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Magnetic Fields (at 60 Hz AC) This page last updated April 13, 2012. Magnetic Field Exposure In general, while electric field exposure in homes creates an agitating influence on the body that does not allow deep, restful sleep, magnetic field exposure, on the other hand, creates what some consider to be a more harmful influence by depressing the immune system and vitality. Magnetic fields, particularly from 60 Hz AC building wiring, are a known cancer risk, and when magnetic and electric fields are both present in sleeping areas, the cancer risk is reported to be eleven times higher than with either alone. Electric field exposure can prevent a deep, restful sleep, while magnetic field exposure essentially wears down your immune system and causes a host of symptoms in clients. The building biology profession recognizes four potential sources of unhealthy magnetic field exposure in homes. They include:
These potential sources of magnetic field exposure are measured either coming in from outside or at various "hot spots" from various sources during healthy home evaluations. I use a Magnii Technologies DSP-523 True-RMS 3-Axis Gauss Meter as well as a Tri-Field Gauss Meter to measure magnetic fields. Magnetic fields are created by the flow of electricity through a wire or other metallic path (water pipe, gas line). These create "flux" lines of measurable magnetic field exposure that extend out around the wire like a tube. The flux field runs parallel to the wire source. The field strength diminishes by a straight one:to:one ratio, whereby at half the distance to zero field strength, the level is half. For example, if the wire has a magnetic field strength of 100 milliGauss (mg) and it drops off to near 0 milliGauss at ten feet, then at five feet the level would be 50 mG. This is what happens with magnetic fields from outside power lines, from wiring errors on inside circuits, and from electric current on water pipes and grounding conductors. These are all discussed separately below. The most common sources of magnetic field exposure, however, are from so-called "point sources." These include transformers, electric motors and your breaker panel and electric meter (whether it is a digital smart meter or older analog mechanical meter). Point sources do have high magnetic field exposure levels, however the good news is the field strength drops off rather quickly. In fact, magnetic fields from transformers, motors and your breaker panel and meter drop off exponentially or logarithmically by what is known as the "one over r cubed" law. Thus, at half the distance to zero, the field strength is already only 1/8th the strength that it is right at the source. The field is high but compact, and rarely extends more than two to three feet from these types of sources. The magnetic field from your refrigerator motor, when running, and your breaker panel and meter might extend closer to three feet, but again, the field does drop off rather quickly. Magnetic fields from linear sources, on the other hand, like power lines and current on a water pipe or grounding conductor under your floor drop off much more slowly. The magnetic field from current on a water pipe or grounding conductor can extend several feet into the room from under the floor, and the magnetic field from an outside power line, especially transmission lines, can extend for half a city block, gradually dropping off by a direct inverse "one over r" relationship, where "r" is distance. To help you visualize this, please view diagrams of EMFs prepared by Oram's mentor and fellow building biologist, Spark Burmaster of Chaseburg, Wisconsin, click here. Before we discuss how to protect protect oneself from these types of EMFs, we need to ask what are the safe exposure limits for human exposure to magnetic fields? While the regulatory agencies in this country allow what we consider to be high levels of magnetic field exposure, our profession has adopted the more stringent standards used in Europe. As a result, magnetic field exposure levels during the daytime above 1 to 2 milliGauss (mG) are considered by our profession to be relatively unhealthy. At night, when we take our rest, we prefer to see levels below 0.5 mG. This is documented by research that is linked to from my website on the page entitled, EMF Research Citations. The building biology guidelines are given below, but first we need to review what governmental and non-governmental regulatory agencies say about this topic in this country and around the world: The US Environmental Protection Agency states, "In the U.S., there are no federal standards limiting occupational or residential exposure to power line EMF." Others, however, including electrical engineer and building biologist Vicki Warren writing on Dr. Mercola's website, emf.mercola.com, state that the EPA does recommend magnetic field safe exposure limits as follows: "The EPA has proposed a safety standard of 1 mG." The World Health Organization's International Agency for Research on Cancer (IARC), however, finds that human exposure to levels of 300-400 nT (3-4 mG) and up are considered to be potentially carcinogenic. The BioInitiative Report, published by the University of Albany in New York, found biological effects occurring at 10 mG, and stated that, "other researchers used a cut-point of around 2-3 mG, or sometimes even less, as a 'high' average". (References provided here.) The California EMF Program was created by the California Public Utilities Commission (CPUC) and is administered by the California Department of Health Services (CDHS). It sets no safe exposure levels for exposure to magnetic fields, however they do comment on whether EMFs are a health hazard. From the Executive Summary of the California EMF Risk Evaluation for policymakers and the public: "On behalf of the California Public Utilities Commission (CPUC), three scientists who work for the California Department of Health Services (DHS) were asked to review the studies about possible health problems from electric and magnetic fields (EMFs) from power lines, wiring in buildings, some jobs, and appliances. The CPUC request for review did not include radio frequency EMFs from cell phones and radio towers... "THE CONCLUSIONS AFTER REVIEWING ALL THE EVIDENCE:
"HOW AND WHY THE CONCLUSIONS DIFFER FROM THOSE OF OTHER RECENT REVIEWS: While there are important differences between the three DHS reviewers' conclusions, the DHS scientists are more inclined to believe that EMF exposure increased the risk of the above health problems than the majority of the members of scientific committees convened to evaluate the scientific literature by the National Institutes of Environmental Health Sciences Working Group (NIEHS) in 1998, the International Agency for Research on Cancer (IARC) in 2001, and British National Radiological Protection Board (NRPB) in 2001." (emphasis added) Two local electric utilities in Southern California have weighed in on the subject. The Los Angeles County Department of Water and Power (DWP) sates: "EMF exists wherever there is electricity: in homes, in workplaces and near power lines. Electric fields exist whenever equipment is plugged in, but magnetic fields exist only when equipment is turned on. Both types of fields get weaker with distance from their source. Until more is known, your best strategy is to stay informed and, if you think it's necessary, to limit your exposure. You may be able to reduce your exposure by identifying EMF sources, changing the way you use electric appliances and increasing your distance from EMF sources." Southern California Edison power company states: "While there are no federal or California established limits for EMF exposure, some nongovernmental organizations have issued advisory limits. These limits, however, are much higher than the relatively low levels of EMF found in homes, schools, and offices, or even the EMF exposures being studied in relation to childhood leukemia. The advisory limits apply only to short term EMF exposures far higher than those in residential or typical occupational settings. For example, the International Commission on Non-Ionizing Radiation Protection recommends that the general public not be exposed to magnetic field levels above an average of 833 milliGauss (mG). In contrast, the average magnetic field level found in U.S. homes is approximately 1 mG. Field levels within inches of some appliances can range in the 10's or 1000's of mG and diminish to below 1 mG within a few feet. Field levels directly underneath larger transmission line are often below 100 mG under normal operating conditions." The acceptable level of 833 mG quoted above by Southern California Edison is actually lower than some safe exposure limits accepted around the world for magnetic field exposure, which vary greatly. The high end of the range includes values of 10,000 mG (1 million nanoTesla) according to the American Conference of Governmental Industrial Hygienists (1996) and 50,000 mG (5 million nanoTesla) set by the DKE German Commission for Electrical, Electronic & Information Technologies of DIN and VDE and the German Association of Professional Engineers for occupational workers. (References provided here.) The level quoted above for the International Commission for Non-Ionizing Radiation Protection (ICNIRP) of 833 mG is quite a bit less than these acceptable levels. Compare that, however, to safe exposure levels of only 2 mG (200 nT) as recommended by both Swedish engineers within the Tjanstemannens Centralorganisation (TCO) and the US Congress (1996). Natural background levels are found to be less than 0.0002 nT (0.02 mG). (References provided here.) The European building biology profession adopted rather stringent limits for EMF exposure in 2003, which were updated in 2008, based upon European research, the precautionary principle, and the consensus of health agencies on that continent. The American branch of our profession, which certified me and other building biologists in this country, has adopted the same standards as our European counterparts (see below). Wikipedia defines the Precautionary Principle as follows: "The precautionary principle or precautionary approach states that if an action or policy has a suspected risk of causing harm to the public or to the environment, in the absence of scientific consensus that the action or policy is harmful, the burden of proof that it is not harmful falls on those taking the action. "This principle allows policy makers to make discretionary decisions in situations where there is the possibility of harm from taking a particular course or making a certain decision when extensive scientific knowledge on the matter is lacking. The principle implies that there is a social responsibility to protect the public from exposure to harm, when scientific investigation has found a plausible risk. These protections can be relaxed only if further scientific findings emerge that provide sound evidence that no harm will result. "In some legal systems, as in the law of the European Union, the application of the precautionary principle has been made a statutory requirement." The following information is reprinted from the 2008 Standard of Building Biology Testing Methods, which includes a definition of levels of risk as well as reference citations. The standards can be accessed here. In the building biology profession, acceptable limits of AC magnetic field exposure in the sleeping area are listed as follows:
From the guidelines:
In areas of the house or home office that we occupy during the day or evening, we are less stringent than sleeping areas. Generally we are not concerned with daytime magnetic field exposure levels up to 0.5 mG, and only slightly concerned from 0.5 to 2.0 mG for healthy people. We are more concerned when levels exceed 2.0 mG, as that is the level at which harmful biological activity is known to begin to occur. We are most concerned when levels exceed 5.0 mG. We must bear in mind that EMF consultants like myself deal with two groups of people in our work. The first is those who are known to be electro-hypersensitive, or EHS. This group is conservatively estimated to be 3-5% of the current population (Levallois, Neutra, Lee and Hristova, 2002; Schreirer, Huss and Roosli, 2006). EHS is a recognized, compensable disability in the Swedish health care system. Studies by medical researchers show that electrical hypersensitivity has a biological basis, however the syndrome is much more studied and accepted by researchers and doctors in Europe than in this country. The Parliamentary Assembly of the Council of Europe, a branch of the European Parliament, passed Committee Resolution 1815 in May of 2011. Entitled, "The potential dangers of electromagnetic fields and their effect on the environment," the resolution strongly urges sweeping reforms in the way governments, science, medicine, media and industry approach the issue of the adverse impact of electromagnetic fields on the health of all people from appliances, wireless devices and power lines that we are all exposed to in modern society. The Council of Europe resolution sheds new light on the degree to which research and clinical experience is showing that long-term use of devices and appliances in common use as well as exposure to power lines do have adverse health effects even at exposure levels considered by governmental regulatory agencies to be safe. This is particularly true for the growing number of people in the world who are termed "electro-hypersensitve." As an example with cell towers, the resolution urges recognition of these people and creation of areas within each country that are "wavefree." Here is the actual passage in the resolution pertaining to the EHS: "8.1.4. pay particular attention to 'electrosensitive' people who suffer from a syndrome of intolerance to electromagnetic fields and introduce special measures to protect them, including the creation of wave-free areas not covered by the wireless network;" The full Council of Europe document can be accessed here. The building biology profession is planning an upcoming annual conference to be held this October 2012 in Washington, DC, entitled, "Healthy Bodies, Healthy Buildings; Creating Safe Havens in a Toxic, ElectroMagnetic World". Our committee is planning to have several presentations, as you can see from the speaker lineup, specifically on the health impact of EMFs on the electro-hypersensitive population and on the public in general presented by nationally renowned MDs and researchers. There is a physiological basis for electro-hypersensitivity as documented in the following publications:
These electrically-sensitive people, as well as anyone with chronic illness and those segments of the population that are at high risk, including children, the elderly, and pregnant women, all require a higher standard or threshold when deciding what a safe exposure level should be for any type of EMF. These people cannot tolerate what otherwise healthy people can and they are at much higher risk for adverse biological effects according to extensive research and their own experience. For those reasons, we adhere more strictly to the safe exposure guidelines recommended by my profession. The other population we deal with is everyone else in society who is normally healthy and asymptomatic around various EMFs. What is a safe exposure level for them? Again, we generally recommend the same safe exposure limits we do for electrically-sensitive individuals as a precautionary measure. Our goal is to protect people from possible harm if at all possible. The standards can be relaxed under certain circumstances, but as long as the individual is made aware of what the research shows and what the potential risks have been shown to be, they can take their own measurements and consider those taken by building biologists and other EMF experts and decide for themselves what level of potential risk they are willing to expose themselves to on a long-term basis. Precaution is our primary goal. How do we protect ourselves from each of the specific types of magnetic fields? Magnetic Fields from Outside Overhead or Underground Powerlines Overhead transmission and distribution lines produce potentially significant magnetic fields due to the distance between conductors. There is no cancellation possible when conductors are separated several feet apart. Magnetic fields therefore extend in concentric rings equally in all directions for dozens of feet around each wire like a tube or tunnel. These flux fields pass through virtually all building materials. The only materials capable of effectively shielding against magnetic field exposure are expensive nickel alloys used in the aerospace industry and available from such retailers as Less EMF. Such materials do not eliminate lines of flux. They just compress them, and if the shielding is not wide enough, the lines of flux simply bend around the edges, so to speak, by propagating towards you from the edges of the shielding material. Overhead or underground distribution lines carrying lower voltage can likewise emit strong magnetic fields throughout a neighborhood due to imbalances between loads carried on the hot and neutral conductors from so-called "pipe current," discussed below. Governments around the world differ in how they are handling this issue. England has been grappling with implementing a moratorium on residential construction around existing powerlines and trying to issue a ban on constructing new powerlines near existing residences. Russia has reportedly banned powerlines in close proximity to residences for decades. The best way in my profession's opinion to protect yourself against magnetic fields from any source is to reduce or eliminate that source, if possible, or increase your distance, if reduction is not possible. With outside overhead or underground powerlines, the obvious solution is to increase your distance. When I measure virtually the same elevated magnetic field strength throughout a home, with only slight reduction as I move, for instance, from the front of the house to the back, the cause will be an outside overhead or buried powerline. I will find the same magnetic field strength levels outside the house, gradually increasing as I walk towards the source, just as is the case inside. There is really nothing you can do about magnetic field levels above 1-2 milliGauss that come inside your home from powerlines except to make a decision whether or not you are safe when these elevated levels are present and whether that means you need to relocate. One always needs to consider the balance between constant exposure to what many experts, including my profession, consider to be a known source of biological harm versus your body's particular ability to repair any cellular damage potentially caused by such a source. Many in the alternative medical community say this should include consideration of one's heredity and family history of illness as well as your lifestyle, most importantly diet. Of course, you primarily need to consider whether you are healthy or already symptomatic in making your decision. Magnetic Fields from Electric Current on Metal Water Service Supply Pipes The cause of this type of magnetic field is electric current flowing in or out of your house on your incoming water service supply pipe, if it is metal, and/or your cable TV line from the electrical systems in your neighbors' houses. This causes magnetic fields in certain places in your home, most notably from under the floor above a basement or crawl space. These paths can also run in walls and ceilings. Ideally all electric current that enters the home on the hot conductors of the electric supply lines should leave the home on the neutral (return) conductor of the same electric supply lines. In actual fact, some of the return current also runs in and out of your home through a metal water service supply pipe and on the sheathing of the cable TV cable. This current then enters the homes of your neighbors via the metal city water main or cable company's lines. These grounding paths therefore interconnect the electrical systems of each home up and down the street with each other, including yours. When present, current flowing on these parallel paths results in an unbalanced load between the hot conductors compared to the load on the neutral conductor of the electric drop service line coming into your house from the electric utility transformer. As noted above, some of this current is carried on the water pipes and the grounding conductor running in the slab or crawl space, and possibly in some of the interior walls and ceilings. It will also be carried on the electric drop service as it runs up the side of your house. All of this can create unhealthy magnetic field exposure in several rooms on the first and possibly second floors. This is generally not a problem in most houses in Southern California, particularly in Orange County, because the water department usually installs a dielectric union (plastic ring) in the water line at the street to keep surges of electric current in one house from flowing on the metal water pipe to neighboring houses (not to reduce magnetic fields). Electric current on metal water pipes is a problem, however, in some houses in Orange County and many more in Los Angeles County and in other parts of the countryin in virtually every house supplied by city water. Electric current can be measured as high as 1-2 Amps on the water service supply pipe and this current can potentially spread throughout the building on the water pipes and all other metallic paths, such as metal gas lines and metal air ducts. This can create unhealthy magnetic field exposure in different rooms in the building. This is not due to improper grounding. Rather, it is a matter of electricity running on parallel paths in addition to the one and only path it should be running on, which is the neutral conductor of the electrical drop service. This results in unbalanced loads, which in turn causes a lack of the cancellation of magnetic flux normally found in circuits and plastic AC power cords where the hot and neutral conductors are side-by-side and have equal current. When that happens, you thus have equal but opposite magnetic flux size that produces no net current and therefore no magnetic fields. When metal water pipes carry current, however, there is no cancellation because there is no other metal conductor laying right next to the pipe carrying the same amount of current in the opposite direction, as there is in circuits and appliance cords. Hence, you potentially have magnetic fields in amounts that our profession and others consider to be unhealthy. "Knob and Tube" Wiring So-called "knob and tube wiring," used extensively throughout the country until the 1930s and 1940s, consists of individual hot and neutral conductors running through walls, basements and attics that are separated by a few inches. They were wrapped around ceraminc knobs nailed to floor joists when the wire ran along the joist, and fed through ceramic tubes when they ran through joists. This type of wiring, which still carries currents in homes built in that era, has two particular drawbacks. It produces high electric fields at all times, and it also produces high magnetic fields when current is flowing through the wires. This is because it does not allow the magnetic field around the neutral conductor to cancel the magnetic field around the hot conductor because of the separation. I will often measure magnetic field levels in excess of 10 mG within a foot or two of a wall containing "knob and tube" wiring (when loads are on). In the short term the solution is to be aware of the magnetic field exposure levels and how far they extend from the floors, walls and ceilings in which they are located so that you can minimize the amount of time you spend near these areas, again when lights and appliances are on. You can also keep the lights off most of the time and therefore not be exposed to this unhealthy influence when you walk by the areas in which the wires are located. The long-term solution, however, is to replace the knob and tube wiring with new wiring, preferably metal-clad. Doing so will also remove a significant source of markedly elevated electric field exposure, which is present whether loads are turned on or not (but disappear when you shut off the breaker). Knob and tube circuits are also ungrounded, so you will be fixing that problem (of not having grounded outlets), too. Wiring Errors We recommend that clients have their electric breaker panel and circuits evaluated for wiring errors. Wiring errors are another potential source of magnetic field exposure. They are caused by incorrect wiring practices that are inadvertent but common during the installation of electrical wiring, however long ago that occurred in the past. They also occur when new wiring is added, particularly by homeowners and handymen over the years who don't know how to wire properly. Wiring errors cause parallel paths for neutral return current to flow, which causes magnetic field exposure along the route of the branch circuit(s) when electric loads are turned on. These fields extend out into occupied rooms from walls, ceilings and floors. They also occur when new wiring is added. The magnetic fields caused by wiring errors create the most serious and detrimental effects on occupant health, in our opinion. These errors need to be traced and fixed to provide a healthy environment for clients, especially if you are EMF-sensitive. Also, if you ever install Stetzer filters, it is imperative to find and repair all wiring errors. This is because Stetzer filters, which reduce one type of EMF, can unfortunately aggravate the magnetic fields that wiring errors and current on grounding paths create. We recommend testing for and repairing any wiring errors, then continue to use your Stetzer filters for the benefits that they provide, namely reduction of "electro-pollution" caused by harmonic frequencies of 60 Hertz, the frequency of AC electricity in house wiring. Wiring errors can be tested for at the breaker panel and if discovered, the source can be traced out and repaired in the branch circuitry. We work in conjunction with an electrician to guide them in implementing a protocol developed by our faculty, who are electrical engineers, to find and fix these errors. Current on the Cable TV Grounding Wire Another potential source of electric current flowing into a house is on the grounded portion of the incoming cable TV wire, and it can also be easily fixed. Even if you don't have active service at this time, this current path can still exist as long as the cable is still installed and connected outside to the utility at the pole or underground. This current flows because the cable TV wiring is connected at the utility pole (or ground level green cable box out near the street) to the streetside electric utility grounding system, which also carries current on it. This current then jumps onto the electrical system in your house whenever you plug in a DVD or VCR player that has a grounded (three-pronged) plug on it and it has a cable TV cable connected to it. You will notice that television plugs are never grounded for this reason, so they do not pass on current from electricity on the ground of the cable TV cable. This current can create magnetic field exposure in the rooms beside and above the route of the circuit from the circuit breaker panel to the outlet in the room that the DVD player is plugged into. It is best to check for the cable TV cable as another path for electric current and magnetic field exposure, particularly after the current has been removed from the water pipe. The best solution is to install a cable TV ground loop isolator in the cable TV cable on the street side of the ground connector. This can be ordered from 21 Best by clicking here. Order the VRD-1FFj Cable TV RF Isolator / Digital Cable TV RF Ground Loop Isolator. "Point Sources" of Magnetic Field Exposure Finally, so-called "point sources" of magnetic field exposure also exist throughout most homes, particularly in bedrooms, a home office and kitchen. Elevated magnetic field levels can be measured within one to two feet of all transformers. Transformers are required to step "line voltage" of 120 Volts from electric outlets down to lower voltages, such as 12-14 Volts, to run circuit boards within all electronic appliances. These include printers, laptop computers, modems, computer speaker systems, and LCD (liquid crystal display) electronic clocks. These transformers are also found inside the cabinet of electronic appliances when the cabinet is big enough to house them, such as a computer tower (central processing unit, or CPU), monitor and even electric clock radios. Therefore, there is a magnetic field extending out one to two feet from the back of these cabinets where the electric power cord attaches to the appliance. On the other hand, when the cabinet is small enough, the transformer is housed in a small, square box that is plugged directly into an outlet, often on a surge protector or power strip. That power strip, loaded with transformers, is usually located right at people's feet at their computer workstation, and should be moved a few feet away from any part of your body. You may also have an in-line free-standing transformer for some of your electronic devices, such as laptop computers and printers. These, too, should be moved several feet away from your toes. This is also discussed in the section on safer use of computers. Specifically, you will have magnetic fields created by the transformer in an electric clock radio, although it only extends out about one to two feet at most. Whether you keep the electricity in the bedroom on at night (due to metal-clad wiring in your walls) or shutting off circuits because they are plastic-jacketed, you will need a battery-powered clock, which does not produce harmful magnetic field exposure. You will not want to keep the digital clock radio near the bed with metal-clad wiring in the walls, even if you move the clock away, because you will not want the electric field exposure from the unshielded AC power cord of the clock. Electrically-powered clocks with analog hands on a clock face, as opposed to digital, have a very large magnetic field, extending three to four feet, well onto your pillow, from the electric motor that moves the clock hands. This type of electric clock should never be on a bedside table. In your kitchen you will have magnetic field exposure right next to and behind your refrigerator when the electric compressor motor is running. For this reason do not sit or sleep on the other side of the wall from a refrigerator. You will also have smaller magnetic fields from the transformers in digital clocks throughout the kitchen, but they only extend out a foot or so. Avoid standing next to a stovetop that has a digital clock and controls at the front, right in front of your abdomen. This is not healthy and should be avoided. Click here for recommendations on avoiding point sources of magnetic field exposure at your computer workstation. To view an extensive list of links to web sites documenting the health effects of exposure to EMFs caused by wireless devices, including cell phones, cordless telephones and wireless Internet (Wi-Fi) routers, click here. To learn about Smart electric meters, click here. To view an extensive list of links to web sites documenting the health effects of exposure to EMFs in general, click here. To return to the main Articles on EMFs page, click here. © 2012 Create Healthy Homes. All rights reserved.
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