Safe products FAQ

Mobile antennas( 11 )
A mast with mobile antennas has been erected next to our day-care centre/school. Is this safe?

Based on research the WHO has recommended the introduction of limit values for radio signals in residential areas. These limit values will depend on the frequency, and are set at 4.7 Watts per square meter for GSM signals (900 MHz) and 10 Watts per square meter for UMTS signals (2000 MHz). Telenor has chosen to introduce an additional precautionary measure: Indoor areas where people reside shall not be exposed to stronger radio signals from mobile telephony antennas than 0.047 Watts per square meter. For GSM, this limit value is 100 times stricter than the WHO's limit values and for UMTS the limits are 200 times as strict. For outdoor areas, Telenor abides by the WHO's and the Norwegian Radiation Protection Authority's limit values.

The signals from mobile antennas installed on masts or on house roofs/façades are so weak that the indoor signal strength will be below the Telenor limit values. This is also the case if the antennas are installed on the roof of a school or on a nearby building. The relevant values have been measured over several years, and confirm that the margins are acceptable. It is only if you find yourself directly in front of an antenna (i.e. in the same height and at the angle where the antenna is directed), and if you are less than 30 meters away that the Telenor limit values can be exceeded. To exceed the WHO's limit values you need to be closer than three meters from the antenna.

Radio signals from the Telenor antennas are transmitted in a fixed direction, similar to the rays from a flashlight. Below the antenna mast, or at ground level in front of a building with antennas on the roof or the façade you will never get signals as high as 0.047 Watts per square meter. The maximum strength of the signals near a mobile antenna mast, or near a building with mobile antennas on the roof or façade, will be approximately 0.01 Watts per square meter. A direct consequence of having mobile antennas installed in your local environment is that all mobile phones will transmit weaker signals. This is due to the fact that the signal only has to reach the nearby mobile antenna.

There is a mobile antenna on the roof of the block of flats where we live. Is this safe?

The radiation inside a building will often be lower if there is a mobile antenna on the roof, then if the antenna is installed on a neighbouring building. This is due to the fact that the radio signals are transmitted in a fixed direction, similar to the rays from a flashlight. Normally, both the GSM and the UMTS systems transmit in rays that are angled at approximately 5 to 10 degrees downward from the antenna. Horizontally, the signals are spread out in an approximately 35-degree radius in the direction the antenna is aimed. Behind, over, under and to the side of the antenna, the signal is only 1 to 10 per cent as strong as in the aiming direction of the antenna. It will therefore only send a weak signal down through the roof on which it is installed, and a similarly weak signal is registered behind the antenna and through the wall the antenna is installed on.
Telenor has decided that the maximum signal strength indoors in residential areas should not exceed 1 per cent of the WHO's limit value.

Is it safe for children to play near masts with mobile antennas?

If you are concerned about safety in relation to radiation from mobile antennas, you should be aware that masts with mobile antennas only emit very weak signals down on the ground and around the mast, in fact less than 1 per cent of the limit value. The maximum amount of radiation that can reach the ground will be directly in front of the aiming direction and at a distance of approximately 100 meters from the mast (but even there the radiation is very weak). This is due to the fact that the antennas transmit radio signals through a very narrow ray that is only to a modest degree aimed at the ground. If you find yourself directly below the mast, the effect is comparable to the light that strikes you if you fix a flashlight on your head pointing it straight ahead, rather than the amount of light that falls on you when you find yourself caught in the beam of the light from the flashlight.

How strong is the signal strength from a mobile antenna on a mast or building?

The effect from an outdoor mobile antenna is 10 to 15 Watts, sometimes considerably lower. You will have to be closer than approximately 3 meters (directly in front of the antenna, and at the same height) to achieve a signal output to match the level of the limit values of the WHO and the Norwegian Radiation Protection Authority.
To provide mobile coverage in scarcely populated areas, Telenor sometimes uses a low-effect transmitter or an amplifier. Both these devices have a maximum transmitting effect of approximately 1 Watt. This permits the antennas to be installed in areas that have a shorter distance to domestic buildings and other constructions without increasing the strength of the radio signals more than in other areas. Such solutions contribute to the widespread and extensive mobile coverage that Telenor is known for, and also reduce the signal strength from both mobile antennas and mobile phones used in the area.

How strong is the signal strength from an indoor mobile antenna?

As opposed to outdoor mobile antennas that are meant to cover up to one hundred square kilometres, indoor antennas are only meant to cover a few floors of a building within a radius of approximately 100 meters. The transmitted effect is therefore considerably lower than that of outdoor antennas. In addition, another type of antenna solution is also used occasionally, where the antenna is much smaller and where the signal is spread out in all directions, which means that no special area will be exposed to higher radiation levels. The amount of radiation emitting from an indoor antenna is comparable to the signal from an active mobile phone located in the same place as where the antenna is installed.

Why are mobile antennas installed on domestic buildings?

Mobile antennas that are installed on domestic buildings made of wood emit much weaker signals than regular mobile antennas. A typical effect volume would be 1-2 Watts, which is equal to what a mobile phone would emit in an area with weak mobile coverage. Mobile antennas on domestic buildings made of brick or concrete are normally of a type that emits up to 15 Watts. As the outer roofs and walls are made of brick or concrete, the radio signals are prevented from penetrating the building. 90-99 per cent of the signals outside walls or roofs will normally not penetrate such buildings.
The radiation inside domestic buildings will often be lower when it has antennas installed on its roof or on the façade, than if an antenna was installed on a nearby mast.

A number of antennas are often installed in the same place? Now that yet another mobile network is rolled out (UMTS), how will this effect the total radiation?

Both Telenor and NetCom hold GSM licenses for the 900 MHz- and 1800 MHz-frequency bands and UMTS on the 2000 MHz frequency band. Normally this will involve separate antennas for each frequency band. In some cases NetCom and Telenor will want to install antennas at the same location. Both operators will then be using their own antennas.

The same requirements apply regardless of whether an installation has one or more antennas. The limit values will never be exceeded in residential areas. Whenever Telenor conducts measurements at such installations, it is always the total amount of radiation that is measured. This will then be compared with the relevant limit values. Wherever a number of mobile antennas have been installed on the same construction, a number of these will normally be receivers, which do not emit any radio signals at all.

If several of the antennas of Telenor are aimed in the same direction, this will exclusively be because signals are transmitted from different mobile systems (GSM900, GSM1800 and/or UMTS) in this direction. These antennas will remove part of the total load by each receiving its share of the total amount of mobile calls. The total traffic volume in an area is normally not affected by the fact that new mobile systems are developed. The total radiation at a given site will therefore not necessarily be noticeably stronger.

Is the new 3G network, UMTS, more dangerous than GSM?

There are no indications that radio signals from the new mobile network will involve an increased health risk. On the contrary, there is much to suggest that radiation from UMTS equipment is lower than that emitting from GSM equipment. UMTS phones and antennas transmit with lower effect than GSM equipment. The UMTS frequencies are also somewhat higher than the GSM frequencies, which make them less capable of penetrating the human body. UMTS equipment does not transmit on constant pulses, as GSM does. Combined, this ensures that the WHO has introduced a less strict limit value in the frequency band for UMTS radio signals than for GSM radio signals.

Do mobile antennas constantly send out signals?

Yes. But in periods with low mobile traffic the radiation from the antennas will be lower. The difference is particularly great for UMTS antennas, where the transmitted effect from the antennas in periods with less mobile traffic is reduced to as little as 10 per cent compared to periods when mobile traffic is at its maximum.

Can we trust the limit values?

The current limit values are based on more than 30 years of serious research on radiation issues. This has led researchers to the conclusion that an increase in the temperature is the dominating biological effect of being exposed to radio signals from mobile telephony. The WHO has nevertheless chosen to introduce very high safety margins before fixing a maximum exposure effect on people. This is done to take into account any possible biological effects that so far, in spite of extensive research, have failed to materialise. The WHO's limit values were subject to revision in the latter part of the 1990s but no cause for stricter limit values could be found. In the EU, and in most other countries, the WHO's recommended limit values will be adopted as national guidelines. The Norwegian Radiation Protection Authority has also adopted these limit values. It is therefore widely recognised that the WHO limit values provide a safe and sound guide for use of radio signals in society. Telenor, however, has chosen to introduce a limit value for residential areas that is 100 times stricter than the WHO's own value.

Will large antennas send stronger signals than small antennas?

No, larger antennas will ensure reduced radiation in all other directions than where the antenna is aimed, if you compare them to smaller antennas. Normally, the local environment will benefit from the use of a large antenna, which efficiently prevents the signals from being transmitted in other directions than straight ahead.

Mobile phones( 13 )
Why does my ear heat up following long calls on the mobile phone?

The emission of radio waves will cause a certain temperature increase in liquids, which is what our body largely consists of. The size of this increase will depend on the intensity and frequency of the radio waves. Radio waves from a cellular phone have a favourable frequency and the intensity is very low. Even at maximum effect, the radio waves from the mobile phone will never raise the temperature by more than 0.1 degrees, an increase which cannot be registered by human beings. Batteries, however, and in particular the amplifying chip in the mobile phone, will heat up during long periods of use. The phone is constructed in such as way as to lead heat away from this chip, and distribute it evenly all over the handset.
It is also a fact that you can feel a warm sensation if you hold any warm object to your ear. The pressure against your ear ensures that the bloodstream around the ear is altered and the blood volume increases (your skin turns red when something is pressed against it). Since your blood temperature is higher than that of the skin surface, this will feel like a slight increase in the temperature in your ear.

Can mobile phones cause headaches?

Occasionally, people report various health problems such as headaches, aching muscles or skin irritations, which they ascribe to exposure to electromagnetic fields such as radio signals. Various kinds of equipment are identified as possible sources of such afflictions, including power lines, antennas, PCs or TV screens, electric cookers and/or mobile phones. This type of ultra-sensitivity to electromagnetic fields is described as a form of allergy, and is often referred to as electromagnetic hypersensitivity. Among those suffering from this condition, a small number of individuals are afflicted to such an extent that they have to adjust their lifestyle. However, research and blind tests have failed to establish any connection between the reported afflictions and exposure to electromagnetic fields. The WHO has prepared a facts sheet about electromagnetic hypersensitivity. For more information please refer to the WHO website.

Should children's use of mobile phones be restricted?

Research does not indicate that children's use of mobile phones involves any added health risk. It is, however, not possible to prove that mobile phone use is 100% risk-free. Although the research in this field is at an advanced stage, a lot of new research is carried out in certain special areas. Pending the ultimate results, both national and international health institutions have adopted a precautionary approach to children's use of mobile phones. The reason for this is that children's brains are in a development phase, and that previous research in other areas has shown that children are more influenced by the environment than what is the case with adults. To rule out any negative effects, in spite of the fact that no such ill effects have ever been documented, certain precautionary measures could be introduced for children, such as:

  • Using an earplug and a cable (hands-free equipment)

  • Avoiding long calls

  • Sending SMS/MMS rather than calling

If you do not own such hands-free equipment, it is recommended that the mobile phone be used outdoors, in densely populated areas, i.e. where there is good mobile coverage. The mobile handset will then emit much weaker signals.

How do you measure the signal strength from a mobile phone?

Radio waves from mobile systems have nothing to do with radioactive radiation. In this context we are talking about radio waves that mobile phones and mobile antennas emit.
The WHO has introduced a means of measuring and a unit of measurement for radiation from mobile phones. This standard is called SAR (Specific Absorption Rate). In practice, the radiation from mobile phones is measured by placing finely tuned sensors inside an artificial head, made to resemble a human head. The mobile phone is at the same time attached to the head's artificial "ear" while it emits signals at full strength.

In this way it is possible to measure the SAR, which is the total radiation effect that can be measured during a mobile phone call. The SAR is measured in Watts/kilograms. The WHO has introduced a limit of 2 Watts/kg. All mobile phones currently available at sales outlets must be SAR tested, and the test results must be printed on the product packaging or in the user manual. Today's mobile phones normally have a SAR of between 0.5 - 1.2 W/kg.
The limit values for radiation are issued with a wide safety margin with respect to health hazards and also have a safety factor of 50. The human body will normally endure a strain that is 50 times higher than the limit value.

How strong are the radio waves from a mobile phone?

The quality of the mobile coverage is the deciding factor when it comes to how much radiation your mobile phone emits. The SAR that is described in the above question (2 Watt/kg) is applicable where the mobile coverage is weak, and the mobile signals are transmitted at maximum strength to reach the antenna. In most situations, the mobile phone will reduce its transmitting power significantly, as the nearest mobile antenna is likely to be fairly close. If the coverage is excellent, the mobile phone may actually reduce its radiation by as much as 99.9 per cent, i.e. down to 1/1000th.

Are there methods of reducing the signal strength from mobile phones?

In principle, no. The mobile phone ensures that the signals sent are not stronger than what is required to reach the nearest antenna. If you want to keep the radiation at a minimum, you would benefit from calling from an area that has good mobile coverage.
You should be aware that metal handset cases, unoriginal antenna capsules and similar could block the radio signals from the mobile phone's antenna. If this happens, the mobile phone will increase its transmitting power to compensate for the loss of signal (metal blocks radio signals).

Will UMTS/3G phones emit more radio waves than GSM phones?

No. Even though the UMTS system will transmit larger quantities of digital information, such as live images, the radiation will be less than with the GSM system. This is because the UMTS phones' radio signals are weaker than GSM phones. Customers will also more often hold the UMTS phones in front of them rather than directly against their ears.

UMTS phones will have a maximum transmitting power of 0.25 Watts. 1 500 times per second, the phone will evaluate whether it is possible to reduce this transmitting power. As a result, the phone will always choose the weakest available signal required to maintain contact with the mobile network.
If a UMTS phone is used to download data with a high-speed “Turbo 3G connection,” the phone will send at full strength (0.25 Watts) but only during the short period of the actual data transfer. Full strength is used to ensure maximum speed data transfer. When the phone is used for data transfer, its will rarely be placed next to the ear, and the exposure will be less than during a regular phone call.

Users should be aware that inside all UMTS phones is a GSM phone that is used as backup for the UMTS signals in areas that have no UMTS coverage. When the phone is used in areas without UMTS coverage, it will send the same signals as a regular GSM phone.

Is it possible to reduce the signal strength by using hands-free equipment (earplug and cable)?

All new mobile phones comply with the WHO's requirements for maximum radiation when placed directly against users' ears. The intensity of the radio signals is greatly reduced with distance. The margins up to the recommended limit value (see the above question “How do you measure the signal strength from mobile phones?”) will therefore be even higher when the distance between the mobile phone and the body increases. Radiation directed at the body will actually be reduced to approximately 1/100th (i.e. a 99 per cent reduction) if the mobile phone is held at a distance of 50 cm from the body. For daily use, the earplug and cable will represent the best solution with respect to the recommended limit values for mobile radiation, as long as the mobile phone is held at a greater distance from the body.
See also the below question on wireless hands-free equipment (Bluetooth).

Does the mobile phone emit radio waves when it is not in use?

All mobile phones that are "on" will send short "messages" to the mobile network at intervals (approximately once an hour when the mobile handset is immobile, more often when the handset is moving fast, e.g. when in a car). The reason for this is that the mobile network must receive information of where your mobile phone is at all times. These messages are of a three-second duration. This procedure is called signalling. The transmitting power of such signalling will correspond to the mobile coverage that exists in the area. Other than these three-second messages, the mobile phone sends no radio signals when not in use.

Is it wise to use wireless hands-free equipment (Bluetooth)?

Bluetooth is the common name for a technology for wireless transmission of signals over short distances (up to ten meters). Since the Bluetooth earplug is designed to transmit signals to mobile phones that are maximum ten meters away, the transmitting power will be very low. As long as you keep the mobile phone at least 20 centimeters away from your body, you will achieve a substantial reduction in the amount or radiation directed at your body. Bluetooth hands-free equipment is therefore a good solution for people who want the greatest possible safety margin, and who dislike having a cable running between the mobile phone and the earplug.

Some people claim that using mobile phones is playing hazard with your health. How much research is conducted on radio waves and mobile phone use?

Continuous research is done to work out the health effects of mobile phone use. The situation is made complex by the fact that contradictory reports are produced at regular intervals. Some research reports claim that mobile phone use involves increased health hazards, whereas others conclude that it is impossible to prove that there is any link between mobile radiation and health. Quite frequently, new research results are mixed with old reports that are brought to light again.
More than 150 independent authorities and expert panels in Canada, England, Holland and Norway have all drawn more or less the same conclusion: based on today's extensive knowledge it is impossible to prove that mobile phones affect people's health, but it cannot be effectively ruled out. See overview of current research on the subject: http://www.gsmworld.com/health/links/independent.shtml

According to the Norwegian Radiation Protection Authority, any damage suffered from the use of mobile phones will be microscopic. The Authority still recommends a "strategy of caution until conclusive research can be produced". Norwegian authorities have not found reason to issue any warnings against mobile phone use as long as the phones comply with the established SAR.

How do mobile phones emit radio waves in comparison to other electric/electronic articles: microwave, PCs etc?

All electric devices emit a certain amount of radiation (electromagnetic fields). The radiation from mobile phones and other devices are not always comparable, since the frequencies can be very different. Our bodies have different limits of tolerance for the various frequencies, and the limit values take this into account.
The strongest signals emit from devices that contain radio transmitters or high-voltage, such as wireless telephones, microwave ovens and TV/PC screens. Lamps and fluorescent tubes also emit more radiation than what is commonly assumed.

The WHOs limit values apply for all such equipment, not only mobile phone systems. There is also a clear tendency that new TVs, PC screens and microwave ovens emit weaker radiation than their older counterparts.

Radiation from mobile phones is of the same kind (i.e. approximately the same frequency) as microwave ovens and wireless phones. The radiation from a mobile phone in use will be just as modest as the radiation emitting from these devices.

Where can I get more information on mobile radiation and health?

There are many reliable sources of information regarding mobile radiation and health, available on the Internet. Here is a selection: