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Review The Effect Of Extremely Low Frequency Electromagnetic Field To Public Health By Anand Mohan Paul ABSTRACT: This article has been composed in consultation with various internationally recognized documents prevailing in this context and meant for general public reading and cognizance. Through the article, it is envisaged to provide an overview of extremely low frequency (ELF) Electromagnetic  field (EMF) and its effects to human health by illustrating the fundamentals pertaining to ELF Electromagnetic  field with respect to the overall frequency spectrum, identification of  ELF Sources &its exposure level, measurement technique,  recommended  safe exposure limit, adverse affect of exposure to Human health etc .It has also been exercised to demonstrate the protective measures to be undertaken in compliance with the recommendation  put forward by  world health Organization( WHO) to avoid adverse human health hazard from excessive exposure. Few references have been furnished at the end  of this article for further reading pertaining to the various aspect of ELF Electro-magnetic  field / Radiation. ELECTRO-MAGNETIC SPECTRUM Electro-magnetic spectrum is a continuous pictorial presentation of entire frequency / wavelength of Electro-Magnetic wave. The continuous spectrum is sub divided into various frequency/ wavelength zone based on their application in various field like domestic, industrial, scientific, medical etc. The various parts of the spectrum are designated in the diagram based on the frequency range as well as their application.

DIAGRAM: •	Static field                        :  This field is static in nature and is not related to the wave. •	 0 HZ to 10 3 HZ         :  Extremely Low Frequency wave which includes electromagnetic wave   related to the Electricity either 50 / 60 HZ and its various harmonics •	10 3 HZ to 10 5.5 HZ         : Very Low Frequency Wave •	105.5 HZ  to 10 8.5 HZ       : Radio wave where AM and FM radio signal operates as wireless Signal •	10 8.5 HZto10 12: HZ     : Micro-wave signal which is used in microwave heating and microwave communication •	10 12 HZ to 10 14.5 HZ     : Infra Red wave which is used for heating, ON/ OF control etc. •	  10 14.5 HZ  to 10 15 HZ     : Visible Light •	101 5 HZ to 10 17.5 HZ       : Ultra violet Light •	10 17 HZ onward              : X-ray, Gamma Ray etc. All the above mentioned waves are not capable to ionize the atom by breaking the chemical bond. Based on the ionizing capability, wave of frequency range 10 15 HZ and higher    has been proved for having  the capacity to break the chemical bond between atoms to produce ions which  cause a radical change in the material. It is also proved that as higher the frequency of a wave, higher is its ionizing power. Based on ionizing characteristics Electro-magnetic waves having frequency 1015  or more are termed as ionizing wave where as frequency less than 1015 is termed as Non –ionizing wave.

FUNDAMENTAL OF EXTREMLY LOW FREQUENCY ELECTRO - MAGNETIC FIELD (ELF-EMF) The ELF electromagnetic field is created when an alternate current (A.C) is passed in a conductor which is the result of the movement of electrons through a conductor. The A.C electric current in turn produces two types of field a)	A.C Electric field b)	A.C magnetic field The A.C electric field arises from electric charges when accumulates on an object and creates a tendency to be repelled or attracted by other charges. The A.C electric field represents the force that electric charge exerts on other charges. This force may either attractive (If the charges are opposite in nature) or repulsive (as for the similar type of charge). The electric field (attractive and or repulsive) is measured in Volt/meter. A.C magnetic fields arise from the motion of electric charges i.e. current; the motion of moving a charge... The A.C magnetic field forms  a closed continuous doughnut shaped loop around the current and radiates at a right angle to the direction of current... The strength of .A.C magnetic field is measured in units of ampere turn which is usually expressed in terms of the corresponding magnetic induction measured in units of Tesla (T). In some countries, another unit i.e. Guess( G) is commonly used for measuring magnetic induction. These two units are related by 1 Gauss = 100 micro –Tesla. This electro-magnetic field travel as a wave at the speed of light, characterized   by frequency and wavelength. Considering the frequency of normal A.C electricity (50 /60 HZ) and its various harmonics, this electro-magnetic wave is included at the lowest frequency part of electro-magnetic spectrum which is designated  as ELF wave. This 50/60 HZ frequency is originated at the electric power generating station and ends up in our house hold appliances, utility plant equipments etc.. Higher voltage changes the strength of the field but not the frequency or wavelength as the wave always travels with the speed of light ,irrespective of its value. The radiation due to electromagnetic wave is termed as EMR( Electro-Magnetic radiation) while the electro-magnetic field is termed as EMF. EMF or EMR are similar terminology ,generally refer to the entire range of electro magnetic spectrum from ELF to x Ray/Gamma Ray. However the terminology EMF is used more often than EMR because radiation sounds scary and its use for low frequency region may create confusion with more dangerous radiation like X-Ray/Gamma ray. In general article written for general public reading, EMF is used loosely to indicate the low frequency electro-magnetic field coming from power lines, power equipment, home wiring, home appliances , T.V, Computer monitor etc. EMF METER AND MEASUREMENT OF ELF EMF An ELF EMF meter is a scientific instrument for measuring ELF electromagnetic fields which are usually emitted from man-made sources such as electrical wiring, power lines, Electrical home appliances,  Various electrical equipment at power station, electrical substation, utility plant  etc.. Most meters measure the electromagnetic field / radiation by measuring separately electric and magnetic field. Some of the meter can also include to measure RF radiation and is termed as tri-field meter. There are many different types of EMF meters, but the two largest categories are single axis and tri-axis meter. Single axis meter only measures one dimension of the field and the axisof the instruments have to be tilted and turned on all three axes to obtain a full measurement which takes the longer time to complete a survey. A tri-axis meter measures all three axes simultaneously, but these models tend to be more expensive. K-2 meter is an EMF meter that uses flashing lights to signal an increase in electromagnetic field energy. The majority of EMF meters are suitable for operation in the frequency range 1 HZ to 1000HZ and could be extended up to 1 MHZ, However ,as most of the electromagnetic fields encountered in everyday application are generated by household or industrial appliances/equipment, operating at 50 /60 HZ alternating field, the majority of available EMF meters are calibrated to 50 or  60 Hz alternating fields. The electric and magnetic field range which could be made available in the common available meter are 1-5 kv /meter and 10 Micro Gauss to 1 gauss respectively and accuracy in the range of 2 to 5%. ELF EMF SOURCE AND INTENSITY IN& AROUND HOME /WORK PLACE Electromagnetic field spectrum is divided into ionizing and non ionizing zone. Frequency spectrum 10 15 HZ Upwards is considered ionizing spectrum and special human safety and precautions are already in place for handling and working in that frequency. However this review study is concerned for the non ionizing area which is below 1015 HZ and particularly important for extremely low frequency (up to 103 HZ) range  where most of our electrical power related equipment and utilization are concerned except telephone and communication system which are working in the range of 105 to 107 HZ. The entire electromagnetic field prevailing around us are created either naturally or by man made. Natural source of EMF are earthen magnetic field, sunlight etc. where as man made non ionizing sources are generated by current carrying power equipment ( like electric generator, Transformer, Switchgear / switchboard. Power distribution  equipment overhead lines ,electric train, tramways etc) house wiring, , daily house hold electrical appliances( like Hair dryer, Television, Micro-wave, Washing Machine, kitchen equipment, Vacuum Cleaner, , electric razor, electric clock, electric blanket/waterbed, fluorescent light etc. If It is considered the overall average EMF in and around us, it could be concluded that we are in  a bath with the weak EMF  , a major part of which are originated from various man made electrical and communication equipment intended to use for modernization of life and  this man made weak EMF  is rapidly growing due to the contribution by mobile phone network and other various modern electrical equipment/appliances which are big concern to the international community considering the adverse effect to human health. The interaction capacity of any electro-Magnetic wave with biological organization depends on the content of energy and frequency. Any living body particularly human bodies are transparent to some frequency but not all. For example sunlight can penetrate skin deep and is mostly absorbed due to which sun screen cream is used to protect skin from strong sunlight whereas magnetic field can largely pass through the human body. Due to the above reasons and to avoid the health hazard of living body particularly human being from non ionizing EMF exposure, International Research Organizations undertook various project at different times in order to estimate the safe limit of EMF exposure and one of the pioneer i.e. International Commission of Non Ionizing Radiation Protection ( ICNIRP) has provided a guide line for the maximum exposure limit of extremely low frequency electric and magnetic field in our normal living and work place. The same recommendation forms the basis for current European Union exposure limit. .ICNIRP Guide line is given below: 1)	Electric field strength at a distance of 30 cm from the source : 5 kV / Meter 2)	Magnetic field strength at a distance of 30 cm from the source : 100 Micro-Tesla However, most stringent guideline has been recommended by EPA ( Environment protection Agency) and is followed by few governments. EPA recommended magnetic field exposure limit 3mG ( 0.3 Micro-Tesla) whereas Swiss and Sweden Government follow the limiting value 1 Micro-Tesla and 0.1 Micro Tesla respectively. The ELF electric and magnetic field stress expected from various house hold electric appliance at a distance of 30 cm are tentatively as follows Item Description                                   Electric Field                   Magnetic Field Volt / Meter		      Micro-Tesla Electric Oven				         10				25 Toaster					80				30 Electric Iron					120				20 Vacuum Cleaner				50				15 Electric shaver 				10				30 Micro-wave oven				150				8 Fluorescent Lamp 				100				20 Hair Dryer					80				25 The above figure is tentative only and can vary based on equipment enclosure, leakage protection etc. Accordingly in order to decide the exact exposure at a particular point /Area in our living or working place from the various daily use ELF EMF Source as well as due to the various installed electrical power equipment, it is always recommended to measure the average electric and magnetic field and overall EMF  strength using  tri-axis EMF field  meter and the measured figure shall be compared with the most stringent guide line , recommended by the international organization of repute for deciding the exact course of action. EFFECT OF ELF EMF ON PUBLIC HEALTH With the development of social living condition, the use of electricity which is within ELF (50/60 Hz and its harmonics ) has become an integral part of everyday life and can not be separable. Consequently effect of this ELF EMF exposure to public health has raised a big concern considering its adverse effect. Various international organization like world health organization ( WHO),International Agency for research on cancer ( IARC), International commission on non ionizing radiation protection ( ICNIRP), EPA  have starter research work to investigate the said adverse effect due to ELF EMF exposure  and several project have been executed by the various authorities including the above organization and volunteers. Even WHO established special task force group in 1996 to investigate the potential health risk associated with the emitting EMF and the same task force concluded a review pertaining to the health implication of ELF field in 2007 as follows: There is no substantial health risk associated with the exposure of ELF Electric field generally encountered by people in normal living and working area. Available evidence suggests that apart from simulation arising from electric charge induced on the surface of the body, the effect of exposure  up to 20 kV/meter are few and innocuous. Electric field has not shown  any effect on reproduction or development in animal at strength even at  100 kV/meter. However the effect of magnetic exposure of electro-magnetic field  could cause health hazard depending on the magnitude of exposure. Hence the overall effect is determined mainly by the magnitude of magnetic exposure and the duration of the same which has been illustrated below based on short term effect and long term effect. •	Short term effect of acute exposure As per task group investigation report, there is a substantial biological effect from acute exposure at high level (> 100 Micro Tesla). The external ELF magnetic field induces electric field and currents in the body which at very high field strength cause nerve and muscle stimulation and change in nerve cell excitability in the centre nervous system. Volunteer exposure of ELF magnetic field to 5000 Micro Tesla has proved a little effect on number of clinical and physiological tests including blood pressure changes, ECG, heart rate, body temperature etc. Some investigation has been reported that acute exposure of ELF magnetic field may suppress secretion of melatonin, a hormone connected with our day night rhythms. Suppression of melatonin can also contribute to an increased incidence of breast cancer as it is suggested that melatonin might be a protective hormone against breast cancer. There is no direct convincing evidence that exposure of ELF magnetic field cause direct damage of biological molecules including DNA. It is thus unlikely that they could initiate the process of carcinogenesis. Some scientist believes that acute exposure can increase the rate of cancer Leukemia etc. However the subject is under study by various organizations including WHO to determine and confirm if ELF exposure can influence cancer promotion or co-promotion. In 1979, Wertheimer and Leeper reported an association between childhood Leukemia and wiring connections at their homes to the electrical distribution lines. Since then, a large number of studies have been conducted to follow up this important result. On further analysis of this paper, US national Academy of Science suggested in 1996 that residence (especially child) near power lines are associated with an elevated risk of childhood leukemia but not with other cancer. Similar result has been found by various volunteer studies particularly with the people who are in High Voltage and Extra High Voltage electrical occupation and it is shown the similar type of biological changes take place in them with the course of time. The list of changes are more which also includes time of visual motor reaction, skin temperature, content of blood glucose, decrease of TPI ( Total Prognostic Index), connected to male sexual function, mental fastness, decrease in adaptation possibility of cardio vascular system etc. Various Volunteer studies have highlighted  the risk on human health from occupational exposure, but for rigid and confirmed result it needs further investigation which is underway. •	Potential Long Term Effect Most of the scientific research examination on long term risk from ELF magnetic field exposure has focused on childhood leukemia. In 2002, IARC published a monograph classifying long term exposure of ELF magnetic field as “Possibly Carcinogenic to Human.” A larger number of other adverse health effect has been studied to determine the possible association with long term exposure of ELF magnetic field. This includes childhood cancer, cancer in adult, depression, suicide, cardiovascular disorder, reproductive dysfunction, development disorder, immunological modification, neuron behavioral effects etc. WHO task force concluded that scientific evidence supporting an association between long term ELF magnetic field exposure and all the above health effect is much weaker than childhood Leukemia.. However various volunteer studies do not support Task group recommendation and strongly believe for  an association of long term exposure of ELF Magnetic field with  the above health effects. The US National Institute of Environmental Health Science (NIEHS) through their international panel concluded in 1998( after completion of 5 year RAPID program, using criteria established by the IARC ) that ELF field should be considered as “POSSIBLE HUMAN CARCINOGEN”. This decision of NICHS working group was based mainly on the appearance of consistency in epidemiological studies and suggested that residence near power lines are subjected to an apparently high risk of Leukemia in childhood. Working group also found limited evidence for an increased occurrence of Chronic Lymphocyte Leukemia (CLL) in the occupational group CONCLUSION AND RECOMMENDATION With due attention to the various observation, analysis, report etc established through the research evidence of various reputed international organization as well as volunteers, it is highlighted  that  high level short term exposure of ELF electro-magnetic field could have an adverse health effects. Accordingly International exposure guideline has been designed (ICNIRP 1998, IEEE 2002) to protect public and the worker particularly professional involved in electrical installation, operation and maintenance work. The same exposure guide line shall be strictly adopted by policy maker. It is highly recommended in compliance with  ELF EMF protection program to measure the exposure from various sources where co- existence of ELF EMF emitting equipment and people /public is possible to decide further course of protection action. As current scientific and accepted information is only weakly suggestive and does not establish a rigid evidence  on a  long term exposure of ELF field at levels normally encounter in our living environment and adverse health effect particularly childhood Leukemia, the benefit of further exposure reduction on health is unclear. However it is evident that there is a knowledge gap and uncertainty of the scientific evidence towards the exact adverse health effect of the long term exposure. Several International EMF projects are ongoing and the objective of the EMF project is to help national authorities/Utility companies by identifying the detrimental effect of human health and to decide what protective measures are needed. It will take few years to complete the required research and evaluation for publication by WHO. Till that time and to avoid the danger of ill effect ( If any) of the exposure  to public ,WHO has  recommended the followings: 1)	It is highly recommended that the ELF Field exposure condition of any existing facilities shall be measured to identify the requirement for   protective measures. 2)	   Strict adherence to existing national or international safety standard for the exposure limits which is based on the current knowledge to protect every one in the population. 3)	 Large conduction object such as metal fence, barrier or similar metallic structures permanently installed near high voltage electrical installation/transmission line shall be grounded. 4)	  Avoid parking car, truck or any heavy metal body temporarily or permanently under or very near to the high voltage power lines. 5)	 Provide fence or barrier around strong ELF magnetic field source( Like Transformer, Reactor, High current and harmonies producing power electronics devices etc) to preclude unauthorized access to high exposure area. 6)	Close consultation with local authority and public for installation of  new power lines, electrical utility  despite the exposure limit may not be in danger. Open discussion and communication between electric power utility and the public during planning stage can help public understanding and greater acceptance of  the  new facility. 7)	An effective system of health information and communication amongst scientist, government bodies, industry and public shall be established which can help to raise general awareness program to deal with ELF exposure and reduce any mistrust and fear. 8)	Government and Industry should monitor the development of science in the field and promote research program to further reduce the uncertainty of the scientific evidence on the health effects of ELF field exposure. 9)	Member state are encouraged to establish effective communication program with all stake holders to enable decision making, improving co-ordination, consultation among industry, local government and citizen in the planning process of ELF emitting faculties. 10)	During construction of any new electrical facility and designing new electrical equipment including appliances, low cost ways of reducing exposures may be explored. 11)	In case of strong magnitude of ELF field, the only protective measures available is to limit the personnel access by maintaining distance considering field strength of concentrated coil equipment diminishes with the distance cubed ( 1/d 3) 12)	 Cardiac pacemaker or any implanted electro-mechanical devices are subjected to electro-magnetic interference (EMI) due to strong ELF field. Individual should contact with the doctor or manufacturer for the exact effect. WHO urges manufacturer of these devices to make them less susceptible to EMI. Further reading 1)	WHO -. Extremely low frequency fields. Environmental Health Criteria, Vol. 238.Geneva, World Health Organization, 2007. 2)	IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Non-ionizing radiation, Part 1: Static and extremely low-frequency (ELF) electric and magnetic fields. Lyon, IARC, 2002 (Monographs on the Evaluation of Carcinogenic Risks to Humans, 80). 3)	ICNIRP -. Exposure to static and low frequency electromagnetic fields, biological effects and health consequences (0-100 kHz). (ICNIRP 13/2003). 4)	ICNIRP –  Guidelines for limiting exposure to time varying electric, magnetic and electromagnetic fields (up to 300 GHz). Health Physics 74(4),494-522. 5)	IEEE Standards Coordinating Committee 28. IEEE standard for safety levels with respect to human exposure to electromagnetic fields, 0-3 kHz. New York, NY, IEEE - The Institute of Electrical and Electronics Engineers,2002 (IEEE Std C95.6-2002) 6)	Repacholi M and Greenebaum B (1998): Interaction of static and ELF electric and magnetic field with living system. 7)	NIEHS (1998) : Assessment of health effect from exposure to power line frequency electric & magnetic field ( Portier C.J and Wolfe MS ( eds), NIEHS working Group Report. 8)	Man Health and Hazard in the Electrical Environment : Cyril W. Smith & Simon, Best St. martin’s Press Inc. 1989 About the Author : The Author of this article, Mr. Anand Mohan Paul, is a Professional Electrical Engineer having engineering experience more than 20 years in the electrical system design  for Oil & Gas industry, Coal Based / Gas based  thermal power plant, H.V and EHV substation etc,. Mr. Paul has completed his Master degree in electrical engineering, specialization with  Electrical Machines and Power system from University College Of Science and Technology, Calcutta University, India. Presently Mr Paul is   working with ADNOC Group company where he has been appointed  since 1998.