significantly. The increase in the number and type of EMF sources in sensitive mediums such as hospitals has led researchers to measure EMFs to assess the potential risk to patients and staff. For this reason, this study aims to determine the radio frequency electromagnetic field (RF-EMF) levels to which patients and staff are exposed voluntarily or unintentionally in the hospital environment and to control their compliance with the limits defined in the standards. In order to achieve these goals, three different types of RF-EMF measurements were carried out as, short-term, long-term, and band selective in 21 state hospitals in the Samsun Province, Turkey. Total RF-EMF in the band between 100kHz and 3GHz is measured using PMM-8053, while band selective is conducted using SRM-3006 in the frequency range from 27MHz up to 3GHz. The recorded RF-EMF values were statistically analyzed, and the main RF-EMF sources in the medium were determined. The highest average RF-EMF exposure level obtained for short-term measurements was 2.52V/m. For long-term measurements, the highest average RF-EMF was 3.11V/m and the highest mean RF-EMF was 2.29V/m. Within our measurements, the limit of 3V/m set by the Information and Communication Technologies Authority (ICTA) was exceeded in the hospital, although the highest RF-EMF was below the limit level set by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Long-term measurement results showed that the RF-EMF level at midday was higher than at night; the highest RF-EMF was measured in the afternoon and during evening hours. The mean RF-EMF levels are 1.01V/m, 1.15V/m, 1.12V/m, and 0.84V/m, for morning, afternoon, evening, and night respectively. The RF-EMF level measured during the afternoon hours maybe about 37% higher than the RF-EMF levels measured at night. The main sources of total RF-EMF in the environment determined from the band-selective RF-EMF results were base stations located outside the hospital and their contribution to total RF-EMF was 92.6%. Systems that make the most contribution to the RF-EMF in the environment are base stations using the LTE 800, GSM 900, GSM 1800, LTE 1800, and UMTS 2100 frequency bands. Among these, the UMTS 2100 frequency band gave the highest contribution with 40.42%. With the use of these main RF-EMF sources, an empirical model that helps in computing the total E of the medium with 99.8% accuracy was proposed.

Developing GIS portal to ensure sanitary and epidemiological surveillance of transferring radio engineering objects

In recent years, in the Russian Federation there has been an increase in the levels of radiofrequency electromagnetic fields in residential areas, including due to an increase in the number of base stations (BS). The purpose of sanitary and epidemiological surveillance at the stages of placement and commissioning of base stations (BS) is to prevent their adverse effects on public health. The increase in the number of base stations, together with the advent of new electronic equipment and antennas, provide opportunities for improving the processes of their accounting at the stage of placement and monitoring of the levels of radiofrequency electromagnetic fields at the operation stage. This automation tool can be a geo-information portal for providing sanitary and epidemiological surveillance of cellular base stations. The prototype of the geo-information portal allows both calculating the size of sanitary protection zones (SPZ) and building restriction zones (RZ) from the BS in online mode, displaying the results of calculations in graphical form and issuing sanitary and epidemiological conclusions for the placement and operation of base stations. The geo-information portal has the ability to synchronize with the data of the radio frequency center. Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing will be able to receive up-to-date analytical data. There will be completely automated processes of collecting, processing and storing information on BS.

Developing GIS portal to ensure sanitary and epidemiological surveillance of transferring radio engineering objects

In recent years, in the Russian Federation there has been an increase in the levels of radiofrequency electromagnetic fields in residential areas, including due to an increase in the number of base stations (BS). The purpose of sanitary and epidemiological surveillance at the stages of placement and commissioning of base stations (BS) is to prevent their adverse effects on public health. The increase in the number of base stations, together with the advent of new electronic equipment and antennas, provide opportunities for improving the processes of their accounting at the stage of placement and monitoring of the levels of radiofrequency electromagnetic fields at the operation stage. This automation tool can be a geo-information portal for providing sanitary and epidemiological surveillance of cellular base stations. The prototype of the geo-information portal allows both calculating the size of sanitary protection zones (SPZ) and building restriction zones (RZ) from the BS in online mode, displaying the results of calculations in graphical form and issuing sanitary and epidemiological conclusions for the placement and operation of base stations. The geo-information portal has the ability to synchronize with the data of the radio frequency center. Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing will be able to receive up-to-date analytical data. There will be completely automated processes of collecting, processing and storing information on BS.

Comprehensive radiofrequency electromagnetic field measurements and assessments: a city center example.

In this study, radiofrequency electromagnetic field (RF-EMF) measurements were carried out between 2016 and 2018 in one the largest provinces of Turkey; measurement results are compared with the limit values determined by International Commission on Non-Ionizing Radiation Protection (ICNIRP) and Turkey's Information and Communication Technologies Authority (ICTA). In the first stage of a three-phase evaluation, short-term RF-EMF measurements were conducted in 500 locations over a 2-year period. In the second stage, short-term RF-EMF measurement results were analyzed to determine selected locations for long-term RF-EMF measurements to be carried out, including variation of RF-EMF during the day. In the last stage, band selective measurements were taken and the main sources of RF-EMF in the environment were determined. Overall, RF-EMF values do not exceed the limits determined by ICNIRP and ICTA, and they are below levels that threaten public health. In the short-term RF-EMF measurements, RF-EMF levels doubled after fourth generation (4G) systems were introduced. In the long-term RF-EMF measurements, RF-EMF values in the day are 35.4% more than at night. The total measured RF-EMF within the city center is 99.3% base station sourced. Among the six main RF-EMF sources, the devices operating in UMTS2100 band have the most contribution to total RF-EMF of medium with 31.2%. Additionally, we found short-term average electric field strength data are best described by the "exponential distribution," while long-term RF-EMF measurement data is best described by the "Burr distribution."

A real-world quality assessment study in six ExpoM-RF measurement devices

Exposimeters measuring radiofrequency electromagnetic fields (RF-EMF) are commonly used to assess personal exposure to RF-EMF in real-life environments. They are usually calibrated in an anechoic chamber using single, well-defined signals such as the center frequency of each band, and standardized orientations, but it is not clear how different devices compare in the real environment where complex mixtures of signals from all directions are present. We thus tested the comparability of six ExpoM-RF exposimeters before and after calibration in an anechoic chamber by varying their position and orientation while repeatedly measuring 15 microenvironments (9 walking routes, 4 tram routes and 2 bus routes) on 6 different days. We modelled the geometric mean levels of RF-EMF as a function of orientation, position, device ID, whether the device was recently calibrated, correcting for the microenvironment in which each measurement took place. We found that systematic differences introduced by device ID, calibration, day of the week, orientation and position are relatively small compared to exposure differences between microenvironments. Any corrections (if desired) should include both device ID and calibration session, but would have a small impact considering the negligible differences between devices. This supports the validity of previous exposure measurement studies relying on ExpoM-RF devices, which did not correct for device ID. We further found that summarizing the exposure per microenvironment as geometric means results in better models than arithmetic means and medians, and recommend that further exposure assessment studies report observed levels as geometric means.

Environmental radiofrequency electromagnetic field levels in a department of pediatrics

Preterm neonates constitute a vulnerable population that is highly sensitive to its environment. Given the increased use of wireless communication devices (mobile and digital enhanced cordless telecommunications, WiFi networks, etc.), neonates hospitalized in a department of pediatrics are potentially exposed to radiofrequency electromagnetic fields (RF-EMF). Strikingly, data on RF-EMF levels in pediatric units have not previously been published.The objective of the present study was thus to quantify the RF-EMF levels in a 34-bed tertiary department of pediatrics with a neonatal critical care unit (NCCU) and a neonatal intensive care unit (NICU). To this end, we used triaxle antenna dosimeters to map the RF-EMF levels in the environment and to measure spot emissions from medical devices. In a first set of experiments, RF-EMF levels at 144 points in the staff area and in the children's rooms in the NCCU and NICU were evaluated over a 24-h period. In a second set of measurements performed in a Faraday chamber, we measured the RF-EMF levels emitted by the medical devices to which neonates are potentially exposed in the department of pediatrics.The RF-EMF levels were significantly higher in the NCCU than in the NICU (p < 0.05). Although the two units did not differ significantly with regard to the average maximum values, the single greatest value recorded in the NCCU (6 V/m GSM + UMTS 900 (UL) frequency band, in the staff area) was more than twice that recorded in the NICU (3.70 V/m in the UMTS 2100 (UL) frequency band, in the children's rooms). The NCCU and NICU did not differ significantly with regard to the time during which the RF-EMF level at each measurement point was more than two standard deviations above its mean. The RF-EMF level was significantly higher during the day than during the night (p < 0.001). The various medical devices used in the NICU did not emit detectable amounts of RF.Overall, RF-EMF levels in the NCCU and NICU were very low. It is probable that the RF-EMFs measured here were primarily generated by the parents' and staff members' activities, rather than by medical devices. However, a combination of low-level, chronic exposure with transient, elevated peak values in a vulnerable population of preterm neonates may be of particular concern. In a department of pediatrics, decreasing preterm neonates’ exposure to RF-EMFs should primarily involve a limitation on the use of wireless communication devices by staff members and parents.

Radiofrequency electromagnetic fields, screen time, and emotional and behavioural problems in 5-year-old children.

Little is known about the exposure of young children to radiofrequency electromagnetic fields (RF-EMF) and potentially associated health effects. We assessed the relationship of RF-EMF exposure from different sources and screen time exposure with emotional and behavioural problems in 5-year-old children. Cross-sectional study including 3102 children aged 5 years from the Amsterdam Born Children and their Development (ABCD) study, in the Netherlands. Residential RF-EMF exposure from mobile phone base stations was estimated with a 3D geospatial radio wave propagation model. Residential presence of RF-EMF indoor sources (cordless phone base stations and Wireless Fidelity (WiFi)), children's mobile phone and cordless phone calls and screen time exposure (computer/video game and television watching) was reported by the mother. Teachers (n = 2617) and mothers (n = 3019) independently reported child emotional and behavioural problems using the Strengths and Difficulties Questionnaire. No associations were found between mobile phone and cordless phone calls and emotional and behavioural problems. Children exposed to higher RF-EMF levels from mobile phone base stations showed higher odds of maternal-reported emotional symptoms (OR 1.82, 95%CI 1.07 to 3.09). Children with cordless phone at home had lower odds of teacher-reported problematic prosocial behaviour (OR 0.68, 95%CI 0.48 to 0.97) and of maternal-reported peer relationship problems (OR 0.61, 95% CI 0.39 to 0.96). Children who watched television ≥1.5 h/day had higher odds of maternal-reported hyperactivity/inattention (OR 3.13, 95%CI 1.43 to 6.82). Mobile phone and cordless phone calls, which lead to peak RF-EMF exposures to the head, were not associated with any emotional and behavioural problems in 5-year-old children. Environmental RF-EMF exposure from mobile phone base stations and from indoor sources and television watching, which both contribute very little to RF-EMF exposure, were associated with specific emotional and behavioural problems but mainly when reported by the mothers. We cannot, however, discard residual confounding or reverse causality. Further longitudinal research in particular as children will increase the use of telecommunication devices with the age may help to better understand the exact contribution of the different RF-EMF exposure sources if any. Moreover, a thorough control for confounding is essential for a correct interpretation of the studies on screen time and emotional and behavioural problems.

Impact of input data uncertainty on environmental exposure assessment models: A case study for electromagnetic field modelling from mobile phone base stations

BackgroundWith the increased availability of spatial data and computing power, spatial prediction approaches have become a standard tool for exposure assessment in environmental epidemiology. However, such models are largely dependent on accurate input data. Uncertainties in the input data can therefore have a large effect on model predictions, but are rarely quantified. MethodsWith Monte Carlo simulation we assessed the effect of input uncertainty on the prediction of radio-frequency electromagnetic fields (RF-EMF) from mobile phone base stations at 252 receptor sites in Amsterdam, The Netherlands. The impact on ranking and classification was determined by computing the Spearman correlations and weighted Cohen׳s Kappas (based on tertiles of the RF-EMF exposure distribution) between modelled values and RF-EMF measurements performed at the receptor sites. ResultsThe uncertainty in modelled RF-EMF levels was large with a median coefficient of variation of 1.5. Uncertainty in receptor site height, building damping and building height contributed most to model output uncertainty. For exposure ranking and classification, the heights of buildings and receptor sites were the most important sources of uncertainty, followed by building damping, antenna- and site location. Uncertainty in antenna power, tilt, height and direction had a smaller impact on model performance. ConclusionsWe quantified the effect of input data uncertainty on the prediction accuracy of an RF-EMF environmental exposure model, thereby identifying the most important sources of uncertainty and estimating the total uncertainty stemming from potential errors in the input data. This approach can be used to optimize the model and better interpret model output.

Temporal trends of radio-frequency electromagnetic field (RF-EMF) exposure in everyday environments across European cities

BackgroundThe rapid development and increased use of wireless telecommunication technologies led to a substantial change of radio-frequency electromagnetic field (RF-EMF) exposure in the general population but little is known about temporal trends of RF-EMF in our everyday environment. ObjectivesThe objective of our study is to evaluate temporal trends of RF-EMF exposure levels in different microenvironments of three European cities using a common measurement protocol. MethodsWe performed measurements in the cities of Basel (Switzerland), Ghent and Brussels (Belgium) during one year, between April 2011 and March 2012. RF-EMF exposure in 11 different frequency bands ranging from FM (Frequency Modulation, 88MHz) to WLAN (Wireless Local Area Network, 2.5GHz) was quantified with portable measurement devices (exposimeters) in various microenvironments: outdoor areas (residential areas, downtown and suburb), public transports (train, bus and tram or metro rides) and indoor places (airport, railway station and shopping centers). Measurements were collected every 4s during 10–50min per environment and measurement day. Linear temporal trends were analyzed by mixed linear regression models. ResultsHighest total RF-EMF exposure levels occurred in public transports (all public transports combined) with arithmetic mean values of 0.84V/m in Brussels, 0.72V/m in Ghent, and 0.59V/m in Basel. In all outdoor areas combined, mean exposure levels were 0.41V/m in Brussels, 0.31V/m in Ghent and 0.26V/m in Basel.Within one year, total RF-EMF exposure levels in all outdoor areas in combination increased by 57.1% (p<0.001) in Basel by 20.1% in Ghent (p=0.053) and by 38.2% (p=0.012) in Brussels. Exposure increase was most consistently observed in outdoor areas due to emissions from mobile phone base stations. In public transports RF-EMF levels tended also to increase but mostly without statistical significance. DiscussionAn increase of RF-EMF exposure levels has been observed between April 2011 and March 2012 in various microenvironments of three European cities. Nevertheless, exposure levels were still far below regulatory limits of each country. A continuous monitoring is needed to identify high exposure areas and to anticipate critical development of RF-EMF exposure at public places.

What input data are needed to accurately model electromagnetic fields from mobile phone base stations?

The increase in mobile communication technology has led to concern about potential health effects of radio frequency electromagnetic fields (RF-EMFs) from mobile phone base stations. Different RF-EMF prediction models have been applied to assess population exposure to RF-EMF. Our study examines what input data are needed to accurately model RF-EMF, as detailed data are not always available for epidemiological studies. We used NISMap, a 3D radio wave propagation model, to test models with various levels of detail in building and antenna input data. The model outcomes were compared with outdoor measurements taken in Amsterdam, the Netherlands. Results showed good agreement between modelled and measured RF-EMF when 3D building data and basic antenna information (location, height, frequency and direction) were used: Spearman correlations were >0.6. Model performance was not sensitive to changes in building damping parameters. Antenna-specific information about down-tilt, type and output power did not significantly improve model performance compared with using average down-tilt and power values, or assuming one standard antenna type. We conclude that 3D radio wave propagation modelling is a feasible approach to predict outdoor RF-EMF levels for ranking exposure levels in epidemiological studies, when 3D building data and information on the antenna height, frequency, location and direction are available.

Low levels of radiofrequency electromagnetic fields and cancer cell proliferation in vivo.

e15049 Background: The incidence of hepatocellular carcinoma (HCC) is increasing but five-year survival remains dismal. Intrabuccal administration of amplitude-modulated radiofrequency electromagnetic fields (RF EMF) is a novel, non-invasive treatment modality resulting in whole body absorption of very low levels of RF EMF. Recent studies show that this approach elicits radiological responses in patients with HCC and breast cancer (J Exp Clin Cancer Res, 2009, 28:51; Br J Cancer, 2011, 105:640). Using an in vitro exposure system replicating the levels of exposure achieved in humans, we have shown that HCC cells and breast cancer cells are growth inhibited by HCC-specific and breast cancer-specific frequencies, respectively. Additionally, RF EMF exposure causes modulation of gene expression and disruption of the mitotic spindle (Br J Cancer 2012, 106:307). Methods: HCC cells were exposed to radiofrequency electromagnetic fields modulated at specific frequencies previously identified in HCC patients. MicroRNA arrays compared exposed and control groups of HCC cells. HCC cells were injected subcutaneously in NOD SCID mice. Following palpable tumor establishment, mice were exposed to HCC-specific RF EMF at a specific absorption rate of 0.4 W/kg and euthanized following excessive tumor burden. Results: We identified increased levels of miRNAs targeting proteins belonging to the PI3K pathway, specifically IP3/DAG signaling and intracellular calcium release, a pathway frequently disrupted in HCC and breast cancer. While HCC xenografts grew in control mice, we observed significant tumor shrinkage in mice exposed to HCC-specific modulation frequencies and residual xenograft tumor cells were infiltrated with fibrous tissue and showed significantly decreased proliferation and increased apoptosis. There was no evidence of altered cell proliferation or fibrosis in other organs. Conclusions: These findings are the first in vivo evidence of the efficacy of RF EMF in HCC and uncover a novel mechanism that targets cancer cell growth at specific modulation frequencies, by means of changes in PI3K signaling and release of intracellular calcium.

Electromagnetic fields and the public: EMF standards and estimation of risk

Mobile communications are a relatively new and additional source of electromagnetic exposure for the population. Standard daily mobile-phone use is known to increase RF-EMF (radiofrequency electromagnetic field) exposure to the brains of users of all ages, whilst mobile-phone base stations, and base station units for cordless phones, can regularly increase the exposures of large numbers of the population to RF-EMF radiation in everyday life. The need to determine appropriate standards stipulating the maximum acceptable short-term and long-term RF-EMF levels encountered by the public, and set such levels as general guidelines, is of great importance in order to help preserve the general public's health and that of the next generation of humanity.