Electric And Magnetic Fields Exposure Research Articles

Joint Uplink and Downlink EMF Exposure: Performance Analysis and Design Insights

Installing more base stations (BSs) into the existing cellular infrastructure is an essential way to provide greater network capacity and higher data rate in the 5th-generation cellular networks (5G). However, a non-negligible amount of population is concerned that such network densification will generate a notable increase in exposure to electric and magnetic fields (EMF) over the territory. In this paper, we analyze the downlink, uplink, and joint downlink&uplink exposure induced by the radiation from BSs and personal user equipment (UE), respectively, in terms of the received power density and exposure index. In our analysis, we consider the EMF restrictions set by the regulatory authorities such as the minimum distance between restricted areas (e.g., schools and hospitals) and BSs, and the maximum permitted exposure. Exploiting tools from stochastic geometry, mathematical expressions for the coverage probability and statistical EMF exposure are derived and validated. Tuning the system parameters such as the BS density and the minimum distance from a BS to restricted areas, we show a trade-off between reducing the population's exposure to EMF and enhancing the network coverage performance. Then, we formulate optimization problems to maximize the performance of the EMF-aware cellular network while ensuring that the EMF exposure complies with the standard regulation limits with high probability. For instance, the exposure from BSs is two orders of magnitude less than the maximum permissible level when the density of BSs is less than 20 BSs/km2.

Occupational exposures to electromagnetic fields in the INTEROCC study

Objectivesto assess workplace exposures to electric and magnetic fields (EMF) at radio frequencies (RF) and extremely low frequencies (ELF); to estimate brain cancer risks from occupational ELF magnetic fields.MethodsPersonal interviews...

Future needs of occupational epidemiology of extremely low frequency electric and magnetic fields: review and recommendations

The occupational epidemiological literature on extremely low frequency electric and magnetic fields (EMF) and health encompasses a large number of studies of varying design and quality that have addressed many...

Public health impact of extremely low-frequency electromagnetic fields.

IntroductionThe association between exposure to extremely low-frequency electric and magnetic fields (ELF) and childhood leukemia has led to the classification of magnetic fields by the International Agency for Research on Cancer as a “possible human carcinogen.” This association is regarded as the critical effect in risk assessment. Creating effective policy in light of widespread exposure and the undisputed value of safe, reliable, and economic electricity to society is difficult and requires estimates of the potential public health impact and associated uncertainties.ObjectivesAlthough a causal relationship between magnetic fields and childhood leukemia has not been established, we present estimates of the possible pubic health impact using attributable fractions to provide a potentially useful input into policy analysis under different scenarios.MethodsUsing ELF exposure distributions from various countries and dose–response functions from two pooled analyses, we calculate country-specific and worldwide estimates of attributable fractions (AFs) and attributable cases.ResultsEven given a wide range of assumptions, we find that the AF remains < 10%, with point estimates ranging from < 1% to about 4%. For small countries with low exposure, the number of attributable cases is less than one extra case per year. Worldwide the range is from 100 to 2,400 cases possibly attributable to ELF exposure.ConclusionThe fraction of childhood leukemia cases possibly attributable to ELF exposure across the globe appears to be small. There remain, however, a number of uncertainties in these AF estimates, particularly in the exposure distributions.

Developing Policy in the Face of Scientific Uncertainty: Interpreting 0.3 μT or 0.4 μT Cutpoints from EMF Epidemiologic Studies

There has been considerable scientific effort to understand the potential link between exposures to power-frequency electric and magnetic fields (EMF) and the occurrence of cancer and other diseases. The combination of widespread exposures, established biological effects from acute, high-level exposures, and the possibility of leukemia in children from low-level, chronic exposures has made it both necessary and difficult to develop consistent public health policies. In this article we review the basis of both numeric standards and precautionary-based approaches. While we believe that policies regarding EMF should indeed be precautionary, this does not require or imply adoption of numeric exposure standards. We argue that cutpoints from epidemiologic studies, which are arbitrarily chosen, should not be used as the basis for making exposure limits due to a number of uncertainties. Establishment of arbitrary numeric exposure limits undermines the value of both the science-based numeric EMF exposure standards for acute exposures and precautionary approaches. The World Health Organization's draft Precautionary Framework provides guidance for establishing appropriate public health policies for power-frequency EMF.

The Effects of Electromagnetic Fields From Power Lines on Avian Reproductive Biology and Physiology: A Review

Electrical power lines are ubiquitous in the developed world and in urban areas of the developing world. All electrical currents, including those running through power lines, generate electric and magnetic fields (EMFs). Electrical power lines, towers, and distribution poles are used by birds for perching, hunting, and nesting. Therefore, many bird species, like humans, are exposed to EMFs throughout their lives. EMFs have been implicated in adversely affecting multiple facets of human health, including increasing the risks of life-threatening illnesses such as leukemia, brain cancer, amyotrophic lateral sclerosis, clinical depression, suicide, and Alzheimer’s disease. A great deal of research and controversy exists as to whether or not exposure to EMFs affects the cellular, endocrine, immune, and reproductive systems of vertebrates. Laboratory work has used mice, rats, and chickens as models for this EMF research in an effort to understand better the possible implications of EMF exposure for humans. However, EMF exposure of wild birds may also provide insight into the impacts of EMFs on human health. This review focuses on research examining the effects of EMFs on birds; most studies indicate that EMF exposure of birds generally changes, but not always consistently in effect or in direction, their behavior, reproductive success, growth and development, physiology and endocrinology, and oxidative stress under EMF conditions. Some of this work has involved birds under aviary conditions, while other research has focused on free-ranging birds exposed to EMFs. Finally, a number of future research directions are discussed that may help to provide a better understanding of EMF effects on vertebrate health and conservation. We dedicate this paper to Professor Ross Adey whose exceptional talents as a researcher and mentor will be greatly missed. We thank Ross Adey and Bob McGivern for advice about the physiological effects of EMFs and with respect to avian fertility. K. J. Fernie thanks Hydro Québec, Elliot Block and Dave Bird for logistical support and/or advice during her EMF research, as well as the Canadian Wildlife Service during her current research. We also thank Wolfgang Wiltschko and Roland Prinzinger for access to literature. Financial support for EMF work by K. J. Fernie has been provided by McGill University, Hydro-Québec, the Department of Natural Resource Sciences, the John K. Cooper Foundation, the Wilson Ornithological Society, the Province of Québec Society for the Protection of Birds (P.Q.S.P.B.), the International Osprey Foundation, and the Orville Erickson Memorial Scholarship. Financial support for S. J. Reynolds has been provided by the Natural Environment Research Council, the National Science Foundation, the University of Memphis, and the University of Birmingham.

Blood melatonin and prolactin concentrations in dairy cows exposed to 60 Hz electric and magnetic fields during 8 h photoperiods.

Two experiments were conducted to test the hypothesis that electric and magnetic field (EMF) exposure may result in endocrine responses similar to those observed in animals exposed to long days. In the first experiment, 16 lactating, pregnant Holstein cows were assigned to two replicates according to a crossover design with treatment switchback. All animals were confined to wooden metabolic cages and maintained under short day photoperiods (8 h light/16 h dark). Treated animals were exposed to a vertical electric field of 10 kV/m and a horizontal magnetic field of 30 microT (EMF) for 16 h/day for 4 weeks. In a second, similar experiment, 16 nonlactating, nonpregnant Holstein cows subjected to short days were exposed to EMF, using a similar protocol, for periods corresponding to the duration of one estrous cycle. In the first experiment, circulating MLT concentrations during the light period showed a small numerical decrease during EMF exposure (P < .05). Least-square means for the 8 h light period were 9.9 versus 12.4 pg/ml, SE = 1.3. Melatonin concentrations during the dark period were not affected by the treatment. A similar trend was observed in the second experiment, where MLT concentrations during the light period tended to be lower (8.8 pg/ml vs. 16.3 pg/ml, P < .06) in the EMF exposed group, and no effects were observed during the dark period. Plasma prolactin (PRL) was increased in the EMF exposed group (16.6 vs. 12.7 ng/ml, P < .02) in the first experiment. In the second experiment, the overall PRL concentrations found were lower, and the mean plasma PRL concentration was not affected by treatment. These experiments provide evidence that EMF exposure may modify the response of dairy cows to photoperiod.

Occupational magnetic field exposure and myocardial infarction incidence.

Studies on healthy volunteers have seen reduced heart rate variability after exposure to extremely low-frequency electric and magnetic fields (EMF). Because reduced heart rate variability has been linked to cardiovascular disease risk, it has been hypothesized that exposure to EMF might increase the risk of cardiovascular disease. One epidemiologic study has shown increased mortality from cardiovascular conditions in utility workers with elevated exposure to magnetic fields, but several other epidemiologic studies have failed to confirm this result. We tested the hypothesis that occupational EMF exposure increases the risk of myocardial infarction in a large population-based case-control study of myocardial infarction, with detailed information on potential confounders. We used data from the SHEEP study, which is a population-based case-control study of acute myocardial infarction in Stockholm. Occupational EMF exposure was based on job titles 1, 5, and 10 years before diagnosis. We used 2 approaches to classify exposure: first, specific individual job titles with presumed elevated EMF exposure, and second, classification of subjects according to a job-exposure matrix. We found no increased risk of myocardial infarction in subjects classified as having elevated EMF exposure. For the highest exposure category of > or = 0.3 microT according to the job-exposure matrix, the adjusted relative risk was = 0.57 (95% confidence interval = 0.36-0.89). The results of this study do not support the hypothesis that occupational EMF exposure increases the risk of myocardial infarction.

50-60 Hz electric and magnetic field effects on cognitive function in humans: a review.

This paper reviews the effect of 50-60 Hz weak electric, magnetic and combined electric and magnetic field exposure on cognitive functions such as memory, attention, information processing and time perception, as determined by electroencephalographic methods and performance measures. Overall, laboratory studies that have investigated the acute effects of power frequency fields on cognitive functioning in humans are heterogeneous, in terms of both electric and magnetic field (EMF) exposure and the experimental design and measures used. Results are inconsistent and difficult to interpret with regard to functional relevance for possible health risks. Statistically significant differences between field and control exposure, when they are found, are small, subtle, transitory, without any clear dose-response relationship and difficult to reproduce. The human performance or event related potentials (ERPs) measures that might specifically be affected by EMF exposure, as well as a possible cerebral structure or function that could be more sensitive to EMF, cannot be better determined.

Foreseeable Health Risk of Electric and Magnetic Field Residential Exposures

Exposure to electric and magnetic fields (EMFs) emanating from the generation, distribution and utilization of electricity is widespread. The major debate in recent years has been the possibility that EMFs influence various effects on the human body especially development of cancer. Epidemiologists were the first scientists to publicize this fact through human population studies. Current investigations into this topic split up over diverse areas of research. This paper provides a review of information on health risk of EMF residential exposure. Four major areas have been considered for evaluating the possible risks with emphasis on recent studies. These include safety standards for EMFs, residential field measurement surveys, biological and epidemiological studies of diseases with foreseeable association with EMFs including childhood leukemia, breast cancer, and pregnancy adverse outcomes. On the basis of review findings, it is difficult to provide a robust conclusion about health risk of EMFs, raising the significance of researching this area further. No policy advise is offered, however, as a voluntary precautionary measure, public health professionals, regulatory authorities, standard setters, electric utilities, and individuals are encouraged to advocate minimizing EMF exposures wherever possible.

Responses of the estrous cycle in dairy cows exposed to electric and magnetic fields (60 Hz) during 8-h photoperiods

To study the effects of exposure to extremely low frequency (ELF) electric and magnetic fields (EMF) on the estrous cycle of dairy cows under short-day photoperiod, 16 non-lactating, non-pregnant Holstein cows were exposed to a vertical electric field of 10 kV/m and a horizontal magnetic field of 30 μT for 16 h per day in a cross-over design consisting of two sequences. Each sequence included three periods, and each period corresponded to the duration of one estrous cycle. All animals were maintained under short photoperiod (8 h light/16 h dark) during the trial. Exposure to EMF had an impact on the duration of a complete estrous cycle ( P<0.01) and on the duration of the luteal phase ( P<0.01). The mean duration of one cycle was 19.5±0.4 for the control and 21.3±0.4 days for the exposed animals, respectively. The mean duration of the luteal phase was 15.4±0.4 days for the control and 17.2±0.4 days for the exposed group. The total area under the progesterone (P 4) curve, the amplitude of the curve or the slope of the P 4 rise at the onset of the luteal phase were not affected by EMF exposure. Results indicate that exposure to EMF may increase the duration of the estrous cycle.

Health risks of electromagnetic fields. Part I: Evaluation and assessment of electric and magnetic fields.

Exposure to electric and magnetic fields (EMF) emanating from the generation, distribution, and utilization of electricity is widespread. The major debate in recent years has focused on the possibility that exposure to EMF may result in adverse health consequences, including the development of cancer. This article provides a review and evaluation of potential health risks associated with residential and occupational exposure to EMF. In addition to reviewing data from laboratory, epidemiology, and clinical studies, we examine exposure data from field measurement surveys and exposure guidelines that have been established for EMF. Currently, the evidence in support of an association between EMF and childhood cancer is limited, although this issue warrants further investigation. Evidence of an association between EMF exposure and adult cancers, derived largely from occupational settings, is inconsistent, precluding clear conclusions. There is little evidence of an association between EMF and noncancer health effects. Epidemiological studies of EMF and population health are limited by exposure measurement error and the lack of a clear dose/response relationship in studies suggesting possible health risks. Further research is needed to clarify the ambiguous findings from present studies and to determine if EMF exposure poses a health risk.

Effect of Electric and Magnetic Fields (60 Hz) on Production, and Levels of Growth Hormone and Insulin-Like Growth Factor 1, in Lactating, Pregnant Cows Subjected to Short Days

Electric and magnetic fields (EMF) are generated by the transmission of electricity through high tension lines traversing rural areas. Previous studies showed increased dry matter intake (DMI) and fat corrected milk in dairy cows exposed to EMF. Because EMF exposure has been shown to suppress pineal release of melatonin in some species, it was hypothesized that EMF effects resemble those of exposure to long days. Previous studies have shown that DMI and milk production increase in dairy cattle in response to long day photoperiods, and this has been observed in association with increased circulating insulin-like growth factor 1 (IGF-1), but not growth hormone (GH). The hypothesis that EMF act by modifying the response to photoperiod was tested by subjecting dairy cows to controlled EMF exposure while keeping them under short-day conditions. Sixteen lactating, pregnant Holstein cows were exposed to a vertical electric field of 10 kV/m and a horizontal magnetic field of 30μT in a crossover design with treatment switchback. Two groups of eight cows each were exposed to EMF for 16h/d in either of two sequences. Each sequence consisted of three consecutive 28-d periods. All animals were maintained under short day conditions (8h light, 16h dark) during the trial. DMI and plasma IGF-1 were increased (P<0.01) during EMF exposure (17.03 vs.16.04kg/d, SE=0.4; 137±6ng/ml vs 126±6, respectively). The mean GH concentration was not affected, but a treatment×hour interaction was detected, with GH lower for the EMF exposed animals during the first 16h of the sampling period, and higher for the last 8h. Overall, the yield of milk or its components was not affected by EMF exposure, but milk yield was significantly higher for the exposed animals during wk 4 of treatment.

Should the threshold limit value for power frequency (60 Hz) magnetic fields be changed? Perceptions among scientists and other risk experts.

Over the past few years several studies have raised questions about childhood cancer and exposure to electric and magnetic fields (EMFs). Reports by the National Academy of Sciences and the National Cancer Institute concluded that there is no clear, convincing evidence that exposure to electric power lines and electric power appliances is a threat to human health, whereas the National Institute of Environmental Health Sciences concluded that there is weak evidence that EMF exposure may be a leukemia hazard. Based on the conflicting agency reports on EMF, what do experts in the field of bioelectromagnetics believe regarding the effectiveness of the American Conference of Governmental Industrial Hygienists (ACGIH) guidelines? Surveys were sent to 163 participants at the 1997 annual Department of Energy Contractors meeting on Electric and Magnetic Fields. Approximately one-half (49%, n = 81) of the participants returned the survey. Utility workers demonstrated greater levels of agreement with the current TLV standard in comparison to government, university, and other private sector workers. Utility workers were less likely to perceive that ACGIH guidelines should be changed to be made more strict. In addition, workers who had worked at their present job for 10 years or more indicated less agreement with the acceptability of ACGIH guidelines to protect workers' health. The scientists and other risk experts in this study illustrate the importance of how type of industry may influence perceptions of TLV effectiveness.

Review of the epidemiologic literature on EMF and Health.

Exposures to extremely low-frequency electric and magnetic fields (EMF) emanating from the generation, transmission, and use of electricity are a ubiquitous part of modern life. Concern about potential adverse health effects was initially brought to prominence by an epidemiologic report two decades ago from Denver on childhood cancer. We reviewed the now voluminous epidemiologic literature on EMF and risks of chronic disease and conclude the following: a) The quality of epidemiologic studies on this topic has improved over time and several of the recent studies on childhood leukemia and on cancer associated with occupational exposure are close to the limit of what can realistically be achieved in terms of size of study and methodological rigor. b) Exposure assessment is a particular difficulty of EMF epidemiology, in several respects: i) The exposure is imperceptible, ubiquitous, has multiple sources, and can vary greatly over time and short distances. ii) The exposure period of relevance is before the date at which measurements can realistically be obtained and of unknown duration and induction period. iii) The appropriate exposure metric is not known and there are no biological data from which to impute it. c) In the absence of experimental evidence and given the methodological uncertainties in the epidemiologic literature, there is no chronic disease for which an etiological relation to EMF can be regarded as established. d) There has been a large body of high quality data for childhood cancer, and also for adult leukemia and brain tumor in relation to occupational exposure. Among all the outcomes evaluated in epidemiologic studies of EMF, childhood leukemia in relation to postnatal exposures above 0.4 microT is the one for which there is most evidence of an association. The relative risk has been estimated at 2.0 (95% confidence limit: 1.27-3.13) in a large pooled analysis. This is unlikely to be due to chance but, may be, in part, due to bias. This is difficult to interpret in the absence of a known mechanism or reproducible experimental support. In the large pooled analysis only 0.8% of all children were exposed above 0.4 microT. Further studies need to be designed to test specific hypotheses such as aspects of selection bias or exposure. On the basis of epidemiologic findings, evidence shows an association of amyotrophic lateral sclerosis with occupational EMF exposure although confounding is a potential explanation. Breast cancer, cardiovascular disease, and suicide and depression remain unresolved.

Examination of the Melatonin Hypothesis in Women Exposed at Night to EMF or Bright Light

It has been hypothesized that the increased incidence of breast cancer in industrial societies is related to greater exposure to power-frequency electric and magnetic fields (EMF) and/or the presence of high levels of light at night (LAN). EMF and LAN are said to reduce circulating levels of the hormone melatonin which, in turn, allows estrogen levels to rise and stimulate the turnover of breast epithelial stem cells and increase the risk for malignant transformation. Three laboratory-based studies, in which a total of 53 healthy young women were exposed at night to EMF or to LAN under controlled exposure conditions, were performed to determine whether such exposures reduce melatonin and are associated with further alterations in estrogen. All-night exposure to industrial-strength magnetic fields (60 Hz, 28.3 microT) had no effect on the blood levels of melatonin or estradiol. In contrast, nocturnal melatonin levels were profoundly suppressed, and the time of peak concentration was significantly delayed in women exposed to LAN, regardless of whether they were in the follicular or luteal phase of the menstrual cycle. These changes, however, were not associated with alterations in point-for-point matching measures of estradiol. Women who chronically secrete high or low amounts of melatonin each night (area-under-curve range: 86-1,296 pg/mL) also did not differ in their blood levels of estradiol. Taken together, these results are consistent with a growing body of evidence which generally suggests that environmental EMF exposure has little or no effect on the parameters measured in this report.

Neurodegenerative diseases, suicide and depressive symptoms in relation to EMF

In 1979 the first study was published which indicated that environmental exposure to power frequency, electric and magnetic fields (EMF), might increase the risk of chronic disease. This was a study on cancer. However, this research area has gradually evolved and come also to include outcomes other than cancer. The purpose of this paper is to provide a better understanding of the literature on neurodegenerative diseases and on suicide and depressive symptoms in relation to EMF by using a meta-analysis technique. It is concluded that for amyotrophic lateral sclerosis, there are relatively strong data indicating that electric utility work may be associated with an increased risk. However, EMF exposure is only one of several possible explanations to this. For Alzheimer's disease the combined data on an association with EMF are weaker than that for ALS. For suicide an overall assessment yields the conclusion that the support for an association is weak. For depressive symptoms the assessment is more complex, but the overall conclusion is nevertheless that the evidence is relatively weak. For other diseases, such as Parkinson's, there is not enough information for an assessment.

Neurodegenerative diseases, suicide and depressive symptoms in relation to EMF.

In 1979 the first study was published which indicated that environmental exposure to power frequency, electric and magnetic fields (EMF), might increase the risk of chronic disease. This was a study on cancer. However, this research area has gradually evolved and come also to include outcomes other than cancer. The purpose of this paper is to provide a better understanding of the literature on neurodegenerative diseases and on suicide and depressive symptoms in relation to EMF by using a meta-analysis technique. It is concluded that for amyotrophic lateral sclerosis, there are relatively strong data indicating that electric utility work may be associated with an increased risk. However, EMF exposure is only one of several possible explanations to this. For Alzheimer's disease the combined data on an association with EMF are weaker than that for ALS. For suicide an overall assessment yields the conclusion that the support for an association is weak. For depressive symptoms the assessment is more complex, but the overall conclusion is nevertheless that the evidence is relatively weak. For other diseases, such as Parkinson's, there is not enough information for an assessment.

Adverse human reproductive outcomes and electromagnetic fields: a brief summary of the epidemiologic literature.

Power frequency fields are of concern as risk factors for adverse reproductive outcomes. This report briefly summarizes the epidemiologic evidence of potential associations between a number of adverse reproductive outcomes and parental exposures to electric and magnetic fields (EMFs). Over the last decade numerous reviews of the human literature regarding these potential associations have been published. These reviews, in general, have concluded that: (1) evidence is lacking for a strong association between a woman's use of a video display terminal (VDT) and fetal loss, (2) evidence is lacking for a strong association between a woman's use of a VDT and adverse reproductive outcomes other than fetal loss, primarily a result of too few available data, and (3) the paucity of data on other parental EMF exposures and subsequent adverse outcomes of pregnancy limits drawing a valid scientific conclusion. Since those earlier reviews appeared, the number of new investigations have been relatively small. These new studies do not substantially alter the above summary conclusions. The lack of epidemiologic data in this area, coupled with some speculations about potential biological effects associated with EMFs, raises the importance of researching this area further.

Evaluation of in vitro effects of 50 and 60 Hz magnetic fields in regional EMF exposure facilities.

A weak association between magnetic-field exposure and increased incidences of cancer has been reported. While alterations in cellular processes after in vitro magnetic-field exposures have also been reported to provide plausibility for this association, other laboratories have been unable to repeat the findings. As part of an accelerated electric- and magnetic-field (EMF) research program, the National Institute of Environmental Health Sciences with the Department of Energy identified the replication of the published positive effects as a priority. Regional EMF exposure facilities were established to investigate major in vitro effects from the literature. These included effects on gene expression, intracellular calcium, colony growth in soft agar, and ornithine decarboxylase activity. The laboratories that first reported these effects provided experimental protocols, cell lines, and other relevant experiment details. Regional facility studies included sham/sham exposures (no applied field in either chamber) and were done in a blinded fashion to minimize investigator bias. In nearly all experiments, no effects of magnetic-field exposure were found. The effort provided insight into dealing with the difficulty of replication of subtle effects in complex biological systems. Experimental techniques provided some clues for the differences in experimental results between the regional facility and the original investigator. Studies of subtle effects require extraordinary efforts to confirm that the effect can be attributed to the applied exposure.