A pooled analysis of magnetic fields and childhood leukaemia

The effects of extremely low frequency electromagnetic fields exposure at 1 mT on hemogram and blood biochemisgtry in rats

The biological effects of extremely low-frequency electromagnetic fields (ELF-EMF) exposure are not fully clarified. We conducted this investigation to explore the effects of ELF-EMF on hematologic and biochemical indexes in adult rats. Thirty adult male Sprague-Dawley rats were exposed to ELF-EMF at 1 mT for 24 weeks, while another 30 SD rats were sham exposed. During the exposure, peripheral blood was collected every 4 weeks to analyze the hematologic parameters and biochemical indexes. The morphology of liver and kidney was detected by hematoxylin-eosin staining at the end of the experiment. Exposed to ELF-EMF at 1 mT did not exert any statistic difference on hematologic parameters including total white blood cell count, neutrophil ratio, lymphocyte ratio, red blood cells, hemoglobin concentration and platelets count, compared to the control group. Similarly, biochemical indexes, such as glucose, lipid profile, liver function and renal function, were not affected by ELF-EMF exposure. In addition, no morphological change was observed in the liver and kidney from the exposure group. The exposure to ELF-EMF at the intensity of 1 mT for 24 weeks did not affect hematologic and biochemical indexes in adult rats.

Extremely Low-Frequency Magnetic Fields and the Risk of Childhood B-Lineage Acute Lymphoblastic Leukemia in a City With High Incidence of Leukemia and Elevated Exposure to ELF Magnetic Fields

It is important to study the relationship between extremely low-frequency magnetic fields (ELF-MFs) and childhood leukemia, particularly in locations with a high incidence of this neoplasm in children and an elevated exposure to ELF-MF, such as Mexico City. The aim was to investigate the association between ELF-MF exposure and the risk of B-lineage acute lymphoblastic leukemia (B-ALL). A case-control study was conducted in Mexico City during the period from 2010 to 2011. Residential 24-h ELF-MF measurements were obtained for 290 incident B-ALL patients and 407 controls, aged less than 16 years. Controls were frequency-matched by sex, age (±18 months), and health institution. The adjusted odds ratios (aOR) and 95% confidence intervals (CIs) were calculated. ELF-MF exposure at <0.2 μT was used to define the reference group. ELF-MF exposure at ≥0.3 μT was observed in 11.3% of the controls. Different ELF-MF intensity cutoff values were used to define the highest exposure category; the highest exposure category for each cutoff value was associated with an increased risk of B-ALL compared with the corresponding lower exposure categories. The aORs were as follows: ≥0.2 μT = 1.26 (95% CI: 0.84-1.89); ≥0.3 μT = 1.53 (95% CI: 0.95-2.48); ≥0.4 μT = 1.87 (95% CI: 1.04-3.35); ≥0.5 μT = 1.80 (95% CI 0.95-3.44); ≥0.6 μT = 2.32 (95% CI: 1.10-4.93). ELF-MF exposure as a continuous variable (per 0.2 μT intervals) was associated with B-ALL risk (aOR = 1.06; 95% CI: 1.01-1.12). In the present study, the proportion of children exposed to ≥0.3 μT is among the highest reported worldwide. Additionally, an ELF-MF exposure ≥0.4 μT may be associated with the risk of B-ALL. Bioelectromagnetics. © 2020 Bioelectromagnetics Society.

Metabolomics and psychological features in fibromyalgia and electromagnetic sensitivity

Fibromyalgia (FM) as Fibromyalgia and Electromagnetic Sensitivity (IEI-EMF) are a chronic and systemic syndrome. The main symptom is represented by strong and widespread pain in the musculoskeletal system. The exact causes that lead to the development of FM and IEI-EMF are still unknown. Interestingly, the proximity to electrical and electromagnetic devices seems to trigger and/or amplify the symptoms. We investigated the blood plasma metabolome in IEI-EMF and healthy subjects using ¹H NMR spectroscopy coupled with multivariate statistical analysis. All the individuals were subjected to tests for the evaluation of psychological and physical features. No significant differences between IEI-EMF and controls relative to personality aspects, Locus of Control, and anxiety were found. Multivariate statistical analysis on the metabolites identified by NMR analysis allowed the identification of a distinct metabolic profile between IEI-EMF and healthy subjects. IEI-EMF were characterized by higher levels of glycine and pyroglutamate, and lower levels of 2-hydroxyisocaproate, choline, glutamine, and isoleucine compared to healthy subjects. These metabolites are involved in several metabolic pathways mainly related to oxidative stress defense, pain mechanisms, and muscle metabolism. The results here obtained highlight possible physiopathological mechanisms in IEI-EMF patients to be better defined.

Exposure To Extremely Low-Frequency Magnetic Fields In Low- And Middle-Income Countries: An Overview

To compare extremely low-frequency magnetic field (ELF-MF) exposure in the general population in low- and middle-income countries (LMICs) with high-income countries (HIC), we carried out a systematic literature search resulting in 1483 potentially eligible articles; however, only 25 studies could be included in the qualitative synthesis. Studies showed large heterogeneity in design, exposure environment and exposure assessment. Exposure assessed by outdoor spot measurements ranged from 0.03 to 4μT. Average exposure by indoor spot measurements in homes ranged from 0.02 to 0.4μT. Proportions of homes exposed to a threshold of ≥0.3μT were many times higher in LMICs compared to HIC. Based on the limited data available, exposure to ELF-MF in LMICs appeared higher than in HIC, but a direct comparison is hampered by a lack of representative and systematic monitoring studies. Representative measurement studies on residential exposure to ELF-MF are needed in LMICs together with better standardisation in the reporting.

An Investigation Into the Effects of Long-Term 50-Hz Power-Frequency Electromagnetic Field Exposure on Hematogram, Blood Chemistry, Fibrosis, and Oxidant Stress Status in the Liver and the Kidney From Sprague-Dawley Rats

Power-frequency electromagnetic fields (PF-EMFs) at 50 Hz are potential health risk factors. This study aimed to explore the effects of long-term exposure to 50-Hz PF-EMFs on general physiological conditions in Sprague-Dawley (SD) rats. During a 24-week exposure period, the body mass and water and food intake of the animals were recorded regularly. The hematologic parameters were detected every 12 weeks, and blood chemistry analyses were performed every 4 weeks. After sacrifice, morphology was identified by hematoxylin-eosin, Masson, and immunohistochemical staining. Fibrosis-related gene expression and oxidative stress status were also detected. Compared with the control group, exposure to 30, 100, or 500 μT PF-EMF did not exert any effect on body mass, food intake, or water intake. Similarly, no significant differences were found in hematologic parameters or blood chemistry analyses among these groups. Furthermore, morphological assays showed that exposure to PF-EMFs had no influence on the structure of the liver or kidney. Finally, fibrosis-related gene expression and oxidative stress status were unaltered by PF-EMF exposure. The present study indicates that 24 weeks of exposure to PF-EMFs at intensities of 30, 100, or 500 μT might not affect hemograms, blood chemistry, fibrosis, or oxidative stress in the liver or kidney in SD rats. © 2020 Bioelectromagnetics Society.

Radiation protection in non-ionizing and ionizing body composition assessment procedures

Body composition assessment (BCA) represents a valid instrument to evaluate nutritional status through the quantification of lean and fat tissue, in healthy subjects and sick patients. According to the clinical indication, body composition (BC) can be assessed by different modalities. To better analyze radiation risks for patients involved, BCA procedures can be divided into two main groups: the first based on the use of ionizing radiation (IR), involving dual energy X-ray absorptiometry (DXA) and computed tomography (CT), and others based on non-ionizing radiation (NIR) [magnetic resonance imaging (MRI)]. Ultrasound (US) techniques using mechanical waves represent a separate group. The purpose of our study was to analyze publications about IR and NIR effects in order to make physicians aware about the risks for patients undergoing medical procedures to assess BCA providing to guide them towards choosing the most suitable method. To this end we reported the biological effects of IR and NIR and their associated risks, with a special regard to the excess risk of death from radio-induced cancer. Furthermore, we reported and compared doses obtained from different IR techniques, giving practical indications on the optimization process. We also summarized current recommendations and limits for techniques employing NIR and US. The authors conclude that IR imaging procedures carry relatively small individual risks that are usually justified by the medical need of patients, especially when the optimization principle is applied. As regards NIR imaging procedures, a few studies have been conducted on interactions between electromagnetic fields involved in MR exam and biological tissue. To date, no clear link exists between MRI or associated magnetic and pulsed radio frequency (RF) fields and subsequent health risks, whereas acute effects such as tissue burns and phosphenes are well-known; as regards the DNA damage and the capability of NIR to break chemical bonds, they are not yet robustly demonstrated. MRI is thus considered to be very safe for BCA as well US procedures.

Extremely Low-Frequency Magnetic Fields Exposure Measurement during Lessons in Elementary Schools

Schools are an important place for children's exposure to electromagnetic fields, which may cause adverse health effects. To better understand environmental extremely low-frequency magnetic fields (ELF-MFs) exposure among elementary school students, we measured numeric values of ELF-MFs in five classrooms at four schools during digital learning class hours. The measurement of ELF-MFs was taken with an EMDEX II field analyzer. Specifically, we examined the level of exposure to ELF-MFs for each student's seating position in the classroom. The results showed that ELF-MFs exposure levels were lower than those in the International Commission on Non-Ionizing Radiation Protection guidelines; however, there were significant differences in the level of magnetic field exposure at each school and at each student's seat. The exposure to ELF-MFs at students' seat positions was mostly caused by electrical appliances, electronic wiring, and distribution boxes, but the exposure level decreased as the distance increased. Therefore, it is important to design safe and appropriate environments for digital learning in schools, such as proper seating arrangements, to avoid ELF-MFs exposure to students as much as possible. Future studies should measure ELF-MFs levels in other areas and investigate the effects of exposure to ELF-MFs during school hours on children's health.

Gaps in Knowledge Relevant to the "Guidelines for Limiting Exposure to Time-Varying Electric and Magnetic Fields (1 Hz-100 kHz)"

Sources of low-frequency fields are widely found in modern society. All wires or devices carrying or using electricity generate extremely low frequency (ELF) electric fields (EFs) and magnetic fields (MFs), but they decline rapidly with distance to the source. High magnetic flux densities are usually found in the vicinity of power lines and close to equipment using strong electrical currents, but can also be found in buildings with unbalanced return currents, or indoor transformer stations. For decades, epidemiological as well as experimental studies have addressed possible health effects of exposure to ELF-MFs. The main goal of ICNIRP is to protect people and the environment from detrimental exposure to all forms of non-ionizing radiation (NIR). To this end, ICNIRP provides advice and guidance by developing and disseminating exposure guidelines based on the available scientific research. Research in the low-frequency range began more than 40 years ago, and there is now a large body of literature available on which ICNIRP set its protection guidelines. A review of the literature has been carried out to identify possible relevant knowledge gaps, and the aim of this statement is to describe data gaps in research that would, if addressed, assist ICNIRP in further developing guidelines and setting revised recommendations on limiting exposure to electric and magnetic fields. It is articulated in two parts: the main document, which reviews the science related to LF data gaps, and the annex, which explains the methodology used to identify the data gaps.

The role of dwelling type when estimating the effect of magnetic fields on childhood leukemia in the California Power Line Study (CAPS)

PURPOSE

The type of dwelling where a child lives is an important factor when considering residential exposure to environmental agents. In this paper, we explore its role when estimating the potential effects of magnetic fields (MF) on leukemia using data from the California Power Line Study (CAPS). In this context, dwelling type could be a risk factor, a proxy for other risk factors, a cause of MF exposure, a confounder, an effect-measure modifier, or some combination.

METHODS

We obtained information on type of dwelling at birth on over 2,000 subjects. Using multivariable-adjusted logistic regression, we assessed whether dwelling type was a risk factor for childhood leukemia, which covariates and MF exposures were associated with dwelling type, and whether dwelling type was a potential confounder or an effect-measure modifier in the MF-leukemia relationship under the assumption of no-uncontrolled confounding.

RESULTS

A majority of children lived in single-family homes or duplexes (70%). Dwelling type was associated with race/ethnicity and socioeconomic status but not with childhood leukemia risk, after other adjustments, and did not alter the MF-leukemia relationship upon adjustment as a potential confounder. Stratification revealed potential effect-measure modification by dwelling type on the multiplicative scale.

CONCLUSION

Dwelling type does not appear to play a significant role in the MF-leukemia relationship in the CAPS dataset as a leukemia risk factor or confounder. Future research should explore the role of dwelling as an effect-measure modifier of the MF-leukemia association.

Cluster Analysis of Residential Personal Exposure to ELF Magnetic Field in Children: Effect of Environmental Variables

Personal exposure to Extremely Low Frequency Magnetic Fields (ELF MF) in children is a very timely topic. We applied cluster analysis to 24 h indoor personal exposures of 884 children in France to identify possible common patterns of exposures. We investigated how electric networks near child home and other variables potentially affecting residential exposure, such as indoor sources of ELF MF, the age and type of the residence and family size, characterized the magnetic field exposure patterns. We identified three indoor personal exposure patterns: children living near overhead lines of high (63–150 kV), extra-high (225 kV) and ultra-high voltage (400 kV) were characterized by the highest exposures; children living near underground networks of low (400 V) and mid voltage (20 kV) and substations (20 kV/400 V) were characterized by mid exposures; children living far from electric networks had the lowest level of exposure. The harmonic component was not relevant in discriminating the exposure patterns, unlike the 50 Hz or broadband (40–800 Hz) component. Children using electric heating appliances, or living in big buildings or in larger families had generally a higher level of personal indoor exposure. Instead, the age of the residence was not relevant in differentiating the exposure patterns.

Evaluation in humans of ELF-EMF exposure on chromogranin A, a marker of neuroendocrine tumors and stress

Chromogranin A (CgA), which is a major protein in adrenal chromaffin cells and adrenergic neurons, is a clinically relevant endocrine and neuroendocrine tumor marker including pheochromocytomas, neuroblastomas, and related neurogenic tumors. In this study, we looked at the effect in humans of chronic daily exposure to a 50-Hz magnetic field. We examined in 15 men (38.0 ± 0.9 years) the effects of chronic daily exposure to a 50-Hz magnetic field for 1-20 yrs both at home and at work. EMDEX II dosimeters were used to record magnetic field all day long every 30 s. for 1 week. The weekly geometric mean of the individual exposures ranged from 0.1 to 2.6 μT. Blood samples were taken hourly between 20:00 h and 08:00 h. CgA patterns of exposed subjects were compared to age-matched controls. The results of exposed subjects were compared with those for 15 unexposed men who served as controls and whose individual exposure was ten times lower ranging from 0.004 to 0.092 μT. This work shows that in the control group the serum CgA levels exhibited a nighttime peak with a progressive decline of the serum concentrations and a nadir in the morning. Both the profile and the serum concentrations of CgA, a marker of neuroendocrine tumors and stress, did not appear to be impaired in the subjects chronically exposed over a long period (up to 20 yrs) to magnetic fields though a trend toward lower levels were found at the highest exposure (>0.3 μT). This does not rule out, however, that the potential deleterious risk of ELF-EMF on frail populations such as children and the elderly may be greater at low exposure and should hence be documented, at least for their residential exposure.

Extremely low frequency electromagnetic fields and cancer: How source of funding affects results

While there has been evidence indicating that excessive exposure to magnetic fields from 50 to 60 Hz electricity increases risk of cancer, many argue that the evidence is inconsistent and inconclusive. This is particularly the case regarding magnetic field exposure and childhood leukemia. A major goal of this study is to examine how source of funding influences the reported results and conclusions. Several meta-analyses dating from about 2000 all report significant associations between exposure and risk of leukemia. By examining subsequent reports on childhood leukemia it is clear that almost all government or independent studies find either a statistically significant association between magnetic field exposure and childhood leukemia, or an elevated risk of at least OR = 1.5, while almost all industry supported studies fail to find any significant or even suggestive association. A secondary goal of this report is to examine the level of evidence for exposure and elevated risk of various adult cancers. Based on pooled or meta-analyses as well as subsequent peer-reviewed studies there is strong evidence that excessive exposure to magnetic fields increases risk of adult leukemia, male and female breast cancer and brain cancer. There is less convincing but suggestive evidence for elevations in several other cancer types. There is less clear evidence for bias based on source of funding in the adult cancer studies. There is also some evidence that both paternal and maternal prenatal exposure to magnetic fields results in an increased risk of leukemia and brain cancer in offspring. When one allows for bias reflected in source of funding, the evidence that magnetic fields increase risk of cancer is neither inconsistent nor inconclusive. Furthermore adults are also at risk, not just children, and there is strong evidence for cancers in addition to leukemia, particularly brain and breast cancer.

Long-Term Monitoring of Extremely Low Frequency Magnetic Fields in Electric Vehicles

Extremely low frequency (ELF) magnetic field (MF) exposure in electric vehicles (EVs) has raised public concern for human health. There have been many studies evaluating magnetic field values in these vehicles. However, there has been no report on the temporal variation of the magnetic field in the cabin. This is the first study on the long-term monitoring of actual MFs in EVs. In the study, we measured the magnetic flux density (B) in three shared vehicles over a period of two years. The measurements were performed at the front and rear seats during acceleration and constant-speed driving modes. We found that the B amplitudes and the spectral components could be modified by replacing the components and the hubs, while regular checks or maintenance did not influence the B values in the vehicle. This observation highlights the necessity of regularly monitoring ELF MF in EVs, especially after major repairs or accidents, to protect car users from potentially excessive ELF MF exposure. These results should be considered in updates of the measurement standards. The ELF MF effect should also be taken into consideration in relevant epidemiological studies.

Parental occupational exposure to low-frequency magnetic fields and risk of leukaemia in the offspring: findings from the Childhood Leukaemia International Consortium (CLIC)

OBJECTIVES

Previously published studies on parental occupational exposure to extremely low-frequency magnetic fields (ELF-MF) and risk of acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML) in their offspring were inconsistent. We therefore evaluated this question within the Childhood Leukemia International Consortium.

METHODS

We pooled 11 case-control studies including 9723 childhood leukaemia cases and 17 099 controls. Parental occupational ELF-MF exposure was estimated by linking jobs to an ELF-MF job-exposure matrix (JEM). Logistic regression models were used to estimate ORs and 95% CIs in pooled analyses and meta-analyses.

RESULTS

ORs from pooled analyses for paternal ELF-MF exposure >0.2 microtesla (µT) at conception were 1.04 (95% CI 0.95 to 1.13) for ALL and 1.06 (95% CI 0.87 to 1.29) for AML, compared with ≤0.2 µT. Corresponding ORs for maternal ELF-MF exposure during pregnancy were 1.00 (95% CI 0.89 to 1.12) for ALL and 0.85 (95% CI 0.61 to 1.16) for AML. No trends of increasing ORs with increasing exposure level were evident. Furthermore, no associations were observed in the meta-analyses.

CONCLUSIONS

In this large international dataset applying a comprehensive quantitative JEM, we did not find any associations between parental occupational ELF-MF exposure and childhood leukaemia.

Melatonin Levels and Low-Frequency Magnetic Fields in Humans and Rats: New Insights From a Bayesian Logistic Regression

The present analysis revisits the impact of extremely low-frequency magnetic fields (ELF-MF) on melatonin (MLT) levels in human and rat subjects using both a parametric and non-parametric approach. In this analysis, we use 62 studies from review articles. The parametric approach consists of a Bayesian logistic regression (LR) analysis and the non-parametric approach consists of a Support Vector analysis, both of which are robust against spurious/false results. Both approaches reveal a unique well-ordered pattern, and show that human and rat studies are consistent with each other once the MF strength is restricted to cover the same range (with B ≲ 50 μT). In addition, the data reveal that chronic exposure (longer than ∼22 days) to ELF-MF appears to decrease MLT levels only when the MF strength is below a threshold of ~30 μT ( log B thr [ μ T ] = 1 . 4 - 0 . 4 + 0 . 7 ), i.e., when the man-made ELF-MF intensity is below that of the static geomagnetic field. Studies reporting an association between ELF-MF and changes to MLT levels and the opposite (no association with ELF-MF) can be reconciled under a single framework. Bioelectromagnetics. 2019;40:539-552. © 2019 Bioelectromagnetics Society.

Residential exposure to electromagnetic fields during pregnancy and risk of child cancer: A longitudinal cohort study

OBJECTIVE

We assessed whether exposure to electromagnetic fields during pregnancy increases the risk of childhood cancer.

METHODS

We studied a retrospective cohort of 784,944 newborns in Quebec, Canada between 2006 and 2016 who were followed for cancer one decade after birth. The exposures were residential distance to the nearest high voltage power transformer station and transmission line. We determined the incidence of childhood cancer, and estimated hazard ratios and 95% confidence intervals (CI) in Cox proportional hazards regression models adjusted for maternal and birth characteristics.

RESULTS

There were 1114 incident cases of cancer during 4,647,472 person-years of follow-up. Residential proximity to transformer stations was associated with a somewhat greater risk of cancer, but there was no association with transmission lines. Compared with 200 m, a distance of 80 m from a transformer station was associated with a hazard ratio of 1.08 (95% CI 0.98, 1.20) for any cancer, 1.04 (95% CI 0.88, 1.23) for hematopoietic cancer, and 1.11 (95% CI 0.99, 1.25) for solid tumours.

CONCLUSIONS

Residential proximity to transformer stations is associated with a borderline risk of childhood cancer, but the absence of an association with transmission lines suggests no causal link.

Effects of electromagnetic fields on osteoarthritis

Osteoarthritis (OA), characterized by joint malfunction and chronic disability, is the most common form of arthritis. The pathogenesis of OA is unclear, yet studies have shown that it is due to an imbalance between the synthesis and decomposition of chondrocytes, cell matrices and subchondral bone, which leads to the degeneration of articular cartilage. Currently, there are many therapies that can be used to treat OA, including the use of pulsed electromagnetic fields (PEMFs). PEMFs stimulate proliferation of chondrocytes and exert a protective effect on the catabolic environment. Furthermore, this technique is beneficial for subchondral trabecular bone microarchitecture and the prevention of subchondral bone loss, ultimately blocking the progression of OA. However, it is still unknown whether PEMFs could be used to treat OA in the clinic. Furthermore, the deeper signaling pathways underlying the mechanism by which PEMFs influence OA remain unclear.

Changes over time in the reported risk for childhood leukaemia and magnetic fields

There have been many studies from 1979 to the present reporting raised risks for childhood leukaemia with exposure to power-frequency magnetic fields. There are also suggestions that the reported risk has been decreasing. We examine trends in the risk over time from all available studies. For 41 studies, we combine reported risks using inverse-variance weighting, drawing risk estimates from previous pooled analyses where possible for greater consistency. We examine the cumulative risk for studies published up to each successive calendar year for all studies and for various subsets, and test for a trend over the period. The cumulative relative risk has indeed declined, for our most rigorous analysis from a maximum 2.44 in 1997 to 1.58 in 2017, but not statistically significantly when tested as a linear trend. We find suggestions of higher risks in studies looking at higher exposures and in studies with better quality exposure assessment. We conclude that there is a decline in reported risk from the mid 1990s to now, which is unlikely to be solely explained by improving study quality but may be due to chance, and an elevated risk remains.

Magnetocarcinogenesis: is there a mechanism for carcinogenic effects of weak magnetic fields?

Extremely low-frequency (ELF) magnetic fields have been classified as possibly carcinogenic, mainly based on rather consistent epidemiological findings suggesting a link between childhood leukaemia and 50-60 Hz magnetic fields from power lines. However, causality is not the only possible explanation for the epidemiological associations, as animal and in vitro experiments have provided only limited support for carcinogenic effects of ELF magnetic fields. Importantly, there is no generally accepted biophysical mechanism that could explain such effects. In this review, we discuss the possibility that carcinogenic effects are based on the radical pair mechanism (RPM), which seems to be involved in magnetoreception in birds and certain other animals, allowing navigation in the geomagnetic field. We review the current understanding of the RPM in magnetoreception, and discuss cryptochromes as the putative magnetosensitive molecules and their possible links to cancer-relevant biological processes. We then propose a hypothesis for explaining the link between ELF fields and childhood leukaemia, discuss the strengths and weaknesses of the current evidence, and make proposals for further research.

Use of Machine Learning in the Analysis of Indoor ELF MF Exposure in Children

Characterization of children exposure to extremely low frequency (ELF) magnetic fields is an important issue because of the possible correlation of leukemia onset with ELF exposure. Cluster analysis—a Machine Learning approach—was applied on personal exposure measurements from 977 children in France to characterize real-life ELF exposure scenarios. Electric networks near the child’s home or school were considered as environmental factors characterizing the exposure scenarios. The following clusters were identified: children with the highest exposure living 120–200 m from 225 kV/400 kV overhead lines; children with mid-to-high exposure living 70–100 m from 63 kV/150 kV overhead lines; children with mid-to-low exposure living 40 m from 400 V/20 kV substations and underground networks; children with the lowest exposure and the lowest number of electric networks in the vicinity. 63–225 kV underground networks within 20 m and 400 V/20 kV overhead lines within 40 m played a marginal role in differentiating exposure clusters. Cluster analysis is a viable approach to discovering variables best characterizing the exposure scenarios and thus it might be potentially useful to better tailor epidemiological studies. The present study did not assess the impact of indoor sources of exposure, which should be addressed in a further study.

Childhood leukemia risk in the California Power Line Study: Magnetic fields versus distance from power lines

Pooled analyses have suggested a small increased risk of childhood leukemia associated with distance and with exposure to high magnetic fields from power transmission lines. Because magnetic fields are correlated with distance from lines, the question of whether the risk is due to magnetic fields exposure or to some other factor associated with distance from lines is unresolved. We used data from a large records-based case-control study to examine several research questions formulated to disentangle the relationships among magnetic fields, distance from high voltage lines, and childhood leukemia risk. In models examining an interaction between distance and magnetic fields exposure, we found that neither close proximity to high voltage lines alone nor exposure to high calculated fields alone were associated with childhood leukemia risk. Rather, elevated risk was confined to the group that was both very close to high voltage lines (<50 m) and had high calculated fields (≥0.4 μT) (odds ratio 4.06, 95% CI 1.16, 14.3). Further, high calculated fields (≥0.4 μT) that were due solely to lower voltage lines (<200 kV) were not associated with elevated risk; rather, risk was confined to high fields attributable to high voltage lines. Whilst other explanations are possible, our findings argue against magnetic fields as a sole explanation for the association between distance and childhood leukemia and in favor of some other explanation linked to characteristics of power lines.

The carcinogenic potential of non-ionizing radiations: The cases of S-50 Hz MF and 1.8 GHz GSM radiofrequency radiation

Epidemiological studies have suggested that human exposure to extremely low-frequency electromagnetic fields from the electric power and to mobile phone radiofrequency electromagnetic fields induce an increased risk of developing malignant tumours. However, no adequate laboratory data, in particular long-term carcinogenicity bioassays to support the epidemiological evidence, have yet been available. This motivated the Ramazzini Institute to embark on a first project of four large life-span carcinogenic bioassays conducted on over 7000 Sprague Dawley rats exposed from prenatal life until natural death to S-50 Hz MF alone or combined with gamma radiation or formaldehyde or aflatoxin B1. Results now available from these studies, which started concurrently, have shown that exposure to Sinusoidal-50 Hz Magnetic Field (S-50 Hz MF) combined with acute exposure to gamma radiation or to chronic administration of formaldehyde in drinking water induces a significantly increased incidence of malignant tumours in males and females. A second project of two large life-span carcinogenic bioassays was conducted on over 3000 Sprague Dawley rats exposed from prenatal life until natural death to 1.8 GHz GSM of mobile phone radio base station, alone or combined with acute exposure to gamma radiation. Early results from the experiment on 1.8 GHz GSM alone show a statistically significant increase in the incidence of heart malignant schwannoma among males exposed at the highest dose.

A high throughput screening system of coils for ELF magnetic fields experiments: proof of concept on the proliferation of cancer cell lines

Background

It has been demonstrated that relatively small variations of the parameters of exposure to extremely low frequency magnetic fields (ELF-MF) can change significantly the outcome of experiments. Hence, either in trying to elucidate if these fields are carcinogenic, or in exploring their possible therapeutic use, it is desirable to screen through as many different exposures as possible. The purpose of this work is to provide a proof of concept of how a recently reported system of coils allows testing different field exposures, in a single experiment.

Methods

Using a novel exposure system, we subjected a glioblastoma cancer cell line (U251) to three different time modulations of an ELF-MF at 60 different combinations of the alternated current (AC) and direct current (DC) components of the field. One of those three time modulations was also tested on another cell line, MDA-MB-231 (breast cancer). After exposure, proliferation was assessed by colorimetric assays.

Results

For the U251 cells, a total of 180 different exposures were tested in three different experiments. Depending on exposure modulation and AC field intensity (but, remarkably, not on DC intensity), we found the three possible outcomes: increase (14.3% above control, p < 0.01), decrease (16.6% below control, p < 0.001), and also no-effect on proliferation with respect to control. Only the time modulation that inhibited proliferation of U251 was also tested on MDA-MB-231 cells which, in contrast, showed no alteration of their proliferation on any of the 60 AC/DC field combinations tested.

Conclusions

We demonstrated, for the first time, the use of a novel system of coils for magnetobiology research, which allowed us to find that differences of only a few μT resulted in statistically different results. Not only does our study demonstrate the relevance of the time modulation and the importance of finely sweeping through the AC and DC amplitudes, but also, and most importantly, provides a proof of concept of a system that sensibly reduces the time and costs of screening.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5376-z) contains supplementary material, which is available to authorized users.

Upper bound on the biological effects of 50/60 Hz magnetic fields mediated by radical pairs

Prolonged exposure to weak (~1 μT) extremely-low-frequency (ELF, 50/60 Hz) magnetic fields has been associated with an increased risk of childhood leukaemia. One of the few biophysical mechanisms that might account for this link involves short-lived chemical reaction intermediates known as radical pairs. In this report, we use spin dynamics simulations to derive an upper bound of 10 parts per million on the effect of a 1 μT ELF magnetic field on the yield of a radical pair reaction. By comparing this figure with the corresponding effects of changes in the strength of the Earth’s magnetic field, we conclude that if exposure to such weak 50/60 Hz magnetic fields has any effect on human biology, and results from a radical pair mechanism, then the risk should be no greater than travelling a few kilometres towards or away from the geomagnetic north or south pole.

Pulsed electromagnetic fields: promising treatment for osteoporosis

Osteoporosis (OP) is considered to be a well-defined disease which results in high morbidity and mortality. In patients diagnosed with OP, low bone mass and fragile bone strength have been demonstrated to significantly increase risk of fragility fractures. To date, various anabolic and antiresorptive therapies have been applied to maintain healthy bone mass and strength. Pulsed electromagnetic fields (PEMFs) are employed to treat patients suffering from delayed fracture healing and nonunions. Although PEMFs stimulate osteoblastogenesis, suppress osteoclastogenesis, and influence the activity of bone marrow mesenchymal stem cells (BMSCs) and osteocytes, ultimately leading to retention of bone mass and strength. However, whether PEMFs could be taken into clinical use to treat OP is still unknown. Furthermore, the deeper signaling pathways underlying the way in which PEMFs influence OP remain unclear.

EVALUATING EXTREMELY LOW FREQUENCY MAGNETIC FIELDS IN THE REAR SEATS OF THE ELECTRIC VEHICLES

In the electric vehicles (EVs), children can sit on a safety seat installed in the rear seats. Owing to their smaller physical dimensions, their heads, generally, are closer to the underfloor electrical systems where the magnetic field (MF) exposure is the greatest. In this study, the magnetic flux density (B) was measured in the rear seats of 10 different EVs, for different driving sessions. We used the measurement results from different heights corresponding to the locations of the heads of an adult and an infant to calculate the induced electric field (E-field) strength using anatomical human models. The results revealed that measured B fields in the rear seats were far below the reference levels by the International Commission on Non-Ionizing Radiation Protection. Although small children may be exposed to higher MF strength, induced E-field strengths were much lower than that of adults due to their particular physical dimensions.

Power-frequency magnetic fields at 50 Hz do not affect fertility and development in rats and mice

In the present study, the effects of power-frequency magnetic fields (PF-MF) on fertility and development were investigated in rats and mice. Adult Sprague-Dawley rats and C57BL/6J mice were divided into four groups: a sham exposure group and 30-µT, 100-µT and 500-µT PF-MF exposure groups. The rats were exposed for 24 weeks, and the exposure time for mice ranged from 18 d to 12 weeks, dependent on the different investigated end points. The rats and mice were exposed for 20 h/d. Plasma hormone levels in rats and mice were analyzed. Furthermore, pregnancy rates and implanted embryos were recorded in pregnant mice. Finally, the neonatal growth of mice was evaluated. The results showed that none of the three intensities affected the body weight and paired ovary weight in female rats. Meanwhile, none of the three intensities affected the body weight, weights of paired testes, weights of paired epididymis and sperm count in male rats. Similarly, no significant differences were found in plasma sex hormone levels between the different PF-MF exposure groups and the sham exposure group. In addition, the pregnancy rates and implanted embryos were not significantly different between the four groups. Moreover, PF-MF exposures had no effects on either the number of fetuses in pregnant mice or the growth and development of neonatal mice.

Thermal and non-thermal health effects of low intensity non-ionizing radiation: An international perspective

Exposure to low frequency and radiofrequency electromagnetic fields at low intensities poses a significant health hazard that has not been adequately addressed by national and international organizations such as the World Health Organization. There is strong evidence that excessive exposure to mobile phone-frequencies over long periods of time increases the risk of brain cancer both in humans and animals. The mechanism(s) responsible include induction of reactive oxygen species, gene expression alteration and DNA damage through both epigenetic and genetic processes. In vivo and in vitro studies demonstrate adverse effects on male and female reproduction, almost certainly due to generation of reactive oxygen species. There is increasing evidence the exposures can result in neurobehavioral decrements and that some individuals develop a syndrome of "electro-hypersensitivity" or "microwave illness", which is one of several syndromes commonly categorized as "idiopathic environmental intolerance". While the symptoms are non-specific, new biochemical indicators and imaging techniques allow diagnosis that excludes the symptoms as being only psychosomatic. Unfortunately standards set by most national and international bodies are not protective of human health. This is a particular concern in children, given the rapid expansion of use of wireless technologies, the greater susceptibility of the developing nervous system, the hyperconductivity of their brain tissue, the greater penetration of radiofrequency radiation relative to head size and their potential for a longer lifetime exposure.

Characterization of Children's Exposure to Extremely Low Frequency Magnetic Fields by Stochastic Modeling

In this study, children’s exposure to extremely low frequency magnetic fields (ELF-MF, 40–800 Hz) is investigated. The interest in this thematic has grown due to a possible correlation between the increased risk of childhood leukemia and a daily average exposure above 0.4 µT, although the causal relationship is still uncertain. The aim of this paper was to present a new method of characterizing the children’s exposure to ELF-MF starting from personal measurements using a stochastic approach based on segmentation (and to apply it to the personal measurements themselves) of two previous projects: the ARIMMORA project and the EXPERS project. The stochastic model consisted in (i) splitting the 24 h recordings into stationary events and (ii) characterizing each event with four parameters that are easily interpretable: the duration of the event, the mean value, the dispersion of the magnetic field over the event, and a final parameter characterizing the variation speed. Afterward, the data from the two databases were divided in subgroups based on a characteristic (i.e., children’s age, number of inhabitants in the area, etc.). For every subgroup, the kernel density estimation (KDE) of each parameter was calculated and the p-value histogram of the parameters together was obtained, in order to compare the subgroups and to extract information about the children’s exposure. In conclusion, this new stochastic approach allows for the identification of the parameters that most affect the level of children’s exposure.

Reanalysis of risks of childhood leukaemia with distance from overhead power lines in the UK

Our previous study of childhood leukaemia and distance to high-voltage overhead power lines in the UK has been included in an international pooled analysis. That pooled analysis used different distance categories to those we did, which has focussed attention on the effect of that choice. We re-analyse our previous subjects, using finer distance categories. In the 1960s and 1970s, when we principally found an elevated risk, the risk did not fall monotonically with distance from the power line but had a maximum at 100-200 m. This weakens the evidence that any elevated risks are related to magnetic fields, and slightly strengthens the evidence for a possible effect involving residential mobility or other socioeconomic factors.

Exposure to 50 Hz Magnetic Fields in Homes and Areas Surrounding Urban Transformer Stations in Silla (Spain): Environmental Impact Assessment

Exposure to extremely low frequency electromagnetic fields (ELFs) is almost inevitable almost anywhere in the world. An ELF magnetic field (ELF-MF) of around 1 mG = 0.1 μT is typically measured in any home of the world with a certain degree of development and well-being. There is fear and concern about exposure to electromagnetic fields from high- and medium-voltage wiring and transformer stations, especially internal transformer stations (TSs), which in Spain are commonly located inside residential buildings on the ground floor. It is common for neighbors living near these stations to ask for stations to be moved away from their homes, and to ask for information about exposure levels and their effects. Municipality is the closest administration to the citizens that must solve this situation, mediating between the citizens, the utility companies and the national administration. In this case, the municipality of Silla (València, Spain) wanted to know the levels of exposure in the dwellings annexed to the TSs, to compare them with Spanish legislation and the recommendations coming from epidemiological studies. This article presents the first systematic campaign of ELF-MF measurements from TSs carried out in a Spanish city. Many measurements were carried out in the rooms of the apartments doing spatial averages of spatial grid measurements. Measurements are made in the bed and bedrooms and a weighted average and an environmental impact indicator were obtained for each location. We found that old TSs usually provide the highest peak exposure levels. A notable result of this work is that approximately one quarter of the population living above or next to a TS would be exposed to a weighted MF level greater than 0.3 μT, and that about a 10% of this population would not be able to relocate their bedroom or living room to minimize the level of exposure.

Eotaxin‑1 and MCP‑1 serve as circulating indicators in response to power frequency electromagnetic field exposure in mice

The increasing public concern regarding the potential health risks of exposure to electromagnetic fields (EMFs) has led to intensive research in this area. However, it remains unclear whether potential pro-oncogenic effects may be caused by power frequency EMF (PFEMF) exposure. To address the associated risk factors, the present study exposed 4-week old Balb/c mice to 0, 0.1, 0.5 and 2.5 mT of constant 50 Hz Helmholtz coil-type PFEMF for 90 days to explore the circulating chemokine indicators that may be associated with inflammation or cancer. No measurable weight difference existed between the control and PFEMF-exposure groups; however, the Luminex assay clearly demonstrated differentially responsive profiles of circulating chemokines upon PFEMF treatment. Monocyte chemoattractant protein (MCP)-3, macrophage inflammatory protein (MIP)-1α, MIP-1β and MIP-2 levels in serum were not significantly altered by PFEMF during the 3-month exposure period; however, the circulating levels of other chemokines including IP-10, GROα, RANTES, EOTAXIN-1 and MCP-1 exhibited significant changes upon treatment. Among the responsive chemokines, EOTAXIN-1 and MCP-1 were significantly increased by 0.5 mT of PFEMF treatment, which may support their use as indicators of PFEMF exposure. This novel finding highlights the potential pro-inflammatory nature of power frequency, which may shed light on the mechanisms underlying PFEMF-induced diseases, including cancer.

Results of lifespan exposure to continuous and intermittent extremely low frequency electromagnetic fields (ELFEMF) administered alone to Sprague Dawley rats

BACKGROUND

Up to now, experimental studies on rodents have failed to provide definitive confirmation of the carcinogenicity of extremely low frequency electromagnetic fields (ELFEMF). Two recent studies performed in our laboratory on Sprague-Dawley rats reported a statistically significant increase in malignant tumors of different sites (mammary gland, C-cells carcinoma, hemolymphoreticular neoplasia, and malignant heart Schwannoma) when ELFEMF exposure was associated with exposure to formaldehyde (50 mg/l) or acute low dose of γ-radiation (0.1 Gy) (Soffritti et al., 2016a) (Soffritti et al., 2016b). The same doses of known carcinogenic agents (50 mg/l formaldehyde, or acute 0.1 Gy γ-radiation), when administered alone, previously failed to induce any statistically significant increase in the incidence of total and specific malignant tumors in rats of the same colony.

OBJECTIVES

A lifespan whole-body exposure study was conducted to evaluate the possible carcinogenic effects of ELFEMF exposure administered alone to Sprague-Dawley rats, as part of the integrated project of the Ramazzini Institute (RI) for studying the effects on health of ELFEMF alone or in combination with other known carcinogens.

METHODS

Male and female Sprague-Dawley rats were exposed 19 h/day to continuous sinusoidal-50 Hz magnetic fields (S-50 Hz MF) at flux densities of 0 (control group), 2, 20, 100 or 1000µT, and to intermittent (30 min on/30 min off) S-50 Hz MF at 1000 µT, from prenatal life until natural death.

RESULTS

Survival and body weight trends in all groups of rats exposed to ELFEMF were comparable to those found in sex-matched controls. The incidence and number of malignant and benign tumors was similar in all groups. Magnetic field exposure did not significantly increase the incidence of neoplasias in any organ, including those sites that have been identified as possible targets in epidemiological studies (leukemia, breast cancer, and brain cancer).

CONCLUSIONS

Life-span exposures to continuous and intermittent sinusoidal-50 Hz ELFEMFs, when administered alone, did not represent a significant risk factor for neoplastic development in our experimental rat model. In light of our previous results on the carcinogenic effects of ELFEMF in combination with formaldehyde and γ-radiation, further experiments are necessary to elucidate the possible role of ELFEMF as cancer enhancer in presence of other chemical and physical carcinogens.

Proximity to overhead power lines and childhood leukaemia: an international pooled analysis

BACKGROUND

Although studies have consistently found an association between childhood leukaemia risk and magnetic fields, the associations between childhood leukaemia and distance to overhead power lines have been inconsistent. We pooled data from multiple studies to assess the association with distance and evaluate whether it is due to magnetic fields or other factors associated with distance from lines.

METHODS

We present a pooled analysis combining individual-level data (29,049 cases and 68,231 controls) from 11 record-based studies.

RESULTS

There was no material association between childhood leukaemia and distance to nearest overhead power line of any voltage. Among children living < 50 m from 200 + kV power lines, the adjusted odds ratio for childhood leukaemia was 1.33 (95% CI: 0.92-1.93). The odds ratio was higher among children diagnosed before age 5 years. There was no association with calculated magnetic fields. Odds ratios remained unchanged with adjustment for potential confounders.

CONCLUSIONS

In this first comprehensive pooled analysis of childhood leukaemia and distance to power lines, we found a small and imprecise risk for residences < 50 m of 200 + kV lines that was not explained by high magnetic fields. Reasons for the increased risk, found in this and many other studies, remains to be elucidated.

Flavin Adenine Dinucleotide Photochemistry Is Magnetic Field Sensitive at Physiological pH

We present time-resolved optical absorption and magnetic field effect data on the photochemistry following blue light excitation of flavin adenine dinucleotide (FAD) in aqueous solution in the pH range 2.3 to 8.0. Effects of closed form conformations of FAD in ground, excited singlet, and radical pair states exhibit significant influence on the observed kinetics and magnetic field dependence and remarkably, magnetic field effects are observed even at physiological pH where the FAD radical pairs are only 75% less magnetic field sensitive than at pH 2.3.

A proposed explanation for thunderstorm asthma and leukemia risk near high-voltage power lines: a supported hypothesis

Thunderstorm asthma and increased childhood leukemia risk near high-voltage power lines (HVPL) are occurrences whose mechanism of effect is not fully understood. This paper proposes and discusses a key similarity: both thunderstorms and HVPL generate a high enough electrical field in the environment to ionize nearby air and air-borne particles. I argue that the repeatedly demonstrated acute asthma response to pollen-laden air during thunderstorms is largely due to ionization of air-borne allergens, which adhere more readily and in greater quantity in the lungs than non-ionized particles. If these bind to mucous or phagocytic cells, it would enhance immune response. A rapid temperature drop and high ozone also seem to be drivers of thunderstorm asthma. This causal nexus provides strong support for the parallel situation of prolonged exposure to ionized particles near HVPL and an increased rate of childhood leukemia. Here, it is proposed that upwind carcinogens are ionized when passing HVPL and then residential and business areas. Published evidence for most steps are presented, but have not previously been published as a coherent whole, nor has it been suggested that the inhaled ionized micro-particle explanation for acute asthma may also explain development of childhood leukemia over time. The demonstrated series of events leading to increased deposition and retention of ionized particles in airways provides support for explaining both adverse health outcomes: acute thunderstorm asthma and increased risk of childhood leukemia near HVPL. Further support for this explanation of both outcomes is provided by effects of on-going proximity to highways.

Characteristics and potential human health hazards of charged aerosols generated by high-voltage power lines

We investigated the characteristics of charged aerosols produced by high-voltage power lines (HVPLs) to explore the effects on respiratory disease incidence among those who handle HVPLs. Charged aerosol currents and charged aerosol concentrations were measured over 24 h at 12 sites. Aerosol current effective levels were 2.7 times higher compared to exposed and control sites. This pattern of relative enhancement at exposed sites was seen consistently in all measurements and the difference was 1.7 higher at exposed sites. Correlation analysis among all important variables revealed strong positive correlations between currents and concentration, currents and magnetic field, humidity and concentration, and humidity and particles of 10 µm or less (PM₁₀), while negative correlations were observed between charged aerosol concentrations and wind velocity and between wind velocity and humidity. Estimated production of charged aerosols from HVPLs found that people who work with HVPLs are highly likely to be exposed to charged aerosols.

Influence of tissue conductivity on foetal exposure to extremely low frequency magnetic fields at 50 Hz using stochastic dosimetry

Human exposure to extremely low frequency magnetic fields (ELF-MF) at 50 Hz is still a topic of great interest due to the possible correlation with childhood leukaemia. The estimation of induced electric fields in human tissues exposed to electromagnetic fields (EMFs) strictly depends on several variables which include the dielectric properties of the tissues. In this paper, the influence of the conductivity assignment to foetal tissues at different gestational ages on the estimation of the induced electric field due to ELF-MF exposure at 50 Hz has been quantified by means of a stochastic approach using polynomial chaos theory. The range of variation in conductivity values for each foetal tissue at each stage of pregnancy have been defined through three empirical approaches and the induced electric field in each tissue has been modelled through stochastic dosimetry. The main results suggest that both the peak and median induced electric fields in foetal fat vary by more than 8% at all gestational ages. On the contrary, the electric field induced in foetal brain does not seem to be significantly affected by conductivity data changes. The maximum exposure levels, in terms of the induced electric field found in each specific tissue, were found to be significantly below the basic restrictions indicated in the ICNIRP Guidelines, 2010.

Molecular processes involved in B cell acute lymphoblastic leukaemia

B cell leukaemia is one of the most frequent malignancies in the paediatric population, but also affects a significant proportion of adults in developed countries. The majority of infant and paediatric cases initiate the process of leukaemogenesis during foetal development (in utero) through the formation of a chromosomal translocation or the acquisition/deletion of genetic material (hyperdiploidy or hypodiploidy, respectively). This first genetic insult is the major determinant for the prognosis and therapeutic outcome of patients. B cell leukaemia in adults displays similar molecular features as its paediatric counterpart. However, since this disease is highly represented in the infant and paediatric population, this review will focus on this demographic group and summarise the biological, clinical and epidemiological knowledge on B cell acute lymphoblastic leukaemia of four well characterised subtypes: t(4;11) MLL-AF4, t(12;21) ETV6-RUNX1, t(1;19) E2A-PBX1 and t(9;22) BCR-ABL1.

Exosomal small RNA sequencing uncovers the microRNA dose markers for power frequency electromagnetic field exposure

PURPOSE

The potential health risks caused by power frequency electromagnetic field (PFEMF) have led to increase public health concerns. However, the diagnosis and prognosis remain challenging in determination of exact dose of PFEMF exposure.

MATERIALS AND METHODS

Mice were exposed to different magnetic doses of PFEMF for the following isolation of serum exosomes, microRNAs (miRNAs) extraction and small RNA sequencing. After small RNA sequencing, bioinformatic analysis, quantitative real-time PCR (qRT-PCR) validation and serum exosomal miRNA biomarkers were determined.

RESULTS

Significantly changed serum exosomal miRNA as biomarkers of 0.1, 0.5, 2.5 mT and common PFEMF exposure were confirmed. Gene ontology (GO) and Kyoto encyclopaedia of genes and genomes (KEGG) pathway analysis of the downstream target genes of the above-identified exosomal miRNA markers indicated that, exosomal miRNA markers were predicted to be involved in critical pathophysiological processes of neural system and cancer- or other disease-related signalling pathways.

CONCLUSIONS

Aberrantly-expressed serum exosomal miRNAs, including miR-128-3p for 0.1 mT, miR-133a-3p for 0.5 mT, miR-142a-5p for 2.5 mT, miR-218-5p and miR-199a-3p for common PFEMF exposure, suggested a series of informative markers for not only identifying the exact dose of PFEMF exposure, also consolidating the base for future clinical intervention.

"These Power Lines Make Me Ill": A Typology of Residents' Health Responses to a New High-Voltage Power Line

Little attention has been devoted to the potential diversity in residents' health responses when exposed to an uncertain environmental health risk. The present study explores whether subgroups of residents respond differently to a new high-voltage power line (HVPL) being put into operation. We used a quasi-experimental prospective field study design with two pretests during the construction of a new HVPL, and two posttests after it was put into operation. Residents living nearby (0-300 m, n = 229) filled out questionnaires about their health and their perception of the environment. We applied latent class growth models to investigate heterogeneity in the belief that health complaints were caused by a power line. Classes were compared on a wide range of variables relating to negative-oriented personality traits, perceived physical and mental health, and perceptions of the environment. We identified five distinct classes of residents, of which the largest (49%) could be described as emotionally stable and healthy with weak responses to the introduction of a new power line. A considerable minority (9%) responded more strongly to the new line being activated. Residents in this class had heard more about the health effects of power lines beforehand, were more aware of the activation of the new line, and reported a decrease in perceived health afterwards. Based on our findings we can conclude that there is a considerable heterogeneity in health responses to a new HVPL. Health risk perceptions appear to play an important role in this typology, which has implications for risk management.

Electromagnetic fields in neonatal incubators: the reasons for an alert

BACKGROUND

Neonatal incubators are important tools for sick newborns in the first few days of life. Nevertheless, their electric engine, often very close to the newborn's body, emits electromagnetic fields (EMF) to which newborns are exposed. Aim of this paper is to review the available literature on EMF exposure in incubators, and the effects of such exposures on newborns that have been investigated.

METHODS

We carried out a systematic review of studies about EMF emissions produced by incubators, using Medline and Embase databases from 1993 to 2017.

RESULTS

We retrieved 15 papers that described the EMF exposure in incubators and their biological effects on babies. EMF levels in incubators appear to be between 2 and 100 mG, depending on the distance of the mattress from the electric engine. In some cases, they exceed this range. These values interfere with melatonin production or with vagal tone. Even caregivers are exposed to high EMF, above 200 mG, when working at close contact with the incubators.

CONCLUSION

EMF have been described as potentially hazardous for human health, and values reported in this review are an alert to prevent babies' and caregivers' exposure when close to the incubators. A precautionary approach should be adopted in future incubator design, to prevent high exposures of newborns in incubators and of caregivers as well.

24-h personal monitoring of exposure to Power Frequency Magnetic Fields in adolescents - Results of a National Survey

OBJECTIVES

The aim of this exposure assessment study was to gain information about the exposure levels of adolescents in Israel to power frequency (50Hz) magnetic fields (MF) through personal monitoring, and to provide reliable data for national policy development.

METHODS

84 adolescents, 6-10th grade students, carried an EMDEX II meter attached to their body for 24h. The meter recorded the MF every 1.5s. The students documented their activities and microenvironments, such as apartment (awake or asleep), school, transportation, open public areas and other indoor environments.

RESULTS

The geometric mean (GM) of the daily time weighted average (TWA) of all the participants was 0.059 μT (STD = 1.83). This result is similar to those of personal exposure surveys conducted in the UK (GM 0.042-0.054μT), but lower than levels found in the US (GM 0.089 - 0.134μT). The arithmetic mean was 0.073μT, 23% higher than the GM. Fields were lowest at school (GM 0.033μT), and average outdoor exposures were higher than indoor ones. 3.6% of the participants were exposed to daily TWA above 0.2μT. The typical time spent above 0.2μT ranged from few minutes to few hours. The time spent above 0.4μT and 1μT were much shorter, around 1-15min and from few seconds to 2min, respectively. Momentary peaks ever recorded were in the range of 0.35-23.6μT CONCLUSIONS: Exposure of adolescents in Israel is similar to data reported in other countries, being below 0.1μT for the vast majority, with very few average exposures above 0.2μT. Analysis of the different microenvironments allows for a cost-effective and equitable policy development.

Residential magnetic fields exposure and childhood leukemia: a population-based case-control study in California

PURPOSE

Studies have reported an increased risk of childhood leukemia associated with exposure to magnetic fields. We conducted a large records-based case-control study of childhood leukemia risk and exposure to magnetic fields from power lines in California.

METHODS

The study included 5,788 childhood leukemia cases (born in and diagnosed in California 1986-2008) matched to population-based controls on age and sex. We calculated magnetic fields at birth addresses using geographic information systems, aerial imagery, historical information on load and phasing, and site visits.

RESULTS

Based on unconditional logistic regression controlling for age, sex, race/ethnicity, and socioeconomic status using subjects geocoded to a basic standard of accuracy, we report a slight risk deficit in two intermediate exposure groups and a small excess risk in the highest exposure group (odds ratio of 1.50 (95% confidence interval [0.70, 3.23])). Subgroup and sensitivity analyses as well as matched analyses gave similar results. All estimates had wide confidence intervals.

CONCLUSION

Our large, statewide, record-based case-control study of childhood leukemia in California does not in itself provide clear evidence of risk associated with greater exposure to magnetic fields from power lines, but could be viewed as consistent with previous findings of increased risk.

Exposure Modelling of Extremely Low-Frequency Magnetic Fields from Overhead Power Lines and Its Validation by Measurements

A three-dimensional model for calculating long term exposure to extremely low-frequency magnetic fields from high-voltage overhead power lines is presented, as well as its validation by measurements. For the validation, the model was applied to two different high-voltage overhead power lines in Iffwil and Wiler (Switzerland). In order to capture the daily and seasonal variations, each measurement was taken for 48 h and the measurements were carried out six times at each site, at intervals of approximately two months, between January and December 2015. During each measurement, a lateral transect of the magnetic flux density was determined in the middle of a span from nine measurement points in the range of ±80 m. The technical data of both the lines as well as the load flow data during the measurement periods were provided by the grid operators. These data were used to calculate 48 h averages of the absolute value of the magnetic flux density and compared with modelled values. The highest 48 h average was 1.66 µT (centre of the line in Iffwil); the lowest 48 h average was 22 nT (80 m distance from the centre line in Iffwil). On average, the magnetic flux density was overestimated by 2% (standard deviation: 9%) in Iffwil and underestimated by 1% (8%) in Wiler. Sensitivity analyses showed that the uncertainty is mainly driven by errors in the coordinates and height data. In particular, for predictions near the centre of the line, an accurate digital terrain model is critical.

Exposure to extremely low and intermediate-frequency magnetic and electric fields among children from the INMA-Gipuzkoa cohort

Detailed assessment of exposure to extremely low frequency (ELF) and intermediate frequency (IF) fields is essential in order to conduct informative epidemiological studies of the health effects from exposure to these fields. There is limited information available regarding ELF electric fields and on both magnetic and electric field exposures of children in the IF range. The aim of this study was to characterize ELF and IF exposure of children in the Spanish INMA cohort. A combination of spot and fixed measurements was carried out in 104 homes, 26 schools and their playgrounds and 105 parks. Low levels of ELF magnetic fields (ELF-MF) were observed (with the highest 24-h time-weighted average (TWA) exposure being 0.15μT in one home). The interquartile range (IQR) of ELF electric fields (ELF-EF) ranged from 1 to 15V/m indoors and from 0.3 to 1.1V/m outdoors and a maximum value observed was 55.5V/m in one school playground. IQR ranges for IF magnetic and electric fields were between 0.02 and 0.23μT and 0.2 and 0.5V/m respectively and maximum values were 0.03μT and 1.51V/m in homes. Correlations between magnetic and electric fields were weak for ELF (Spearman 0.04-0.36 in different settings) and moderate for IF (between 0.28 and 0.75). Children of INMA-Gipuzkoa cohort were exposed to very low levels of ELF-MF in all settings and to similar levels of ELF-EF compared to the range of previously reported levels, although somewhat higher exposures occurred at home. Children enrolled to our study were similarly exposed to IF in all settings.