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Environmental health criteria 238: Extremely low frequency fields

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Abstract

SUMMARY AND RECOMMENDATIONS FOR FURTHER STUDY: This Environmental Health Criteria (EHC) monograph addresses the possible health effects of exposure to extremely low frequency (ELF) electric and magnetic fields. It reviews the physical characteristics of ELF fields as well as the sources of exposure and measurement. However, its main objectives are to review the scientific literature on the biological effects of exposure to ELF fields in order to assess any health risks from exposure to these fields and to use this health risk assessment to make recommendations to national authorities on health protection programs. The frequencies under consideration range from above 0 Hz to 100 kHz. By far the majority of studies have been conducted on power-frequency (50 or 60 Hz) magnetic fields, with a few studies using power-frequency electric fields. In addition, there have been a number of studies concerning very low frequency (VLF, 3-30 kHz) fields, switched gradient magnetic fields used in magnetic resonance imaging, and the weaker VLF fields emitted by visual display units and televisions. This chapter summarizes the main conclusions and recommendations from each section as well as the overall conclusions of the health risk assessment process. The terms used in this monograph to describe the strength of evidence for a given health outcome are as follows. Evidence is termed "limited" when it is restricted to a single study or when there are unresolved questions concerning the design, conduct or interpretation of a number of studies. "Inadequate" evidence is used when the studies cannot be interpreted as showing either the presence or absence of an effect because of major qualitative or quantitative limitations, or when no data are available. Key gaps in knowledge were also identified and the research needed to fill these gaps has been summarized in the section entitled "Recommendations for research".

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... 1. "Environmental Health Criteria 238: Extremely Low Frequency Fields" with a total of 15 references [56]. ...
... The population is exposed to an increasing exposure to different electromagnetic fields (EMF) ELF, so the need to establish the effects of these exposures is a widely researched topic, which explains why this community is the largest. The most important work of this community is [56]. It dates from 2007 and is closely related to publications from its own community and from other neighboring communities, such as the electrophysiological effects community. ...
... It dates from 2007 and is closely related to publications from its own community and from other neighboring communities, such as the electrophysiological effects community. [56] is a monograph that presents different environmental health criteria (EHC) before exposure to ELF-EMF, evaluates the risks that such exposure entails, and intends to establish recommendations to national authorities on health protection programs. Its importance also lies in establishing the first division of the evidence found in health. ...
Article
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This paper describes the characteristics of contributions made by researchers worldwide in the field of ELF (extremely low frequency) waves from 1957 to 2019. The data were collected through the Scopus database and processed with analytical and bibliometric techniques. The selection of the keywords is an essential step, because ELF has a very different meaning in some areas of medicine, where it is associated with a gene. A total of 12,436 documents were worked on in 12 thematic communities according to their collaborative relationships between authors and documents. Studies included authors publishing in the different thematic areas and the country where the USA stands first with more researchers in this theme than China and Japan. Documents were analyzed from the temporal perspective, their overall contribution, means of publication, and the language of the publication. Research requires extra effort and multidisciplinary collaboration to improve the knowledge, the application, and influence of these fields.
... Other diseases that were lately investigated include neurodegenerative disorders, suicide and depression due to its effect on the melatonin levels, cardio vascular disorders and immune system. Other rich sources that discuss investigations on health risk associated to ELF-EMF are the WHO [18] report, the Bioinitiative report by David Carpenter and Cindy Sage [19], the ICNIRP SCI report by Ahlbom et al. [8] and the California EMF report [20]. Some conclude that the evidence does not support the claim of diseases caused by ELF-EMF except for cancer. ...
... Some conclude that the evidence does not support the claim of diseases caused by ELF-EMF except for cancer. WHO [18] concludes that recent studies show evidence of DNA damage at field levels of 350 mG. Additionally, evidence supports that ELF-EMF yields potential changes to mental processes such as attention and memory, as well as to regulatory functions within the body. ...
... Also according to the IEEE [39], WHO [18] and the three ICNIRP [38] [43] [44] standards the magnetic field under power lines is measured at a height of 1 m above ground level. A field meter with three-axis probes is used to measure the resultant magnetic field. ...
Article
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According to surveyed literature, there may be a health hazard associated with extremely low frequency magnetic fields. This study aims at presenting a recent survey of this literature. It also aims at measuring magnetic field levels close to power transmission lines at inhabited areas in Kuwait to see if current levels are safe and to establish a database of 50 Hz magnetic field levels at inhabited areas. Measurements were made, according to the international standard procedures in winter, spring, summer and fall, and three times of a day. Four inhabited areas were surveyed. Results provide us with an independent view of the levels in the vicinity of power lines and houses. Results show that the highest level is measured in the summer, reaching 115 mG while the minimum level is measured in the fall. We found that some houses were at less than 50 meters distance from the edge of the transmission lines. Some houses were, as close as 22 meters to the line. We found that levels at the entrance of houses and at outdoor parking areas were mostly higher than 4 mG
... The classification of ELF-MF was primarily based on epidemiological findings, showing an association between residential exposure to ELF-MF and childhood leukemia [2]. There is no known biological explanation for this association and the epidemiological findings have not been supported by animal studies [3]. Therefore, it is not known whether the observed association reflects a causal relationship or is due to bias, confounding or chance [2,3]. ...
... There is no known biological explanation for this association and the epidemiological findings have not been supported by animal studies [3]. Therefore, it is not known whether the observed association reflects a causal relationship or is due to bias, confounding or chance [2,3]. In 2005 a large-scale case-control study from Great Britain [4] showed an association between proximity of residence at birth to high-voltage power lines and the risk of childhood leukemia. ...
... The lack of an accepted biological explanation for the observed association between ELF-MF and childhood leukemia have raised doubt about the causality of the association. Several mechanisms of how extremely low-frequency electric and magnetic fields can cause cancer have, however, been proposed [3]. One hypothesis is that the electric field from power lines interacts with airborne pollutant particles and thereby increases the harmful effect of these particles22232425. ...
Article
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We investigated whether there is an interaction between distance from residence at birth to nearest power line and domestic radon and traffic-related air pollution, respectively, in relation to childhood leukemia risk. Further, we investigated whether adjusting for potential confounders alters the association between distance to nearest power line and childhood leukemia. We included 1024 cases aged <15, diagnosed with leukemia during 1968-1991, from the Danish Cancer Registry and 2048 controls randomly selected from the Danish childhood population and individually matched by gender and year of birth. We used geographical information systems to determine the distance between residence at birth and the nearest 132-400 kV overhead power line. Concentrations of domestic radon and traffic-related air pollution (NOx at the front door) were estimated using validated models. We found a statistically significant interaction between distance to nearest power line and domestic radon regarding risk of childhood leukemia (p = 0.01) when using the median radon level as cut-off point but not when using the 75th percentile (p = 0.90). We found no evidence of an interaction between distance to nearest power line and traffic-related air pollution (p = 0.73). We found almost no change in the estimated association between distance to power line and risk of childhood leukemia when adjusting for socioeconomic status of the municipality, urbanization, maternal age, birth order, domestic radon and traffic-related air pollution. The statistically significant interaction between distance to nearest power line and domestic radon was based on few exposed cases and controls and sensitive to the choice of exposure categorization and might, therefore, be due to chance.
... The World Health Organization concluded "there is no consistent evidence that exposure to environmental ELF fields cause direct damage to molecules including DNA", hence it is "unlikely that they may initiate cancer". However, it was cryptically added that "the consistent (epidemiological) pattern of increased risk for childhood leukemia, on balance provided not strong enough evidence for causality but for remaining concern" [3]. ...
... The meta-analysis of 10 studies did not report statistical significant OR. Overall, scientific risk analyses concluded, that there is no association between ELF MF exposures and childhood cancer [1] [3]. ...
... 6) in spite of the suspicion that leukemia risk increases with field amplitude already above the onset value 0.2µT no causal relationship with any cancer could be found at workers with EMF MF exposures which were several orders of magnitudes higher [1] [3]. 7) the hypothesis childhood-leukemia could be causally linked to ELF MF exposure is not supported by any other scientific approaches, neither by in-vitro nor by in-vivo studies; 8) a potential causal link of childhood leukemia with ELF MF cannot be explained by established physical or biological interaction mechanism. ...
Article
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The discussion whether extremely low frequency (ELF) magnetic fields (MF) are causally linked with childhood leukemia is ongoing for almost four decades. Results of epidemiologic studies have indicated such an association might exist and led to IARC's classification of ELF MF as possibly car-cinogenic (class 2B). Although in the meanwhile many epidemiologic studies and meta-analyses of selected studies are available, this did not change the situation. By a new approach of pooling all epidemiologic data, this paper shows that it is possible to come to a convincing conclusion which explains controversial results and reports dose-response relationship, and provides answers to striking facts such as that epidemiologic results on childhood leukemia are independent from field source or exposure metric of whatever kind with no specific favorite. The analysis revealed that the assumption of a causal link between ELF MF exposure and childhood leukemia is no longer plausible and hence that ELF MF's classification as possibly carcinogenic needs revision.
... International reviews of extremely low frequency magnetic field effects recognise the epidemiological associations (e.g. International Agency for Research on Cancer (IARC) [6] World Health Organisation (WHO) [7] but no plausible biological basis indicating a causal link between exposure and disease has been identified (e.g. National Radiation Protection Board (NRPB) [8], Crumpton [9], WHO [7], Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) [10] . ...
... International Agency for Research on Cancer (IARC) [6] World Health Organisation (WHO) [7] but no plausible biological basis indicating a causal link between exposure and disease has been identified (e.g. National Radiation Protection Board (NRPB) [8], Crumpton [9], WHO [7], Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) [10] . Consequently IARC and WHO classify extremely low frequency magnetic fields as a class 2b carcinogen – possibly carcinogenic to humans [6,7]. ...
... National Radiation Protection Board (NRPB) [8], Crumpton [9], WHO [7], Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) [10] . Consequently IARC and WHO classify extremely low frequency magnetic fields as a class 2b carcinogen – possibly carcinogenic to humans [6,7]. The search for plausible biological mechanisms by which magnetic fields may elevate risk of childhood leukaemia has examined direct DNA damage, experimental animal carcinogenesis and changes in gene expression, amongst many others. ...
Article
To seek alterations in gene transcription in bone marrow cells following in vivo exposure of juvenile mice to power frequency magnetic fields, young (21-24-day old) C57BL/6 mice were exposed to a 100µT 50Hz magnetic field for 2h. Transcription was analysed by three methods, High Coverage Expression Profiling (HiCEP), Illumina microarrays and quantitative real-time polymerase chain reaction (QRT-PCR). A pilot HiCEP experiment with 6 exposed (E) and 6 non-exposed (NE) mice identified four candidate responsive transcripts (two unknown transcripts (AK152075 and F10-NED), phosphatidylinositol binding clathrin assembly protein (Picalm) and exportin 7 (Xpo7)). A larger experiment compared 19 E and 15 NE mice using two independent QRT-PCR assays and repeated microarray assays. No significant field-dependent changes were seen, although Picalm showed a trend to significance in one QRT-PCR assay (E/NE=0.91; P=0.06). However, the study was underpowered to detect an effect of this magnitude (52% power at P=0.05). These data indicate the current experimental constraints in detecting small changes in transcription that may occur in response to magnetic fields. These constraints result from technical limitations in the accuracy of assays and biological variation, which together were sufficient to account statistically for the number of differentially expressed transcripts identified in the pilot experiment.
... For example, the alternating electromagnetic fields that are employed in dwellings are between 50 and 60 Hz in most countries. The electric field strength of EMF EMR is typically between 5 V/m and 50 V/m, whereas the magnetic field strength is between 0.01 µTesla and 0.2 µTesla272829. Considerably higher field strength may be accounted in some occupational settings but only for short duration3031. Observational studies have shown that movement in strong static ELF magnetic fields may cause subjective symptoms like vertigo or nausea. ...
... Page 5 of 11Table 1 shows very significant information regarding the indoor and outdoor electric and magnetic field strengths of dwellings located near high voltage power lines. Despite that all electric and magnetic field strengths ofTable 1 are below the international limits [8,24,25,27,28,38] it is important to note the following significant issues: (a) nearly all measured magnetic field strengths, indoors and outdoors, were higher than those ofFigure 2. Note that all measurements ofFigure 2Figure 4 presents significant results from the indoor measurements of electric and magnetic field strengths at different distances when potential designated sources of bias at the 50 Hz were switched on. The magnetic field strengths at contact with the wall of the room (zero meter distance,Figure 4b) show a tendency to be higher than those of the one and two meters distances. ...
Article
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This paper reports preliminary electromagnetic field measurements conducted indoors in selected locations in Greece. The paper focuses on the electromagnetic radiation (EMR) of the extremely low-frequency (ELF) and radiofrequency (RF) frequency bands because these bands are considered as possible human carcinogens according to the Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR). ELF electric and magnetic fields and RF electric fields were measured indoors in several locations in urban, suburban and rural areas of the Zakynthos and Lesvos islands, suburban houses of Ileia Prefecture (Peloponnisos) and urban dwellings of Attica. A total number of 4816 measurements were taken in Zakynthos (276), Lesvos (964), Ileia (29) and Attica (3547) in the frequency range 50 Hz–2500 MHz. Measurements were conducted with NARDA EMR-300 RF survey meter (3935), Aaronia HF and NF spectrum analyzers (795), HI 3604 Holaday ELF survey meter (48) and ANTENNESSA EME SPY (38). The maximum electric field strengths were in most cases below 5 V/m. Strength of electric fields up to 3000 V/m were addressed near high voltage power transmission lines. Stronger average electric fields were measured in urban areas. The strengths of the magnetic field were in most cases lower than 1000 nTesla (1 μTesla), but values up to 6000 nTesla (6 μTesla) were observed near high voltage power transmission lines. The results indicated that the EMR strength values varied but were all below domestic and international established limits.
... As a consequence, it can represent a potential hazard to human health. Human exposure to the ELF magnetic field might cause some negative effects to their health [4]. Researchers have come to the conclusion that ELF magnetic fields can increase the risks of such illnesses as leukemia [5], brain cancer [6], amyotrophic lateral sclerosis [7] and Alzheimer's disease [8]. ...
Article
Human exposure to extremely low frequency magnetic field represents a risk to their health. This paper takes into consideration the level of an extremely low-frequency magnetic field between 30 and 300 Hz emitted by an AC laptop adapter. The experiment consists of testing 17 different AC adapters for laptops. During the testing, laptops are operated in a normal operating conditions as well as under heavy load. The magnetic field measurement is conducted in the area around the AC adapter. Obtained data is evaluated according to the critical level of the magnetic field proposed by safety standards. Furthermore, data is classified by a K-medians method in order to determine the critical levels of the magnetic field exposure in the nearby area of the AC adapter. Obtained classifications are evaluated according to safety standards, giving a critical analysis of magnetic field areas at risk. Due to emission of a very strong magnetic field in certain areas, a recommendation for safety use of the AC adapter is proposed.
... The limitation in most of the studies was that measurement of ELF field density was not included. Field strength of residential ELF-MF has been reported to vary between 0.05 and 0.11 μT in the USA and between 0.025 and 0.07 μT in Europe [44]. The results are inconclusive due to potential confounders and the low number of cases [40]. ...
... In gener‐ al, these effects only take place under fields of considerable intensity, and disappear as ex‐ posure ceases. The biological mechanisms involved in these short‐term effects are relatively well known, as well as the field values (intensity and frequency) that cause them [24][25][26][27]. They are usually classified into two main groups: electrostimulant effects and thermal ef‐ fects. ...
Chapter
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In electric vehicles, passengers sit very close to an electric system of significant power, usually for a considerable amount of time. The relatively high currents achieved in these systems and the short distances between the power devices and the passengers mean that the latter could be exposed to relevant magnetic fields. This implies that it becomes necessary to evaluate the electromagnetic environment in the interior of these vehicles before releasing them in the market. Moreover, the hazards of magnetic field exposure must be taken into account when designing electric vehicles and their components. For this purpose, estimation tools based on finite element simulations can prove to be very useful. With appropriate design guidelines, it might be possible to make electric vehicles safe from the electromagnetic radiation point of view.
... En algunos sectores sociales esta cercanía es motivo de preocupación, llegando en algunos casos a una oposición frontal a la construcción de nuevas instalaciones en las proximidades de sus viviendas. En este sentido, la Organización Mundial de la Salud (OMS) recomienda aplicar el principio de " prevención prudente " , en base a estudios que sugieren una posible relación de los campos magnéticos con la leucemia infantil [1]. Este principio recomienda reducir, siempre que sea posible, la exposición de la población a este tipo de campos, promoviendo la investigación para la búsqueda de soluciones que, con un coste razonable, permitan lograr dicho objetivo. ...
Article
In recent years, there is a social concern about the adverse effects derived from the magnetic field generated by power frequency electrical installations near public areas. A good example are underground power cables. One of the most used techniques to mitigate the magnetic field generated by underground power cables is screen shielding. However, it is difficult to choose the type of screen to use in a particular situation and it dimensions. The main objective of this paper is to show the recommended steps to select and design a suitable screen for a particular case, taking into account economical and technical aspects to meet the mitigation requirements in the final placement. The case of a 132 kV underground power line is taken as an example to show how these steps can be applied. The proposed steps are derived from an in-depth review of the most used screen shapes, and from numerous simulations carried out by means of numerical methods, such as the finite elements method, to solve the coupled electromagnetic-thermal problem.
... From a thermodynamic perspective, it seems unlikely that weak fields such as those encountered in our everyday environment (typically <1 mT) could ever impact either a biological system or a chemical reaction. In the monograph, Extremely Low Frequency Fields Environmental Health Criteria, the World Health Organization state that a biophysically plausible mechanism must produce a significant change to some biological parameter that can be distinguished from random fluctuations [24]. Variations in temperature constitute the major fluctuation in most biological systems and the key parameter is k B T [25]. ...
Article
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Many animals can sense the geomagnetic field, which appears to aid in behaviours such as migration. The influence of man-made magnetic fields on biology, however, is potentially more sinister, with adverse health effects being claimed from exposure to fields from mobile phones or high voltage power lines. Do these phenomena have a common, biophysical origin, and is it even plausible that such weak fields can profoundly impact noisy biological systems? Radical pair intermediates are widespread in protein reaction mechanisms, and the radical pair mechanism has risen to prominence as perhaps the most plausible means by which even very weak fields might impact biology. In this New Views article, I will discuss the literature over the past 40 years that has investigated the topic of magnetic field effects in proteins. The lack of reproducible results has cast a shadow over the area. However, magnetic field and spin effects have proven to be useful mechanistic tools for radical mechanism in biology. Moreover, if a magnetic effect on a radical pair mechanism in a protein were to influence a biological system, the conditions necessary for it to do so appear increasing unlikely to have come about by chance.
... Health concern is based in particular on the puzzling fact that reported CL risk estimates (ORs) exhibit an offset towards increased risk and a seeming dose response in terms of an increase with increasing magnetic field exposure at low MF levels of 0.2 to 0.4 µT [4]- [8]. However, for the general public existing guidelines and regulations allow ELF MF exposures three orders of magnitudes above these values [9] [10]. ...
Article
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In spite of 36 years epidemiologic research, there is still an ongoing controversy about a causal link between childhood leukemia (CL) and exposure to extremely low frequency (ELF) magnetic fields (MF). Public concern has been increased by the fact that ELF MF have been classified as possibly carcinogenic to humans (class 2B) while exposure limits still remain three orders of magnitudes above reported CL risk onset levels. In a new synoptic approach rather than few selected ORs, all reported epidemiological risk estimates (ORs) are analyzed, both pooled together as well as separated into sub-pools of different exposure metric as well as of high and low exposure levels. The results explain the worrying offset of ORs towards increased CL risk as well as the reported puzzling dose-response at low MF levels as an artifact caused by the small-number effect. The synoptic analysis clarifies that ORs critically depend on statistical power. With increasing statistical power ORs decrease and finally converge to and stay at zero risk. This is found consistently at the entire data pool as well as at all sub-pools related to investigated exposure parameters (wire code, distance to MF source, and magnetic field value). Former contradictory results can now be explained. The synoptic analysis provides convincing evidence that the risk of childhood leukemia is not increased by exposure to ELF magnetic fields. IARC's classification of ELF MF needs revision.
... Im Folgenden wird einleitend ein kurzer Überblick über den Stand des Wissens zu gesundheitlichen Risiken von niederfrequenten Magnetfeldern, gruppiert in 4 wichtige Gesundheitsbereiche, gegeben [3, 5, 6, 7, 8, 11, 12, 17]: ■ ■ Krebs: Die von der internationalen Krebsagentur IARC 2002 vorgenommene Beurteilung, dass bei Langzeitexposition ab 0,4 µT möglicherweise eine Verdoppelung des Risikos von Kindern, an Leukämie zu erkranken, besteht, hat ihre Gültigkeit behalten (für Erwachsene oder für andere Krebsarten liegen keine entsprechenden Hinweise vor). Es handelt sich um einen statistischen Zusammenhang . ...
... However, whether electromagnetic fields originating from household appliances represent a health risk remains uncertain. Because of the lack of sufficient data of the biological effects of IF-MF, the World Health Organization (WHO) has recommended the research of IF-MF on biological systems [4]. In addition, studying the biological effects of IF-MF exposure, especially in susceptible individuals such as children, during development is essential for preserving the life of the next generation. ...
Article
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Recently we have reported that intermediate-frequency magnetic field (IF-MF) exposure transiently altered the mRNA expression levels of memory function-related genes in the hippocampi of adult male mice. However, the effects of IF-MF exposure during brain development on neurological biomarkers have not yet been clarified. In the present study, we investigated the effect of IF-MF exposure during development on neurological and immunological markers in the mouse hippocampus in 3- and 7-week-old male mice. Pregnant C57BL/6J mice were exposed to IF-MF (21 kHz, 3.8 mT) for one hour per day from organogenesis period day 7 to 17. At adolescence, some IF-MF-exposed mice were further divided into exposure, recovery, and sham-exposure groups. The adolescent-exposure groups were exposed again to IF-MF from postnatal day 27 to 48. The expression of mRNA in the hippocampi was examined using a real-time RT-PCR method, and microglia activation was examined by immunohistochemical analysis. The expression levels of NR1 and NR2B as well as transcription factors (CaMKIV, CREB1), inflammatory mediators (COX2, IL-1 b,TNF-α), and the oxidative stress marker heme-oxygenase (HO)-1 were significantly increased in the IF-MF-exposed mice, compared with the control group, in the 7-week-old mice, but not in the 3-week-old mice. Microglia activation was not different between the control and other groups. This study provides the first evidence that early exposure to IF-MF reversibly affects the NMDA receptor, its related signaling pathways, and inflammatory mediators in the hippocampus of young adult mice; these changes are transient and recover after termination of exposure without histopathological changes.
... Elektromanyetik alana maruziyet sonrası vücutta melatonin salınımının azaldığı ve bu azalmaya bağlı olarak vücut biyoritminin bozulduğu öne sürülmektedir [23]. Melatoninin meme kanseri oluşumunda koruyucu rolü olduğundan, elektromanyetik alana maruziyetin herhangi bir nedenle oluşan meme kanserinin ortaya çıkışını hızlandırabileceği belirtilmektedir [24]. ...
Article
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It’s proposed that electromagnetic fields can easily enter the body and can change some vitual conditions. Today magnetic field and electromagnetic wave properties which affect health and their threshold values proportional to the dose parameters are determined.But the virtual effect of magnetic field against health is not clearly known as the net exposure amount has not yet been determined and studies done on humans are scarce. Further studies are needed to find out the effect of magnetic field exposure against human health. Vücuda kolayca girebilen elektromanyetik alanların birçok yaşamsal olayı etkileyebileceği ileri sürülmektedir. Manyetik alan ve elektromanyetik dalga özellikleri, sağlık etkilerinin hangi doz parametreleri arasında olduğu ve bu parametrelerin eşik değerlerinin ne olması gerektiği günümüzde belirlenmesine rağmen, elektromanyetik alanlara maruz kalma miktarının tam olarak tespit edilememesi ve insan sağlığı üzerine yapılan çalışmaların yetersizliği gibi nedenlerle manyetik alanların insan sağlığı üzerine etkisi henüz net olarak ortaya konulamamıştır. Gittikçe artan manyetik alan maruziyetlerinin insan sağlığı üzerindeki etkilerini belirleyebilmek için ileri çalışmalara gereksinim vardır.
... Various international agencies have recommended exposure limits for both residential as well as occupational exposure. Efforts to address bioeffects and potential adverse health effects carried out since then were reported in [5,6]. ...
Article
Exposure to natural and manmade extremely low frequency (ELF) electromagnetic fields (EMF) have been a concern during previous years. Schumann Resonance (SR) phenomenon is the source of natural ELF EMFs. High voltage (HV) Transmission Lines is one of the major sources of manmade ELF EMFs. Staying around or close to transmission lines have reported to cause ill effects on human health. The health effects can be analyzed by measuring the external and internal fields. The main objective of this study is to do exposure assessment around HVAC line and model the same using a program developed in MATLAB. A double circuit 132 kV, 50 Hz transmission line was selected for this purpose.ELF EMFs around HV line were measured using a low frequency analyzer ME 3830B. Measured external field levels were modeled using regression analysis, support vector machine (SVM), Neural Network (NN) and Hybrid technique. Finally comparative analysis of all modeling techniques was presented.
... An occasional downward (Fig. 1, Genox strain; MMS and cis-platinum) or upward (Fig. 2, same compounds) peak should be considered artifactual and without any significance. Showing no genotoxicity or combined effects our results are also in accordance with most of the data on ELF-MF's genotoxicity and their combined effects with known mutagens [16][17][18][19]. We thus conclude that the applied ELF-MF does not damage DNA and does not influence DNA damage induced by chemical mutagens . ...
... Therefore, magnetic field exposure risk occurs for humans. In literature, there several studies about the effects of magnetic field exposure on human health5678. Thus, analysis of magnetic fields arise from underground power cables has an importance. ...
Conference Paper
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Transmission and distribution lines of electrical energy are generally used to plant far from residential areas. But today, due to the growing population, the cities considerably expanded and electrical network have to lie within the living spaces. Especially, uses of medium voltage underground cables for distribution systems become widespread in such areas. The voltage levels of these cables are not too high and the electric field caused by the voltage is fairly shielded by the cable's screen. However, by the reason of flowing load current through the cable's conductor, low frequency magnetic fields occur around the cable. It is known that this magnetic field strength becomes greater with increasing current. Basically, shielding of low frequency magnetic fields is quite harder than shielding the electric fields. In case of being exposed to this kind of magnetic fields by people may lead to crucial health problems. Therefore, some limit values are introduced by the "International Commission On Non‐Ionizing Radiation Protection" (ICNIRP) and "The Institute of Electrical and Electronics Engineers" (IEEE). For this reason, it has importance of measuring magnetic fields caused by high voltage cables (HVC) in urban areas and the required shielding measures should be taken if needed. In this study, magnetic field strengths at different points above a 12/20 kV, 150 mm 2 (Al), single core HVC are measured for different current values. According to the results obtained, even at low currents, the magnetic field strength values could exceed the limiting values for certain distances.
... Therefore, magnetic field exposure risk occurs for humans. In literature, there several studies about the effects of magnetic field exposure on human health5678. Thus, analysis of magnetic fields arise from underground power cables has an importance. ...
Conference Paper
Full-text available
Transmission and distribution lines of electrical energy are generally used to plant far from residential areas. But today, due to the growing population, the cities considerably expanded and electrical network have to lie within the living spaces. Especially, uses of medium voltage underground cables for distribution systems become widespread in such areas. The voltage levels of these cables are not too high and the electric field caused by the voltage is fairly shielded by the cable's screen. However, by the reason of flowing load current through the cable's conductor, low frequency magnetic fields occur around the cable. It is known that this magnetic field strength becomes greater with increasing current. Basically, shielding of low frequency magnetic fields is quite harder than shielding the electric fields. In case of being exposed to this kind of magnetic fields by people may lead to crucial health problems. Therefore, some limit values are introduced by the "International Commission On Non‐Ionizing Radiation Protection" (ICNIRP) and "The Institute of Electrical and Electronics Engineers" (IEEE). For this reason, it has importance of measuring magnetic fields caused by high voltage cables (HVC) in urban areas and the required shielding measures should be taken if needed. In this study, magnetic field strengths at different points above a 12/20 kV, 150 mm 2 (Al), single core HVC are measured for different current values. According to the results obtained, even at low currents, the magnetic field strength values could exceed the limiting values for certain distances.
... Nowadays, high voltage lines that are positioned in public areas are considered to be a threat to human health because of the electric field they caused. In literature, there are a number of studies which claim that the low frequency electric fields have a harmful effect on the human health2345. Therefore, the issue of electric field should be a crucial component to consider while positioning the transmission lines or even constructing a building around them. ...
Conference Paper
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Human health and safety is one of the major issues in electrical power systems. Especially for the systems known as low voltage which is widely and mostly used in the daily life, various equipment, procedures and standards are developed to keep people in safe against electrical hazards. Similarly, some important precautions have been taken for the urban areas which contain energy transmission lines in. Due to to the voltage level of these transmission lines, electric field occurs around the line conductor. The higher the voltage level is the greater the electric field strength. If the occurred electric field strength exceeds the limiting values specified for public, some harmful and unhealthy effects may come up on human body. These limiting values are identified by the "International Commission On Non‐Ionizing Radiation Protection (ICNIRP)" for human health. Therefore, it is necessary for human safety and health to analyze the electric field strengths around the transmission lines in such urban areas. In this study, electric field strength occurred by a transmission line operate at 154 kV nominal voltage is analyzed by using Finite Element Method. A packaged software, Finite Element Method Magnetics 4.2, is used for simulation study. According to the simulation results obtained, it seen that electric field strengths that occur around a 154 kV transmission line could be at critical levels for certain distances. So, the limiting values specified for people should be taken into account particularly in urban areas when new structures are about to build.
... The measurements performed in classes were found to be below 1 mG. According to the study, the results were not different from the results of home enviroment (34). In an echological descriptive study conducted in the elementary schools of two different cities in Spain (43 and 50 schools), approximately 2 500 considerably low frequency measurements were performed in different areas of the schools (canteen, classes, playground, school enterance etc.); values above 3 mG were found in 6% of the schools in the developed city which had larger schools, while values above 3 mG were not found in any school in the city with a smaller settlement (p>0.05) ...
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This study was performed with the objective to determine the levels of some physical hazards in primary schools. This study is a cross-sectional field survey. In this study which was conducted in 31 primary schools selected by appropriate sampling from the district of Keçiören of the province of Ankara, measurements related with temperature, light, electromagnetic field (EMF) and noise levels were done at hundreds of points. Approval was obtained from Gülhane Military Medical Faculty Ethics Committee (2007/97). Only 47.1% of the classes had a temperature value within the recommended limits (20-21°C). It was found that the illumination levels in 96.8% of the schools were above the standard values. However, the levels of illumination were found to be statistically significantly decreased towards the door and the back line (p<0.05). It was found that electromagnetic field levels were significantly higher in the schools who had a source of electromagnetic field nearby compared to the schools who did not have such a source nearby (p<0.001). It was found that the electromagnetic field levels in computer classes were statistically significantly higher compared to the other classes (p<0.001). Noise levels were found to be statistically significantly higher in classes which had 35 and more students (p<0.05). No statistically significant difference was found in schools near intensive vehicle traffic in terms of noise levels (62.8±5.0 (n=72), 62.0±6.4 (n=79), respectively, p>0.05). It was found that primary schools in the region of Keçiören had aspects which had to be improved in terms of building age, building location, brightness, electromagnetic field and noise levels. School health programs directed to improve negative enviromental factors should be developed.
... These reviewers found a small (16%) but significant elevation in risk (different summary measures from the various studies) but concluded that 'the apparent lack of a clear pattern of exposure and risk substantially detracts from the hypothesis that measured magnetic fields in the work environment are responsible for the observed excess of leukaemia'. Other narrative reviews have come to similar conclusions [2,3]. The more important of these 56 studies are the five cohort studies of electric utility workers that present findings for leukaemia risks in relation to quantitative estimates of magnetic field exposure45678. ...
Article
AimsTo investigate whether leukaemia risks are related to occupational exposure to low-frequency magnetic fields.Methods Leukaemia risks experienced by 73 051 employees of the former Central Electricity Generating Board of England and Wales were investigated for the period 1973-2010. All employees were hired in the period 1952-82 and were employed for at least 6 months with some employment in the period 1973-82. Detailed calculations had been performed by others to enable an assessment to be made of exposures to magnetic fields. Poisson regression was used to calculate relative risks (rate ratios) of developing leukaemia or leukaemia subtypes for categories of lifetime, distant (lagged) and recent (lugged) exposure.ResultsFindings for all leukaemias combined were unexceptional; risks were close to unity for all exposure categories and there was no suggestion of risks increasing with cumulative (or recent or distant) magnetic field exposures. There were no statistically significant dose-response effects shown for acute myeloid leukaemia, chronic myeloid leukaemia or chronic lymphocytic leukaemia. There was a significant positive trend for acute lymphocytic leukaemia (ALL), but this was based, in the main, on unusually low risks in the lowest exposure category.Conclusions This study found no convincing evidence to support the hypothesis that exposure to magnetic fields is a risk factor for leukaemia, and the findings are consistent with the hypotheses that both distant and recent magnetic field exposures are not causally related to the generality of leukaemia. The limited positive findings for ALL may well be chance findings.
... The level of 100 μT rms , which we previously investigated [13], is insufficient since the multiple of 100 µT rms to reference level for public exposure dropped to only ~ 3.7 and equal for occupational exposure [15]. In addition, the World Health Organization (WHO) has recommended the carrying out of high-quality research to assess biological effects in the IF range, because there is limited experimental evidence to support the new reference level [16]. In this study, in response to the gaps in knowledge that have emerged since our previous work [13], we planned to investigate the effects of a magnetic field of 23 kHz and 2 mT rms , (i.e. ...
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The increasing use of induction heating (IH) cooktops has roused public concern in Japan and Europe regarding potential health effects. The purpose of this study was to evaluate the effects of exposure to a magnetic field at 23 kHz (which is the maximum output power frequency of most IH cooktops) on gene expression in a human-fetus-derived astroglia cell line, SVGp12. The cells were exposed to the magnetic field at 2 mTrms [which is approximately 74 times higher than the reference level in the most recent International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines], for 2, 4 and 6 h, using a previously reported exposure system. Gene expression was evaluated using an Agilent cDNA microarray. We did not detect any significant effects of the magnetic field on the gene expression profile. On the contrary, heat treatment at 43°C for 2 h used as a positive control significantly affected gene expression, including inducing heat shock proteins, which indicated that our protocol for microarray analysis was appropriate. From these results, we conclude that exposure of human-fetus-derived astroglia cells to an intermediate-frequency magnetic field at 23 kHz and 2 mTrms for up to 6 h does not induce detectable alteration of gene expression.
... Currently many countries have adopted the recommendations proposed by the International Commission on Non Ionizing Radiation Protection (ICNIRP), which correspond for the general public exposure to 50 Hz time-varying ELF the limit values of 100 μT for the Magnetic Field (B) and 5 kV/m for the Electric Field (E), [1]. However, nowadays, many researchers consider those reference levels very conservative proposing as limits regarding the exposure to electromagnetic fields, much lower values, as 0.4 μT for the Magnetic Field (B) and 100V/m for the Electric Field (E), [2]. The objective of this work was to find and identify the Magnetic Field security zones around High Voltage Power Lines (HVPLs) and at ground level taking into account the values of 100 μT and the reduced value of 0.4 μT. ...
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In this paper it is presented the ELF Magnetic Field Security Zones around High Voltage Power Lines for the limits values set by the International Commission on Non-Ionizing Radiation Protection (ICNIRP), ie 100 μT, and for the lower limit value of 0.4 μT. The study was elaborated for the two types of High Voltage Power Lines more used in Portugal, ie 60 kV and 220 kV. It is also shown the ground level security zones 'vis a vis' the administrative servitude used in Portugal. It is presented a good analytical approximation for the Magnetic Field variation with distance (height) for the two types of High Voltage Power Lines. Finally it is shown a schematic picture of the Magnetic Field security zones around these High Voltage Power Lines, derived from the numeric field analysis.
... In such a situation, the health risk assessment of IF-MF has now become important. The World Health Organization (WHO) also recommended that more research to reveal scientific evidence for health risk of IF-MF should be conducted [1]. Since there have been few reports about exposure to IF-MF with high magnetic flux density, especially long term exposure, it is important to evaluate biological effect of long-term IF-MF exposure. ...
Conference Paper
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Since the opportunities that people are exposed to intermediate frequency (IF) magnetic fields (MF) are increasing, the health risk assessment of IF-MF has now become important. Because there have been few studies about long-term exposure to IF-MF with high magnetic flux density, we have developed a new apparatus capable of IF-MF exposure up to 3.9 mT for in vitro study. In this study, we found out that IF-MF did not affect both cell growth and mutagenicity using the mammalian cell line CHO-K1 and its DNA repair deficient derivatives.
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In recent years, studies have indicated that electromagnetic fields (EMFs) may have harmful effects on human health. The effects on human health of the 50 Hz extremely low frequency EMF (ELF-EMF), which is often used in daily life, are still controversial. In our study, we investigated the in vitro effects of 50 Hz ELF-EMF on the lifespan of erythrocytes, which have no nucleus and organelles, and are therefore relatively more sensitive compared to other cells in the body to any harmful effect that may come from outside. Whole blood obtained from healthy volunteers was exposed to 50 Hz, 0.3 mT ELF-EMF over 35 days. After this time, erythrocytes (red blood cell, RBC) counts in blood, hematocrit (HCT) value, main corpuscular volume (MCV), and erythrocyte osmotic fragility (EOF), an indicator of aging, were examined. At the end of 35 days, RBC and HCT were decreased while MCV and EOF were increased in the blood samples of both the EMF-exposed group and the non-exposed group. However, while there were no statistically significant changes in terms of RBC counts, and HCT between the two groups, it was observed that MCV and EOF increased significantly less in the EMF-exposed group compared to the non-exposed group. These results suggest that 50 Hz ELF-EMF exposure does not affect the lifespan of erythrocytes in vitro, but it may extend erythrocytes’ lifecycles due to a reduction in osmotic fragility of the erythrocytes in in vivo conditions. DOI: http://dx.doi.org/10.5281/zenodo.4447339
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Background. Increasingly more people live in tall buildings and on higher floor levels. Factors relating to floor level may protect against or cause cardiovascular disease (CVD). Only one previous study has investigated the association between floor level and CVD. Methods. We studied associations between floor of bedroom and self-reported history of stroke, venous thromboembolism (VTE), and intermittent claudication (IC) among 12.525 inhabitants in Oslo, Norway. We fitted multivariate logistic regression models and adjusted for sociodemographic variables, socioeconomic status (SES), and health behaviors. Additionally, we investigated block apartment residents ( N=5.374 ) separately. Results. Trend analyses showed that disease prevalence increased by floor level, for all three outcomes. When we investigated block apartment residents alone, the trends disappeared, but one association remained: higher odds of VTE history on 6th floor or higher, compared to basement and 1st floor (OR: 1.504; 95% CI: 1.007–2.247). Conclusion. Floor level is positively associated with CVD, in Oslo. The best-supported explanation may be residual confounding by building height and SES. Another explanation, about the impact of atmospheric electricity, is also presented. The results underline a need to better understand the associations between residence floor level and CVD and multistory housing and CVD.
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Electromagnetic fields (EMFs) are present throughout the modern world and are derived from many man-made sources including overhead transmission lines. The risks of extremely-low frequency (ELF) electromagnetic fields are particularly poorly understood especially at high field strengths as they are rarely encountered at ground level. Flying insects, however, can approach close to high field strength transmission lines prompting the question as to how these high levels of exposure affect behaviour and physiology. Here we utilise the accessible nervous system of the locust to ask how exposure to high levels of ELF EMF impact at multiple levels. We show that exposure to ELF EMFs above 4 mT leads to reduced walking. Moreover, intracellular recordings from an identified motor neuron, the fast extensor tibiae motor neuron, show increased spike latency and a broadening of its spike in exposed animals. In addition, hind leg kick force, produced by stimulating the extensor tibiae muscle, was reduced following exposure, while stress-protein levels (Hsp70) increased. Together these results suggest that ELF EMF exposure has the capacity to cause dramatic effects from behaviour to physiology and protein expression, and this study lays the foundation to explore the ecological significance of these effects in other flying insects.
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Background: Epidemiological studies indicate increased risk of leukemia, lymphoma, and brain tumor among electrical workers exposed to electromagnetic field (EMF). Other investigator reported that continuous exposure of four successive generations of mice to EMF in doses of 1 kV to 5 kV caused tumor formation in offspring. The objective of this study was to evaluate the effect of continuous exposure of three successive generations of mice (Mus musculus L) to EMF of 3 kV, 4 kV, and 5 kV and its implication of chromosomal breakage, as detected by double minute formation.Methods: Four couples of mice of Swiss Webster strain, 3-4 months of age, and 7-40 gram of body weight were exposed to EMF at the doses of 3 kV, 4 kV, and 5 kV, and one couple served as control. Double minute formation was examined in all offspring, except one couple of each group to be exposed with the same doses of EMF to get the F2 generation, and so forth until F3 generation. Twenty metaphases of chromosomes were examined and frequencies of double minute were calculated in the three generations of all group.Results: Frequencies of double minute in F1, F2, and F3 of mice exposed to EMF of 3 kV were respectively 0.78 ± 0.08; 0.83 ± 0.09; and 0.80 ± 0.05. In the 4 kV group were 0.083 ± 0.11; 0.73 ± 0.03; and 0.96 ± 0.15, and in the 5 kV group were 0.96 ± 0.25; 0.75 ± 0.05; and 0.99 ± 0.33, whereas no double minute chromosomes were noted in control group. Frequencies of the double minute in mice exposed to EMF were significantly higher than control group.Conclusions: Continuous exposure of mice during three successive generations to EMF at doses of 3 kV, 4 kV, and 5 kV causes increased chromosomal breakage as detected as double minute chromosome formation. (Med J Indones 2011; 20:109-13)Keywords: chromosomal breakage, double minute, electromagnetic field, mice
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Traumatic insults to the spinal cord induce both immediate mechanical damage and subsequent tissue degeneration. The latter involves a range of events namely cellular disturbance, homeostatic imbalance, ionic and neurotransmitters derangement that ultimately result in loss of sensorimotor functions. The targets for improving function after spinal cord injury (SCI) are mainly directed toward limiting these secondary injury events. Extremely low-frequency electromagnetic field (ELF-EMF) is a possible non-invasive therapeutic intervention for SCI rehabilitation which has the potential to constrain the secondary injury-induced events. In the present review, we discuss the effects of ELF-EMF on experimental and clinical SCI as well as on biological system.
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Exposure to extremely low-frequency magnetic fields (ELF-MF) was evaluated in an International Agency for Research on Cancer (IARC) Monographs as "possibly carcinogenic to humans" in 2001, based on increased childhood leukemia risk observed in epidemiological studies. We conducted a hazard assessment using available scientific evidence published before March 2015, with inclusion of new research findings from the Advanced Research on Interaction Mechanisms of electroMagnetic exposures with Organisms for Risk Assessment (ARIMMORA) project. The IARC Monograph evaluation scheme was applied to hazard identification. In ARIMMORA for the first time, a transgenic mouse model was used to mimic the most common childhood leukemia: new pathogenic mechanisms were indicated, but more data are needed to draw definitive conclusions. Although experiments in different animal strains showed exposure-related decreases of CD8+ T-cells, a role in carcinogenesis must be further established. No direct damage of DNA by exposure was observed. Overall in the literature, there is limited evidence of carcinogenicity in humans and inadequate evidence of carcinogenicity in experimental animals, with only weak supporting evidence from mechanistic studies. New exposure data from ARIMMORA confirmed that if the association is nevertheless causal, up to 2% of childhood leukemias in Europe, as previously estimated, may be attributable to ELF-MF. In summary, ARIMMORA concludes that the relationship between ELF-MF and childhood leukemia remains consistent with possible carcinogenicity in humans. While this scientific uncertainty is dissatisfactory for science and public health, new mechanistic insight from ARIMMORA experiments points to future research that could provide a step-change in future assessments. Bioelectromagnetics. © 2016 Wiley Periodicals, Inc.
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Is there a Cheshire Cat in science? One might believe so, given the many published scientific discoveries that cannot be independently reproduced. The ?replication crisis? in science has become a widely discussed issue among scientists and the lay media and even has its own entry in Wikipedia.
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La radiación electromagnética emitida por la telefonía móvil y las antenas bases puede penetrar en los tejidos de la cabeza humana, pudiendo ser absorbida y transformada en calor. Debido al incremento de la telefonía móvil hay interés en estudiar sus efectos en la salud humana. Se analizó la literatura médica desde 1996 hasta 2013, mediante búsquedas en Internet utilizando Medline y PubMed. Usando modelos matemáticos se estudió los efectos para frecuencias de 0,9GHz. Se empleó el modelo de diferencias fnitas para predecir relaciones de absorción específca en W·m-2. El modelo de elementos fnitos se basó en un corte horizontal de la cabeza de niños de 10 años, a la altura de los ojos. Se utilizó un análisis en dos dimensiones y un espesor mínimo. El modelo de diferencias predijo relaciones de absorción específca, alcanzando de 0,72W·m-2, siendo 2,0 lo admitido por la Unión Europea. Los cálculos de absorción obtenidos de las predicciones por elementos fnitos (para determinar el desplazamiento del campo eléctrico) indicaron una mayor coincidencia para la versión de 2009 (0,685W·m-2). Lanueva versión 2014 alcanzó un máximo de 0,636W·m-2, pero tiene ligeras diferencias entre la 2ª y 3ª subdivisión del hemisferio cerebral. Sin embargo, esta versión más moderna del software de elementos fnitos tiene una buena coincidencia con los resul- tados obtenidos por otros autores. Las modernas herramientas computacionales permiten modelar el efecto de los fonos celulares en el cerebro, existiendo algunas diferencias menores entre las predicciones de los diferentes programas.
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The siting of high voltage overhead transmission lines (HVOTLs) is often subject to public opposition where affected communities seek to protect local places. This study explores the perspectives of local citizens affected by a proposed HVOTL to connect new nuclear power at Hinkley Point in Southwest England. A two-day public workshop was held with 38 participants in an affected line-site community, using deliberative focus group methods to explore perceptions of environmental and social impacts, risks, governance arrangements and technology choices. The findings show how potential health effects from electric and magnetic fields (EMF) and visual impacts are perceived to industrialise rural places, disrupt place attachments and provoke local opposition. The findings challenge the ‘not-in-my-back-yard’ assumption that citizens are selfish place-protectionists that lack the technical sophistication necessary to take a strategic viewpoint on transmission system development. They also reveal how decision making under the former UK Infrastructure Planning Commission's (IPC) (and its successor body the Planning Inspectorate) presents a challenge to procedural justice, as front-loaded developer-led consultation practices curtail citizen input to key decisions on alternative technologies (for example, underground or undersea lines). This is likely to exacerbate public mistrust of transmission system operators and provoke further organised protest.
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A partir da publicação, em 1979, dos resultados de um estudo que apontava para o aumento do risco de leucemia em crianças associado à exposição a campos magnéticos, o interesse pelo tema vem aumentando, e diversos estudos foram publicados. O objetivo desta revisão é apresentar os diferentes métodos utilizados na avaliação da exposição aos campos magnéticos de frequência extremamente baixa, bem como as dificuldades enfrentadas na quantificação dessa exposição, além de relatar os resultados de estudos epidemiológicos publicados nos últimos 10 anos. A falta de um modelo fisiopatológico que explique uma possível influência dos campos magnéticos na saúde e a dificuldade para quantificar a exposição têm sido os maiores obstáculos da pesquisa na área. Leucemia e tumores do sistema nervoso central têm sido os efeitos mais estudados. Leucemia em crianças é o desfecho mais consistentemente associado à exposição a campos magnéticos. Estudos mais recentes apontam a associação entre esclerose lateral amiotrófica e campos magnéticos.
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Background: We extend our previous study of childhood leukaemia and proximity to high-voltage powerlines by including more recent data and cases and controls from Scotland, by considering 132-kV powerlines as well as 275 and 400 kV and by looking at greater distances from the powerlines. Methods: Case–control study using 53 515 children from the National Registry of Childhood Tumours 1962–2008, matched controls, and calculated distances of mother's address at child's birth to powerlines at 132, 275, and 400 kV in England, Wales and Scotland. Results: Our previous finding of an excess risk for leukaemia at distances out to 600 m declines over time. Relative risk and 95% confidence interval for leukaemia, 0–199 m compared with>1000 m, all voltages: 1960s 4.50 (0.97–20.83), 2000s 0.71 (0.49–1.03), aggregate over whole period 1.12 (0.90–1.38). Increased risk, albeit less strong, may also be present for 132-kV lines. Increased risk does not extend beyond 600 m for lines of any voltage. Conclusions: A risk declining over time is unlikely to arise from any physical effect of the powerlines and is more likely to be the result of changing population characteristics among those living near powerlines.
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An earlier study demonstrated changes in synaptic efficacy and seizure susceptibility in adult rat brain slices following extremely low-frequency magnetic field (ELF-MF) exposure. The developing embryonic and early postnatal brain may be even more sensitive to MF exposure. The aim of the present study was to determine the effects of a long-term ELF-MF (0.5 and 3mT, 50Hz) exposure on synaptic functions in the developing brain. Rats were treated with chronic exposure to MF during two critical periods of brain development, i.e. in utero during the second gestation week or as newborns for 7 days starting 3 days after birth, respectively. Excitability and plasticity of neocortical and hippocampal areas were tested on brain slices by analyzing extracellular evoked field potentials. We demonstrated that the basic excitability of hippocampal slices (measured as amplitude of population spikes) was increased by both types of treatment (foetal 0.5mT, newborn 3mT). Neocortical slices seemed to be responsive mostly to the newborn treatment, the amplitude of excitatory postsynaptic potentials was increased. Foetal ELF-MF exposure significantly inhibited the paired-pulse depression (PPD) and there was a significant decrease in the efficacy of LTP (long-term potentiation induction) in neocortex, but not in hippocampus. On the other hand, neonatal treatment had no significant effect on plasticity phenomena. Results demonstrated that ELF-MF has significant effects on basic neuronal functions and synaptic plasticity in brain slice preparations originating from rats exposed either in foetal or in newborn period.
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Abstract In the last years, it has been discussed frequently whether there are any harmful effects of electromagnetic fields on human health. Electromagnetic fields are generated by several natural and man-made sources. Part of the electromagnetic spectrum called Radiofrequency is used in communication systems such as mobile (cellular) phone and computer. The aim of our study was to explore different self-reported symptoms that may be associated with exposure to electromagnetic fields. This survey study was conducted, using a questionnaire, on 350 people aged +9 years in Turkey. The chi-square test was used for data analysis. Self-reported symptoms were headache, vertigo/dizziness, fatigue, forgetfulness, sleep disturbance-insomnia, tension-anxiety, joint and bone pain, lacrimation of the eyes, hearing loss and tinnitus. As a result of the survey, the study has shown that users of mobile phone and computer more often complained of headache, joint and bone pain, hearing loss, vertigo/dizziness, tension-anxiety symptoms according to time of daily usage (p < 0.05). In users of mobile phone and computer, women significantly (p < 0.05) complained more often of headache, vertigo/dizziness, fatigue, forgetfulness and tension-anxiety than men.
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A large number of epidemiologic studies examining the potential effect of residential exposure to extremely-low frequency (ELF) magnetic fields and childhood leukemia have been published. Two pooled analyses [Ahlbom A, Day N, Feychting M, Roman E, Skinner J, Dockerty J, Linet M, et al. (2000). A pooled analysis of magnetic fields and childhood leukaemia. Br J Cancer. 83(5):692-698; Greenland S, Sheppard AR, Kaune WT, Poole C, Kelsh AM (2000). A pooled analysis of magnetic fields, wire codes, and childhood leukemia. Epidemiology. 11(6):624-634], which included the major epidemiologic studies on ELF magnetic fields and childhood leukemia showed twofold increase in childhood leukemia risk in association with residential ELF exposure above 0.3-0.4 μT. Based on "limited" epidemiologic evidence linking ELF exposure to childhood leukemia and "inadequate evidence" for carcinogenicity of ELF in rodent bioassays, the International Agency for Research on Cancer (IARC) classified ELF magnetic fields as a possible human carcinogen (2B classification) [International Agency for Research on Cancer (IARC) (2002). Non-ionizing radiation, Part 1: Static and extremely low-frequency (ELF) electric and magnetic fields. IARC monographs on the evaluation of carcinogenic risks to humans. Vol. 80. IARC Press: Lyon], confirmed by WHO on the basis of studies published after 2000 [World Health Organization. Extremely low frequency fields. In: 238 Environmental health criteria, Geneva: WHO; 2007]. The analysis of more recent studies of ELF magnetic fields and childhood leukemia had small findings and propose methodological improvements concerning the uncertainties in epidemiological approaches and exposure assessment, bias in selection of controls [Kheifets L, Oksuzyan S (2008). Exposure assessment and other challenges in non-ionizing radiation studies of childhood leukaemia. Radiat Prot Dosimetry. 132(2):139-147]. By the end of 2010, 37 countries had been identified for possible participation in the International study TRANSEXPO. The pilot work has been completed in five countries (Finland, Hungary, Israel, Switzerland and Bulgaria). In 2008, Bulgaria through the National Centre of Public Health Protection joined with pilot study in TRANSEXPO Project. At this first stage of the project our investigation was directed to performing measurements in dwellings with built-in transformer stations, collecting data of population and cancer registry and choosing the epidemiology design feasible for continuing the project. Taking into account the available sources of information in Bulgaria (different registers of the population) needed for epidemiological approach, it was found that the most appropriate epidemiology design would be the nested case-control study. Control group could be collected in accordance with the international requirements for such epidemiological studies. This approach could be modified in the course of the further study in order to ensure achievement of the purposes of the main international requirements of the study.
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An inaccurate evaluation of exposure is considered a possible cause for the inadequate conclusiveness of epidemiological research on adverse effects of extremely low frequency-magnetic fields (ELF-MF). The objective of this study is to provide an evaluation of current ELF-MF exposure in workers, the specific contribution of occupational exposure to overall 24-h exposure, and the representativeness of a job exposure matrix (JEM). ELF-MF exposure was monitored in 543 workers for 2 days using personal meters. Time-weighted average (TWA) levels at work, at home and outside the home were calculated. A JEM based on the 1988 International Standard Classification of Occupations (ISCO 88) was created. Median exposure at work, at home and outside the home were 0.14, 0.03 and 0.05 mT, respectively. Occupational exposure accounted for about 60% of 24-h exposure. In the JEM, about 50% of the classified occupations included significantly different individual TWAs. Occupational exposure to ELF-MF appeared low. Median exposure levels at home and outside were 20–28% of the occupational level, giving a minor contribution to overall day-to-day exposure. The frequent occurrence of workers with different TWA included under the same job title highlights the risk of misclassification in epidemiological studies on ELF-MF effects based on JEM.
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Background: High-voltage overhead power lines (HVOLs) are a source of extremely low-frequency magnetic fields (ELF-MFs), which are classified as possible risk factors for childhood acute leukaemia (AL). The study was carried out to test the hypothesis of an increased AL incidence in children living close to HVOL of 225–400 kV (VHV-HVOL) and 63–150 kV (HV-HVOL). Methods: The nationwide Geocap study included all the 2779 cases of childhood AL diagnosed in France over 2002–2007 and 30 000 contemporaneous population controls. The addresses at the time of inclusion were geocoded and precisely located around the whole HVOL network. Results: Increased odds ratios (ORs) were observed for AL occurrence and living within 50 m of a VHV-HVOL (OR=1.7 (0.9–3.6)). In contrast, there was no association with living beyond that distance from a VHV-HVOL or within 50 m of a HV-HVOL. Conclusion: The present study, free from any participation bias, supports the previous international findings of an increase in AL incidence close to VHV-HVOL. In order to investigate for a potential role of ELF-MF in the results, ELF-MF at the residences close to HVOL are to be estimated, using models based on the annual current loads and local characteristics of the lines.
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Since the early seventies, potential health risks from ELF (Extremely Low frequency electromagnetic Fields) exposure (50 Hz) have been extensively treated in the literature (more than 1000 references registered by WHO (World Health Organisation), 2007). After 30 years of worldwide research, the major epidemiological output is the possible modest increased risk (by a factor 2) of childhood leukaemia in case of a long exposure to an ambient magnetic flux density (B-field) higher than 0.4 µT. However, this fact has not been confirmed by in vivo and in vitro studies. Moreover it has not been validated by any adverse health biological mechanisms neither for adults nor for children. International recommendations (ICNIRP, International Commission on Non-Ionising Radiation Protection) are currently, for general public, not to exceed a B-field of 100 µT (50 Hz) and an E-field of 5 kV/m (50 Hz). Herein, a rough overview of typical values of ELF fields will be presented followed by a brief literature survey on childhood leukaemia and ELF. The potential carcinogenic effect of ELF would be linked to electrical disturbances in cell behaviour. The major concern linking childhood leukaemia and ELF is thus to determine the response of bone marrow cells under ELF fields. With that purpose, transmembrane potential will be targeted and linked to the E-field at that level. This paper is three-folded: (1) the electric interactions between ambient ELF fields and the body are studied both qualitatively and quantitatively. Different sources of internal E-field are analysed and classified according to their potential risk; (2) the hypothesis of contact current is detailed; (3) key actions to undertake are highlighted. Based on the current state of the art and some authors' own developments, this paper proposes simple low cost enhancements of private electrical installations in order to anihilate the major source of potential effects of ELF.
Article
Non-ionising radiation protection generally proceeds by establishing a dichotomy. Certain effects are regarded as established, and scientific bodies set exposure guidelines designed basically to prevent such effects. At low frequencies the principal such effect is induced electric fields in tissues, and at high frequencies is heating. For all other effects, regarded as not being established, traditional scientific bodies tend not to set exposure guidelines nor even to propose other precautionary measures, but to leave responsibility for that to non-scientific or political processes and bodies. Both parts of this paradigm are criticised. For established effects, exposure guidelines cannot be set from the science alone but need an understanding of economic, social and political consequences. For non-established effects, the issues are still largely scientific and need the input of scientists.
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In previous epidemiological studies, elevated leukemia rates have been found in a collection of occupational categories of “electrical workers.” In this study, spot measurements were taken of the Extremely Low Frequency (below 100 Hz) electric and magnetic field exposures of “electrical workers” at 114 work sites at an electric utility, an aerospace firm, a municipal government, motion picture theaters, and TV repair shops. For comparison, the fields were measured in 18 residences and 3 offices. The residential measurements had 95th percentiles at 3.4 × 10 Tesla for magnetic fields and 33.1 volts/meter for electric fields. For magnetic fields, the 95th percentile of the residential measurements was exceeded by 59 percent of the occupational measurements, covering all the “electrical worker” job categories with the exception of radio operators. The highest magnetic field encountered was 1250 × 10 Tesla on a battery-powered fork lift operator, which had not been considered an “electrical worker” occupation previously. Only 25 percent of the occupational electric fields were above the 95th percentile measured in residences, and these were all in the job categories for power line workers, power station operators, and TV repairers. This survey indicates that many “electrical workers” have some exposures to elevated fields. However, the wide variability in field exposures over time and between workers will necessitate better exposure measurements to assess more rigorously the association between leukemia rates and electromagnetic fields. Bowman, J.D.; Garabrant, D.H.; Sobel, E.; Peters, J.M.: Exposures to Extremely Low Frequency (ELF) Electromagnetic Fields in Occupations with Elevated Leukemia Rates. Appl. Ind. Hyg. 3:189–194; 1988.
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The author states that the purpose of this review paper is to present to this symposium of biologists interested in possible effects of extremely low frequency (ELF) electric and magnetic fields upon living organisms what is known about the natural background noise in the 10** minus **3 Hz to 100 Hz frequency region. Secular variations of the earth's magnetic field originate within the earth while geomagnetic storms and ″micropulsations″ are caused by processes in the ionosphere, magnetosphere and, possibly, interplanetary space. These phenomena are described briefly, as are the steady and slowly varying electric fields at the earth's surface caused mainly by lightning and ion separation in clouds. Earth-ionosphere cavity resonances between 8 Hz and 30 Hz are discussed: their average amplitudes near 10 Hz are 0. 63 pT/Hz** one-half for the magnetic flux density and 0. 1 mv/(mHz** one-half ) for the electric field. Above 30 Hz the field intensity of atmospheric noise varies with location and season and the average level decreases with increasing frequency up to about 2 kHz.
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In the general environment, at home and in the factory or office, people are exposed to electromagnetic radiation from computers, domestic appliances, power transmission lines and manufacturing tools and products. It is often thought that the electromagnetic fields associated with these may have adverse effects, and indeed court cases have sometimes upheld this. The evidence, however, remains ambiguous and a causal relationship between the fields and illness is not accepted generally. Despite this, in most developed countries, safety codes or laws have been adopted to protect the individual. These define permitted levels of exposure to both static and time-varying fields, the effects of both of which are considered in this article.
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Introduction The acute leukemias of childhood are a heterogeneous group of diseases. In reviewing the descriptive and analytic epidemiology of these malignancies, we have emphasized specific subgroups, as defined by morphology [the French-American-British (FAB) classification], cytogenetic features, or molecular markers. There is evidence that specific subtypes of leukemia may have distinct etiologies, and that molecular abnormalities associated with particular subtypes may be linked with specific causal mechanisms. Moreover, the mutations produced at the successive stages of leukemogenesis, from initiation through induction to promotion, may all involve separate etiologic processes. It is also important to note that changes over time in diagnostic practice and precision may account in part for some reported epidemiologic trends. Moreover, changes in terminology and classification schemes for leukemia make it difficult to perform direct comparisons among studies, especially if risk factors differ for different subgroups. However, in assessing risk factors, studies of the childhood leukemias present several methodologic advantages. The interval between exposure to putative risk factors and the onset of leukemia may be shorter, recall of exposures is likely to be better, and intervening factors may be fewer than those associated with adult leukemias. These characteristics of childhood leukemia may facilitate identification of the most likely risk factors for each leukemia subtype. Furthermore, they lend themselves to an approach that includes both population studies and molecular epidemiologic techniques, permitting the design of research to assess genetic-environmental causal interactions. © Cambridge University Press 2006 and Cambridge University Press, 2009.
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This paper presents a detailed comparison of numerical and analytical calculations of the low-frequency electric and current density fields, induced by an applied uniform axial magnetic field, in an equatorially stratified sphere having the conductivity distribution σ(φ) = σ0e-λ cos(pφ) with p ∈ {1,2} and λ > 0. As shown by the analytic solution, the resulting induced fields are fully three-dimensional, and the model therefore serves as a rigorous test of numerical codes. The numerical method is a scalar-potential finitedifference scheme based on Stevenson's method for isolated conducting bodies. This computer code was recently shown to provide excellent agreement with results computed independently by a modified Finite-Difference Time-Domain method. Nevertheless, both codes share some underlying similarities, such as their common use of parallelepiped material voxels to represent the conductivity distribution, and of an edge-based staggered grid to model the electric fields. Therefore, it is of value to compare the numerical results with analytic ones. The analytic model has a freely adjustable contrast parameter, and supports both π- and 2π-periodic conductivity distributions. Numerical and analytical results are compared for several configurations. Full three-dimensional volumetric correlation coefficients are typically of the order of 99% or better. As might be expected, the main differences occur at the surface of the sphere, where the true circumferential fields are most poorly approximated by the staircasing approximation inherent in the numerical approximation.
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It is important to understand the relationships between cardiac excitability and stimulus features such as duration, frequency, repetition pattern, wave-shape, electrode configuration, current density, and current pathway. Much of our knowledge of these effects is derived from studies directed toward therapeutic uses of cardiac stimulation, such as cardiac pacing and defibrillation. We can better evaluate cardiac hazards if we understand the principles of cardiac electrophysiology presented in Chapter 5. The reviews in Chapters 3 and 4, concerning principles of excitable membranes, will also be referred to in this chapter.
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The EMF and Breast Cancer on Long Island Study (EBCLIS) was a case-control study designed to evaluate the possible association between exposure to electromagnetic fields (EMFs) and breast cancer. Eligible women were participants in the population-based Long Island Breast Cancer Study Project, were under 75 years of age at enrollment, were residentially stable, and were identified between August 1, 1996, and June 20, 1997. Of those eligible, 576 cases and 585 controls participated in EBCLIS (87% and 83%, respectively). In-home data collection included various spot and 24-hour EMF measurements, ground-current magnetic field measurements, wire mapping of overhead power lines servicing the home, and an interview. Odds ratios and 95% confidence intervals were based on multivariate logistic regression analyses. All odds ratios were close to 1 and nonsignificant. For the highest quartile of 24-hour EMF measurements, the odds ratio was 0.97 (95% confidence interval (CI): 0.69, 1.37) in the bedroom and 1.09 (95% CI: 0.78, 1.51) in the most lived-in room. For the highest exposure category of ground-current measurements, the odds ratio was 1.13 (95% CI: 0.88, 1.44) in the bedroom and 1.08 (95% CI: 0.85, 1.38) in the most lived-in room. These and other EBCLIS results agree with other recent reports of no association between breast cancer and residential EMF exposures.
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The effect of stress induced by an electric field on the adrenal gland cortex of mice was examined by means of corticosterone serum assay and evaluation of the lipid profile of the different zones of the cortex. Six generations of experimental mice were exposed to a 10 kV/m electric field from conception and corresponding control groups were sham exposed. Mice were sacrificed at 35 days (n = 10), as adults (n = 20) and at 18 months (old mice) (n = 10). Blinded lipid estimates were performed on histological preparations of the adrenals, serum corticosterone levels were determined, and the results were statistically analyzed. The mean lipid volume in the zona glomerulosa of the exposed adult male group was significantly higher than that of the control group (P = 0.004). The median daytime corticosterone level of the exposed male mice was also significantly higher than that in the controls (P = 0.02). The lipid profiles and corticosterone values in the other subgroups did not differ significantly. As chronic stress increases the lipid volume of all the zones of the adrenal cortex and stimulates the zona glomerulosa to corticosterone secretion, the data suggest that the electric field acted as a chronicmore » stressor in the adult male mice. 21 refs., 6 figs., 2 tabs.« less
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Eμ-pim-1 transgenic mice are predisposed to develop lymphomas. Due to their low spontaneous tumour incidence and their increased sensitivity towards the lymphomagen ethylnitrosourea these mice may present an interesting model for short-term carcinogenicity testing. Here, we report on the further exploration of this transgenic mouse model with two additional carcinogens known to have, among others, the lymphohaematopoietic system as target, i.e. benzo[a]pyrene (B[a]P) and 12-O-tetradecanoylphorbol-13-acetate (TPA). B[a]P, given three times a week (by gavage) for 13 weeks at 4.3, 13 or 39 mg/kg body weight, resulted in a dose-related increase in lymphomas up to a 90% incidence in Eμ-pim-1 mice during the observation period of 40 weeks. B[a]P also induced tumours of the forestomach within this observation period, though at a lower incidence and apparently equally effective in wildtype and transgenic mice. TPA, on the other hand, was unable to induce lymphomas (or tumours in any other organ) in either transgenic or wildtype animals within the observation period of 44 weeks, when applied dermally at the maximum tolerated dose of 3 μg/mousee twice a week for 35 weeks. Molecular analysis showed that B[a]P-induced lymphomas in transgenic mice were of T-cell origin, 80% of which had elevated levels of c-myc expression. None of the lymphomas had increased N-myc expression and mutation analysis of the ras-gene family revealed a K-ras mutation in only one out of eight tumours investigated. Also, none of the lymphomas showed aberrant expression of p53 as determined by immunohistochemistry. It is concluded that the Eμ-pim-1 mouse model will not be very suitable for short-term carcinogenicity testing in general: only genotoxic chemicals that have the lymphohaematopoietic system as target for carcinogenesis in wild-type mice, appear to be efficiently identified.
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Some experimental and epidemiologic evidence suggests that residential exposure to power-frequency magnetic fields can increase breast cancer risk. This association was investigated in a nested case-control study of female breast cancer within a cohort of African Americans, Latinas, and Caucasians in Los Angeles County, California. Incident breast cancer was ascertained from 1993 to 1999 by linkage to county and state tumor registries. Controls were selected from a random sample of cohort members without breast cancer at baseline. Exposure was assessed in 1995–2001 by means of wiring configuration coding (an indirect measure of magnetic field exposure that has been associated with increased risk of childhood leukemia in Los Angeles and elsewhere in North America) in all homes occupied over the previous 10 years for 743 cases and 699 controls and by measurement of magnetic fields in the bedroom over a 7-day period for 347 cases and 286 controls. The estimated risk of breast cancer was not higher among women with wiring configuration codes associated with the highest magnetic fields (for a very high current configuration relative to very low, the adjusted odds ratio was 0.76 (95% confidence interval: 0.49, 1.18)). Stronger measured fields were not significantly associated with increased risk. These data suggest that residential magnetic field exposures commonly experienced by US women do not influence risk of breast cancer. breast neoplasms; electricity; electromagnetic fields; environmental exposure Abbreviations: CI, confidence interval; SEER, Surveillance, Epidemiology, and End Results.
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Aims: To investigate cancer incidence in workers exposed to high levels of extremely low frequency magnetic fields (ELF-MF). Methods: A cohort based on the engineering industry was established. Industries assumed to use resistance welding in production were chosen in order to increase the prevalence of high exposed subjects and to reduce the influence of confounding factors. All men and women employed in these branches during 1985–94 were selected, 537 692 men and 180 529 women. Occupation, based on census information from 1980, 1985, and 1990, was linked to a job exposure matrix on ELF-MF. Four exposure groups were used by stratifying on mean workday ELF-MF exposure, using the lowest exposure group as reference. Cancer incidence was obtained by linkage to the Swedish Cancer Registry. Results: Men in the very high exposure group showed an increased incidence of tumours of the kidney, pituitary gland, and biliary passages and liver; for these cancer sites an exposure–response relation was indicated. Women in the very high exposure group showed an increased incidence of astrocytoma I–IV, with a clear exposure–response pattern. An association was suggested in the high exposure group only, for cancer of the corpus uteri and multiple myeloma. Decreased risks in the very high exposure group among men were found for cancer of the colon and connective tissue/muscle. Conclusions: The results on cancer of the liver, kidney, and pituitary gland among men are in accordance with previous observations. Regarding brain tumours and leukaemia, the outcome for women provided further support of an association. The hypothesis of a biological mechanism involving the endocrine system was partly supported.
Article
Background: Most epidemiological studies on adverse health effects among women in relation to occupational magnetic field exposure have been based on information about men’s exposure. Aims: To create a job-exposure matrix for occupational exposure to extremely low frequency magnetic fields among women. Methods and Results: Measurements were performed using personal magnetic field meters (Emdex Lite) carried by the subjects for 24 hours on a normal workday. Subjects were volunteer women working in the occupations identified as common among women in Stockholm County based on the 1980 census. A total of 471 measurements were made in 49 different occupations, with a minimum of 5 and a maximum of 24 measurements in each occupation. The included occupations cover about 85% of the female population gainfully employed in 1980. Parameters representing average and peak magnetic field exposures, temporal change in the exposure, and proportion of time spent above certain exposure levels were calculated both for the workday and for the total 24 hour period grouped by occupational titles. The occupations with higher than average exposure were cashiers, working proprietors in retail trade, air stewardesses, dental nurses, cooks, post-office clerks and kitchen maids. Conclusions: This new job-exposure matrix substantially increases the knowledge about magnetic field exposure among women and can be used for exposure assessment in future studies.
Article
OBJECTIVE To investigate whether risks of leukaemia are related to occupational exposure to magnetic fields. METHODS The mortality experienced by a cohort of 83 997 employees of the former Central Electricity Generating Board of England and Wales was investigated for the period 1973–97. All employees were employed for at least 6 months with some employment in the period 1973–82. Computerised work histories were available for 79 972 study subjects for the period 1971–93. Detailed calculations were performed by others to enable a novel assessment to be made of exposures to magnetic fields. Two analytical approaches were used, indirect standardisation (n=83 997) and Poisson regression (n=79 972). RESULTS Based on serial mortalities for England and Wales, the standardised mortality ratio of 84 for all leukaemias (observed 111, expected 132.3) was similar to that of 83 for all causes (observed 14 845, expected 17 918). No significant positive trends were found for the risks of various types of leukaemia (chronic lymphatic leukaemia, acute myeloid leukaemia, chronic myeloid leukaemia, all leukaemia) either with lifetime cumulative exposure to magnetic fields or with such exposures received in the most recent 5 years. CONCLUSIONS There are no discernible excess risks of leukaemia as a consequence of occupational exposure to magnetic fields in United Kingdom electricity generation and transmission workers.
Article
OBJECTIVES—To investigate a broad range of occupational, hobby, and lifestyle exposures, suggested as risk factors for Philadelphia chromosome positive (Ph+) chronic myeloid leukaemia (CML). METHODS—A case-control study, comprising 255 Ph+CML patients from southern Sweden and matched controls, was conducted. Individual data on work tasks, hobbies, and lifestyle exposures were obtained by telephone interviews. Occupational hygienists assessed occupational and hobby exposures for each subject individually. Also, occupational titles were obtained from national registries, and group level exposure—that is, the exposure proportion for each occupational title—was assessed with a job exposure matrix. The effects of 11 exposures using individual data and two exposures using group data (organic solvents and animal dust) were estimated. RESULTS—For the individual data on organic solvents, an effect was found for moderate or high intensity of exposure (odds ratio (OR) 3.4, 95% confidence interval (95% CI) 1.1 to 11) and for long duration (15-20 years) of exposure (OR 2.1, 95% CI 1.1 to 4.0). By contrast, the group data showed no association (OR 0.69, 95% CI 0.27 to 1.8; moderate or high intensity versus no exposure). For extremely low frequency electromagnetic fields (EMFs), only individual data were available. An association with long occupational exposure to EMFs was found (OR 2.3, 95% CI 1.2 to 4.5). However, no effect of EMF intensity was indicated. No significant effects of benzene, gasoline or diesel, or tobacco smoking were found. OR estimates below unity were suggested for personal use of hair dye and for agricultural exposures. CONCLUSIONS—Associations between exposure to organic solvents and EMFs, and Ph+CML were indicated but were not entirely consistent. Keywords: risk factors; epidemiology; case-control study
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In this case-control study, the authors aimed to examine whether use of an electric bedding device increased breast cancer risk in African-American women. Cases were 304 African-American patients diagnosed with breast cancer during 1995-1998 who were aged 20-64 years and lived in one of three Tennessee counties. Controls were 305 African-American women without breast cancer who were selected through random digit dialing and frequency-matched to cases by age and county. Information on the use of an electric blanket or heated water bed and other risk factors was collected through telephone interviews. Breast cancer risk associated with use of an electric bedding device increased with the number of years of use, the number of seasons of use, and the length of time of use during sleep. When women who used an electric bedding device for more than 6 months per year (and therefore were more likely to have used a heated water bed, which generates lower magnetic fields) were excluded, the corresponding dose-response relations were more striking. Similar trends in dose response were shown in both premenopausal and postmenopausal women and for both estrogen receptor-positive and estrogen receptor-negative tumors. The use of electric bedding devices may increase breast cancer risk in African-American women aged 20-64 years. Such an association might not vary substantially by menopausal status or estrogen receptor status.
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Epidemiology suggests a possible relationship between exposure to power frequency magnetic fields (EMF) and breast cancer. One mechanism through which EMF could stimulate breast cancer induction is via altered expression of oncogenes and/or tumor suppressor genes that regulate normal and neoplastic growth. To evaluate the hypothesis that EMF action in the breast is mediated by alterations in gene expression, transcript levels of c-myc and a battery of other cancer-associated genes were quantitated in human breast epithelial cells exposed to pure, linearly polarized 60 Hz EMF with low harmonic distortion. HBL-100 cells and normal (non-transformed) human mammary epithelial cells were exposed to EMF flux densities of 0.1, 1.0 and 10.0 Gauss (G) for periods ranging from 20 min to 24 h; concurrent sham controls were exposed to ambient fields (<0.001 G) only. Gene expression was quantitated using ribonuclease protection assays. EMF exposure had no statistically significant effect on basal levels of c-myc transcripts in either human breast cell model, and had no effect on alterations in c-myc expression induced by 12-O-tetradecanoylphorbol-13-acetate. Transcript levels of c-erbB-2, p53, p21, GADD45, bax, bcl-x, mcl-1, and c-fos were also unaffected by EMF exposure. These results suggest that EMF is unlikely to influence breast cancer induction through a mechanism involving altered expression of these genes.
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The precautionary principle, a recommendation to consider action to avoid a possible harm even if it is not certain to occur, is variously defined and interpreted. We present a range of definitions with an emphasis on their requirements for strength of evidence of harm and for actions to be taken. We describe the variety of approaches that have been adopted in developing policy to address the issue of possible health effects of electric and magnetic fields (EMF) in the face of scientific uncertainty. Further, we discuss specific aspects of scientific uncertainty regarding EMF health risks particularly relevant to the development of precautionary principle policy. We define and discuss prudent avoidance and other unique features of applications of the precautionary principle to EMF. We conclude with examples from EMF policy decisions of risk tradeoffs that need to be considered in developing any precautionary principle policy, and provide recommendations for better ways to define and implement the precautionary principle.
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The pineal gland has been considered a magnetic receptor organ that regulates circadian rhythms by means of the secretion of melatonin, a potent oncostatic agent that prevents the initiation and promotion of cancer. ELF electromagnetic radiation, similar to that generated by power lines, can alter melatonin plasma levels. To study this effect, 4 OF1 mice generations have been reared subjected to a lifelong 15 μT, 50 Hz magnetic field action. This magnetic field was generated inside a Helmholtz coil system. The concentration of melatonin in the blood has been determined on 40 male mice of the third generation by means of RIA, as they reached sexual maturity (3 months). A radical decrease, more remarkable at night, of the melatonin plasma levels and the loss of the night-day secretion rhythm was observed in the experimental group. These results could be the consequence of the applied magnetic field cumulative effect. The secretion rhythms of other hormones, at the level of the hypothalamic-hypophyseal axis, might be altered as an effect of those results. This chronobiological change could explain the different findings in the 4 generations of mice subjected to the same experimental model.
Article
Two potential mechanisms in detection of a 60-Hz electric field by albino rats were examined: field-induced movement of the vibrissae and field-induced vibration of the skin. Specifically, the experiment tested field detection in a moving stream of air designed to mask field-induced movement of the skin, fur, and vibrissae. Rats were trained to detect electric fields and were then tested at field intensities from 0–25 kV/m rms. As previously reported, rats demonstrate unmistakable behavioral evidence of field detection at all intensities above 7.5 kV/m. After establishing detection in still air, field detection was re-examined in moving air (average air velocity approximately 2.8–6.8 m/s). The primary result is that the wind produced no change in detection at field intensities above threshold (> 7.5 kV/m). Indeed, at these intensities detection was virtually identical in still and moving air. A secondary finding is that moving air produced statistically significant (P < .05) but apparently contradictory effects on detection when the field intensity was below threshold. On no-field trials the wind lowered scores (i.e., fewer presses on the field-off lever); however, on subthreshold field trials, the wind actually increased detection scores (i.e., more presses on the field-on lever). While this no-field and subthreshold field result is interesting and deserves further study, we place primary emphasis on the finding that, if the field was detectable in still air, it was also detectable in moving air. This result leads us to believe that movement of the vibrissae, fur, or skin is not likely to be the main mechanism of electric-field detection in our subjects. © 1993 Wiley-Liss. Inc.
Article
The effect of a 50 Hz, vertical magnetic field on the excretion of urinary 6-sulphatoxymelatonin (aMT6s) of male and female Wistar rats was studied in a self-controlled experiment. Twenty rats were kept in metabolic cages under 9:15 h light:dark conditions. The urine of the animals was collected twice per day for 5 consecutive days. The concentration of aMT6s in the rat urine was measured by 125I radioimmunoassay. The rats were exposed to 5 and 500 μT flux density for 24 h. The excretion of urinary aMT6s did not show significant changes during or after magnetic field exposure. © 1995 Wiley-Liss, Inc.
Article
The authors tested the hypothesis that exposure to a 30-kV/m, 60-Hz electric field produces significant change (stress) in the social behavior of adult male baboons (Papio cynocephalus anubis). One group of eight baboons was exposed to an electric field (12 hours per day, 7 days per week for 6 weeks) while a second group of eight baboons was maintained in a sham-exposure (control) condition. Exposed subjects and control subjects were compared over three, six-week experimental periods (pre-exposure, exposure, and post-exposure). Performance rates of six categories of social behaviors (passive affinity, active affinity, approach, tension, threat, and attack) and four categories of nonsocial behaviors (forage, manipulate, posture, and stereotypy) were used to compare the two groups. The results of our study indicate that (1) there were no significant differences between the two groups during the pre-exposure or post-exposure periods; (2) during the exposure period, experimental and control groups exhibited statistically significant differences in the mean performance rates of three behavior categories; (3) within-group comparisons across periods indicate that the experimentally exposed group exhibited statistically significant changes in passive affinity, tension, and stereotypy; and (4) changes in behavior performance among the exposed subjects reflect a stress response to the electric field.
Article
Male OF1 mice were exposed continuously to a magnetic field of 50 Hz and 15 μT (rms) in order to elucidate the possible alterations in testis histology and its endocrine function caused by this exposure. Mothers were chronically exposed from the age of 6 weeks and had their offspring under the same experimental conditions. Offspring were sacrificed at the age of 10 weeks and the testes were removed and studied histologically. Serum testosterone levels were measured by enzymatic immunoassay. A significant increase in the size and weight of the testes, not related to the increment of the body weight (gonadosomatic index increased), was found in the experimental group compared to the control group. Histologically, this finding is due to an increase in the interstitial tissue, associated with increased levels of testosterone in the blood. Complete spermatogenesis was found in all the animals, in both the control and experimental groups. No differences were found in the morphology of the seminiferous epithelium.
Article
We obtained original individual data from 15 studies of magnetic fields or wire codes and childhood leukemia, and we estimated magnetic field exposure for subjects with sufficient data to do so. Summary estimates from 12 studies that supplied magnetic field measures exhibited little or no association of magnetic fields with leukemia when comparing 0.1-0.2 and 0.2-0.3 microtesla (μT) categories with the 0-0.1 μT category, but the Mantel-Haenszel summary odds ratio comparing >0.3 μT to 0-0.1 μT was 1.7 (95% confidence limits = 1.2, 2.3). Similar results were obtained using covariate adjustment and spline regression. The study-specific relations appeared consistent despite the numerous methodologic differences among the studies. The association of wire codes with leukemia varied considerably across studies, with odds ratio estimates for very high current vs low current configurations ranging from 0.7 to 3.0 (homogeneity P = 0.005). Based on a survey of household magnetic fields, an estimate of the U.S. population attributable fraction of childhood leukemia associated with residential exposure is 3% (95% confidence limits = -2%, 8%). Our results contradict the idea that the magnetic field association with leukemia is less consistent than the wire code association with leukemia, although analysis of the four studies with both measures indicates that the wire code association is not explained by measured fields. The results also suggest that appreciable magnetic field effects, if any, may be concentrated among relatively high and uncommon exposures, and that studies of highly exposed populations would be needed to clarify the relation of magnetic fields to childhood leukemia.
Article
A Canadian case-control study explored the etiology of thyroid cancer, including occupational exposure. Analysis of job history from 1272 thyroid cancer patients and 2666 controls revealed statistically significant risks among the following occupations: Wood Processing, Pulp and Papermaking (odds ratio [OR] = 2.54, 95% confidence interval [CI] = 1.11–5.83); Sales and Service (OR = 1.26, 95% CI = 1.05–1.52); and Clerical (OR = 0.81, 95% CI = 0.67–0.97). ORs were adjusted for age, sex, province, cigarette smoking, education, self-reported exposure to radiation at work, and duration of employment. Exposure to ionizing radiation or electromagnetic fields at work (inferred from job histories) did not affect risk, nor did socioeconomic status, measured by education, income, or occupational prestige. Possible explanations for the results and further investigations are discussed.
Article
Studies in our laboratory have revealed that extremely low-frequency (ELF) magnetic fields (MF) suppress gap junctional intercellular communication (GJIC) in cultured cells. To explore the molecular mechanisms, the effect of 50-Hz, 0.8-mT MF on connexin43 gene transcription was studied. Transcriptional levels of the connexin43 gene in the mouse fibroblast cell line NIH3T3 and Chinese hamster lung (CHL) cells were examined by Northern blot analysis using a 32P-labeled connexin43 probe. Cells had been exposed to MF for 24 h and/or had received 2 h of 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment. The connexin43 gene transcriptional level did not change significantly in any exposure groups.
Article
It was previously observed that weak, pulsed, extremely-low-frequency magnetic fields increased developmental abnormalities in early chick embryos. However, the biological response was not always obtained. In the present study it is shown that the varying AC fields incidence on the embryos is linearly related to slight changes in the values of the horizontal component of the geomagnetic field, especially during the gastrulation phase of the developing organisms. No relationship was found with the value of the vertical component of the earth's field. These results suggest that weak pulsed magnetic fields have only the potentiality to be effective on early embryos, their incidence depending on small changes of the earth's field value and/or inclination angle.
Article
Reports a survey of the exposure of staff in the UK Electricity Supply Industry to power-frequency magnetic fields. Two hundred and fifty-eight staff from a variety of jobs and locations wore a monitor for 1 week each. The results form a substantial body of data which adds significantly to the understanding of occupational exposures. The results show that fields encountered in shops, offices and distribution sites were roughly half those in power stations, which in turn were half those in transmission sites. Office workers based on transmission sites experienced higher fields (geometric mean of individual time-weighted average fields: 0.48 mu T) than those at headquarters offices (0.18 mu T). In power stations, electrical workers experienced higher fields (0.46 mu T) than mechanical workers (0.25 mu T). Amongst transmission and distribution staff, the highest fields (1.16 mu T) were experienced by transmission substation attendants and the lowest fields (0.17 mu T) by staff working predominantly in domestic environments.
Article
This study was designed to assess the effect of exposure to long-term extremely low-frequency electric and magnetic fields (ELF-EMF) from a 500 kV transmission line on IL-1 and IL-2 activity in sheep. The primary hypothesis was that the reduction in IL-1 activity observed in our two previous short-term studies (10 months) was due to EMF exposure from this transmission line. To repeat and expand these studies and to characterize the components of EMF responsible for the previously observed reduction in IL-1 activity, the current experiment examined not only the effect of exposure to electric and magnetic fields, but also the magnetic field component alone. In the current study, IL-2 was examined to characterize the effects of EMF exposure an an indicator of T cell responses. 45 Suffolk ewe lambs were randomized into three groups of 15 animals each. One group of animals was placed in the EMF pen, located directly beneath the transmission line. A second group was placed in the shielded MF (magnetic field only) pen, also directly beneath the transmission line. The third group of animals was placed in the control pen located several hundred meters away from the transmission line. During the 27 month exposure period, blood samples were taken from all animals monthly. When the data were analyzed collectively over time, no significant differences between the groups were found for IL-1 or IL-2 activity. In previous studies ewe lambs of 8-10 weeks of age were used as the study animals and significant differences in IL-1 activity were observed after exposure of these animals to EMF at mean magnetic fields of 3.5-3.8 muT (35-38 mG) and mean electric fields of 5.2-5.8 kV/m. At the start of the current study EMF levels were reduced as compared to previous studies. One interpretation of the current data is that magnetic field strength and age of the animals may be important variables in determining whether EMF exposure will affect IL-1 activity. (C) 2001 Wiley-Liss, Inc.
Article
This study was designed to assess the neuroendocrine response of male Long-Evans rats to sustained or intermittent 60-Hz electric fields when exposed for 1 or 3 h at 100 kV/m. No significant differences were noted in corticosterone, prolactin, or thyrotropin levels between exposed and sham-exposed rats. A statistically significant increase (P < .01) in growth hormone was noted in rats exposed to intermittent electric fields for 3 h. Emphasis was placed on good experimental design and the need to avoid standard laboratory stressors (excessive handling, temperature extremes, transportation, noise, etc.) known to be present in many biomedical studies. The importance of avoiding reactions due to extraneous factors in experiments predicated on investigating physiological function in relation to electric field exposure is discussed.
Article
The mechanisms involved in sensing, signaling, and coordinating changes resulting from magnetic field-induced stress show substantial similarities to those of heat shock, e.g., magnetic field-induced heat shock 70 gene (HSP70) expression involves heat shock factor (HSF) activation and heat shock element binding. However, an additional requirement for transactivation of HSP70 expression by magnetic fields is the binding of Myc protein, indicating that additional elements and/or pathways are involved in the induction of HSP70 expression by magnetic fields. To investigate the possible participation of additional genetic elements in magnetic field-induced HSP70 expression, we examined both magnetic field exposure and heat shock on protein–DNA binding of the transcription factors HSF, AP-1, AP-2, and SP-1 in four human cell lines. The binding sites for these transcription factors are present in the HSP70 promoter. AP-1 binding activity, normally not increased by heat shock, was increased by magnetic fields; heat shock induced an increase only in HSF binding. Although intersecting and converging signaling pathways could account for the multiplicity of elements involved in magnetic field-induced HSP70 transcription, direct interaction of magnetic fields with DNA is also a possible mechanism. Because magnetic fields penetrate the cell, they could well react with conducting electrons present in the stacked bases of the DNA. J. Cell. Biochem. 70:297–303, 1998. © 1998 Wiley-Liss, Inc.
Article
We found in a previously reported study that exposure to a 30-kV/m, 60-Hz electric field had significant effects on the social behavior of baboons. However, it was not established whether or not the effects were related specifically to the 30-kV/m intensity of the field. A new experiment was conducted to determine whether or not exposure to a 60-Hz electric field at 60 kV/m would produce like changes in the baboons' social behavior. We exposed one group of eight male baboons to an electric field 12 hours a day, 7 days a week, for 6 weeks. A second group of eight animals was maintained under sham-exposure (control) conditions. Rates of performing on each of six categories of social behavior and on four categories of nonsocial behavior were used as criteria for comparing exposed with unexposed subjects and for within-group comparisons during three six-week experimental periods: Pre-Exposure, Exposure, and Post-Exposure. The results indicate that (1) during the exposure period, exposed animals exhibited statistically significant differences from controls in means of performance rates based on several behavioral categories; (2) across all three periods, within-group comparisons revealed that behaviors of exposed baboons were significantly affected by exposure to the electric field; (3) changes in performance levels probably reflect a stress response to the electric field; and (4) the means of response rates of animals exposed at 60 kV/m were higher, but not double, those of animals exposed at 30 kV/m. As in the 30-kV/m experiment, animals exposed at 60 kV/m exhibited significant differences in performances of Passive Affinity, Tension, and Stereotypy. Mean rates of performing these categories were 122% (Passive Affinity), 48% (Tension), and 40% (Stereotypy) higher in the exposed group than in the control group during exposure to the 60-kV/m field.