[Proposal for magnetic/electromagnetic fields protection norms on national level].

INTRODUCTION: The modern life is not possible without application of magnetic/electromagnetic fields, which can be both helpful and harmful for human body. INFLUENCE OF MAGNETIC/ELECTROMAGNETIC FIELDS ON BIOLOGICAL SYSTEMS: The non-ionizing radiation, especially magnetic/electromagnetic fields of all frequencies (0-300 GHz), can have many harmful effects on the human health that is confirmed by numerous epidemiological studies, studies with volunteers, animal studies, and in vitro studies. Proposal for magnetic/electromagnetic fields protection norms on national level based on the WHO Program for Environment, International Commission on Non-Ionizing Radiation Protection (ICNIRP)], and WHO International EMF Project. CONCLUSION: Protection from harmful effects of the magnetic/electromagnetic fields is still a great problem in many countries of modern society--huge costs, impaired quality of life, and more important, damage to the human health. Numerous data and publications of harmful effects of the magnetic/electromagnetic fields represents one's country basic necessary documentation for making decisions and law documents for protection norms on national level concerning the health maintenance according to the ICNIRP normatives.

Do naturally occurring magnetic nanoparticles in the human body mediate increased risk of childhood leukaemia with EMF exposure?

PURPOSE: To develop the hypothesis that magnetic nanoparticles, found in many organisms and often involved in biological reactions to weak electromagnetic fields (EMF), mediate EMF-induced DNA damage which could result in increased risk of childhood leukaemia and other cancers. MATERIALS AND METHODS: An analysis of current research into magnetic nanoparticles. Physics estimates and the development of the hypothesis that intracellular magnetic nanoparticles chronically change the free radical concentration and can mediate the enhanced rate of DNA damage in hematopoietic stem cells. RESULTS: The properties of magnetic nanoparticles are considered and the naturally occurring magnetic field generated by a magnetic nanoparticle within a cell is calculated to be in the range of about 1-200 millitesla, which exceeds the level of the natural geomagnetic field by orders of magnitude. Experiments are summarized on the biological effects of static magnetic field in this range. It is shown that magnetic nanoparticles can increase the rate of free radical formation by a few percent, in the course of an idealized radical-pair reaction in a cell. A mechanism is discussed that explains how weak alternating magnetic fields, of the order of 0.4 muT, could cause an increase in the rate of leukaemia via millitesla fields produced around superparamagnetic nanoparticles in hematopoietic stem cells. CONCLUSIONS: The postulated presence of magnetic nanoparticles located in hematopoietic stem cells could constitute a cancer risk factor. Superparamagnetic nanoparticles can possibly mediate increased level of leukaemia caused by background exposure to low-frequency weak EMF.

Multiple magnet ingestion as a source of severe gastrointestinal complications requiring surgical intervention.

OBJECTIVE: To raise awareness of the dangers associated with magnet ingestion in children. DESIGN: Case report and review of the literature. SETTING: Tertiary care children's hospital. Patient Four-year-old boy with minimal physical findings but with a clinical history and imaging suggesting complications from multiple magnet ingestion. Intervention Laparoscopic removal of magnets and repair of magnet-induced enterotomies. Outcome Measure Clinical course. RESULTS: Full recovery after surgical intervention. CONCLUSIONS: Ingestion of multiple magnets can cause minimal initial physical examination findings but result in significant complications, including bowel perforation, volvulus, ischemia, and death. Early surgical intervention can prevent significant morbidity and mortality. Clinical vigilance should be exercised in these cases and early surgical consultation with an aggressive surgical approach is recommended. Parents should be warned against the dangers of children's toys that contain these powerful magnets.

A randomized, double-blind, placebo-controlled clinical trial using a low-frequency magnetic field in the treatment of musculoskeletal chronic pain.

Exposure to a specific pulsed electromagnetic field (PEMF) has been shown to produce analgesic (antinociceptive) effects in many organisms. In a randomized, double-blind, sham-controlled clinical trial, patients with either chronic generalized pain from fibromyalgia (FM) or chronic localized musculoskeletal or inflammatory pain were exposed to a PEMF (400 microT) through a portable device fitted to their head during twice-daily 40 min treatments over seven days. The effect of this PEMF on pain reduction was recorded using a visual analogue scale. A differential effect of PEMF over sham treatment was noticed in patients with FM, which approached statistical significance (P=0.06) despite low numbers (n=17); this effect was not evident in those without FM (P=0.93; n=15). PEMF may be a novel, safe and effective therapeutic tool for use in at least certain subsets of patients with chronic, nonmalignant pain. Clearly, however, a larger randomized, double-blind clinical trial with just FM patients is warranted.

Magnetic attraction leading to a small bowel obstruction in a child.

Foreign body ingestion in small children is common yet only 1% of cases require operative management of associated complications (Arana et al. in Eur J Pediatr 160:468-472, 2001). A 6-year-old boy was referred to our institution with a 12 h history of abdominal pain. This pain was diffuse and crampy in nature and associated with multiple episodes of non-bilious, non-bloody emesis. On evaluation he was stable and his abdomen demonstrated slight distention and tenderness without peritoneal signs. Plain abdominal radiographs demonstrated some distended loops of small bowel and a radio-opaque foreign object within the mid-abdomen. A small bowel obstruction secondary to foreign body ingestion was diagnosed and an emergent laparotomy performed. Upon exploration, a transition zone was noted near the ileocecal valve. Further exploration revealed the obstruction to be caused secondary to the apposition of two small (8 mm) magnets, one in the proximal ileum and the other near the ileocecal valve, resulting in an internal hernia. The magnets were easily separated relieving the obstruction and both were removed via two small bowel enterotomies. After being presented with the magnets, his parents suspected that they came from the clothes of a Polly Pocket (Mattel, Inc., El Segundo, CA) doll. The patient had an uneventful post-operative course and was discharged to home on the second post-operative day. This case demonstrates the complications that may occur with multiple magnet ingestion. It highlights the need for close observation and early surgical intervention in children with a suspected history of foreign body ingestion, a clinical picture of gastrointestinal distress, and radiographic evidence of a radio-opaque foreign object.

Investigation of the sources of residential power frequency magnetic field exposure in the UK Childhood Cancer Study.

There is an unexplained association between exposure to the magnetic fields arising from the supply and use of electricity, and increase in risk of childhood leukaemia. The UK Childhood Cancer Study (UKCCS) provides a large and unique source of information on residential magnetic field exposure in the UK. The purpose of this supplementary study was to investigate a sample of UKCCS homes in order to identify the particular sources that contribute to elevated time-averaged exposure. In all, 196 homes have been investigated, 102 with exposures estimated on the basis of the original study to be above 0.2 microT, and 21 higher than 0.4 microT, a threshold above which a raised risk has been observed. First, surveys were carried out outside the property boundaries of all 196 study homes, and then, where informed consent had been obtained, assessments were conducted inside the properties of 19 homes. The study found that low-voltage (LV) sources associated with the final electricity supply accounted together for 77% of exposures above 0.2 microT, and 57% of those above 0.4 microT. Most of these exposures were linked to net currents in circuits inside and/or around the home. High-voltage (HV) sources, including the HV overhead power lines that are the focus of public concern, accounted for 23% of the exposures above 0.2 microT, and 43% of those above 0.4 microT. Public health interest has focused on the consideration of precautionary measures that would reduce exposure to power frequency magnetic fields. Our study provides a basis for considering the options for exposure mitigation in the UK. For instance, in elevated-exposure homes where net currents are higher than usual, if it is possible to reduce the net currents, then the exposure could be reduced for a sizeable proportion of these homes. Further investigations would be necessary to determine whether this is feasible.

Intestinal perforation caused by magnetic toys.

Accidental ingestion of foreign bodies is a common problem in children, but ingestion of magnets is rare. When multiple magnets are ingested, they may attract each other through the intestinal walls, causing pressure necrosis, perforation, fistula formation, or intestinal obstruction; as has been reported in 13 cases in the past 10 years. We report the fifth case in the literature of intestinal perforation and fistula caused by the ingestion of 2 small magnetic pieces of a toy by a 3-year-old boy. We find it necessary that sanitary authorities give more information to parents and physicians about the potential risks of these magnetic toys.

Intestinal volvulus and perforation caused by multiple magnet ingestion: report of a case.

Ingested magnets can cause intestinal fistulas, perforation, and obstruction. There have been reports of magnet ingestion causing intestinal volvulus, but multiple magnet ingestion causing perforation and intestinal volvulus in a child is very unusual. We report the case of a 4-year-old girl, who ingested four magnets she acquired as toys, which caused intestinal volvulus and perforation as a result of pressure necrosis, several days after ingestion. At surgery we repaired two perforations, but additional bowel resection was not required. The patient was discharged on postoperative day 10. If multiple magnet ingestion is suspected in a child, the child must be monitored carefully. If there are signs of obstruction, emergency surgery is mandatory.

Residential magnetic fields, contact voltage and their relationship: the effects of distribution unbalance and residential proximity to a transmission line.

In previous studies, modeling and measurements have suggested a positive relationship between the average residential magnetic field (B(avg)) and the voltage from the residential water line to earth (V(W-E)). This voltage is the source of exposure to contact current that has been hypothesized to behave as a confounder with respect to the association between residential magnetic fields and childhood leukemia. The previous modeling effort has only considered the influence of distribution lines on the B(avg):V(W-E) relationship. This study extends that analysis to include the effect of distribution line unbalance and the presence of nearby transmission lines. The results show that, compared to balanced systems, unbalanced distribution systems had increased B(avg) and V(W-E), with a relatively greater effect on (VW-E). The presence of a transmission line proportionally increased B(avg) and V(W-E) more on balanced systems than unbalanced systems and attenuated the relationship of B(avg) with V(W-E) on systems with 25% unbalance. Increases in B(avg) due to the transmission line were confined to distances within 100-200 m of the line, but increases in V(W-E) extended to the furthest distance included in the model (365 m). The observations reported may be relevant to prior epidemiological studies of magnetic fields and childhood leukemia, and suggest that research efforts continue to explore the role of contact current in potentially explaining those studies.

[Estimation of magnetic radiation effects on leucocytes]. / Ocena skutków oddzialywania promieniowania magnetycznego na leukocyty.

A lot of epidemiological and experimental research has been done recently into effects of magnetic fields (MF) on live bodies. Among others, the effects of MF on human immunological system are studied. Primary cells of the immunological system are leucocytes. A reduction of leucocyte count and any changes in their activity may lead to disturbances in the immunological system and growth of neoplasm. This paper presents a review of research into the effects of magnetic radiation on leucocytes. It describes, among other things, the influence of MF on leukocyte count changes, leucocyte cellular cycles, chromosome defects and DNA synthesis disorders in leucocytes. There is a lot of discrepancy in literature and at this stage it is difficult to draw consistent conclusion as regards the health effects of MF. Some papers claim that MF may reduce the number of leukocytes and modify their proliferation processes. In addition, there is some risk (although small) that MF will cause the aberration of the leukocyte chromosomes. As a result of leukocytes exposure to MF micronuclei were found in them, as well as changes in the activity of cytokines and natural killer cells. Considering that papers published so far present largely varied results, it is difficult to formulate solid conclusions about MF negative effects.

Are neutrons involved in the pathogenesis of life-threatening cardiac arrhythmias?

Geomagnetic fields protect the earth from the adverse effects of cosmic rays, whose activity can be indirectly measured by monitoring the level of neutrons in the environment. The number and days of discharges from automatic implantable cardioverter defibrillators (ICD) in patients with cardiac arrhythmias are inversely correlated with the daily level of geomagnetic activity (GMA). The aim of the present was to determine whether neutron levels on days of AICD discharges are higher than average. Days on which discharges occurred were recorded in 31 patients bearing ICDs for managing ischemic cardiomyopathy. Daily neutron levels obtained from the monitoring data of the Russian Academy of Sciences in Moscow were analyzed using Student's t test. The mean (+/-SD) daily neutron level for the 1096-day period was 8299.29 +/- 294.236 imp/min (median 8252), and for days of ACID discharge, 8423.93 +/- 274.187 imp/min (median 8443) (p = 0.0002). The mean neutron activity on days of AICD discharges in response to ventricular disturbances was significantly higher than the mean level over the 1096-day study period. Whether this relation is a direct result of low GMA or due to an independent role of neutrons in the pathogenesis and timing of cardiac arrhythmias is unknown.

Leukemia attributable to residential magnetic fields: results from analyses allowing for study biases.

Nearly every epidemiologic study of residential magnetic fields and childhood leukemia has exhibited a positive association. Nonetheless, because these studies suffer from various methodologic limitations and there is no known plausible mechanism of action, it remains uncertain as to how much, if any, of these associations are causal. Furthermore, because the observed associations are small and involve only the highest and most infrequent levels of exposure, it is believed that the public health impact of an effect would be small. We present some formal analyses of the impact of power-frequency residential magnetic-field exposure (as measured by attributable fractions), accounting for our uncertainties about study biases as well as uncertainties about exposure distribution. These analyses support the idea that the public health impact of residential fields is likely to be limited, but both no impact and a substantial impact remain possibilities in light of the available data.

Alteration in cellular functions in mouse macrophages after exposure to 50 Hz magnetic fields.

The aim of the present study is to investigate whether extremely low frequency electromagnetic fields (ELF-EMF) affect certain cellular functions and immunologic parameters of mouse macrophages. In this study, the influence of 50 Hz magnetic fields (MF) at 1.0 mT was investigated on the phagocytic activity and on the interleukin-1beta (IL-1beta) production in differentiated macrophages. MF-exposure led to an increased phagocytic activity after 45 min, shown as a 1.6-fold increased uptake of latex beads in MF-exposed cells compared to controls. We also demonstrate an increased IL-1beta release in macrophages after 24 h exposure (1.0 mT MF). Time-dependent IL-1beta formation was significantly increased already after 4 h and reached a maximum of 12.3-fold increase after 24 h compared to controls. Another aspect of this study was to examine the genotoxic capacity of 1.0 mT MF by analyzing the micronucleus (MN) formation in long-term (12, 24, and 48 h) exposed macrophages. Our data show no significant differences in MN formation or irregular mitotic activities in exposed cells. Furthermore, the effects of different flux densities (ranging from 0.05 up to 1.0 mT for 45 min) of 50 Hz MF was tested on free radical formation as an endpoint of cell activation in mouse macrophage precursor cells. All tested flux densities significantly stimulated the formation of free radicals. Here, we demonstrate the capacity of ELF-EMF to stimulate physiological cell functions in mouse macrophages shown by the significantly elevated phagocytic activity, free radical release, and IL-1beta production suggesting the cell activation capacity of ELF-EMF in the absence of any genotoxic effects.

Melatonin protects against pressure ulcer-induced oxidative injury of the skin and remote organs in rats.

Pressure ulcers (PU) cause morphological and functional alterations in the skin and visceral organs; the damage is believed to be due to ischemia/reperfusion (I/R) injury. In this study, we examined the role of oxidative damage in PU and the beneficial effect of treatment with the antioxidant melatonin. PU were induced by applying magnets over steel plates that were implanted under the skin of rats; this compressed the skin and caused ischemia. Within a 12-hr period, rats were subjected to five cycles of I/R (2 and 0.5 hr respectively), followed by an additional 12 hr of ischemia (to simulate the period at sleep at night). This protocol was repeated for 3 days. In treatment groups, twice a day during reperfusion periods, melatonin (5 mg per rat) was either applied locally as an ointment on skin, or administered i.p. (10 mg/kg). At the end of the experimental period, blood and tissue (skin, liver, kidney, lung, stomach, and ileum) samples were taken for determination of biochemical parameters and for histological evaluation. Local treatment with melatonin inhibited the increase in malondialdehyde levels; an index of lipid peroxidation, myeloperoxidase activity; an indicator of tissue neutrophil infiltration, and the decrease in glutathione; a key antioxidant, in the skin induced by PU, but was less efficient in preventing the damage in visceral organs. However, systemic treatment prevented the damage in the visceral organs. Significant increases in creatinine, blood urea nitrogen, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase and collagen levels in animals with PU were prevented by melatonin treatment. The light microscopic examination exhibited significant degenerative changes in dermis and epidermis in the PU rats. Tissue injury was decreased especially in the locally treated group. Findings of the present study suggest that local and/or systemic melatonin treatment may prove beneficial in the treatment of PU.

[Biological and health effects on electric and magnetic fields at extremely low frequencies]. / Effetti biologici e sanitari dei campi elettrici e magnetici a frequenze estremamente basse.

While the enormous benefits of using electricity in everyday life and health care are unquestioned, during the past 20 years the general public has become increasingly concerned about potential adverse health effects of exposure to electric and magnetic fields at extremely low frequencies (ELF). Such exposures arise mainly from the transmission and use of electrical energy at the power frequencies of 50/60 Hz. The international scientific community is addressing the associated health issues through in vitro, in vivo and epidemiological studies, although present research results are often contradictory. The purpose of this paper is to provide information about the possible impacts of exposure to electric and magnetic field at ELF frequencies on health within the community and the workplace. Information comes from recent research studies on this subject and from epidemiological pooled studies recently reviewed by eminent authorities.

[Pre- and early natal exposure to geomagnetic field as risk for melanoma and basal cell skin tumors].

Histories of 173 male and female patients with melanoma and basal cell skin tumors (BCST) were followed to elucidate the influence of pre- and early natal exposure to geomagnetic field (GMF) on future incidence of cancer. A positive correlation was established between exposure to GMF during critical months of prenatal period, on the one hand, and melanoma detection, on the other. However, a similar correlation involving BCST was inverse which suggests a difference in the etiologies. Tumor regression coefficients which link total Ki-indices for critical months of pre- and early natal exposure with tumor detection time are presented.

Estudo histológico comparativo de implantes (ímãs) em órbitas de coelhas / Comparative histologic study of implants (magnets) in orbits of female rabbits

OBJETIVOS: Avaliação microscópica dos sinais da reação inflamatória causada pela fixação de implante orbitário (ímã, recoberto por ouro). MÉTODOS: Estudo experimental em 54 coelhas adultas, divididas em três grupos de 18, com 3 subgrupos de 6, avaliação com uma, três e seis semanas de pós-operatório. Fixação, no rebordo inferior da órbita, de implante (ímã e ouro) por meio de cola, parafuso ou fio inabsorvível (Mersilene 5.0®). As órbitas contralaterais (sem implante) compuseram o grupo-controle. RESULTADOS: Sinais histológicos de reação inflamatória à fixação orbitária do implante foram observados, com cianoacrilato, parafuso, ou sutura inabsorvível (Mersilene 5.0®), até a sexta semana pós-operatória, com predomínio do processo inflamatório crônico e fibrótico cicatricial, sem demonstrar diferenças estatisticamente significativas na maior parte dos casos. CONCLUSÃO: O exame histopatológico demonstrou, na maior parte das órbitas com e sem implante, presença de reação inflamatória aguda e crônica até a sexta semana pós-operatória, com predomínio de processo inflamatório crônico e fibrótico cicatricial, sem demonstrar, na maior parte dos casos, diferenças estatisticamente significante entre os grupos experimental e controle.

Arc and resistance welding and tumours of the endocrine glands: a Swedish case-control study with focus on extremely low frequency magnetic fields.

BACKGROUND: Mechanisms for potential effects of extremely low frequency (ELF) magnetic fields on carcinogenesis have not been identified. A potential pathway could be an interaction with the endocrine system. AIMS: To analyse occupational exposure to ELF magnetic fields from welding, and tumours of the endocrine glands. METHODS: This case-control study was based on a cohort with an increased prevalence of high exposed individuals. A total of 174 incident cases of tumours of the endocrine glands, 1985-94, were identified and data were obtained from 140 (80%) of these cases; 1692 controls frequency matched on sex and age were selected, and information on 1306 (77%) individuals was obtained. A short questionnaire was sent to a work administrator at the workplaces of the cases and controls. The exposure assessment was based on questions about job tasks, exposure to different types of welding, and exposure to solvents. RESULTS: There was an overall increased risk for all tumours of the endocrine glands for individuals who had been welding sometime during the follow up. The increased risk was attributable to arc welding; for resistance welding there was no clear evidence of an association. We found an increased risk for the adrenal glands in relation to arc welding, and for the parathyroid glands in relation to both arc welding and resistance welding. An imprecise increase in risk was also noted for tumours of the pituitary gland for arc welding. No confounding effect was found for solvent exposure, and there was no sign of biological interaction. CONCLUSION: The increased risks of endocrine gland tumours related to welding might be explained by exposure to high levels of ELF magnetic fields.

Poisson regression analysis of ungrouped data.

BACKGROUND: Poisson regression is routinely used for analysis of epidemiological data from studies of large occupational cohorts. It is typically implemented as a grouped method of data analysis in which all exposure and covariate information is categorised and person-time and events are tabulated. AIMS: To describe an alternative approach to Poisson regression analysis using single units of person-time without grouping. METHODS: Data for simulated and empirical cohorts were analysed by Poisson regression. In analyses of simulated data, effect estimates derived via Poisson regression without grouping were compared to those obtained under proportional hazards regression. Analyses of empirical data for a cohort of 138 900 electrical workers were used to illustrate how the ungrouped approach may be applied in analyses of actual occupational cohorts. RESULTS: Using simulated data, Poisson regression analyses of ungrouped person-time data yield results equivalent to those obtained via proportional hazards regression: the results of both methods gave unbiased estimates of the "true" association specified for the simulation. Analyses of empirical data confirm that grouped and ungrouped analyses provide identical results when the same models are specified. However, bias may arise when exposure-response trends are estimated via Poisson regression analyses in which exposure scores, such as category means or midpoints, are assigned to grouped data. CONCLUSIONS: Poisson regression analysis of ungrouped person-time data is a useful tool that can avoid bias associated with categorising exposure data and assigning exposure scores, and facilitate direct assessment of the consequences of exposure categorisation and score assignment on regression results.