General EMF questions
At your house
Computers (including WiFi) - at home, office, or at school
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General EMF Questions
Powerlines, substations and mobile phone base stations. How far away is safe?
This is a question we are often asked and, unfortunately, there is no easy answer. The research into the health effects of electric and magnetic fields (EMFs) from these structures has primarily focussed on field levels rather then distance.
Powerlines, which are part of the electricity distribution system, come in various sizes (voltages) from 400 kilovolts (kV) (largest) to 230 volts (smallest). On the whole, the higher the voltage of the line, the higher the EMFs and the further you have to be away for the fields to drop away to a background level. A significant exception to this is the 132kV lines, which can carry very unbalanced power loads, which mean they have much higher EMFs than you would expect from the size.
Health research since the major 1979 study by Nancy Wertheimer and Ed Leeper , has concentrated largely on childhood leukaemia. The World Health Organisation classified extremely low frequency electromagnetic fields (ELF EMFs such as from powerlines and electric appliances) as possibly carcinogenic (cancer causing). Increased risk of leukaemia is now recognised internationally as being linked with magnetic field levels of 0.3 microtesla [2,3]. Other childhood and adult cancers [4,5,6,7,8], clinical depression, suicide, miscarriage, and other reproductive problems [9,10,11,12] and some forms of dementia have also been linked to EMF exposure [13,14,15,16].
There is much more information about the health effects of EMFs from powerlines in the free article "Powerfrequency EMFs and Health", with lots of listed and detailed research studies supporting our conclusions.
Electric fields have been less researched as they are stopped by most building materials. However, we have found that about half of UK homes can have high electric fields due to the way the house wiring is done. High electric and magnetic fields together multiply the risk of serious ill health [5,6].
The only way to know for sure whether you are in levels of EMF below those at which health effects have been found, is to measure them. A suitable meter to measure the fields is the EMFields ELF meter available for hire, and which comes with easy to follow instructions and comparisons with the levels that research has shown are linked to ill-health.
Substations or transformers
Substations generate low frequency EMFs such as those which are found near powerlines. Magnetic fields can extend out for some distance, depending on the size of the substation and the type of demand for electricity that it supplies.
Underground cables run from the substation to the house, businesses, etc. that it supplies. The cables give off very high levels of magnetic field close by. This can be a particular problem for houses with small or no front gardens, or where the cables pass near the garden.
The way that substations are connected can sometimes give rise to 'net' currents which can produce very high fields indeed in the houses between them. The electricity supply is unaffected and the electricity company does not usually see the high fields as a problem.
Mobile phone masts or base stations
High frequency EMFs, or microwaves, are radiated from mobile phone masts. These can cover a few metres, or several kilometres. How far depends on a number of factors. These will include
The number of operators, the height of the base station, the power of the antennas, the direction of the antennas, the physical and / or electronic uptilt or downtilt of the antennas, the quality of equipment, the local geography, the type of buildings and building structures in the immediate area.
It is impossible to determine the amount of exposure in any one place based only on the distance to the nearest mast (or mast complex). The only way to find out for certain is to measure the strength of the field in volts per metre and the amount of pulsing microwaves. The Acoustimeter, available to hire from EMFields indicates the level of radiofrequency radiation (RF) and the pulsing of the transmission, both in lights and as a digital readout. It is easy to use, comes with instructions and enables you to see what you and your family are exposed to.
Many people report very debilitating health symptoms as a result of living near mobile phone base stations [17,18,19,20,21] including an increased risk of cancer [22,23]. The World Health Organisation have classified radiofrequency electromagnetic fields (RF EMFs, such as from base stations, cordless phones and wireless internet) as a class 2B carcinogen). It is not just a psychological effect as birds and other creatures have been affected badly .
The evidence increases, but finding unexposed populations to compare with is getting more difficult. Sometimes protection is the best and only option.
 Wertheimer N & Leeper E, (1979) Electrical Wiring Configurations and Childhood Cancer, American Journal of Epidemiology 109(3): 273-284
Where can I find location maps for powerlines and mobile phone masts?
If you are keen to find the locations of powerlines and phone masts near you, Powerwatch's free article by the title "Location maps for Powerlines and mobile phone masts" (available from Powerwatch's article library, towards the bottom, in the 'Reference material' section) is a great place to start.
Do EMFs present a problem for hearing aids?
The power used by hearing aids is very small, there are few mains-frequency EMF problems associated with their use as far as we are aware. If switched to inductive loop mode, hearing aids can buzz close to high power electricity cables or transformers.
Hearing aids are often sensitive to microwaves, especially digital pulsing ones such as are emitted by GSM mobile phones and base stations. These can cause buzzing noises and a high pitched whine. Wireless Local Area computer networks can cause clicking / scratching sounds, as can some 3G mobile phone systems. The hearing aids should be protected by good design, but often aren't. It is a defect in the hearing aid.
Older aids were particularly prone to these problems but some new models still seem to have the problem.
Induction loops amplify sound for the hard of hearing in their own home for watching TV, or in public places, like theatres, meeting rooms, etc. Sound is amplified and transmitted using a large loop of wire wound around the room or building. This sound cannot be heard directly but is picked up by a special loop and receiver worn by the person who is hard of hearing, and fed to a hearing aid. This induction loop system causes quite high levels of EMFs that change continually with the broadcast sound. There is no scientific evidence of any harm from EMFs generated by audio induction loops, and we are unaware of any anecdotal evidence that suggests otherwise.
These next systems are primarily used in people's homes rather than in public places.
Infra-red systems work by transmitting the sound signal using an infra-red beam, from the television or HiFi to a head set worn by the person who is hard of hearing. This use of infra-red light uses very low power and is free of any electromagnetic hazard.
Microwave systems have a microwave transmitter attached to the television set or HiFi. The receiver is in the headset worn by the person listening. The headsets are safe, but the transmitter gives off high fields. You should sit a reasonable distance away from the transmitter unit.
Are interactive whiteboards in classrooms an EMF problem?
Interactive whiteboards in classrooms can be a very valuable teaching and learning tool. From an EMF point of view, systems which are powered using wires are not a problem at all. There are other ways of powering the systems that we are not as happy with.
The teacher will be subject to constant low levels of microwaves whilst the system is working. Children going up to use the console will be exposed during the time of use, but not otherwise.
Although this works at a lower power, we cannot recommend it, as some people, and it is impossible at the moment to predict who, can be affected by levels of microwave exposure as low as 0.05 volts per metre. The effects reported have included memory, learning and concentration difficulties and behavioural disturbances, not problems you want to introduce into a classroom, see references below.
This type of system means that all members of the class are exposed to a continual background microwave exposure whilst the system is operational, whether they are using the console or not. In view of the concerns about microwave exposure, even at low levels, we feel we would not like to see this type of system in use in places of learning, especially when a wired system is easy to install.
The following problems were identified by researchers looking at the effects of exposure to low levels of microwaves. In most cases the exposure source was a mobile phone mast, and the subjects were nearby residents; it is not clear how long each day the subjects were exposed to the mast signals, compared with potential classroom exposure. As interactive whiteboards are newer than mobile phone masts, the studies have not yet been done, though the amount of exposure may be similar in many cases.
Learning and memory problems (Freiburger 2002, Santini 2002, Navarro 2003, Oberfeld 2004, Abdel-Rassoul 2007)
The school study reported by Powerwatch showed that both parents and teachers were concerned about "uncharacteristic behaviour" shown by pupils in a school which had had a mast for nearly three years when compared with one without.
If you want to find out more about the health risks from microwaves, there is a very informative multi-part article 'Radiofrequency EMFs and Health' in our free article library.
How do the different units of magnetic field measurement compare?
The most usual measure of magnetic flux in the UK is the microtesla. In the US the Gauss is found more frequently.
Causes of Childhood Cancer
Childhood cancer, especially leukaemia, has been steadily rising since the beginning of the last century, though the reasons for this are not clear. It is possible that children with weaker immune systems began to survive long enough to develop this sort of serious illness, when previously they would have succumbed to other childhood diseases, such as measles, whooping cough, diphtheria, TB, that have become less serious with the advent of mass immunisation policies.
Proximity to powerlines and levels of magnetic field exposure of 0.4 µT or more have been linked with an increased risk of childhood leukaemia. A previously unknown peak in childhood acute lymphoblastic leukaemia (ALL) between the ages of 2 and 6 began to appear in the developing world at the same time as electricity began to be used as a widespread source of power.
Before 1950, most forms of childhood cancer were nearly always fatal. Fortunately, treatment programmes have improved greatly, so that most children diagnosed with this devastating disease will recover. It is always traumatic, though, especially for the child, but also for their families and friends, and has significant long-term physical, emotional and mental health consequences. We would all want to spare them their ordeal.
However, the search for the causes of childhood cancer has not had the same degree of success as has the treatment programmes. What is clear is that childhood cancers are rarely caused by one thing. They are usually a combination of factors all coming together, when if there were only a few of these factors, the illness would be much less likely to manifest itself.
The factors involved may include: genetic predisposition, chemical exposure, electromagnetic field exposure, diet, infections, X-rays, air and water pollution, light at night, fluoride, etc, etc.
There are also lifestyle changes that may make children less susceptible to developing cancer.
This subject is covered in far more depth, including hundreds of useful scientific references, in our series of articles on childhood cancer in the free Powerwatch website article library. These discuss all these factors and more, and the role they may play in the development (or prevention) of these illnesses.
Why do the EMFields PRO and the Gigahertz 3030b give different electric field readings?
The EMFields PRO and the Gigahertz 3030b appear to give quite different electric field readings, with the 3030b presenting a figure roughly twice that of the PRO. This is not a calibration error or inaccuracy, but instead a different method of measuring the electric field.
The 3030b is designed to measure the electric field at the end of the instrument in direct relation to ground. This is why they recommend using the earthing lead they provide with the instrument, and doing so is required for your measurement of the electric field relative to ground to be accurate. The PRO is designed to measure the electric field level to which your body is exposed, so it is relative to your body, instead of to ground.
For example, birds can perch on very high-voltage powerlines without being injured. This is because they only have a low number of Volts across their body. However, they are technically sitting at hundreds of thousands of Volts. In this situation, the 3030b would read hundreds of thousands of Volts (off-scale), but the PRO would read only a few hundred or less.
The 3030b can be used like the PRO (without the earthing lead), but if used this way it will give higher readings. If held in the same manner as the PRO (at the bottom, around the battery compartment) then it will give readings roughly twice that of the PRO.
I would like to take my measurement instruments with me when I travel, and this will involve a plane journey. They will have to go through the X-ray machine. Will this damage them in any way?
They will not be damaged by X-rays. It is likely to be easier to get them through in your main luggage as the authorities will want assurances that they won't be used on the plane. It should not hold up the main luggage as long as the outline can be clearly seen - i.e. do not wrap them together or in aluminium foil.
What Planning regulations may apply to mobile phone base stations?
Many of the planning guidelines for mobile phone infrastructure, such as PPG8, are only guidelines, they are not legally binding. Some of the guidelines have been challenged in law, and have created case-law precedence which will have more force of law than the guidelines themselves. Scotland have their own guidelines NPPG19 and PAN62 advice note and Wales have their TAN19 panning guidelines.
We give some brief comments below, but probably the most informative websites with respect to UK mobile phone mast planning issues are www.planningsanity.co.uk, www.mastsanity.org and www.mastaction.co.uk.
General Permitted Development Orders
Telecommunications 'transmission devices' require planning permission unless they are "permitted development" as defined in the General Permitted Development Order (as amended). Masts up to 15 metres high, and most antennas on buildings, come within "permitted developments" and local councils can have little say over the siting of these. They can suggest alternative sites, but few councils actually do this. Masts over 15 metres high do need full planning permission.
GPDO Order 2001 paragraphs A.1(g) and A.1(h) set a limit on the number of antenna systems that may be placed on a particular building without the need to seek planning permission. Operators have managed to effectively get around most of the restrictions by claiming that they offer "a mobile phone network" that uses both GSM and 3G and allows them to have GSM900, GSM1800 and 3G counted as "one system".
Small antennas and 'de minimis' developments
These do not need full planning permission. Small antennas can be fixed to most existing structures and no permission is required, just notification. 'De minimis' additions are outside of planning and are considered as those which are not being development within the meaning of Section 55 of the Town and Country Act 1990 (subsection 2), and not materially affecting the external appearance of the building or other structure. See: link for further information about such base-station antennas.
Breaches of output conditions
Planning permission is solely granted on the condition that the exposure guidelines are not exceeded. In practice it is most unlikely that masts will ever exceed the high ICNIRP Guidance levels that are currently in force.
Planning Policy Guideline 8 (PPG8)
In August 2001, the UK Government announced the revised PPG8 on telecommunications. This should be read bearing in mind the following points:
(Notice No. 12 HC 330 had suggested "Operators should make a declaration that emissions likely to be produced by a new base station are 'as low as reasonably practicable', as suggested in the Stewart Report".
In summary, there is usually little you can do to oppose a new mast. If you act quickly then you can insist that other sites are considered. However, most masts are now sited in residential areas to cope with the large number of mobile phone calls residents are making from their houses and so there is limited scope for using alternative sites. The "radius" for fill-in coverage is often only several hundred metres and in towns and cities small base stations are sometimes necessary every 50 to 100 metres in every direction! People need to greatly reduce their mobile phone use to avoid more base-stations being installed close to their homes (often on lamp-posts now).
How can I find out when a mobile phone mast was erected?
The best place to find out is the local council. If planning permission was necessary to erect the mast, they should have the records. If planning permission wasn't needed, and it was the subject of a General Permitted Development Order (GPDO), the council may have the information as operators often inform the council, though they are not obliged to do so in all circumstances.
If the council do not have the details, you may want to contact the operator direct, either from the information on the mast, or through the sitefinder website query section.
Are phones with low SARs safer?
SARs are one way of measuring the amount of radiation emitted by a mobile phone. The higher the SAR, the greater the amount of microwaves that are likely to be absorbed by the head. New phones in the UK are forced by law to display maximum SAR levels in the manual that comes with the phone. Unfortunately, most phones and their accompanying manuals come in blister packs, so you will not have sight of the manual before purchase, unless you ask to see a copy of the appropriate manual that shopkeepers have assured us they will have available for customers to see.
Using SARs for comparison, German scientists from the Institute for Satellite and Mobile Communication, reported that some models of mobile phones expose users to up to 20 times more radiation than others on the market. They produced a list of 25 models of phones together with their SARs, which became out of date almost immediately because phone manufacturers bring out new models and old ones become redundant at a quicker rate than the list can be updated and accurate. We do not believe that lists of SARs are a useful guide to the layman, anyway, as SARs are based only on thermal effects, which is not what most concerned scientists are worried about.
The SAR values quoted for mobile phones assume that a mobile phone is transmitting at its maximum possible power for a period of 6 minutes. Depending on the location of the tissue, and the thermal conductivity of neighbouring tissue and local blood flow, 'maximum SAR' figures can vary over at least a 10-fold range. Dr Michael Kundi (from the University of Vienna) said that the mechanisms involved in keeping the temperature at an acceptable level for proper biological functioning could become exhausted, or the strain induced in the system might have some adverse effects in the long run.
There are considerable variations of efficiency of any given handset. In response to low signal strength, an efficient handset powers up less than an inefficient handset, thus exposing the head to lower radiation. Some phones with a high peak SAR actually produce lower SARs under normal use conditions than phones with a low peak SAR, sometimes with a power reduction factor of up to 1000 or even several million-fold with 3G/UMTS handsets.
The power level that a mobile phone operates at during a call depends on the quality of the radio link to the base station. If the link is good (lots of bars), a low output power level will be used, whereas if the link is poor (few bars), a higher output level will be used.
When you have the choice, you could always use an ordinary wired land-line telephone in preference to your mobile phone. If you need to use your mobile, you could always protect yourself with a phone pouch, or a hands-free headset, which significantly reduce the emissions to your head, whatever the SAR of your phone.
How do I know whether I can trust the research done to support mobile phone EMF safety microchips?
Evaluating the usefulness of support documentation for devices that protect against EMFs:
1. Valid Citation
All citations for studies and papers should be correctly referenced, mainly so that it is easy to validate that the person stated as the author exists, and the organisation they work for has a recognised authoritative voice, with any potential biases expressed or likely to be known by the wider scientific community. For an author not to put this information on a paper is highly dubious. Normally, the front page will also include information regarding the journal that the paper was published in, or the conference at which the paper was presented.
Example of good citation
An example of a report giving less than adequate citation
Not only is Taylor a highly common name, but with no other title, nor any links to any institution that he or she belongs to there is no way of validating whether this person exists. The study location also is rounded down to a relatively large city in Australia - once again, no way of checking whether it was ever done.
It is also highly likely that the "study" is not published in a scientific journal of any kind, nor is it likely to have been presented at a scientific conference, as if it were, there would be some kind of reference to it here.
2. Experimentation Method
Experiments should give details of the participants, and as much information as possible on the environment they were in at the time of experiment. If doses / levels of substances or other such values are used, the reasons for using these values should be explained with citations where appropriate.
Example of good methodology (taken from a 3 page methodology)
An example of a report with poor methodology
Certifying a device used in a study indicates that it has passed electric and electronic safety testing, but as such there may not be any reasonable evidence to suggest it has the ability to measure what it claims. This is especially true when the units of measurement in question may be unusual and not used in regular scientific experimentation. The device may not have adequate scientific backing from scientists other than those in the particular piece of research referred to, and a small number of worldwide users of a device does not necessarily mean that its ability to diagnose any medical problems is assured.
The measurement scale of, e.g. 0 - 100, also has no clear meaning, without defined, recognised units. It may be that something very useful is being measured but if so there should be some explanation of how the technology works. In actual fact, many devices are well known for being used for "false diagnosis" - this may be largely due to the fact they do not measure what they purport to, or anything that anybody else recognises.
Whilst a small number of people can be good to look for initial trends, larger numbers are needed to make general claims. It is important to show how study participants are chosen, what potentially important factors has been looked for, and the environmental conditions that the experiment was conducted in. Without these it is likely that the paper would be rejected in its entirety even if it was submitted to a journal for publishing.
3. Results and Conclusions
Results and conclusions should be based firmly on what was tested, with appropriate reservations and tentative hypotheses, as necessary, clearly expressed as such. No extravagant claims should be made which appear to be out of context, or are unsupported by the research findings.
With regard to devices that are supposed to protect against microwave radiation, there are some companies which claim that using their device makes the person healthier than normal. This is clearly bizarre, and should be regarded as suspicious. Claims should be not only supported by the research, but by common sense as well.
The conclusions should be more than a statistical summary of the results. There should be an explanation as to how the results are actually achieved experimentally, and some comments to explain the results produced, similar to the following examples:
There should be references to other work that show similar results or that look at closely related science, and how the current study fits into the ongoing scientific debate. The following is an example of some references that you would expect to see in standard research.
Research that does not at least partially address all of these issues is likely to have been poorly conducted. Studies without good independent research backing up the findings with a plausible explanation, need to be further investigated before being accepted as a valid evaluation of a product.
Do answer phones for ordinary and cordless phones give off EMFs?
The only way to be sure whether or not the answer phone attached to your phone is giving off EMF radiation is to measure the fields. A suitable meter to do this is the EMFields PRO meter.
Are Digital Cordless Phones (DECT) dangerous?
There has been quite a lot of publicity about the research showing that using digital cordless (DECT) phones results in similar adverse health effects as using a mobile phone, including the risk of developing brain tumours [1,2,3,4]. This research seems to be scientifically sound and the evidence for problems is growing.
It seems that because of their convenience, people, such as teenagers wanting privacy from parental ears, talk for long periods of time on cordless phones. Unfortunately, it may have unforeseen consequences that neither they nor their parents could have anticipated.
There is a more detailed free article on DECT phones in the EMFields library.
We do not discuss particular models of DECT phones, as these are changed too rapidly for us to be able to assess them.
 Hardell L et al, (2006) Pooled analysis of two case-control studies on the use of cellular and cordless telephones and the risk of benign brain tumours diagnosed during 1997-2003, International Journal of Oncology 28:509-519
Why do I still get ES symptoms when I'm using my corded landline?
If you are close to a source of RF noise (e.g. a neighbour has a DECT phone, or WiFi), then in some circumstances your landline may pick up this "noise" and re-radiate it along the line. If you are electrically sensitive, you may react to this in a similar way to the reaction you get when using a mobile or DECT phone, although the symptoms would usually be milder. You can screen this RF noise out by using one of our ADSL / ferrite filters.
At Your House
Why do I have high ambient levels of magnetic fields in my home?
If you have high levels of magnetic fields in your home that you cannot easily pin down to electrical equipment, it may be due to faulty wiring or net / stray currents.
What are net currents?
Substations supplying an area with electricity are interconnected in a way that is intended to ensure a constant voltage supply, to avoid equipment malfunction. Some properties have high levels of magnetic fields as a result of a fault or faults having developed in the supply cables between two substations. This produces an unbalanced or net current.
The net current forms a loop between the substations and because it isn't balanced out by a current in the opposite direction (as it would be in a single cable carrying both 'go' and 'return' currents) then it can create quite high EMFs over a wide area.
Magnetic fields coming into a property from outside are usually from underground cables carrying the power supply from house to house, often running under the pavement outside. If there is no front garden or the property is a basement flat, the magnetic fields could be quite high even without net currents, but should fall off rapidly as you move away from the cables by a couple of metres.
If the magnetic field in a property is higher that usual (say above 0.1 microtesla) and is similarly high throughout the ground floor, the house is likely to be within the net current loop, which can affect a few houses, or even a few streets. If the field drops away slowly, as you move away from the source, the property may be affected by the net current but not within the loop.
Net Currents and Stray Currents
Stray currents are net currents that have transferred to metal water or gas pipes, or even to the Earth itself. In most UK areas the final electricity circuits are connected as Protective Multiple Earth (PME) circuits. This connects the Neutral conductor to Earth every hundred metres or so. Undetected faults in the Neutral conductor lead to currents transferring to the Earth (damp earth is a surprisingly good conductor), which then also 'takes rides on' any underground metal pipework. The effects of raising EMF levels are similar to simple Net currents but it is usually harder to locate the problem and cure the fault.
Usual drop off distance from a supply source
With powerlines, magnetic fields reduce with the square of the distance. That is, if you double the distance from the source, the magnetic field levels are a quarter the strength. With substation transformers, the fields fall off even faster.
How do you know whether a property is affected by a net current?
Because net currents arise from an uncorrected distribution fault, they are unpredictable. The only way to find out if a property is affected is by measuring the magnetic field levels and determining whether they reduce as predicted above, or whether they fall away very slowly, or hardly at all. The last two instances mean that the property is likely to be affected by net currents. Your decision as to whether to buy or rent such a property may be affected by this discovery. A suitable meter to do this would be the EMFields PRO meter.
Responsibility of electricity supply companies
Electricity supply companies see their responsibility in terms of ensuring power distribution at accepted voltage supply guidelines i.e. 230 volts +10% - 6%, rather than minimising electromagnetic field levels to customers. Therefore, if a fault develops which results in net currents affecting some properties, they usually do not feel the need to do anything, as the supply is unaffected.
Proving a Net Current problem
You need to plot the fall off of magnetic field with distance to the cable using a suitable meter, such as the EMFields PRO. If the EMF level falls off more slowly than with the square of the distance, then you probably have some degree of net or stray current involvement.
The graph, below, assumes you measure 5 microtesla measured at 1 metre from the source - you will have to scale it for other values of starting magnetic field level. If it falls off at or below the thick middle line (square) then net or stray currents are not a problem. The higher the readings are above this line, the more net and stray currents are a part of the problem. If the readings are above the top dotted line then it is likely that there are a number of stray current problems in the area.
There is a caution with regard to these fall-off curves. If the starting level at one metre away from the main source (e.g. the cables under the pavement) is less than about 0.5 microtesla, then the fall-off will slow down rapidly as in most residential areas there is a background level everywhere of about 0.02 or 0.03 microtesla and the fall-off below about 0.05 microtesla will be very slow.
Are there wall insulation materials that can stop incoming microwaves?
Some insulation materials that look like metallised plastic do screen against microwaves, some do not! There are too many brands and types (models are changed from time to time, which may well have different properties to the ones tested) to be able to provide a definitive list of ones that do and ones that don't. You often cannot tell by looking at them. The only way to find out for certain is to test with an instrument such as the Acoustimeter, before screening large areas.
Where can I find an electrician who understands about house wiring for low EMFs?
We know of very few who understand the issues and are effective at wiring or remedial work to achieve low EMFs in homes. They must exist, but you will have to contact people locally and ask them about their understanding, knowledge and expertise and make your decision based on their answers. There is an excellent free article on the article site, which should give an electrician who wishes to develop his or her expertise the information they need to do the job well.
Any we do know of will be added below when we find them, or if they contact us.
Paul Goulding, Arnold Electrical, Unit 3A, Sherbrook Enterprise, 100 Sherbrook Road, Daybrook, Nottingham Tel: 0115 920 9816 (added Jan 2012)
What is the best way to wire a house to reduce electromagnetic fields in the home?
The current UK practice of wiring a house using 'ring' circuits can often lead to high electric and magnetic fields. In Europe 'radial' or 'tree and branch' wiring is more common than in the UK and these result in much lower levels of EMFs in buildings.
In addition, running wires in metal conduit will reduce the fields to virtually zero. For new build homes this is the best option.
There are different types of screened cable available when running wires in metal conduits is not possible.
Mineral insulated cables can be expensive to install, some are fire retardant and are likely to need extra residual current devices or RCDs. There are difficulties with some braided cables which need earthing at every junction point, and some need extra space to allow for the necessary larger bending requirement.
Most cables, including reasonably priced, flexible cable can be bought from an electrical goods supplier, such as used by professional electricians. Very competent DIYers can also re-wire houses, but it is important to remember that it is now illegal for unqualified people to undertake major electrical work without formal independent third-party inspection and test.
"House wiring and EMFs", which can be found in the free article library, has detailed information about the different types of circuit, cable specifications and what type to use in which situation, for the use of the competent DIYer, or professional electrician. demand In the UK only competent people can make wiring changes and the house wiring will require Part P inspection, testing and certification before you can sell the house.
"House wiring and EMFs", which can be found in the free article library, has detailed information about the different types of circuit, cable specifications and what type to use in which situation, for the use of the competent DIYer, or professional electrician. In the UK only competent people can make wiring changes and the house wiring will require Part P inspection, testing and certification before you can sell the house.
Which creates the strongest RF signal, DECT phones or WiFi?
DECT signals are almost always a lot stronger and more continuous than WiFi signals. Neither are WiFi signals very 'active', that is, they have lots of gaps in them, unless someone is downloading very large files or a video stream. WiFi signals generally fall off very quickly.
Both can be blocked with paint or screening material, however, low emission phones such as the Siemens Eco DECT-PLUS, or dLANs instead of WiFi will enable these emissions to be considerably reduced for less expenditure.
Change your equipment, encourage your neighbours to change theirs.
I have RF radiation coming through a laminate floor. Can I screen it?
It depends on whether your laminate can be lifted and replaced, some don't take kindly to being taken apart. If it does come apart, lift the laminate and put a good layer of aluminium cooking foil underneath. The cooking foil should be 'earthed' in at least one place to a metal water pipe or the mains electricity safety earth. This prevents increasing the levels of power-frequency electric fields in the room that would otherwise occur. Re-lay the laminate on top of the earthed foil.
If the laminate floor resists being lifted and replaced, you may need to seek an alternative method.
How long will the screening paint continue to work?
The manufacturer of the YShield paint have said that the top coat of paint (the paint you use to cover the black) will deteriorate and need repainting long before the screening properties of the screening paint underneath will.
Yshield paint has been around for many years and the paint is just as effective after ten years as it is after two days. We have good reasons to believe that the UK-made Blocpaint (by an ISO 9001 company) will be just as effective, but it hasn't been around long enough yet to check this out. There has been no change in effectiveness after 3 years (2011).
Why does my Acoustimeter have problems picking up WiFi/wLan in some places?
A WiFi/wLAN receiver is tuned to be extra sensitive at WiFi frequencies so that it can detect the signals over a considerable distance.
Typically 5 millivolts per metre (0.005 V/m or c. -79 dBm/m2) will give an indication of a "full strength signal" and the system will be able to work at full speed (11 Mbs upwards depending on the technical Standard and frequency band being used).
1 mV/m (0.001 V/m or -86 dBm/m2) will give a good performance.
WiFi/wLAN Access Points are generally 200 mW or 500 mW. 200 mW generates about 2 V/m at 1 metre, 0.2 V/m at 10 metres, 0.02 V/m at 50 metres clear line of sight (no obstacles). In buildings these fall to more commonly 0.05-0.1 V/m at 10 metres, 0.02 V/m at 5 metres distance.
Longer ranges can be achieved by using a good external antenna with better gain. + 15 dB can easily be achieved.
The receivers in mobile phones have similar sensitivities though some can pick up SMS messages at -102 dBm/m2.
The Acoustimeter should record a WiFi/ wLAN working in a laptop when it connects. Typically this would read several volts per metre peak about 50 cm from the screen. It is possible that some laptops have adaptive power control and the wLAN access point is actually fairly close, in which case the signals from the laptop will be much lower even when transmitting.
The Acoustimeter is a broad-band measurements device for assessing human exposure. Its lowest reading is at 0.02 V/m (20 millivolts per metre) peak signal strength.
We know of no scientific or medical reports showing that levels below 0.05 V/m affect people, though there may be people with extreme sensitivity who might react to levels below this; fortunately such sensitivity is uncommon.
Why is my laptop giving off microwave (RF) radiation?
Most laptops now are sold with WiFi built-in, as it is assumed by the manufacturers that they will be used at home with a wireless internet system, or whilst the purchaser is 'on the move'.
If you do not wish to use it in this way, you may want to disable the WiFi system as your laptop will continue to radiate RF until it is disabled. Laptops vary as to how to achieve this, so we recommend that you look at the manufacturer's instructions to find out how this can be done. You may need to contact them directly if it is not clear.
Some software updates may re-enable your WiFi system, so it is worth while checking every now and again to ensure that the wireless capacity remains disabled.
Increasingly, laptops are being sold with a Bluetooth capability as well. This may be situated in a different part of the laptop to the WiFi circuitry, and will have to be separately disabled. Again, we refer you to the manufacturer's instructions or we suggest you contact them directly.
If you are unsure whether your laptop is emitting RF radiation or not, you can easily find out by hiring or buying one of EMFields RF monitors.
Is it true that trains are all going to become WiFi enabled?
Many people who suffer from electrical sensitivity are finding it harder to travel by train. Far from 'letting the train take the strain' they are increasingly being excluded from access to public transport. One person told us "I couldn't contemplate taking a train journey in a carriage offering wireless internet facilities. I get headaches after 10 minutes of exposure to radiofrequency radiation." She continues "electrosensitives will become increasingly isolated from work places and public spaces."
Travellers exposed frequently to these microwave sources may well develop electrical hypersensitivity, with all the lifestyle changing problems that this diagnosis carries with it.
Many railway stations now offer online internet access for use by business passengers waiting for trains on platforms or in the waiting areas. There is sometimes a charge for the service that may put off people wanting to use the system to watch video or play games or music, but many may decide to use the system to pass the time.
Almost all long-distance UK trains now have at least some WiFi Access. Many have all the carriages with active WiFi - this is terrible for EHS people. As the availability of WiFi is increasing all the time, you will need to ask your train operator which services and which carriages have active WiFi installed.
I don't want a WiFi connection to broadband internet - what options do I have?
To connect to the internet, you need one of two things: either a cable connection (via a company such as NTL) or a standard phone line. With old-fashioned dial-up internet the computer communications will use the normal voice line and you will not be able to use the telephone at the same time, unless you have two lines (and separate numbers) for the telephone and for the dial-up modem.
However, modern internet connections normally use a technology called ADSL (Asymmetrical Digital Subscriber Line). This technology needs to be enabled at your local telephone exchange, but almost 100% of the UK (as of Summer 2011) is now supported. Lowest is in rural Scotland where it falls to only 98%. Many areas now have super-fast SDSL (Synchronous Digital Subscriber Line). Contact your phone provider (for example BT) and ask them if they can provide broadband to your house - if so they are also likely to be able to send a package containing all you need to connect your computer to the internet (modem, ADSL filter and cables). The modem enables the computer to connect, and the filter ensures that you can use the telephone at the same time as the internet (with only one line) without having either service compromised. We do not recommend wireless (WiFi) modems and recommend non-wireless Routers (rather than modems) as they provide a "firmware firewall" which makes it very difficult to hack into your computer and steal your personal information.
Both cable and ADSL.SDSL internet connections are entirely free of microwave EMF emissions, and we have no reason to believe they could be a risk to health.
It is very important however, if you are concerned about health effects from wireless communication devices, not to use one of the "BT Home hubs" to connect your computer to the internet, as they act as both a wireless access point (WiFi) and a DECT base unit (cordless phones) whenever they are powered. For an alternative, ask in your local computer store for a non-wireless "router" - there are a number of brands that manufacture these, and they are very secure, reliable and require very little setting up.
I have more than one computer and want them all to be able to use the internet - do I have to use WiFi?
No, not at all. If you have purchased a router for your internet connection (see FAQ above), then you will have a number of network "ports". These are the sockets at the back of the router that you plug the network cable from your computer into. You can have as many computers as you have ports provided you have a cable for each. The router will make sure that the machines can all share the internet at the same time. If you need more connections, then you need to purchase a multi-way Ethernet "switch" which can provide many more connection sockets. They are not expensive.
One of the computers I need to connect to is in a different room - I have a laptop I would like to use in different rooms - do I have to use WiFi?
Again, Wifi is still completely unnecessary. The best options for this is using two dLAN units, which can connect computers and laptops using the electrical power wiring in the building. The units are plugged into a standard power socket on the wall, and have a computer network port for attaching the laptop or computer to. Plug one into a socket near your router (see two FAQ points above if you are unsure whether you have a router or what one is) and connect it to the router with normal computer networking cable. The whole house wiring should now be connected to the network, and you can use the other dLAN unit in any room you would like to use your laptop in - just plug it in, turn it on, and connect the laptop via computer networking cable.
If you need to earth your laptop when plugged into the mains because of sensitivity to the high electric fields it causes, then you will also need to earth the laptop when connected to dLAN units. You will also need to earth ANY laptop running on internal batteries when connected to a dLAN or the mains-frequency electric fields at the keyboard will rise substantially.
Home Networking: What are these Homeplug/dLAN devices and are they a viable EMF-safe alternative to a wireless LAN?
Homeplug devices, also referred to as dLAN devices, are an alternative solution to Wireless LAN. They connect to one another through the mains wiring in a building, allowing access to the network/internet from any mains socket in the building.
What kind of EMF's do they emit?
Homeplug devices do add RF noise to the mains wiring. However, the levels we have measured (a few tens of microvolts) are negligible in comparison with Wireless LAN devices, and what increase in fields that we did see was only in very close proximity to mains wiring (within a few tens of centimetres). Since we already advise against spending large amounts of time in such close proximity to mains wiring, we believe that the fields generated are unlikely to cause problems other than in the the most highly electrically sensitive people.
We still think that wired Ethernet is the best option, however Homeplug devices seem to be a reasonable compromise provided that you are aware that there are potential problems, and we consider it to be vastly preferential to a Wireless LAN.
There are additional security considerations when it comes to dLANs. Because they use the mains wiring to transfer data, this means that anybody on your wiring circuit can add their own dLAN unit and listen to the network traffic. Since most houses have their own wiring circuit, this is only relevant in shared housing and some flats.
Are the concerns about the health effects of using Wireless Local Area Network (wLAN) systems in school classrooms unfounded?
A number of schools have dismantled their wireless networks after lobbying by worried parents and teachers, and others are under pressure to follow suit. We ask whether this level of concern is warranted.
The technology used in wireless systems, such as wLANs is novel in human evolutionary experience. This part of the electromagnetic frequency spectrum was virtually silent for most of humanity's evolution. Human biological responses have not had sufficient time to adapt to deal with the levels of radiofrequency we are beginning to surround ourselves with.
Wireless networks involve daily exposure of children, or of staff members, to microwaves in enclosed environments. WLAN systems emit radiofrequency (microwave) radiation into the rooms they are used in, and the emitted radiation levels could be made worse because of building characteristics using microwave-reflective structures such as reinforced concrete or metal joists, or classroom furniture made of steel, etc.
The UK guidelines that limit public exposure to microwave radiation have been set at a level which adequately protects us from the acute effects of thermal damage. What we know from some of the research that has been done is that body tissues respond to electromagnetic fields at very low levels indeed, small fractions of the allowed exposure levels.
We know that there are specific parts of the electromagnetic frequency that seem to elicit biological responses, whilst those parts above and below may not have the same effect (the window effect). It also seems that a biological response is not necessarily dependant on the amount of power that the person is exposed to. It is not a matter of more power producing a greater response.
Formal laboratory studies usually do not allow for a) the window and power variations referred to above, or b) the different susceptibilities within the population. Not everybody seems to be affected (like not everybody reacts badly to penicillin or peanuts).
It seems that the effect is cumulative rather than purely instantaneous, and that cascade effects, from gene expression to protein modification, to cellular ion transport are all affected.
Pulsing signals such as those used in WiFi systems appear to elicit a stronger response than those with just a steady carrier signal.
The symptoms that have been consistently reported include:-
Many of the reports come from real life community exposure to the sort of radiofrequency radiation that children are likely to be exposed to in school classrooms where wLAN systems are in use. Interactive whiteboards can also add to the electromagnetic field levels in the school.
It was reported in December 2011 that 1 in 10 secondary school pupils suffers from ME, characterised by overtiredness, problems in memory and concentration. We do not know whether the prevalence is higher, lower, or the same in schools which have WiFi in comparison with those that don't.
These symptoms are certainly not the ones we would like to see our schoolchildren suffer unnecessarily. The educational system is not finding it easy to meet its attainment goals, and schoolroom aggression appears to be on the increase. These trends are likely to be due to a number of different interlinked causes. But if microwave radiation may make the situation worse, we believe it is a good idea to think about introducing radiating systems into the school environment.
It is usually the formal laboratory studies only which are referred to by many authorities, including the UK's Health Protection Agency, who conclude that there is no risk to anybody, although some international organisations are not quite so dismissive. ICNIRP, the European regulatory body, whose guideline limits have been adopted by the UK government, concluded after a literature review "Results of epidemiologic studies to date give no consistent or convincing evidence of a causal relation between exposure from radio frequency fields (RFs) and any adverse health effect. On the other hand, these studies have too many deficiencies to rule out an association. Despite the ubiquity of new technologies using radio frequency fields, little is known about population exposure from RF sources, and even less about the relative importance of different sources."
A recent report from the Organisation for Economic and Co-operative Development (OECD, an international organisation helping governments tackle the economic, social and governance challenges of a globalised economy), looked at the educational achievement in schools in 32 countries. The researchers found that the pupils' performance in maths and reading dipped among students who used computers every day either at home or school.
The Vienna Chamber of Doctors has warned that wLAN emits high levels of radiation. The Public health department of Salzburg has specifically warned that wLAN and DECT should not be put in schools and nurseries. The German Doctors appeal, the Bamburger appeal, also now includes a warning about wLAN. The German teachers' union has told its members to resist the rollout of wLAN into schools in Germany on safety grounds. Lakehead University in Canada has decided not to put in wireless computers as the technology they use has never been tested and so not proved to be safe.
Are parents' and teachers' concerns about wLANs in schools unfounded?
Powerwatch believes that the studies that have been done on microwave exposure, both occupational and epidemiological, together with the experience of residents of communities with mobile phone masts (who experience a similar sort of level of radiation as will be found in a school classroom with a wLAN system), are sufficiently consistent to raise the question as to whether living and studying in places with microwave radiation at low levels is without health effects for at least some members of the general population. It may be that only a certain percentage of the population is, or will ever be affected by this form of environmental pollutant. As there are no biological markers that have yet been discovered to identify those who are affected in this way as compared with those who are being affected by something else, the situation is likely to remain unclear for some time.
Meanwhile we think that a precautionary response is the appropriate one.
Computers can be linked with wires. This method has never been associated with health risks, so whilst further investigation takes place in real life situations and not just in the laboratory, we recommend this way of making the new computer technology and internet access available to our young people.
Are games consoles safe?
Many games consoles, especially older ones, are no different to most other standard household electronic goods and should not expose you to significant levels of EMFs.
Some of the latest-generation consoles (XBOX 360, Nintendo Wii, Sony Playstation 3) are all wirelessly enabled. These all have the capability to have wireless controllers, and have either integrated or add-on WiFi. Some modern handheld consoles (Nintendo DS, Sony PSP) also have WiFi built in.
There is currently no research either way on WiFi at the moment, however WiFi enabled devices give off similar strength EMFs as an average Mobile Phone Mast would give at under 100m. There is strong scientific evidence for mobile phone masts causing a variety of serious health issues, so we consider it prudent to take a precautionary approach and avoid prolonged use of WiFi enabled devices.
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