52
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Effects of 60 Hz magnetic fields on teenagers and adults

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Background

          As use of electrical devices has increased, social concerns about the possible effects of 60 Hz electromagnetic fields on human health have increased. Accordingly, the number of people who complain of various symptoms such as headache and insomnia has risen. Many previous studies of the effects of extremely low frequency (ELF) magnetic field exposure on children have focused on the occurrence of childhood leukaemia and central nervous system cancers. However, very few provocation studies have examined the health effects of ELF magnetic fields on teenagers.

          Methods

          In this double-blind study, we simultaneously investigated physiological changes (heart rate, respiration rate, and heart rate variability), subjective symptoms, and magnetic field perception to determine the reliable effects of 60 Hz 12.5 μT magnetic fields on teenagers. Two volunteer groups of 30 adults and 30 teenagers were tested with exposure to sham and real magnetic fields for 32 min.

          Results

          ELF magnetic field exposure did not have any effects on the physiological parameters or eight subjective symptoms in either group. Neither group correctly perceived the magnetic fields.

          Conclusions

          Physiological data were analysed, subjective symptoms surveyed, and the percentages of those who believed they were being exposed were measured. No effects were observed in adults or teenagers resulting from 32 min of 60 Hz 12.5 μT magnetic field exposure.

          Related collections

          Most cited references28

          • Record: found
          • Abstract: found
          • Article: not found

          Heart rate variability: a noninvasive electrocardiographic method to measure the autonomic nervous system.

          The autonomic nervous system (ANS) plays an important role not only in physiological situations, but also in various pathological settings such as diabetic neuropathy, myocardial infarction (MI) and congestive heart failure (CHF). Autonomic imbalance associating increased sympathetic activity and reduced vagal tone has been been strongly implicated in the pathophysiology of arrhythmogenesis and sudden cardiac death. Among the different available noninvasive techniques for assessing the autonomic status heart rate variability (HRV) has emerged as a simple, noninvasive method to evaluate the sympathovagal balance at the sinoatrial level. It has been used in a variety of clinical situations including diabetic neuropathy, MI, sudden death and CHF. The standard measurements intervening in the analysis of HRV comprise time domain indices, geometric methods and components of the frequency domain. Measurements of HRV are generally performed on the basis of 24 hour Holter recordings (long-term recordings) or on shorter periods ranging from 0.5 to 5 minutes (short-term recordings). The use of long or short-term recordings depends on the type of study that has to be realised. Established clinical data based on numerous studies published during the last decade consider decreased global HRV as a strong predictor of increased all-cause cardiac and/or arrhythmic mortality, particularly in patients at risk after MI or with CHF. This article reviews the mechanism, the parameters and the use of HRV as a marker reflecting the activity of the sympathetic and vagal components of the ANS on the sinus node, and as a clinical tool for screening and identifying patients particularly at risk for cardiac mortality.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            The effect of mental stress on heart rate variability and blood pressure during computer work.

            The aim was to evaluate the cardiovascular and subjective stress response to a combined physical and mental workload, and the effect of rest. Twelve females who had no prior experience of laboratory experiments participated in the study. Computer-work-related mental stressors were either added to or removed from a standardized computer work session in the laboratory. Beat-to-beat blood pressure and electrocardiogram (ECG) were recorded continuously during the experiment. The participants reported subjective experiences of stress in six categories using an 11-point scale before and at the end of the work. Heart rate variability (HRV) variables were calculated from the ECG recordings, and a reduction in the high-frequency component of HRV and an increase in the low- to high-frequency ratio were observed in the stress situation compared to the control session. No changes were seen in the low-frequency component of HRV. The stressors induced an increase in blood pressure compared to baseline that persisted, and for the diastolic pressure it even increased in the subsequent control session. No differences were observed for subjective experience of stress with the exception of a time trend in the exhaustion scale, i.e. a progression in reported exhaustion with time. The results-and the dissociation between HRV and blood pressure variables-indicate that HRV is a more sensitive and selective measure of mental stress. It could be speculated that heart rate-derived variables reflect a central pathway in cardiovascular control mechanisms ("central command"), while the blood pressure response is more influenced by local conditions in the working muscles that partly mask the effect of changes in mental workloads. In the rest period after each work session, HRV and blood pressure variables were partly normalized as expected. However, an 8-min period of rest was insufficient to restore blood pressure to resting values.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              A pooled analysis of magnetic fields and childhood leukaemia

              Previous studies have suggested an association between exposure to 50–60 Hz magnetic fields (EMF) and childhood leukaemia. We conducted a pooled analysis based on individual records from nine studies, including the most recent ones. Studies with 24/48-hour magnetic field measurements or calculated magnetic fields were included. We specified which data analyses we planned to do and how to do them before we commenced the work. The use of individual records allowed us to use the same exposure definitions, and the large numbers of subjects enabled more precise estimation of risks at high exposure levels. For the 3203 children with leukaemia and 10 338 control children with estimated residential magnetic field exposures levels < 0.4 μT, we observed risk estimates near the no effect level, while for the 44 children with leukaemia and 62 control children with estimated residential magnetic field exposures ≥ 0.4 μT the estimated summary relative risk was 2.00 (1.27–3.13), P value = 0.002). Adjustment for potential confounding variables did not appreciably change the results. For North American subjects whose residences were in the highest wire code category, the estimated summary relative risk was 1.24 (0.82–1.87). Thus, we found no evidence in the combined data for the existence of the so-called wire-code paradox. In summary, the 99.2% of children residing in homes with exposure levels < 0.4 μT had estimates compatible with no increased risk, while the 0.8% of children with exposures ≥ 0.4 μT had a relative risk estimate of approximately 2, which is unlikely to be due to random variability. The explanation for the elevated risk is unknown, but selection bias may have accounted for some of the increase. © 2000 Cancer Research Campaign
                Bookmark

                Author and article information

                Journal
                Environ Health
                Environ Health
                Environmental Health
                BioMed Central
                1476-069X
                2013
                24 May 2013
                : 12
                : 42
                Affiliations
                [1 ]Department of Medical Engineering, Yonsei University College of Medicine, Seoul, Republic of Korea
                [2 ]Graduate Program in Biomedical Engineering, Yonsei University, Seoul, Republic of Korea
                [3 ]LS Industry Systems Co., Ltd, Chunan, Choongnam, Republic of Korea
                [4 ]Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Republic of Korea
                Article
                1476-069X-12-42
                10.1186/1476-069X-12-42
                3681577
                23705754
                32a3b7d8-4ed7-41ac-a1f1-8d1db8d18e11
                Copyright ©2013 Kim et al.; licensee BioMed Central Ltd.

                This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

                History
                : 12 December 2012
                : 20 May 2013
                Categories
                Research

                Public health
                elf,physiological changes,subjective symptoms,perception
                Public health
                elf, physiological changes, subjective symptoms, perception

                Comments

                Comment on this article