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Health Effects Of Electromagnetic Fields In Housing, Schools And Offices

by Andrew Michrowski, Ph.D. Architecture

The Planetary A ssociation for Clean Energy, Inc
100 Bronson Avenue, Suite 1001 OTTAWA, Ontario K1R 6G8
(613) 236-6265; fax: 235-5876

Quebec Order of Architects Environmental Committee invited lecture
McGill University, Montreal, November 20, 2001

In our growing independence on electromagnetic technology ranging from electric power through the wireless telecommunication systems, we find ourselves absorbing electric and magnetic wave frequencies from less than 60 Hertz (or cycles per second) to greater than 2 GigaHertz.

The human species has evolved from a broad band of such frequencies originating from planetary and extra-planetary sources. Our bodies also emit electromagnetic fields. But in the last few decades, human exposure has dramatically risen – more than a trillion times. We can expect further quantum leaps in exposure if the plans to have every dwelling, school, office and store in the world become a microwave transmitter for wireless computer and like linkages.

In the last 2 decades, the scientific community has begun to study the various effects on living organisms of both magnetic and electric fields. From this research we know that generally speaking, magnetic fields affect cells, tissue, glands, genes and muscles, both in positive and in negative ways, depending on such factors as frequency, intensity, duration and waveform. We also know that electric fields tend to affect the nerve system, including our skin. As the waves become shorter in length in accordance with the increase in frequency, so the electric and magnetic fields become less important for the study of biological effects and scientists focus on their combined effect – that is, their total power – to determine the rate of absorption by the human body. This is reason why standards associated with cellular phones and microwave ovens, for example, discuss only the level of power. 

Unabated concern by the public has resulted in major health assessments by several governments. The most is the 1998 US National Institute of Environmental Health review. It led to spin-offs, such as that from the World Health Organization earlier this year. Other studies have characterized typical groupings of electromagnetic field conditions in housing, office environments and schools, leading to a definition of cause-effect relationships.

We know now that for the powerfrequency (60Hz) at 0.60 milliGauss there is no known deleterious effect on the general population. Yet hypersensitive individuals, who now account for almost 20% of the population in Canada can accurately identify and describe the sensation of field of lower intensity. Various epidemiological studies indicate at long-term and chronic exposure of 1mG (such as can be experience during sleep, at work and in schoolrooms), serious health risks commence. The risk appears to escalate proportionally with higher intensity to the degree that the WHO determined that 4mG is a too high level, while the standard-setting authority, the US National Council on Radiation Protection and Measurement proposed in 1995 that eventually no federally funded day-care centre, school, playground and housing should have fields higher than 2mG. Individuals who are more susceptible to adverse health effects from continuous exposure to levels ranging from 1 to 2mG are the foetus, young children, pregnant women, those who are already ill, the elderly and the hypersensitive.

Fortunately, for the powerfrequency, good architectural design practice and observance of the current Electrical Code makes it possible to achieve magnetic fields lower than 1mG in all zones of long-term human occupancy. Unfortunately, few designers and fewer electricians still seem to know how to apply judicious wiring and localization protocols in real-life scenarios. These errors by omission or by lack of training have led to a situation that Canadian buildings have generally the most elevated powerfrequency magnetic fields in the world, often much higher than the 4 mG barrier proposed by the WHO, about twice the US indoor environment and about 10 times that of the European Union, as determined by a Canada Mortgage and Housing Corporation study.

With regards to powerfrequency electric fields, in Canadian buildings, these are generally lower than the absolutely safe level of 6 Volt/metre. But there is an exception to this rule, and this exception affects probably three-quarters of Canadians. It is the site of our pillow on which we rest our precious heads everything we sleep! This oversight is the result of the frequent placement of wiring in the wall at the head of bedsites, in addition to the generally inadequately wire gauge insulation in most lighting fixtures usually chosen near our beds. Already at 10V/m, powerfrequency electric fields aggravate sleeping patterns, leading to chronic fatigue and general weakening of the body’s defence. Fortunately this problem is very easy and inexpensive to solve – either by re-arrangement of the wiring, or by shielding with appropriate plastic and rubber material at next to the head of the bed. We must also note that, according to specialists, chemically sensitive individuals are almost always electrosensitive, whether they are aware of it or not. Such individuals may demonstrate greater irritability or hyperactivity when exposed to even very low electric field intensities.

Though radiofrequency and microwaves are very easy and inexpensive to shield – any meshing adapted to the size of the wavelength in question – from chicken coop mesh to mosquito meshing, much like the devices used in microwave oven doors - these fields also present unique design considerations. For example, metallic frames of doors and windows act as condensing lenses for incoming microwave signals. Such focusing can easily magnify an altogether safe microwave front into a concentrated beam that may exceed Canada’s Safety Code 6 standards for this bandwidth. This phenomenon is particularly relevant in buildings near cellular phone antennae, radar installations and police and taxi radio transmitters. That is not so rare these days as many hospitals and apartment blocks, because their prominence in the urban skyline lease their roofs for such microwave transmitting devices. Though it is true that one of the safest places is to be directly underneath a transmitter, it is also true that the most dangerous may be right next to it, especially with the optical magnification into a bed, or into a seat! Satellite dishes, by the very nature of their parabolic magnification design and their antenna function, capture and focus almost any electromagnetic emission within line of sight and then dump this broadband spectrum field directly underneath. If the satellite embraces an electric distribution line, for example, this powerfrequency will be focused directly below, sometimes with a 10-fold magnification. It is not a good idea to occupy such a location for extended periods of time.

We should note that about 2/3 of the elevated fields found indoors are caused by errors associated with indoor wiring and the particular electrical grounding system we tend to employ in Canada. Only when outdoor fields are prevalently over 2mG (in such cases as where a transmission line overwhelms the entire environment surrounding a building - from above, sideways, and in a certain degree, even from the ground level), there is basically nothing one can do inside the structure to reduce fields to less than 2mG, except the distance factor, which may not necessarily be an option. 

Let us examine the various design considerations for specific type of structures. 


Schools tend to be extended in size, necessitating linearity in the wiring configuration. This means that wires of considerable amperage are often extended within classrooms, often diagonally. Thus a child’s seat, located directly above such a cable can have a field as high as 9mG while two partners away can have a field of under 1mG. Such a child may be rebuked and punished for learning incompetence and even medicated for hyperactivity when the fault lies with the building’s designers and electricians who have not been trained to understand the consequences of their installation practices! Aligning these cables along corridor walls or other lesser-occupied zones could alleviate such a situation. Another error, usually sourced by re-wiring, renovations and the like results in improper wiring between the main electric panel and the subpanels, resulting in massive magnification in magnetic fields and in violation of the current Electrical Code (but perhaps permitted in previous codes at the time of construction).

Schools may also have unusual microwave environments, sometimes because they may have an antenna indoors (an aspect of being “modernized” for wireless computer services). Students tend to use cellular phone en masse during inter-class periods, often generating power densities indoors higher than allowed by our national safety standard.

Computer classrooms present a special condition associated with the high density of appliances and their positioning which may subject certain pupils in hazardous exposure – even when each computer alone may actually be “safe”. The large number of computers, whose screens act as positive ion generators, can rapidly extinguish all available negative ions and present undesirable physiological effects on those present, including listlessness and decreased ability to learn – especially when the building is airtight or windows are not allowed to be opened so that no fresh negative ions may be introduced from the outdoors.

Office environment 

The office environment is one scattered with a large variety of potential “hotspots” associated with all types of appliances. But these elevated fields generally have very short ranges. The reason for this is that most appliances use transformers, whose field dissipation ratio is about 10 times greater than that for normal wiring. Anomalies can also be caused by heavy-duty cable layouts, horizontally and vertically – as in the school classroom situation.

The individual workstation should always be carefully planned for avoidance of unnecessary fields. A very common error involves the placement of some transformer in a power bar too close to the worker.


Homes have probably the most elevated fields. Very few factories in Canada, even power generation stations, have fields as high as the place where we use to let rest aside all of our worries and our frets about life, where we live with our beloved ones and where we raise our bundles of joy! Why? Because the socio-economics of our society do not allow for the professionalism in design and installation that our homes deserve! (Also perhaps because there is no union to speak out for the home dweller?)

In the Canadian situation, too often the residential electric service and the water service are separated by significant distances, sometimes at opposite ends of the building. This configuration results in the fact that the grounding wire – a single wire – carries the current that exists both at the electric panel and throughout the municipal water distribution system, right through the living zones of the house. A single wire with 1 Ampere of current has a magnetic field of 2mG 1 metre away. In urban areas, it is altogether common to have sustained currents in the grounding wire of near 3A, with spikes of up to 30A during high electric consumption periods, just when the family is enjoying dinner, studying or recreating. That passage of current amounts to fields of around 6mG, which circulate in the residence even if all appliances were to be turned off (and even if the typical Canadian resident were enjoying a candlelit meal). This nefarious situation can be remediated by designing configurations in which the electrical panel and the water service are located at very close range so that such currents travel in some isolated, uninhabited zone of the house. If the house has been built, this problem can be tackled by grounding the main panel to grounding rods rather than to the water mains, a protocol permitted by the current Electrical Code and accepted by utility companies across Canada. Current from the municipal pipes can also travel in all conducting water pipes inside the home. This current can be removed by placing a dielectric coupler or any non-conducting material such as a plastic or rubber tubing between the water mains and indoor plumbing.

Then there are numerous types of electrical wiring errors, which can create all manner of excessive electric or magnetic fields indoors – all of which are violations of the Electrical Code.


At the vanguard of technology developments, hospitals are budding grounds for all sorts of technofields, both in powerfrequency range as well as in the radiofrequency and microwave ranges. The fields can be so elevated that the current Canadian standard for magnetic fields of 1,000mG exists to render legal the use of such equipment as the crown jewels of any fashionable hospital – the scanner. Then hospitals have all kinds of security systems (most operating in radiofrequency ranges), polluting lighting fixtures by the beds, monitors, automated beds, medical devices each of which can produce “hot spots”, usually near to patients (and which have the potential of even genetically modify hosts of microbes). Hospitals also acquiesce to the leasing of their roofs and perimeter walls for cellular phone antennae as a means for increasing revenues.

Professionals design hospitals. So professionals should take extra care to ensure the lowest possible electromagnetic field levels since it is well known that certain diseases worsen in the presence of powerfrequency magnetic field levels higher than 1mG and that genes can change their expression starting at this intensity. A number of drugs interact with low-level radiofrequency fields, causing unsafe synergisms. Here it is distance that provides the measure of protection to both the client and the server and layout is everything as well as judicious configuration of wiring and lighting fixtures.


In many built environments, technofield levels are too elevated for even minimum health risk conditions. Fortunately, appropriate design and careful oversight in installation can provide citizens with acceptable, safe and generally no-risk levels of electromagnetic fields. 

This notable item, full-page on Canada's national newspaper is a welcome introduction to the problems of electrical hypersensitivity and to the fact that there are increasing intrusions of radio-frequency and microwave signals in our electric power distribution and delivery systems, as more and more technologies now use electric wiring for their own purposes. 

Filtering on a piecemeal basis can work in some instances and it should, in our opinion, we done by the electrical supply companies or by the manufacturers of the devices that now dump their pollution onto the general population. 

And, as we are all aware, filtering does not correct other significant wiring errors which, in North America, account for about two thirds of all elevated residential powerfrequency magnetic fields, and which usually are higher in our homes than in industrial, commercial and educational institutions. Fortunately, it is often less expensive to correct wiring errors (and the harmonics, etc) than to filter. 

Attached is an overview of the complexity of electromagnetic pollution in North American buildings, which was presented at McGill University sometime ago. 

Andrew Michrowski
The Planetary Association for Clean Energy, Inc.
100 Bronson Avenue, Suite 1001 Ottawa, Ontario K1R 6G8 Canada

(613) 236-6265

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