Alterations of biological parameters in mice chronically exposed to low-frequency (50 Hz) electromagnetic fields

Associations between solar and geomagnetic activity and peripheral white blood cells in the Normative Aging Study

It has been hypothesized that solar and geomagnetic activity can affect the function of the autonomic nervous system (ANS) and melatonin secretion, both of which may influence immune response. We investigated the association between solar geomagnetic activity and white blood cell counts in the Normative Aging Study (NAS) Cohort between 2000 and 2013. Linear mixed effects models with moving day averages ranging from 0 to 28 days were used to evaluate the effects of solar activity measures, interplanetary magnetic field (IMF), and sunspot number (SSN), and a measure of geomagnetic activity, K Index (K), on total white blood cell (WBC), neutrophil, monocytes, lymphocyte, eosinophil, and basophil concentrations. After adjusting for demographic and health-related factors, there were consistently significant associations between IMF, SSN, and K_p index, with reductions in total WBC, neutrophils, and basophil counts. These associations were stronger with longer moving averages. The associations were similar after adjusting for ambient air particulate pollution and particle radioactivity. Our findings suggest that periods of increased solar and geomagnetic activity result in lower WBC, neutrophil, and basophil counts that may contribute to mil mild immune suppression.

Immunity and electromagnetic fields

Despite many studies, the question about the positive or negative influence of electromagnetic fields (EMF) on living organisms still remains an unresolved issue. To date, the results are inconsistent and hardly comparable between different laboratories. The observed bio-effects are dependent not only on the applied EMF itself, but on many other factors such as the model system tested or environmental ones. In an organism, the role of the defense system against external stressors is played by the immune system consisting of various cell types. The immune cells are engaged in many physiological processes and responsible for the proper functioning of the whole organism. Any factor with an ability to cause immunomodulatory effects may weaken or enhance the response of the immune system. This review is focused on a wide range electromagnetic fields as a possible external factor which may modulate the innate and/or adaptive immunity. Considering the existing databases, we have compiled the bio-effects evoked by EMF in particular immune cell types involved in different types of immune response with the common mechanistic models and mostly activated intracellular signaling cascade pathways.

Influence of the static magnetic field on red blood cells parameters and platelets using tests of CBC and microscopy images

The present study was undertaken to investigate the influence of the static magnetic field (SMF) on the platelets and red blood cells counts (RBCs), haemoglobin (HGB), haematocrit (HCT), mean cell volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) in female rats (in-vitro). The results were analysed using tests of complete blood count (CBC) and microscopic images. The SMF in millitesla (mT) was generated using a fabricated electromagnetic exposure technique, and it has used for different time (minutes) of exposure. Statistical analysis for both tests investigated that the values of SMF affected the RBCs parameters and platelets for exposed Rats significantly for both tests. At 42.5 mT: RBCs counts have been affected (decreased) significantly (p < 0.05) at 30 min exposure, HCT (%) has affected (increased) significantly (p < 0.05) at 10 min and 30 min of exposure. The highest effects of SMF on the values of RBCs, HGB and HCT (%) were found at 34.8 mT after exposed to 15 min Variation of time of exposure and the values of SMF affected (p < 0.05) on the values of RBCs, HGB and HCT (%). The lowest effect of SMF was on the value of MCV (fl) at 6.4 mT at 15 min We found the effects of SMF on the platelet counts significant. Microscopy images of RBCs parameters and platelet count (PLT) support results got from the CBC test.

Long-Term Study on the Effects of Housing C57BL/6NCrl Mice in Cages Equipped With Wireless Technology Generating Extremely Low-Intensity Electromagnetic Fields

The recent development of mouse cages equipped with monitoring wireless technology raised questions on the potential effects on animals induced by electromagnetic fields (EMFs) generated by electronic boards positioned underneath the cages. The aims of this study were to characterize the EMF produced by digitally ventilated cages (DVC) and perform a clinicopathological study on mice maintained in DVC for up to 1 year. The EMFs were measured in empty individually ventilated cages (IVC) and DVC. Male (n = 160) and female (n = 160) C57BL/6NCrl mice were randomly housed in IVC and DVC in a single rack, 4 mice per cage. Body weight and food and water consumption were recorded at 14-day intervals. At sacrifice (days 60, 120, 180, and 365), body and testes weight was measured, and necropsy, hematology, bone marrow cytology, histology, and immunohistochemistry for cleaved-caspase 3 on the testes were performed. Digitally ventilated cages produced extremely low-intensity electric fields ranging from 5 Hz to 3 GHz. No exposure-related clinical signs and mortality occurred. Occasional statistical differences in body weight, food and water consumption, hematology, bone marrow, and histopathology were recorded, but considered without biological or clinical relevance. In conclusion, long-term maintenance in DVC had no definite effects on C57BL/6NCrl mice.

Alterations of Hematologic and Hematopoietic Parameters in Mice Exposed to Pulsed Electromagnetic Field

Effects of pulsed electromagnetic field (PEMF) on hematology and hematopoiesis might vary with different PEMF parameters. The purpose of this study was to evaluate the possible effects of PEMF exposure at different pulses on hematologic and hematopoietic parameters in mice. Groups of male BALB/c mice were whole body exposed or were sham exposed (control) to PEMF at 100, 1000, and 10000 pulses. After PEMF exposure, blood samples and bone marrow cells of mice were collected for hematologic examinations, bone marrow nucleated cell counting, colony-forming units of granulocyte-macrophage (CFU-GM) colony assay, and serum granulocyte-macrophage colony-stimulating factor (GM-CSF) assay. Compared with the control group, white blood cells (WBC) and lymphocytes (LYM) in the 100 and 1000 pulses exposed groups were significantly increased but not changed in the 10000 pulses exposed group. Red blood cells (RBC), hemoglobin (HGB), and platelets (PLT) were not changed in all exposed groups. There was no significant difference in mouse bone marrow nucleated cell number between the control group and each exposed group 7 days after PEMF exposure. The CFU-GM clone number of bone marrow cells and serum GM-CSF level were significantly increased in the 100 and 1000 pulses exposed group but not changed in the 10000 pulses exposed group. Our results indicated that the PEMF exposure at fewer pulses may induce statistically significant alterations in some hematologic and hematopoietic parameters of mice but no changes can be found in the more pulses PEMF-exposed groups.

The Effect of Different Intensities of Static Magnetic Field on Stress and Selected Reproductive Indices of the Zebrafish (Danio rerio) During Acute and Subacute Exposure

The application of equipment and tools that produce a magnetic field is increasing in aquatic ecosystems. In the present study, the effects of acute (1 week) and subacute (3 weeks) exposures to different static magnetic fields (SMFs) of 2.5, 5, 7.5 mT on stress indices (cortisol and glucose), sex steroid hormones (17β-estradiol and 17-α hydroxy progesterone) and fecundity of the zebrafish (Danio rerio) were investigated. The obtained results showed a significant change in cortisol, glucose, 17β-estradiol (E₂) and 17-α hydroxy progesterone (17-OHP) levels by enhancing the intensity and time of exposure to SMFs. In conclusion, the SMFs, especially at higher levels of intensities, showed physiologically harmful effects on the reproductive biology of the zebrafish during acute and subacute exposures.

Effect of electromagnetic waves from mobile phone on immune status of male rats: possible protective role of vitamin D

There are considerable public concerns about the relationship between mobile phone radiation and human health. The present study assesses the effect of electromagnetic field (EMF) emitted from a mobile phone on the immune system in rats and the possible protective role of vitamin D. Rats were randomly divided into six groups: Group I: control group; Group II: received vitamin D (1000 IU/kg/day) orally; Group III: exposed to EMF 1 h/day; Group IV: exposed to EMF 2 h/day; Group V: exposed to EMF 1 h/day and received vitamin D (1000 IU/kg/day); Group VI: exposed to EMF 2 h/day and received vitamin D (1000 IU/kg/day). After 30 days of exposure time, 1 h/day EMF exposure resulted in significant decrease in immunoglobulin levels (IgA, IgE, IgM, and IgG); total leukocyte, lymphocyte, eosinophil and basophil counts; and a significant increase in neutrophil and monocyte counts. These changes were more increased in the group exposed to 2 h/day EMF. Vitamin D supplementation in EMF-exposed rats reversed these results when compared with EMF-exposed groups. In contrast, 7, 14, and 21 days of EMF exposure produced nonsignificant differences in these parameters among all experimental groups. We concluded that exposure to mobile phone radiation compromises the immune system of rats, and vitamin D appears to have a protective effect.

Effects of subchronic extremely low-frequency electromagnetic field exposure on biochemical parameters in rats

The objective of the present study was to systematically determine the effects of 50 Hertz (Hz) magnetic fields (MFs) on biochemical parameters in rats. Sixty-four adult (5 weeks old, 140–165 g) male Sprague–Dawley rats were randomly divided into four groups: sham, 20 µTesla (µT), 100 µT, and 500 µT 50 Hz MF ( n = 16 in each group). The rats in the MF groups were exposed for 2 h daily for up to 4 weeks. Under these experimental conditions, body weight, organ coefficients, biochemical parameters (blood lipids, myocardial enzymes, liver function, and renal function) were measured. We found that 50 Hz MFs had no significant effects on growth or on the majority of blood biochemical parameters, with the exception of creatinine and cholesterol. However, the changes in creatinine and cholesterol were relatively small and unlikely to be clinically relevant.

Differential effects of high and low strength magnetic fields on mouse embryonic development and vasculogenesis of embryonic stem cells

Man-made magnetic fields (MFs) may exert adverse effects on mammalian embryonic development. Herein, we analysed the effect of 10mT 50Hz sinusoidal (AC) or static (DC) MFs versus 1mT MFs on embryonic development of mice. Exposure for 20days during gestation to 10mT MFs increased resorptions and dead fetuses, decreased crown-rump length and fresh weight, reduced blood vessel differentiation and caused histological changes, accompanied with diminished vascular endothelial growth factor (VEGF) protein expression in several organs. In embryonic stem (ES) cell-derived embryoid bodies exposure towards 10mT MFs increased reactive oxygen species (ROS), decreased vascular marker as well as VEGF expression and enhanced apoptosis. In conclusion, our combined data from in vivo and in vitro experiments identified VEGF as an important mediator during embryonic development that can be influenced by high strength MFs, which in consequence leads to severe abnormalities in fetus organs and blood vessel formation.

Effects of 3 Hz and 60 Hz Extremely Low Frequency Electromagnetic Fields on Anxiety-Like Behaviors, Memory Retention of Passive Avoidance and Electrophysiological Properties of Male Rats

INTRODUCTION

The effects of electromagnetic fields on biological organisms have been a controversial and also interesting debate over the past few decades, despite the wide range of investigations, many aspects of extremely low frequency electromagnetic fields (ELF/EMFs) effects including mechanism of their interaction with live organisms and also their possible biological applications still remain ambiguous. In the present study, we investigated whether the exposures of ELF/EMF with frequencies of 3 Hz and 60 Hz can affect the memory, anxiety like behaviors, electrophysiological properties and brain's proteome in rats.

METHODS

Male rats were exposed to 3 Hz and 60 Hz ELF/EMFs in a protocol consisting of 2 cycles of 2 h/day exposure for 4 days separated with a 2-day interval. Short term memory and anxiety like behaviors were assessed immediately, 1 and 2 weeks after the exposures. Effects of short term exposure were also assessed using electrophysiological approach immediately after 2 hours exposure.

RESULTS

Behavioral test revealed that immediately after the end of exposures, locomotor activity of both 3 Hz and 60 Hz exposed groups significantly decreased compared to sham group. This exposure protocol had no effect on anxiety like behavior during the 2 weeks after the treatment and also on short term memory. A significant reduction in firing rate of locus coeruleus (LC) was found after 2 hours of both 3 Hz and 60 Hz exposures. Proteome analysis also revealed global changes in whole brain proteome after treatment.

CONCLUSION

Here, some evidence regarding the fact that such exposures can alter locomotor activity and neurons firing rate in male rats were presented.

Electromagnetic field versus circuit weight training on bone mineral density in elderly women

BACKGROUND AND PURPOSE

Osteoporosis is a common skeletal disorder with costly complications and a global health problem and one of the leading causes of morbidity and mortality worldwide. Magnetic field therapy and physical activity have been proven as beneficial interventions for prevention and treatment of osteoporosis. The purpose of this study was to compare the response of bone mineral content and bone mineral density (BMD) in elderly women to either low-frequency low-intensity pulsed magnetic field (LFLIPMF) or circuit weight training (CWT) on short-run basis (after 12 weeks).

PATIENTS AND METHODS

Thirty elderly women, aged 60-70 years, were randomly assigned into two groups (magnetic field and CWT) (n=15 each group). The session was performed three times per week for magnetic field and CWT groups, for 12 weeks. BMD and bone mineral content of lumbar spine (L2-L4) and femoral neck, trochanter, and Ward's triangle were evaluated before and after 12 weeks of treatment.

RESULTS

Both magnetic field and CWT for 12 weeks in elderly women seem to yield beneficial and statistically significant increasing effect on BMD and bone mineral content (P<0.05). But magnetic field seems to have more beneficially and statistically significant effect than does CWT.

CONCLUSION

It is possible to conclude that LFLIPMF and CWT programs are effective modalities in increasing BMD but LFLIPMF is more effective in elderly women.

Influence of electric, magnetic, and electromagnetic fields on the circadian system: current stage of knowledge

One of the side effects of each electrical device work is the electromagnetic field generated near its workplace. All organisms, including humans, are exposed daily to the influence of different types of this field, characterized by various physical parameters. Therefore, it is important to accurately determine the effects of an electromagnetic field on the physiological and pathological processes occurring in cells, tissues, and organs. Numerous epidemiological and experimental data suggest that the extremely low frequency magnetic field generated by electrical transmission lines and electrically powered devices and the high frequencies electromagnetic radiation emitted by electronic devices have a potentially negative impact on the circadian system. On the other hand, several studies have found no influence of these fields on chronobiological parameters. According to the current state of knowledge, some previously proposed hypotheses, including one concerning the key role of melatonin secretion disruption in pathogenesis of electromagnetic field induced diseases, need to be revised. This paper reviews the data on the effect of electric, magnetic, and electromagnetic fields on melatonin and cortisol rhythms—two major markers of the circadian system as well as on sleep. It also provides the basic information about the nature, classification, parameters, and sources of these fields.

Effects of electromagnetic pulse on serum element levels in rat

Electromagnetic pulse (EMP) was a potentially harmful factor to the human body, and a biological dosimetry to evaluate effects of EMP is necessary. Little is known about effects of EMP on concentration of macro and trace elements in serum so far. In this study, Sprague-Dawley rats were randomly divided into 50-kV/m EMP-exposed group (n = 10), 100-kV/m EMP-exposed group (n = 10), 200-kV/m EMP-exposed group (n = 40), and the sham-exposed group (n = 20). The macro and trace element concentrations in serum were examined at 6, 12, 24, and 48 h after EMP exposure at different electric field intensities. Compared with the sham-exposed groups, the concentration of sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), zinc (Zn), copper (Cu), iron (Fe), selenium (Se), and manganese (Mn) in rat serum was not changed significantly within 48 h after 200 pulses of EMP exposure at electric field intensity of 50, 100, and 200 kV/m although the K level was decreased and the Ca level was increased with the electric field intensity of EMP increasing. In addition, there was a tendency that the Zn level was decreased with the time going on within 48 h after EMP exposure. Under our experimental conditions, EMP exposure cannot affect the concentration of macro and trace elements in rat serum. There was no time-effect or dose-effect relationship between EMP exposure and serum element levels. The macro and trace elements in serum are not suitable endpoints of biological dosimetry of EMP.

The effects of extremely low-frequency magnetic fields on melatonin and cortisol, two marker rhythms of the circadian system

In the past 30 years the concern that daily exposure to extremely low-frequency magnetic fields (ELF-EMF) (1 to 300 Hz) might be harmful to human health (cancer, neurobehavioral disturbances, etc) has been the object of debate, and has become a public health concern. This has resulted in the classification of ELF-EMF into category 2B, ie, agents that are “possibly carcinogenic to humans” by the International Agency for Research on Cancer. Since melatonin, a neurohormone secreted by the pineal gland, has been shown to possess oncostatic properties, a “melatonin hypothesis” has been raised, stating that exposure to EMF might decrease melatonin production and therefore might promote the development of breast cancer in humans. Data from the literature reviewed here are contradictory. In addition, we have demonstrated a lack of effect of ELF-EMF on melatonin secretion in humans exposed to EMF (up to 20 years' exposure) which rebuts the melatonin hypothesis. Currently, the debate concerns the effects of ELF-EMF on the risk of childhood leukemia in children chronically exposed to more than 0.4 μT. Further research is thus needed to obtain more definite answers regarding the potential deleterious effects of ELF-EMF.

The influence of the low-frequency magnetic fields of different parameters on the secretion of cortisol in men

OBJECTIVES

The aim of this paper is to test the influence of long-term application of the low-frequency magnetic fields in magnetotherapy and magnetostimulation on cortisol secretion in men.

MATERIALS AND METHODS

Patients were divided into three groups: 16 men underwent magnetotherapy and 20 men (divided into two groups) underwent magnetostimulation. Magnetotherapy - 2 mT induction, 40 Hz, bipolar square wave, was applied for 20 min to lumbar area. Magnetostimulation (Viofor Jaroszyk, Paluszak, Sieroń (JPS) system, M2P2 program) was applied to 10 patients for 12 min each day. The third group (10 patients) underwent magnetostimulation (Viofor JPS system, M3P3) for 12 min each day using a different machine. All groups had 15 rounds of applications at approximately 10:00 a.m. with intermissions on the weekends. Blood serum was taken four times in a 24-hour period, before applications, the day after applications and a month later. Chemiluminescence micromethod was used to indicate hormone concentrations. Data was statistically analyzed with the analysis of variance (ANOVA) method.

RESULTS

The statistically significant gains in the circadian cortisol profile at 4:00 p.m., be- fore and after application, were observed as a decrease in concentration during magnetotherapy. In magnetostimulation, with the M2P2 program, a significant increase in the cortisol concentration was observed in circadian profile at 12:00 p.m. one month after the last application. After magnetostimulation with the M3P3 program, a significant increase in concentration at 6:00 a.m. and a decrease in concentration at 12:00 p.m. were observed one month later. Statistically significant difference was demonstrated in the participants after the application of magnetotherapy and magnetostimulation with M3P3 program compared to the men submitted to magnetostimulation, with M2P2 program, at 4:00 p.m. after 15 applications.

CONCLUSIONS

Biological hysteresis one month after magnetostimulation suggests long-term influence on the hypothalamo-hypophysial axis. The circadian curves of cortisol secretion a day after magnetotherapy and magnetostimulation with M3P3 program compared to magnetostimulation with M2P2 progam differs nearly by 100%, which proves that they show varied influence on cortisol secretion in men. All changes in the hormone concentration did not exceed the physiological standards of cortisol secretion, which suggests a regulating influence of magnetic fields on cortisol concentration rather than a strong stressogenic impact of magnetostimulation.

Effects of the ELF-MFs on the development of spleens of preincubated chicken embryos

Effects of extremely low-frequency magnetic fields (ELF-MFs) on the histopathology, histomorphometry, ultrastructural changes (transmission electron microscope, TEM), apoptosis and alkaline phosphatase (ALP) activities in the spleens of preincubated white leghorn chicken embryo were investigated. Ninety fertilized eggs were divided into six groups as control (n = 15), sham (n = 15) and four experimental groups (1-4, n = 15). Eggs of experimental groups were exposed to 1.33, 2.66, 5.52 and 7.32 mTs flux intensities established in our previous published experiments and the last intensity was used for studying apoptosis and ultrastructures (TEM) of the spleens of 19-day-old chicken embryos. Eggs of control groups remained intact. Sham groups were placed inside the coil for 24 h before incubation with no exposures, then they were incubated in the same incubator (37°C, 60% humidity) for 19 days. Spleens of chicken embryos were removed, fixed in formalin (10%), and stained with H&E for histopathological and histomorphometrical surveys; TUNEL assay indicated possible change in apoptosis and TEM and biochemical studies were also carried out. Significant decreases in the sizes of the spleens of embryos of experimental groups, hyperemia, damages in spleen parenchyma, decreases in the numbers of splenic nodules, increases in the number of polymorphonuclear cells and sinusoidal spaces of spleens, significant increase in the level of ALP activities, significant increases in the numbers of apoptotic cells, deformed nuclei and swollen mitochondria were observed in experimental groups comparing with those in control and sham groups. ELF-MF created changes which could impair the immune functions.

The influence of pulsed electric field on hematological parameters in rat

The aim of the present study is to investigate whether or not pulsed electric field (PEF) affects some hematological parameters in rats. Sixteen healthy male Wistar rats weighting 150–200 g were used and were randomly divided into two groups. Exposure group ( n = 8) was exposed to a PEF (10 kV m−1 for 1 h d−1) for 10 consecutive days. The control group rats ( n = 8) were not exposed to PEF. The following hematological parameters were measured in both the groups: white blood cells (WBCs), red blood cells (RBCs), hemoglobin (Hb), hematocrit (Ht) and platelets (PLTs). Some of the hematological parameters under investigation were similar in both the groups. Exposure group, exposed for 1 h d−1 during 10 consecutive days, induced a significant increase in the rates of WBC ( p < 0.05), RBC ( p < 0.05), Hb ( p < 0.05), Ht ( p < 0.05) and PLTs ( p < 0.05) in blood when compared with control. These results suggest that PEFs affect the hematological parameters in rat. Results of the parameters are statistically significant.

Mechanisms of geomagnetic field influence on gene expression using influenza as a model system: basics of physical epidemiology

Recent studies demonstrate distinct changes in gene expression in cells exposed to a weak magnetic field (MF). Mechanisms of this phenomenon are not understood yet. We propose that proteins of the Cryptochrome family (CRY) are "epigenetic sensors" of the MF fluctuations, i.e., magnetic field-sensitive part of the epigenetic controlling mechanism. It was shown that CRY represses activity of the major circadian transcriptional complex CLOCK/BMAL1. At the same time, function of CRY, is apparently highly responsive to weak MF because of radical pairs that periodically arise in the functionally active site of CRY and mediate the radical pair mechanism of magnetoreception. It is known that the circadian complex influences function of every organ and tissue, including modulation of both NF-kappaB- and glucocorticoids- dependent signaling pathways. Thus, MFs and solar cycles-dependent geomagnetic field fluctuations are capable of altering expression of genes related to function of NF-kappaB, hormones and other biological regulators. Notably, NF-kappaB, along with its significant role in immune response, also participates in differential regulation of influenza virus RNA synthesis. Presented data suggests that in the case of global application (example-geomagnetic field), MF-mediated regulation may have epidemiological and other consequences.

Effects of electromagnetic pulse on bone metabolism of mice in vivo

OBJECTIVE

To study the effects of electromagnetic pulse (EMP) on bone metabolism of mice in vivo.

METHODS

Twenty-four male BALB/c mice were divided into a control group and 2 experimental groups (n=8). The whole-body of mice in experimental groups were exposed to 50 kV/m and 400kV/m EMP, 400 pulses daily for 7 consecutive days at 2 seconds intervals. Alkaline phosphotase (ALP) activity, serum calcium concentration and osteocalcin level and trabecular bone volume (BV/TV, %) were measured immediately after EMP exposure by biochemical, ELISA and morphological methods.

RESULTS

The ALP activity, serum calcium concentration and osteocalcin level and BV/TV in experimental groups remained unchanged after EMP exposure. Conclusion Under our experimental conditions, EMP exposure cannot affect bone metabolism of mice in vivo.

Detection of probable effects of microwave exposure of blood parameters of RBC, PCV and Hb in rat

The aim of this preliminary investigation was to assess the probable effects of microwave exposure on Hematological parameters of RBC (Red Blood Cell), PCV (Packed Cell Volume) and Hb (Hemoglobin) in rats. For this study 80 Sprague Dawley rats were exposed to 2450 MHZ microwave field for a period of one year. The experiment groups were divided to 5 groups, each 16 (8 males and 8 female), 4 for treatment and one, for control (D, E, F, G and H). The incident power density of the first two experiment groups was 1 mW m(-2) and for next two groups, was 10 mW cm(-2). The daily exposure time was 5 min for groups F and G and 30 min for groups, D and F. The animals in control group (H) were under normal condition without any microwave exposure. In the end of the study the blood samples were taken from the heart of animals under ether anesthesia and determination of blood parameters were performed by cell counter auto analyzer. According to the statistical results, the level of RBC in male groups of F and G and percentage of PCV in female and male groups of F and content of Hb, in female groups of F, were significantly increased in comparison to the control group and variation of results in other groups were not significant.

Studies on antioxidant enzymes in mice exposed to pulsed electromagnetic fields

In this study, 56 female albino mice weighing 30-35 g were used. The animals were divided into a control and an experimental group. The animals in the experimental group were subjected to a pulsed electromagnetic field (PEMF) with a field magnitude of 50 Hz and 2 mT for 8h each day between 0900 and 1700 for 90 days. In both control and experimental groups, blood was sampled at 45, 60, and 90 days in heparinized tubes and erythrocyte malondialdehyde levels, and superoxide dismutase, glutathione peroxidase, catalase, and glucose-6-phosphate dehydrogenase activities were determined. The results revealed that the PEMF applied chronically within the given period and field magnitude does not cause oxidative damage.

Effects of sub-acute exposure to static magnetic field on hematologic and biochemical parameters in pregnant rats

This study investigated the effects of a static magnetic field (SMF) on hematopoiesis and biochemical parameters in female rats. Pregnant rats were exposed to SMF (128 mT-1 hour/day from day 6 to day 19 of pregnancy). At 25 degrees C, the exposure of rats 1 hour/day for 13 consecutive days to SMF induced an increase in hematocrit (Ht) level (+6%, p < 0.05), hemoglobin (Hb) concentration (+12%, p < 0.05) and LDH levels (67%, p < 0.05 ), suggesting an hypoxia-like state. Moreover, exposure to SMF increased blood glucose and decreased insulin release, leading to a diabetic-like state in pregnant rats.

Clastogenicity and aneuploidy in newborn and adult mice exposed to 50 Hz magnetic fields

PURPOSE

To detect possible clastogenic and aneugenic properties of a 50 Hz, 650 muT magnetic field.

MATERIALS AND METHODS

The micronucleus test with CREST (Calcinosis, Raynaud's phenomenon, Esophageal dismotility, Sclerodactility, Telangectasia) antibody staining was performed on liver and peripheral blood sampled from newborn mice exposed to an ELF (Extremely Low Frequency) magnetic field during the whole intra-uterine life (21 days), and on bone marrow and peripheral blood sampled from adult mice exposed to the same magnetic field for the same period.

RESULTS

Data obtained in newborn mice show a significant increase in micronuclei frequencies. In absolute terms, most of the induced micronuclei were CREST-negative (i.e., formed by a chromosome fragment). However, in relative terms, ELF exposure caused a two-fold increase in CREST-negative micronuclei and a four-fold increase in CREST-positive micronuclei (i.e., formed by a whole chromosome). No significant effect was recorded on exposed adults.

CONCLUSIONS

These findings suggest the need for investigation of aneugenic properties of ELF magnetic fields in order to establish a possible relationship to carcinogenesis.

50 Hz Magnetic Fields of 1 mT do not Promote Lymphoma Development in AKR/J Mice

Some epidemiological studies suggest that exposure to power-frequency magnetic fields increases the risk of leukemia, especially in children with high residential exposures. In contrast, most animal studies did not find a correlation between magnetic-field exposure and hematopoietic diseases. The present study was performed to investigate whether chronic, high-level (1 mT) magnetic-field exposure had an influence on lymphoma development in a mouse strain that is genetically predisposed to thymic lymphoblastic lymphoma. Three groups of 160 unrestrained female AKR/J mice were sham-exposed or exposed to sinusoidal 50 Hz magnetic fields beginning at the age of 12 weeks for 32 weeks, 7 days per week, either for 24 h per day or only during nighttime (12 h). Exposure was carried out in a blind design. Exposure did not affect survival time, body weight, lymphoma development or hematological parameters. The resulting data do not support the hypothesis that exposure to sinusoidal 50 Hz magnetic fields is a significant risk factor for hematopoietic diseases, even at this relatively high exposure level.

Possíveis efeitos adversos dos campos eletromagnéticos (50/60 Hz) em humanos e em animais

Os avanços tecnológicos têm aumentado o número de equipamentos elétricos e eletrônicos, seja nas residências ou mesmo no ambiente de trabalho, fazendo com que a população conviva com grande número de fontes de irradiação eletromagnética, com os mais diversos níveis de potência e freqüência. Por muitos anos, alguns cientistas e engenheiros acreditaram que o campo eletromagnético (CEM) com freqüência extremamente baixa não pudesse causar efeitos e alterações significantes no material biológico. O objetivo deste trabalho é verificar os possíveis efeitos adversos dos CEMs em humanos e animais, que foram publicados nos últimos anos, através de uma revisão da literatura disponível em Medline, revistas nacionais e internacionais e catálogos de obras de referência na área dos CEM (50/60 Hz). Como resultado foi observado que o CEM (50/60 Hz) é capaz de produzir diversos efeitos adversos em humanos e animais, como por exemplo: distúrbios na reprodução, doenças degenerativas, efeitos psiquiátricos e psicológicos, alterações citogenéticas, alterações no sistema cardiovascular, nervoso e neuroendócrino, bem como nos parâmetros biológicos e bioquímicos. Apesar de todas estas constatações e devido a muitas controvérsias entre vários autores, faz-se necessário um estudo mais específico e aprofundado sobre o assunto.

Skeletal muscle HSP72 and norepinephrine response to static magnetic field in rat

The present work was undertaken in order to investigate the noradrenergic system and skeletal muscle heat shock protein 72 (HSP72) response to static magnetic field (MF) in male rats. At thermoneutrality (25 degrees C), the exposition of rats 1 hour/day for 5 consecutive days to MF of 128 mT (m tesla) induced an increase in norepinephrine content in gastrocnemius muscle (+25%, p < 0.05) but had no effect at 67 mT (+1%, p > 0.05), indicating a stimulatory effect of sub-acute MF exposure on the noradrenergic system activity. Moreover, exposed rats to MF displayed a non-significant increase of HSP72 levels in gastrocnemius muscles (+29%, p > 0.05). The results indicate that noradrenergic systems in rat's gastrocnemius muscles are affected by MF exposure. Interestingly, sub-acute exposure insufficiency increased HSP72 levels in gastrocnemius muscles.

Effects of Electromagnetic Fields on the Immune Systems of Occupationally Exposed Humans and Mice

The authors examined immunological disorders in 6 individuals who had been exposed occupationally to environmental electromagnetic fields. Comparable effects on mice exposed in a similar environment were also investigated. The human subjects had worked 8 hr/day for 5 yr in a laboratory located above electrical transformers and high-tension cables, and in which there were low-frequency electromagnetic fields of 0.2-6.6 microtesla (microT). The 6 control subjects (matched for socioeconomic parameters, sex, and age) had worked away from the immediate vicinity of transformers and high-tension cables. The authors found statistically significantly lower total lymphocyte, CD4, and CD3 counts, and significantly increased natural killer (NK) cells, in exposed subjects vs. controls. Six months after exposure had ceased, total lymphocyte counts had increased, as had CD4, CD3, and CD19 counts (+13%, +28%, +22%, and +17%, respectively), and NK cell counts were decreased by 26% (not significant) in the same human subjects. In the second part of this study, 12 Swiss male mice housed in cages were exposed in the same room in which the human subjects had been exposed (i.e., 5-microT, 50-Hz magnetic field) for 109 days; 12 additional mice were used as unexposed controls. The total lymphocyte, leukocyte, polymorphonuclear neutrophil, CD4, and NK counts of the exposed mice at 109 days were significantly lower than those of controls. In addition, plasma glucose levels (at 30 days) and amylase activity (at 109 days) were significantly lower, whereas plasma sodium and chloride levels were significantly elevated at 109 days. Results from this study suggest that chronic exposure to a 0.2-6.6-microT magnetic field can lead to decreased immunological parameters (total lymphocytes and CD4 counts) in both humans and mice. The increase in some values once exposure was terminated suggests a causal relationship with exposure to electromagnetic fields, as do the changes in mice, particularly the changes in total lymphocyte and CD4 counts.