EMF risk for operators mounting,adjusting and maintaining base stations

In the recent years concerns whether exposure to electromagnetic fields (EMF) from base station antennae can cause adverse health effects are grown. Great attention is paid on risk of EMF exposure to people living in a close proximity of base stations. In this issue, a point of interest is the personnel mounting, adjusting and maintaining base stations. Their working tasks require stay in high EMF levels’ conditions. There are only few studies concerning this specific occupational group. The results from our previous investigation (COST 281—Graz, 2006) show that in many cases on performing some specific tasks operators are overexposed according to our national legislation, and ICNIRP guidelines. Here, we present an extended study covering more base stations and more precise scenario for performed tasks and working positions. Results of exposure assessment are presented. They include energetic load calculations on the basis of Bulgarian national legislation, and the corresponding SAR values. Data are used to determine permissible time duration for each particular work operation and served as a base for limiting the exposure and proposal for protective measures for the personnel.     

Electromagnetic field levels in the working environment in radio and TV stations

Electromagnetic field sources used for communication always have been subject of serious interest. There are many publications concerning exposure and risk assessment of the working in such environment. Results of epidemiological study performed in Bulgaria in the 1990's show exceeding of the maximal permissible values especially in radio stations for the personnel in 24 h working shift [Israel et al. (1992). Study of the electromagnetic in its influence on personnel working in radio and TV stations, Report, National Centre of Hygiene, Medical Ecology and Nutrition; Israel and Tomov (2001). Epidemiological study of the effects of radiofrequency radiation on operators in radio, TV and relay stations, Proceeding of the Eastern European Regional Meeting and Workshop “Measurements and Criteria for Standard Harmonization in the field of EMF Exposure” and WHO EMF Standards Harmonization Meeting, Varna, Bulgaria, 28 April—3 May, 2001, pp.145–153]. In the last years the situation is strongly influenced by the development of the technology which leads to changes in equipment in radio and TV stations, using lower power, facilitate the working regime. The paper presents data of exposure assessment of different professional groups in selected radio and TV stations. Assessment is being performed on basis of EMF parameters values and energetic load calculations according to the national legislation. Data are compared with the results of previous investigation to evaluate the new situation in this branch. Exposure levels are much lower than those in the previous study, and lower compared to the exposure limits, as well [Israel et al. (1992). Study of the electromagnetic in its influence on personnel working in radio and TV stations, Report, National Centre of Hygiene, Medical Ecology and Nutrition; Israel and Tomov (2001). Epidemiological study of the effects of radiofrequency radiation on operators in radio, TV and relay stations, Proceeding of the Eastern European Regional Meeting and␣Workshop “Measurements and Criteria for Standard Harmonization in the field of EMF Exposure” and WHO EMF Standards Harmonization Meeting, Varna, Bulgaria, 28 April—3 May, 2001, pp.145–153].     

Criticism of the philosophy for development of standards for non-ionizing radiation

The new recommendations of WHO and EC for legislation in Europe and other countries concerning non-ionizing radiation (NIR) health and safety include exposure limits that are very debatable. ICNIRP Guidelines propose exposure limits for electromagnetic fields in the frequency range up to 300 GHz based on short-term exposures and on thermal effects. The new EC proposal for optical and laser safety legislation includes classification of sources of radiation—both lasers and other optical sources, but not requirements for the methodology of classification. On the other hand, many new requirements have been set by the WHO publication “Model Legislation for EMF Protection” concerning the responsibilities in the field of EMF health and safety. Many specialists in the field of developing exposure limits have positions very far away from the proposed of the ICNIRP Guidelines philosophy. The results are different approaches in developing standards and exposure limits, and differences more than 100 times in maximal permissible levels. We, the Bulgarian Program Committee on NIR, try to organize working groups and discuss different philosophy for developing exposure limits for more than 10 years. This paper exposes our position in this area.     

Mobile communications and health of population: the risk assessment, social and ethical problems

Today world population lives in a new electromagnetic environment, characterized with (i) around the clock enforcement of chronic exposure of all age and gender groups to a wide range of modulated electromagnetic fields (EMF) from base stations; (ii) daily, repeated from early childhood throughout entire life exposure to EMF RF mobile phone the brain and vestibular receptor apparatus and auditory analyzers, located directly “under the EMF beam” in the inner ear. On the other hand, the world science and epidemiology is missing well-planned and executed research results of prolonged exposure of EMF RF on the brain. International recommendations and domestic guidelines do not include changing conditions of RF EMF on the population: the brain has become a critical organ, and the children entered the risk group. The population continues to actively use the mobile phone. In this situation the problem of assessing the risk of mobile communications has become a social and ethical.     

Electromagnetic fields in clinical practice of physical and rehabilitation medicine: a health hazard assessment of personnel

The importance of the assessment of the electromagnetic fields /EMF/ background as a health risk factor for the physiotherapy personnel is discussed in this paper. Wide frequency and amplitude ranges as well as large variety of design prescribed in the rehabilitation program form complicated work conditions. In this paper, we attempt to present and classify this specific work environment, i.e., low intensive EMF background with non homogenous frequency and modulation characteristics, stochastic changes running during day, ground or even underground units’ placement and professional specifics, i.e., chronic EMF expositions, personnel’s trunk and hands exposure, dose-measurement absence, lack of program for prevention and prophylaxis for the assessment of the relatively insufficiently elucidated potential of EMF as a harmful factor for medical staff. Our “Study of the biological effects of the EMF among medical staff from PRM wards—potential of risk reduction”/initialized in 1999/and the original survey card structure are presented in general here first. It has been shown the importance to extend the “native” studies among homogenous professional groups, two of them presented there, as well as the study of the biological effects of EMF in their different aspects, especially taking into account the elevated levels of ionizing and non-ionizing radiation in the environment. This includes the special attention on the exposure of medical staff from PRM units and creation of adequate methods for prevention of unnecessary exposure to these physical factors.     

Exposure to electromagnetic fields in the magnetic resonance imaging environment in South Africa

Occupational exposure to radiofrequency (RF) and static magnetic fields at magnetic resonance imaging (MRI) suites is of continuing concern to personnel who routinely work in this environment. Questions regarding the levels of occupational RF and static field exposure have increased with the increasing demand for anesthetics to be administered in this environment. The present study was thus designed towards addressing the above-mentioned problem by gaining information regarding exposure levels of clinical personnel at MRI units in South Africa. Three 1.5 MRI units in Bloemfontein, South Africa were utilized to evaluate the exposure of clinical personnel to the electromagnetic fields present in the MRI environment over a period of time and during different clinical MRI procedures. Three rounds of measurements of RF fields in the MRI environment were done. All the three measurement rounds were focused on the low frequencies, 5 Hz–32 kHz, as well as on the high frequencies, 300 kHz–40 GHz. First round measurements were done to establish the background of the RF fields in and around the magnet room during an MRI examination. Second round RF field measurements were done at a specific location, 1 m away from the bore on the right-hand side of the bed, in the MRI room. The third round measurements were of the same format as the second round, but the specific location was against the magnet bore. Two pieces of Narda Safety Test Solution instruments, the EFA-300 and EMR-300, were used to measure the electromagnetic and magnetic exposure fields generated from the MRI scanners. Results of the measurements indicate that the electromagnetic fields measured during different clinical procedures do not exceed the International Commission on Non-Ionizing Radiation Protection (2000) guidelines in these units. Results from round two and three showed that the RF and gradient exposure 1 m and up against the bore entrance does not exceed these guidelines (rms average over 6 min). Ongoing new developments in MRI scanning create the need for continuously monitoring exposure of patients and workers to the EMF fields in the MRI environment.     

Reduction of Pain in Reflex Sympathetic Dystrophy (RSD) Associated with Objective Biochemical Changes in Circulating Lymphocytes

Summary In an effort to explain the benefit of therapeutic use of electromagnetic fields (EMF) a systemic effect has been proposed by us. To assess the efficacy of this approach, an objective biochemical approach was developed. Ten patients with Reflex Sympathetic Dystrophy (RSD) were clinically evaluated, and lymphocytes were isolated from their blood samples obtained before and after exposure of the uninvolved limb to an EMF. Utilizing a SpectraCell method that includes radio labeled molecules and protein-free media for culturing the lymphocytes, an elevation of the content of fructose, serine, glycine, and calcium cellular metabolic uptake were found following in the culture to EMF in comparison with non-exposed lymphocytes (p < 0.01). In addition, the pain level was determined by a conventional visual analogue scale (VAS) before and after EMF exposure, evidencing a significant pain relief. Specifically, after exposure to 120 pps semi sinewave, 1500Gauss EMF, generated by a THERAMAG^∘ledR device, an improvement in the flexibility of the limb and a reduction in swelling of the affected extremity were detected clinically. These findings are in concert with the new hypothesis that, with relief of pain, lymphocytes are predominately altered in their cell cycle from M phase to S phases associated with increased structuring of intracellular water. A consideration of the basic understanding of the role lymphocytes may be inferred from this preliminary study. An extensive review of the literature on the basic science and therapeutic use of magnetic fields in humans is provided in an attempt to understand the relevance of magnetic therapy of specific pain syndromes.     

Influence of the Interaction of a 900 MHz Signal with Gender on EEG Energy: Experimental Study on the Influence of 900 MHz Radiation on EEG

Summary The effects of electromagnetic fields (EMF) emitted by cellular phones on human electroencephalogram (EEG) were studied during an auditory memory task. The experimental method and the experimental setup are introduced as a credible measurement method of EEG. 19 normal subjects (10 women and 9 men) performed the memory task both with and without exposure to a 900 MHz signal, emitted by a dipole antenna placed near the subjects' head. The energy of the EEG signals was calculated at the time domain. A Fourier transform of the EEG signals was done and the EEG energy was also calculated at the frequency domain. As the Parseval's theorem anticipates the energies were identical. The EEG energy was found concentrated at the four basic bands (α (8–13 Hz), β(14–30 Hz), δ (0–4 Hz) and θ(5–7 Hz)). The primary concern of the present study was the gender related influence of EMF on the spectral energy of EEG. The results show evidence of a strong gender—radiation interaction effect on the EEG energy and on the peak amplitudes within each of the four rhythms. Without radiation the spectral power of males is greater than of females, while under exposure the situation is reversed. Under the influence of EMF the spectral power of the males EEG is decreased while that of the females is increased. In conclusion both the baseline EEG and the changes effected to the EEG power spectrum under the influence of EMF seem to be gender dependent.     

Electromagnetic fields and other physical factors around wind power generators (pilot study)

According to the 20/20/20 strategy by European Union for green energy by 2020 priority should be given to the Renewable Energy Sources. The energy generated from the wind has proven to be of interest for several reasons—wind is available, it is a cheap, and virtually inexhaustible source of energy. In this relation in the last years, many wind power stations were built all around the country. They are being located in proximity of populated areas. Their work besides the generation of electricity is connected to emission of physical factors in the environment that could be essential for human health. In order to avoid overexposure to electromagnetic fields, noise, and vibration to the general public minimal safety distance is being determined theoretically for ‘worst case” conditions basing on the technical characteristics of the generators. After the mounting of installations, measurements have to be performed to determine whether the national and European safety limits for the factors of environment are being kept. The paper presents results of measurement of electromagnetic fields, additionally noise and vibration around one of the biggest wind power parks in Bulgaria. The measurements were made in the close proximity of the generators both for the personnel working conditions and for the population in the closest living areas.     

Immune stimulation in fish and chicken through weak low frequency electromagnetic fields

A hypothesis is proposed how Low Frequency Electromagnetic Field (LF EMF) exposure can stimulate an immune response, based on recent insights in immunology. We hypothesize that the Immunent EMF treatment induces mild stress to cells, which then produce cytokines that function as alarms or so called danger signals for the immune system. In this way EMF treatment takes the place of multiplying pathogens, and the damage these cause, in the triggering of an immune response. In a first series of experiments in␣vitro common carp head kidney-derived phagocytes were used to determine ROS production as a measure for immune activation. Exposure to LF EMF signals (200–5,000 Hz) at 5 μT or 1.5 mT led to 42 or 33% increase in immune activity, respectively, compared to negative control values. EMF could also additionally stimulate chemically pre-stimulated samples up to 18% (5 μT) or 22% (1.5 mT). Significance of increase in ROS production in the total series was: p < 0.0001. In a second series of experiments in␣vitro commercial goldfish were used. Groups of fish were housed under equal conditions in at least four control tanks and 8–16 EMF-exposed tanks. Exposure was done with a predominantly vertical field at field strengths (rms) between 0.15 and 50 μT. Without treatment mortality was about 50% after 18 days, while the treatment at 5 μT reduced it to 20% on average. At field strengths 0.15, 0.5, 1.5, 5, 15 and 50 μT an equally strong effect was found. Reducing the field strength to 0.05, 0.06, 0.01 and 0.003 μT showed a gradually decreasing effect, which only at 0.003 μT is no longer statistically significant. Finally, in␣vitro experiments were done with 560 commercial broiler chickens exposed to infection pressure from coccidiosis. EMF exposure at 6.5 μT reduced intestinal lesions by 40% and improved feed conversion by 8%.     

EMF effects on microcirculatory system

Authors review the importance of studying the effects of electromagnetic fields (EMF) on microcirculatory system, especially in respect of possibility that vasculature may have direct and indirect role in interaction of static magnetic fields (SMF). We outline the physiological importance of microcirculation and relatively new methods of evaluation technique in vivo and explain in details the local and/or whole body exposure effects of SMF with␣range of 0.3–180 mT, power frequency EMF with range of 0.1–30 mT and microwaves at 1.5 GHz with range 0.08–8 W/kg brain average specific absorption rate (SAR) on microcirculatory systems in different tissues in experimental animals.     

On experimental setup in bioelectromagnetics

Bioeffects created by electromagnetic field (EMF) are the subject of intensive studies. This paper critically considers estimations of exposure to EMF in bioelectromagnetic experiments. Results of calculations presented herein show the significant role of the presence of conducting bodies (the exposure system) near an object under test on EMF energy absorption as well as mutual interactions between simultaneously exposed objects. Our aims herein are twofold: firstly to find a way to refer measurement results to free-space conditions in order to enable comparison of results obtained in different laboratories, and secondly to show that EMF energy absorption in any exposed object is different and that this difference is a function of the size of the exposure system, the number of exposed objects, and the particular properties (i.e., the electromagnetic structure) of the objects. In the authors’ opinion the existence of interactions caused by the presence of the exposure system and other exposed objects is a reason why remarkable differences are observed between experiments performed even under supposedly identical conditions. The presented considerations and conclusion suggest wider participation of physicists and engineers in bioelectromagnetic experiments in order to ensure the correctness of metrological aspects of these experiments.     

我国土壤污染防治立法探究

随着土壤污染防治专门立法的启动,我国土壤污染防治的相关制度也将逐步建立,这对于指导土壤污染防治的实践工作具有重要意义。然而在立法过程中各方争议较大且亟待解决的几个关键问题有必要深入探究,主要涉及立法模式的选择、土壤环境管理模式的选择、污染土壤修复目标的确定及特殊污染土壤责任主体的认定。通过探析各争议问题对立法的核心价值及其背景和实质,并基于国情和我国土壤污染的现状,得出结论即应坚持防治并重,建立综合性土壤立法。采取风险管控的方式进行土壤管理。对受污染土壤的修复目标应结合未来土地用途具体分析。特殊历史遗留污染土壤责任主体的认定,则要坚持污染者负担为基本原则,其他相关原则为补充。     

成都地区移动通信基站电磁辐射影响与水平

通过对成都地区典型移动通信基站的电磁环境监测,分析了移动通信基站的电磁环境规律及程度,明确其产生电磁环境影响在10-2W/m2等级,满足国标公众照射限值0.4W/m2的要求,并提出移动通信基站选址需要考虑的问题。     

Influence of a 1,800 MHz electromagnetic field on the EEG energy

The present study investigated the influence of electromagnetic fields (EMF), similar to that emitted by mobile phones, on brain activity. Ten women and ten men, matched for age and educational level, performed a short memory task (Wechsler test), with simultaneous Electroencephalogram (EEG) recordings at 15 scalp electrodes, both without (baseline) and with exposure to an 1,800 MHz signal. The EEG energy was found concentrated at the four basic EEG bands [α (8–13 Hz), β (14–30 Hz), δ (0–4 Hz), and θ (5–7 Hz)]. The analysis revealed that in the presence of EMF, the energy of the β band was significantly greater for females than for males at the majority of the electrodes. Since beta oscillation is associated with the shift of attention during the perception, these findings may indicate that the particular EMF (1,800 MHz signal) exerts an influence on this brain activity, which appears to be gender-related.     

Mutual interactions in bioelectromagnetics

This paper discusses mutual interactions phenomena especially in the case of Transverse ElectroMagnetic (TEM) cell applications as an exposure system in technical and biomedical studies. In many publications is described problem of influence of an object upon the electromagnetic field (EMF) distribution inside a exposure system while inverse effect—influence of exposure system on tested object is overlooked. The problem plays primary role if a correlation between investigations carried out in an enclosure (e.g. TEM cell) and that in the free space is looked for.     

Subcutaneous Arteriolar Vasomotion Changes During and After ELF-EMF Exposure in Mice in Vivo

Summary Biological effects of extremely low-frequency electromagnetic fields (ELF-EMF) on microcirculation were investigated in vivo by monitoring arteriole diameters in conscious mice. Measurements of blood vessel diameter were monitored 33 min non-stop before during and after exposure with ELF-EMF and every 389 ms blood vessel diameter were calculated. Using a dorsal skinfold chamber (DSC), and following caudal vein injection of FITC-dextran 250 kDa, the microvasculature (initial arteriole diameter of 45–80 μm), was examined by intravital microscopy and video images were recorded for a total time of 33 min. Arteriole diameter was continuously measured by on-line analysis using a High-speed Digital Machine Vision System CV-2100, using an edge-gap detection algorithm. Since vessel diameters exhibit rhythmic variation expressed by vasomotion, for estimation of microcirculatory activity we used both raw data for frequency analysis of vasomotion (measured frequencies of vasomotion were in the range 0.008÷0.1 Hz) and evaluate mean blood vessel diameter for each 1 min period of time, and make a comparison between Pre, Exposure/Sham exposure and Post exposure periods, with the aim to evaluate possible changes in mean blood vessel diameter as a result of ELF-EMF action. During EMF exposure and post-exposure periods, arteriole diameters increased significantly compared with the pre-exposure period, and the changes were larger during post-exposure. In contrast to sham exposure, vasodilatation of the microvasculature was significantly greater during exposure and post-exposure to 16 Hz EMF. These findings suggest that ELF-EMF may have potential therapeutic use benefit for treating vascular disorders.     

Interlaboratory comparisons in EMF survey measurements

This article presents methods and results of interlaboratory comparison in the electromagnetic field (EMF) survey measurements performed by Electromagnetic Environment Protection Laboratory. Based on the results, the author analyzed factors affecting the precision of EMF measurements, in particular—difficult to estimate—the “human factor”. In practice, the human factor has never been taken into account in the EMF measurements accuracy estimations budget, and the author estimate the importance of this factor that may include even up to half of the total uncertainty of measurements. Taking into account all factors depredating the accuracy of measurements, the uncertainty of the survey EMF measurements was estimated at the level of 2–4 dB.     

Study of high-frequency electromagnetic field effect on some somatic and neuro-behavioral characteristics in healthy and neurodefective mice

The effect of long-term exposure to high frequency electromagnetic field (HF EMF) on some somatic and neural characteristics was studied in neurodefective Lurcher mutant (+/Lc) and normal wild type mice (+/+). Both newborn and young adult (3 months) animals derived from two strains (C3H, B6CBA) were exposed to HF EMF (870 MHz) from 1st to 21st day or from 91st to 120th day respectively. In animals of both groups and controls we observed the development of body weight. Moreover, in the HF EMF exposed adult B6CBA animals we studied spatial learning ability, motor functions and the CNS excitability. To investigate specific energy absorption rate (SAR) in experimental animals we have done the basic 3D calculations of the electromagnetic energy distribution in the simplified model of the mouse. The HF EMF exposed animals exhibited mild differences of body weight between them and unexposed controls. The long-term exposure to HF EMF did not significantly influence the ability to learn in the Morris water maze. However, significant lower swimming speed was found in the irradiated +/Lc as well as lower motor activity of +/+ in the open field when compared to controls. No significant differences were found between HF EMF irradiated animals and controls in examination of the CNS excitability and motor functions.     

Waste Management in the European Union: National Self-Sufficiency and Harmonization at the Expense of Economic Efficiency?

/ Since 1975, the European Union (EU) has developed an impressive body of waste management legislation, although, according to the principle of subsidiarity, responsibilities belong to the most local level at which the tasks can be carried out effectively. Using economic theory, this paper examines several factors that influence the efficient distribution of regulatory authority among the EU and the member states. We specifically analyze the role of harmonization that, in our opinion, will often lead to an overcentralization. Within this context, a second issue is becoming more important, as ongoing discussions show. If no consensus can be reached about harmonization, should member states be allowed to stop cross-border shipments of waste, or should the EU strive for a common market for waste? We take the position that most objections against waste shipments are not convincing, especially if the member states implement minimum standards for landfills and waste processing facilities and common information and control systems. Competition between different national regulations within adequate constraints that, e.g., control transboundary externalities leads to more efficient waste management structures in Europe than national self-sufficiency or centralized decision-making at the EU level. KEY WORDS: Waste management; European Union; Subsidiarity; Institutional competition; Harmonization; Cross-border shipments of waste