All the dangers assocaited with technostress are not completely understood. The nature of EMF is very complex and the number of EMF sources are rapidly growing.
The entire effect of multiple electromagnetic fields on human physiology is something we are learning more about. However, it is well known that low-frequency magnetic fields can trigger major biochemical responses critical to the functioning of human cells, which operate by complex electrochemical processes. The entire consequences of living in our EMF world may not be known for decades.
Virtually all research on the serious health effects of man-made EMF has come to the conclusion that the adverse health responses from EMF are from long-term cumulative exposure.
Measurements of EMF from common sources.
Remember EMF exposure depends not just on strength of fields, but on proximity and duration of contact.
EMF in milliGauss
|Source||Up to 4 Inches||At 3 feet|
|Blender||50 to 220||0.3 to 3|
|Clothes Washer||8 to 200||0.1 to 4|
|Coffee Maker||6 to 29||0.1|
|Computer||4 to 20||2 to 5|
|Fluorescent lamp||400 to 4000||0.1 to 5|
|Hair dryer||60 to 20,000||0.1 to 6|
|Microwave oven||100 to 500||1.0 to 25|
|Television||5 to 100||0.1 to 6|
|Vacuum cleaner||230 to 1,300||3 to 40|
Power-lines radiation and effects on human health
- The magnetic field from a powerline decreases with distance, but the magnetic field from a powerline varies from moment to moment depending on how much current is flowing in the wire at the time.
- It will be higher during peak electricity usage times. So the only way to know how strong the field is at a given distance, at any particular moment, is to measure it with a gaussmeter . It is recommended to take multiple measurements at various times during the day.
- There could easily be additional sources of field. They might come from underground wires, ground mounted transformers, or even common sources within the home. They will add to the strength of the field emitted by the powerlines. Either field alone could be within tolerable limits, but could possibly exceed tolerable limits when combined.
- The safety or danger of a magnetic field from a powerline depends on more than just the strength of the field. Some research has shown that harmonics (higher frequency fields), radio-frequency signals in the line, and power spikes may have more to do with health effects than just the normal 60 Hz magnetic field.
- The time of day that you are exposed may be very important. Some research shows that exposure during sleep may be more harmful than exposure during waking hours as it affects the melatonin balance which is a hormone that, among other things, fights cancer cells.
- Whether you are located upwind or downwind of the powerline may also be important. Recent research has shown that the corona field around high tension lines can ionize the air around the lines. This ionized air has been thought to attract and concentrate radio-active particles and automotive pollutants that can be harmful.
- There are probably other factors which determine how much EMF your body can tolerate, such as genetic predisposition, how much exposure you receive at work or school, your age, your exposure to harmful chemicals (pesticides, preservatives, etc.) which may be activated by the EMF, your overall health, and so on.
We do not know how much exposure is safe or harmful
While there are official standards for exposure to electric and magnetic fields, they are based on the amount of field needed to cause immediate harm.
There is plenty of evidence to show that biological effects occur at levels well below the standard limits.
In the end, we are each left to decide how much exposure we are willing to accept.
One rule of thumb that is used by some experts is that you should limit your exposure to 60 Hz magnetic fields which are in excess of 2.5 mG. There is not a lot of scientific evidence to support this recommendation, but it is based on the Swedish recommendation for exposure to ELF fields from old fashion computer monitors.
You should get a gaussmeter and make some measurements. At least find out if the fields from the powerline exceed the 2.5 mG guideline.
Reducing Exposure to Magnetic Fields
In general, there are 5 ways to reduce your exposure to magnetic fields:
- Reduce power to the source (if there is no current, there will be no field).
- Apply shielding to the source.
- Apply shielding to yourself.
- Increase the distance between yourself and the source.
- Cancel the incoming field with an equal and opposite field.
Appliances and a Rough Guide to Technostress
The EMFs appliances give off vary greatly from one make and model to another.
The only sure way of knowing is to obtain a meter and measure them.
Houses where large magnetic fields are produced by unseen and un-noticed wiring faults, usually in the power ring-circuits. The only way to determine this is to carry out some loading tests when measuring the fields with a meter.
Alarms plugged in to the mains should be at least 1 metre away from the baby’s bedhead. Battery operated, wire-connected, alarms give off virtually zero fields. The walk-about ‘freedom’ alarms radiate radio-frequency energy next to the child in order to communicate with the parents listening unit.
Chairs (motor adjustable recliners)
There are enormous magnetic fields (several gT) being given off all the time from some of these chairs.
Digital – 200-500 nT @ 30cm, 50-100 nT @ 1m
Analogue – 400-800 nT @ 30cm, 100-400 nT @ 1m
Electrically powered clocks/clock-radios should be at least 1 metre from your head. In older analogue clocks, higher magnetic fields are produced by the motor. Battery driven clocks produce negligible fields.
Most modern computers give off quite low levels of fields. As always, to minimise EMF exposure try to keep the computer as far away from your body as is practical.
It is worth remembering that magnetic fields travel through walls, so watch the use of the next room.
Lap Top Computers – Generally these give off very low EMFs. However when run from the mains adapters they can give off very high electric fields next to the keyboard and display (several hundred volts/metre).
This can cause sensitive people severe problems. The answer is to charge them up away from where you sit, and then run them off their internal re-charged batteries, or run an earth wire from the case to earth.
These usually have a mains transformer which plugs into a power socket. Unplug them when not in use. Some give off quite high levels of electric fields, but it does not seem easy to predict this.
Cookers (electric ovens & hobs):
These give off high magnetic fields when operating (often several microtesla close to). Try to keep as much distance as reasonable while cooking.
Underblankets and overblankets give off high fields. They should always be switched off before getting into bed. Unless you have 3-core screened cable attached to the blanket, it should be switched off at the wall (otherwise the wire will still give off electric fields between the socket and the blanket switch).
This is one place where a ‘Demand Switch’ is useful. Electric overblankets, designed to be left on, are usually run from a low voltage transformer. Both the transformer and blanket give off even higher magnetic fields. Do not use such a blanket if you are concerned about EMFs.
We recommend using re-chargeable battery shavers which are easily available. Mains shavers give off very high electric and magnetic fields. Battery shavers still give off high mixed frequency pulsed magnetic fields.
Be wary of these. Some of the modern high-frequency ones give off high levels of VLF (2kHz-200kHz). Ordinary ones produce high magnetic fields from their ballast coils. The compact fluorescent globes have the additional issue of mercury bein used in the manufacturing process
These give off high fields and are very variable, giving up to 70 microtesla at 15cm (6″). Hligh magnetic fields near the head in the evening are known to interfere with the production of melatonin by the pineal gland. This hormone is responsible for cell re-generation (and is known to have anti-cancer effects) and mood swings (including depression).
It is best if hair dryers are not used after 7.00p.m. at the very latest because of this pineal gland effect.
There are no known EMF problems, though Electrical Sensitives can have symptoms provoked.
Hi-fi, music centres
These can give off high magnetic fields, but the problem is usually high electric fields. Make sure the system has a decent electrical earth connection to the mains supply. This will remove most electric fields.
The heater and its associated wiring will give off high magnetic fields. Bedheads should be at least 1 m away from the immersion heater cupboard wall. Central heating water pumps also give off high magnetic fields.
Some ionisers contain a transformer and give off high magnetic fields. Some only have two-wire mains leads and give off high electric fields. It is worth making sure that they are at least 1m away from a usual sitting or sleeping place.
Lights give off quite high electric fields. Metal framed lamps can give off very high electric fields due to the practice of wiring lights with two-core flex. Always use three-core flex and connect the earth wire to the metal frame. We recommend using screened mains cable for bedside lights.
These are often measured by Electricity Companies to demonstrate what high fields exist inside people’s houses. They can give off up to 30 microtesla at 15cm and 2 microtesla (2000nT) at 1m. They can also leak microwave radiation. Whilst in operation, we recommend that nobody stands nearer than 1m from the oven. If the kitchen is small, it is a good idea to encourage children to stay out of the kitchen whilst food is cooking.
These can give off` very high magnetic fields close to. Stand back at least 50cm. Always have good ventilation as the ozone given off by the copier is affected by the surrounding electric fields.
The motors give off high magnetic fields. Some machines with two-core mains cables give off high electric fields. Statistically significant increases in breast cancer and Alzheimer’s disease have been detected in machinists using industrial machines.
Electric sockets give off electric fields unless metal conduit and metal-clad sockets are used. High magnetic fields may also be generated by the ring-circuit wiring.
Up to 300nT at 1 metre. Night storage heaters should always be at least lm. away from the bed to minimise fields in which people sleep.
These give off high electric and magnetic fields as well as possibly dangerous levels of ultra-violet radiation.
Telephones: (see also Mobile Phones)
Ordinary wired telephones are not usually a problem, though some Electrically Sensitive people do have problems.
Modern televisions, unlike their earlier cathode tube predessessors, give off very little EMR. They can still have a significant EMF presence. This will vary on the models and how the electrical equipment is designed. Always sit at least lm away from the front of the screen.
Smart TVs can create an EMF problem if they connect via wifi.
The cylinder type is better than an upright cleaner, as the motor and wires are further away. Up to 20 microtesla at 30cm. Hand-held cleaners can create high EMF next to your body.
Washing Machines, Dishwashers
These are included together as they are often pushed under work surfaces. Close to they give off high fields of several microtesla. Do not work close by these appliances whilst they are in operation.
These can give high electric and magnetic fields. The magnetic fields come from the water heaters. While on the bed one is very close to these fields so they can pose a significant problem.