Health Hazards from ELF fields
A number of years ago (1970s decade) an awareness and concern about the effects of power frequency EMFs arose. For a number of years it had been known that electrical workers that were in close proximity to very strong magnetic or electric fields sometimes "saw" flashing lights or patterns that were supposed to be due the action of these fields on the nervous system. This was obviously evidence of the fact that EMFs could have some direct effects on a hunan directly, but little attention was paid other than as a curiosity. A blow on the head, an electric shock , or even a momentarily painful sensation such as stubbing a toe would similarly cause a person to "see stars". So this effect of the fields was probably dismissed as in significant. After all the nervous system is known to operate with elec- trical currents, and it was logical to expect that strong EMFs could induce currents in the nervous system, and these would in turn act as stimuli of some kind, producing these visual effects. Life evolved in an environment where some magnetic and electric fields were always present. The earths magnetic field might be used by birds for navigation over oceans, out of sight of land, or during overcast nights in which star patterns are not visible. Electric eels use electric fields for sensing their surroundings as well as for stunning their prey. The point is that some animals may have evolved organs to use these naturally occuring EMFs for sensing. No one thought, for a long time, that weak EMFs had any effect on the human body. Then, it was noticed that some electrical workers and other people exposed to EMFs apparently were having certain types of health problems. These problems, whether real or imagined were occuring at a greater than average frequency than would normally be expected, when compared with statistics from the general population. These problems ranged from fatigue and minor headaches to cases of cancer and heart attacks. However, the correlation was found to be weak or non existent when studies were made. Some studies claimed a definite link, others revealed none. There were contradicting results, and the studies were largely discredited. However, a nagging doubt remained. In the 1970s, electric power had been used for barely four generations, but in the years before WW2, it was not uncommon to find homes without electricity, especially in rural areas. The postwar years brought explosive use of electrical power with the appearance of many new appliances that generated kinds of EMFs that were never encountered before in the home or office. TV sets, flourescent lighting, computers, microwave ovens, electric blankets, and many other gadgets "we couldnt live without" that were nonexistent a generation ago, appeared in the home. Few were aware of or even thought that the 60 Hz and 120 Hz AC fields from electric clocks, hair dryers, and flourescent lighting ballasts would be a problem. Higher frequency fields of 15-50 KHz generated by video displays, compact flourescents, or switching supplies were generally not considered. Today the average home or office is literally full of these field producing devices. While the jury is still out on the biological effects of these fields on the human body, there is still sufficient evidence, both observed and anecdotal, that may be significant. It might be wise to take at least some precautions to try to minimize the production of these fields in new designs, and to check existing equipment for the presence of EMFs. However, one should not go overboard and become an alarmist or scaremonger. Actually, many of the EMFs generated by appliances and computers thought to be possibly hazardous are magnetic in nature and disappear when the equipment is switched off. The practice of simply turning off appliances when not in use would be sufficient. For example, do not leave on computers when not in use. There is no demonstrated evidence that turning off a computer shortens its life. Yes, the semiconductors have to go through a warm up and cool down cycle but there is less wear on the fans and drive motors. Anyway, many computers today have a "green" feature which removes power from certain components (hard drives, etc) after so many minutes of keyboard or mouse inactivity. For every reason you should leave on the computer you can come up with a reason to shut it down. You might as well save electric ity, and energy conservation is not a bad idea. Furthermore, you will help to reduce the electromagnetic smog so prevalent in our environment today. This smog undoubtedly will become another environmental problem in the future, and is already a problem in our cities and crowded suburbs. The authors are old enough to remember that when AM radios were tuned between stations, you heard mainly light background atmospheric noise and distant stations, not a loud, raucous 60 Hz buzzing, and AM reception sounded quite good. Possibly this pervasive racket has contributed to the decline of AM and shortwave radio. In fact, the RF levels of this smog might get bad enough to be hazardous just by themselves. Someone might even dig up statistics to scare the hell out of everyone, write a book about it, and get rich and famous. With too many people today getting much of their science education from mind numbing TV programs, pseudoscience and gullibility reign. As a matter of fact, magnetic jewelry and bodywear is popular and commonly sold at your local mall, and is said to cure many ills. The steady magnetic field produced by permanent magnets is claimed to do this. The notion that time varying magnetic fields are the "bad guys" is currently in vogue. However, if you look at the equations of field theory, time variance of the fields is not the only way currents are induced in objects. If an object is moved in a steady magnetic field, a current will be induced in it. As we move about our planet, we are moving in the earths magnetic field. This is about 0.5 gauss, 100 times stronger than a 5 milligauss time varying field, a level some would claim is hazardous. Yet, we do not all move at a steady pace. The instantaneous velocity of various parts of the body vary when walking, doing tasks, or even from nervous tremors will have some "AC" components. These can be broken down into sinusoidal components, just like an electrical waveform can be broken into a series of sine and cosine waves. A body vibrating at 60 Hz will have a 60 Hz component induced in it, and this applies to any frequency of vibration. This is also the principle of a dynamic microphone. So the argument that the earths steady magnetic field does not cause any harm due to the fact that it cannot induce any current in the body may not be truly correct. True, the frequencies are lower than power frequencies, but it is not known if the frequency of the induced voltages and currents is a factor. Remember, the motion of any body in a steady magnetic field can have the same effect as a time varying field on a non moving body. If this were not true every loudspeaker and dynamic microphone in existence would be in big trouble.
The exact mechanism by which EMFs cause damage to cells of living organisms is not really known, except for the obvious destruction by electrolysis, or heating from resistive losses. Pseudoscientists and fanatics claim all sorts of reasons, some pretty dubious.The induced currents from weak (<1g) magnetic fields are not high enough to cause this heating. It is possible that the induced currents and voltages may in some way interfere with the transmission of nerve impulses, or in the mechanism of cell division, ion transport across cell structures that occur during chemical reactions, or maybe DNA damage that could lead to uncontrolled growth of tissues, loss or damage of immune system functions, and other ways not yet determined. There is no definite evidence as of yet that has been reproducible, predictable, or in any way definitely conclusive. One study claims no correlation at all while another by an equally competent group or organization shows definite results. A definite cause and effect result has not been demonstrated. For a good test, it would be necessary to take a large enough group of people of all ages, preferably a good mix representative of a cross section of humanity, to eliminate any possibility of genetic bias and split it into two groups. One group would be the control group and have little or no exposure to EMFs. The other would be exposed to controlled levels for a periods of time. Medical checkups on all participants would be conducted at intervals and at the end of a period of time the differences in incidence of diseases, etc. between the control group and the group exposed to EMFs could be studied. Then the experiment could be repeated several times. Then possibly valid conclusions could be drawn. But, this is obviously inhuman and unethical for any society that considers itself civilized. So we would have to use laboratory animals. An experiment like this would probably take years and animal results may not apply to humans. So we may have to rely on studies and case histories and never really get a true cause and effect result where we can determine with reliability the existence of the problem, and safe exposure levels in case the EMFs are really hazardous.
An interesting news item surfaced during the writing of this article. An article appeared in the New York Times on July 24 1999 that had a headline stating "Data tying cancer to electric power found to be false". This broad sweeping generalization would lead those readers prone to knee jerk reactions to conclude that all data found so far is false. They might not even bother to read the rest of the article. What actually happened was that two papers published by one scientist were biased, by the elimination data that did not support his conclusions. It is a pretty safe bet that in the near future another study will refute this, with data to back up the claims that EMFs are in fact hazardous. What is needed is to examine all these things objectively. First, suppose that EMFs were scientifically proven to cause problems. A lot of big money interests would get hurt. New restrictive legislation would eventually get passed requiring shielding, modifications to existing equipment, severe restrictions and code requirements on power line placement, and many other nightmares for big money interests. Just think of what could be. New wiring codes, mandatory relocation of power lines, even condemnation of some buildings, such as factories, schools, offices, shopping malls, and who knows what else. Power companies would surely like this problem to vanish and the critics to dry up and blow away. It could be quite expensive to upset the status quo. And dont think it is above big business to cover up and lie about hazardous things to the public. It is often a sad fact that it is cheaper to let a few people die and simply pay off the victims families, in or out of court, than to fix the problem. Witness the auto and the tobacco industries, for starters. And governments have lied to the people throughout history as well. So therefore, form your own opinions and dont always believe what you may hear. And do not believe the fanatics, pseudoscientists, and other nut cases either, they have even less basis in facts. The fact is that quite a few studies have been done that claim to have definite proof either way and the jury is still out..
The following discussion will mention some of these studies, observations, and claims. References will be given at the end of this article for further reading. It is impossible in this article to go into any details of these studies, as space does not permit. However, several websites will be mentioned where inter ested readers can go to, and from these sites many other links can be found. The amount of information is enormous and often conflicting.
In 1972, some reports came from the Soviet Union that referred to various health problems noted among those exposed to EMFs. These problems were not generally serious, being fatigue, headaches, and general malaise. Then, in 1977, Dr. Robert Becker and Biophysicist Andrew Marino testified before the New York State Public Service Commission about some experiments that were made on the effects of low frequency magnetic fields on health. Two years later epidemiologist Nancy Wertheimer and physicist Ed Leeper published a study that showed a link between some childhood cancers and power line proximity to homes. A 1982 study in Washington State showed that leukemia rates were elevated in 10 out of 11 occupations studied where workers were exposed to low frequency EMFs. In 1988 a Maryland Department of Health and Hygiene study noted a higher than normal rate of fatal brain cancers in men employed in electrical occu pations. Johns Hopkins University found in 1989 an elevated cancer risk in New York Telephone Company cable splicers. But, the articles in New Yorker Magazine and the books by Paul Brodeur appearing in the early 1990s probably were the ones that caught the attention of the public. A study in 1991 in Los Angeles found significant associations between childhood leukemia, which is a form of cancer, and power line proximity. Studies in Mexico and Sweden in the 1992-1993 period also showed increased incidence of leukemia in children that lived close to power lines. Studies made in Denmark in 1993 found an association of increased incidences of childhood cancers with power lines, but not specifically leukemia. A Finnish study found an association with nervous system tumors in boys. There were eight studies made examining cancer risk for adults living near power lines, two of which found significant risk. Facts concerning these studies can be found at the website of Information Ventures Inc., also the National Institute for Occupational Safety and Health (NIOSH), and these sites have links to many other sites.
As mentioned before, no exact cause and effect relationship has been yet shown, nor have any exact levels been established. This is true of a lot of things in everyday life, such as social issues, global warming, the taking of vitamin supplements, where definite cause and effect answers are not available, only trends and correlations that are indefinite and subject to questioning. Answers to many of these questions probably will not be available in the lifetime of anyone alive today, as long periods of time are needed to obtain statistically sufficient amounts of data for reasonably valid answers. In some cases a great many factors are involved that must be considered in arriving at a conclusion. In light of these facts a "play safe " approach may be the best course of action. By this it is meant to take the action that based on best available knowledge, (which may turn out to be incorrect), has the fewest risks and/or greatest rewards. However, remember that you could be wrong. In the case of the EMF question there are several approaches that could be used which would reduce exposure yet not impact too severely on your lifestyle. These approaches might reduce energy consumption, lower your electric bill, reduce electromagnetic smog, noise, and environmental pollution, and even improve your radio and TV reception. They will not be harmful or unsafe, and easily changed as needed. One test you can make very easily in your own home: Take a small portable AM radio and tune it to a frequency below 550 KHz where no station is received. You should hear just a hiss or light crackling noise due to atmospheric static. If you hear a buzzing, hum or raspy loud noise sounding like frying bacon, you have some work to do. Much equipment that generates possibly hazardous EMFs also generates enough harmonic energy at AM radio frequencies to be easily detectable on an AM radio as noise. Passing this test is no proof tha there are no strong fields present, as it will not detect magnetic fields, but a failure almost guarantees that there are. Most homes in suburban or city areas will fail this test. Further investigation requires a field meter.
If you build the field meter kit offered on this website, you will be able to find many of the sources of these fields in your home or office. Unless you own the business, you probably will not be able to do very much about fields around the office. However, you certainly can correct some situations at home. By snooping around, you can find the sources of these fields, often in very unexpected places. A list of some offenders found in one of the authors homes is shown below. This is not meant to be a complete list, just what we found:Magnetic field sources: Flourescent lamp ballasts Hair dryer Appliance timers (Plug-In wall type) Electric clocks 120V AC Wall Transformers and Plug in chargers Compact flourescents (Electronic ballasts) Microwave oven (No surprise) Electric range Stereo Receivers TV sets Computer Monitors Almost any remote controlled appliance Telephone answering machine Copier Fax Machine Electronic test equipment - Scope, Bench Power supplies, etc. Electric field sources: Table lamps Heating Pads TV sets Computer Monitors Flourescent Fixtures Compact flourescents Almost anything plugged into 120V outlet even if turned off. Telephone wiring Electronic test equipment - Scope, Bench Power supplies, etc.
Naturally, house wiring especially around the service entrance is also included. In practice, electric fields are easier to reduce or eliminate. However, they are present around anything with 120 or 240V connected to it, even if turned off. This is because the hot lead of the 120V line is brought into the device and connected to a switch. There is some capacitive coupling to the device or appliance housing and anyway the 6 or 8 foot cord is a good "radiator" if plugged into an outlet. A grounded case using a 3 lead cord will reduce the level of the electric field, but many common small appliances such as table lamps and clocks use a two wire cord and any metallic parts are left floating, depending solely on insulation. While this protects from electric shock, it does nothing for E field reduction. Many older appliances are still in use that have only a 2 wire cord. In addition, many individuals that live in older homes or apartment buildings that still have obsolete 2 prong AC outlets. These people often cut the grounding pin off 3 prong plugs on their appliances so they will fit the old 2 prong sockets. This dangerous practice is quite common. There is no protection at all against E fields in this instance. The best way to reduce electric field exposure is to unplug appliances not in use. However, this is not very practical in the case of frequently used appliances such as table lamps or where furniture must be moved to gain access to a wall outlet. Cords can be kept as short as possible by coiling up excess length. 3 wire grounding cords can also be installed on appliances with metal parts in some cases. In addition, cords can be routed away from areas that are occupied for long periods of time, such as beds, desks, and chairs.Magnetic fields can be reduced or eliminated by turning off power to the offending appliance. Magnetic fields at 60 and 120 Hz arise largely from AC current flow and if the current is zero there is no magnetic field. However, some of the worst offenders are items that are constantly energized, such as wall transformers and chargers (commonly called "wall warts"), appliance and light timers, bell transformers, and 120V clocks. Another source of magnetic fields are so called "leaky" appliances. Leaky appliances" are those that consume some power even when turned off. Remote controlled devices such as TV sets, stereo receivers, fan and light controls, and other such items have to have their remote control receivers on at all times so a turn on command can be processed. In addition, "Instant on" TV sets popular several years back had the CRT filaments constantly energized in addition to the remote control receiver. Satellite receivers must have their RF components on at all times to collect authorization codes for their descrambler systems. Our satellite receiver (GI Videocipher II) runs quite warm even when turned off. Telephone answering and fax machines must remain on at all times to be able to receive incoming messages. In fact, attention has been called to the energy wasting characteristics of these appliances by some critics. It would not be surprising to find in the average home 100 watts of electricity used by appliances that are supposedly turned off. And these appliances have 60 Hz transformers that are constantly energized, generating magnetic fields.
Several things could be done in the average home to help this situation:
1) Make sure all appliances are properly grounded 2) Use power outlet strips with a master switch on all remote controlled equipment. Yes, you will have to give up the remote turn on function but the exercise might be good for you. It also makes it easy to unplug things during vacations or lightning storms. Your VCR clock can be fairly useless anyway, since power interruptions probably wipe out the the time settings, unless a backup battery is provided. 3) Do not leave "Wall warts" plugged in when not in use. They will last longer and not be burned out by power surges and lightning hits. 4) Get rid of light dimmers in your house. The high peak current spikes can generate more intense magnetic fields since the resistance of a cooler (dim) filament is lower, drawing high instantaneous currents. Your radio reception will improve as few dimmers are adequately RFI suppressed, with many low end bargain units having no RFI suppression at all. If you have track lighting or low voltage halogen lamps, be aware that some low voltage lighting use high frequency inverters to reduce weight and cost, powering the lamps with high frequency AC. This can radiate and produce EMFs much like a poorly shielded computer monitor. Use lamps that operate directly from 120 or 240V as applicable, so no transformers are needed. 5) Replace flourescent lighting in living areas and kitchens with old fashioned incandescents. They are generally easier on the eyes, have a more pleasant color that is preferred by many homeowners, and generate no RFI and very little EMF. No, they not very energy efficient so simply turn them off when not being used. However, the heat they generate is not always wasted, contributing something to heating the house in winter, reducing load on the furnace. You can make up some energy consumption with measures discussed in these paragraphs such as getting off your butt to manually turn on and off your TV set and VCR. Flourescent lighting does not like too much on-off cycling and the fact that energy consumption is lower encourages one to leave them on, constantly generating strong electric and magnetic fields. You will not see much difference in your electric bills. 6) Stay away from compact flourescents. They generate strong fields like regular flourescents, and dont seem to last as long as claimed, unless left on all the time. They are expensive, and the cheaper ones seem to fail prematurely, the electronic ballasts giving out from heat or power surges. They often do not work well at low temperatures (<0 deg C). You can buy 60W incan- descents for less than 25 cents (USA) that last for 1000 hours or more. This makes it hard to justify a $15 compact flourescent that maybe lasts 5000 hours (if the electronic ballast does not fail first at best, especially considering the EMFs and RFI they produce. This has been the experience and is the opinion of one of the authors. 7) Turn off computers when not in use, even for an hour. Not having a your computer on is good surge protection and will also protect against data loss and/or corruption in the event of power blips. 8) Replace electric motor driven clocks by quartz battery powered ones. They are just as accurate and dont have to be reset after a power interruption. and they generate negligible EMFs 9) Place monitors and TV screens at least 2-3 feet from viewing positions. Use a larger monitor if needed. Most of the newer monitors have improved shielding against EMFs 10) If you are building a new house, use metal conduit for all wiring if you can. Some codes require it in new construction. Also use metal rather than plastic boxes. Steel affords some magnetic shielding as well as complete E field protection. Install underground service entrance. While no protection against magnetic fields, it gets rid of E fields and an unsightly wire. Make sure wiring carrying heavy currents is kept as far as possible from areas that are occupied for long periods, such as bedrooms. If you are buying a home, avoid properties in proximity to high voltage power lines and power substations.
With the exception of the last paragraph, these measures are just prudent energy saving measures requiring only a little effort in time and a little sacrifice in convienience. The use of incandescent lighting is admittedly a step backwards in energy conservation, but it eliminates possibly hazardous EMFs from ballasts, and gets rid of the disposal problem and toxicity that accompany dead flourescent tubes. Ignoring health hazards to save energy is not very smart, as was learned the hard way when superinsulated airtight homes were built some years ago to save energy. The homes proved unliveable due to moisture and vapor buildup, severely polluting the air inside with toxic gases released from building materials used in these homes, as well as trapping all sorts of allergens and bacteria. A corollary here might be drawn with all of our modern appliances and gadgets we "must have" and the possibly hazardous fields they generate. In conclusion, it would be wise to minimize exposure to these fields by taking some simple measures to reduce their levels in the home if possible. Unfortunately, other sources such as power lines and industrial equipment will probably take some form of legislation to institute controls. This in turn will require valid data in the form of reasonable scientific evidence, which may not be available for many years yet. And just think, you likely will be one of the guinea pigs in the grand experiment, maybe a sad statistic as well. You might even make your big contribution to science on the autopsy table, by being studied after dying from a disease that is later traced to fields. Too late for you, of course. But, a few hours checking around your home with a field meter such as the field meter kit offered on this website can help you to avoid this possible fate. These checks will determine what measures you should consider.
A bibliography of articles for further reading is supplied at the end of this article. The authors would like to thank Mr Walter J. Hagen, WA2ALV, Librarian at Adirondack Community College, Queensbury NY for his valuable assistance and contributions in researching material for this article.
Bibliography of EMF Books and articles 1) The Great Power Line Cover-up By Paul Brodeur ISBN # 0-316-10909-6 Little, Brown & Co. 1993 2) Annals of Radiation - The Calamity on Meadow Street By Paul Brodeur New Yorker Magazine July 9 1990 3) Annals of Radiation - The Cancer at Slater School By Paul Brodeur New Yorker Magazine Dec 7 1992 4) Closing the book: are power line fields a dead issue? By Gary Stix Scientific American Magazine Mar 1998 P33 5) Electromagnetic fields may damage hearts By Janet Roloff Science News Magazine Jan 30 1999 V155 i5 P70 6) Fields of fear By Gary Taubes Atlantic Monthly Magazine Nov 1994 P94 7) Power play By David Noland Discover Magazine Dec 1989 P62 8) Department of Amplification By Paul Brodeur New Yorker Magazine Nov 19 1990 P134 9) The ELF in your electric blanket Cover story by Dixie Farley FDA Consumer Magazine Dec 1992 P14 10) Rising tension over high tension lines By Pam Black Business Week Magazine Oct 30 1989 P158 11) Electromagnetic fields: the biological evidence By Robert Pool Science Magazine Sept 21 1990 v249 n4975 P1378 12) Utilities agree: the EMF issue is 'very serious' Electrical World Sept 1991 P14 13) Another way electromagnetic fields may damage tissues Science News Magazine Feb 19 1994 v145 n8 P127 14) Study finds possible link of cancer and power lines New York Times Nov 30 1989 V139 pB26(L) col 1 Websites related to the EMF question 1) Infoventures http://www.infoventures.com 2) Electrosensitivity http://www.feb.se 3) Bridlewood Electromagnetic fields http://www.ncf.carleton.ca 4) California EMF Program Home Page http://www.dnai.com/~emf/ 5) EMFs In The Workplace http://www.cdc.gov/niosh/ 6) EMFRAPID Home http://www.niehs.nih/gov/emfrapid/ 7) ELECTROMAGNETICS Forum http://www.tassie.net.au/emfacts/ 8) BioElectroMagnetics http://www.emfinterface.com/ Note: These websites were accessible as of July 20 1999. URLs may change during or after publication
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