Sensible mobile phone use
Introduction
It is hard to imagine life today without the mobile phone. In the nineties the spread of the mobile telephone underwent exponential growth. In 2009 there were no less than 11 million active mobile subscribers in Belgium. Nearly four million mobile phones are sold each year. The mobile phone also continues to be increasingly popular among young people. Today more than 90% of young people between 10 and 17 years of age have a mobile phone… But is intensive mobile phone use harmful to health in the long term or not? Let us take a closer look at the situation.
Heating effect of radio waves
Because of the scant distance between the device’s antenna and the human body, a person calling on a mobile phone is exposed to a relatively high level of radiation. Even though the device respects the standards, the Superior Health Council recommends moderating mobile phone use. This information sheet explains what these recommendations are based on and what people can do to reduce exposure.
A mobile phone can be used to do an increasing number of things: besides phoning and messaging, reading email, surfing the net and even watching mobile TV. The information (speech, text, images) is sent by radio waves: the mobile phone receives radio waves from the base station and transmits radio waves back to it. These waves are sometimes also called mobile phone radiation.
It is known that radio waves are absorbed by the body. That means that the electromagnetic energy of radio waves is converted into heat by the body. This is called the thermal effect. As a reaction to the heating, our body starts its internal cooling mechanisms, which keep the body temperature constant. This thermal effect is only detrimental to health at high intensity. Today's standards are meant to protect us from the heating effect. There is still research going on to know whether other (non-thermal) effects may occur.
The measure used for the conversion of energy into heat is the Specific Absorption Rate (SAR), expressed in watt per kilogram (W/kg).
Regulation
What are the standards?
Electronic communications equipment such as mobile phones, cordless phones (DECT) and network devices must meet the European RTTE Directive 1999/5/EC (RTTE stands for ‘Radio and Telecommunications Terminal Equipment’). This Directive establishes the essential requirements regarding the prevention of interferences and the protection of the health and safety of the user and other people.
The producer must demonstrate that his products meet these requirements, including compliance with the limit values mentioned in the European harmonised technical standards. The scientific basis for determining the limit values is the recommendations of the ICNIRP (International Commission on Non-Ionizing Radiation Protection). According to the ICNIRP the specific absorption rate (SAR) as a result of electromagnetic radiation with exposure of the head may be no higher than 2 W/kg average for six minutes for 10 gram tissue . The limit value also applies for mobile phones and serves to protect the head against thermal effects.
To measure is to know
The manufacturer must measure the SAR value for each model. Only wireless appliances with a low average power (lower than 20 mW ) are exempt from SAR measurements (for example Bluetooth devices). The measuring procedure is standardised and takes place as follows. A mobile phone to be tested is fastened to the ear of a dummy head. The dummy head is filled with a liquid with the same electrical properties as human tissues. Measuring devices (probes) are fitted inside the dummy head that measure the distribution of the electrical field produced by the mobile phone. The SAR value is calculated based on these measurements.
Many manufacturers put this SAR value in the phone’s instructions for use.
Does the SAR value represent actual exposure?
All laboratories work in the same way because the standard very accurately describes the measuring procedure. This makes the measurement results reproducible and reliable within the margin of measuring uncertainty. But this does not necessarily mean that the SAR value resulting from the test corresponds with the actual exposure. In practice the transmission power is variable. A mobile phone automatically adapts its transmission power depending on the reception quality: better reception means a lower transmission power. How one uses a mobile phone (with an earpiece, sending messages instead of calling) also has an influence on actual exposure, i.e. the actual SAR value. It can as a result be up to a thousand times lower than the SAR value established in the test.
The SAR of mobile phones available on the market is in the 0.2 – 1.6 W/kg range. The most common SAR values are in the region of 0.8 – 0.9 W/kg. You can find a summary of the SAR values on the websiteswww.mmfai.info/public/sar.cfm ('Mobile Manufacturers Forum') andwww.bfs.de/elektro/hff/oekolabel.html (German 'Bundesamt für Strahlenschutz', BFS). The figure above shows the SAR values of the models examined by the BFS.
Health studies
Even though mobile telephones meet the standards, there are still factors that justify further research into the possible health effects of this technology, including limited scientific indications for a possible higher risk of brain cancer in case of prolonged intensive use. Moreover, almost everyone uses mobile phones, and for that reason even slightly higher risks could have a large impact on public health.
Types of studies
There are different types of studies that can be performed to study the relationship between a suspected factor (in this case the electromagnetic radiation of a mobile phone) and symptoms. In epidemiological studies, the frequency of symptoms is analysed in population groups that either use mobile phones or that do not use them. This kind of study can only find a statistical relationship and gives cause for further study. In order to be certain that there is an actual (causal) relationship, researchers perform experimental studies: provocation trials on people or studies on animals (in vivo) and cells (in vitro).
In provocation trials, a volunteer is placed in two different situations. He or she is alternately exposed to an electromagnetic field (from a mobile phone) or placed in a sham situation in which no field is present (he has a mobile phone that does not emit). The volunteers must indicate whether they think that they are being exposed and whether the symptoms get worse or the number of symptoms increases. A provocation trial should be performed double blind in order to limit the influence of the convictions of the participant and researcher.
In vivo and in vitro studies are performed in the same way. A group of animals (or cellular cultures) are exposed to radiation, after which they are studied in comparison with a control group that wasn’t exposed. In contrast to an experiment with human volunteers, the exposure may last much longer: weeks, months or even years.
When scientists give a verdict on the possible health risks, they consider all relevant results – both from epidemiological studies as well as from animal and cell studies. No definitive conclusions can be drawn from a single type of study, because every type of study has its limitations.
When scientists give a verdict on the possible health risks, they consider all relevant results – both from epidemiological studies as well as from animal and cell studies. No definitive conclusions can be drawn from a single type of study, because every type of study has its limitations.
Scientific conclusions
Studies concerning electromagnetic fields unfortunately result in diverse – and sometimes contrary – results, so drawing conclusion becomes difficult. Various scientific bodies examine the scientific results at regular intervals: ICNIRP, SCENIHR (Scientific Committee on Emerging and Newly Identified Health Risks), IARC (International Agency for Research on Cancer). We give answers to some frequently asked questions, based on the publications of these organizations.
Does mobile phone use cause cancer?
According to the recent communication by the International Agency for Research on Cancer (May 2011) there may be a higher risk of brain cancer when intensive use is made of mobile phones. The IARC therefore classified radio waves as ‘possibly carcinogenic to human beings'.
This conclusion was drawn after a joint analysis of available epidemiological studies and research on animals and cells. In most of the studies no indications were found of a higher brain cancer risk, but two large studies (the international research Interphone and a Swedish meta-analysis) indicated a higher risk of glioma and, to a more uncertain degree, of acoustic neuroma, in case of prolonged mobile phone use (total use duration higher than 1500-2000 hours). Research on animals also concluded that there are 'limited indications' for a possible correlation.
The classification 2B, ‘possibly carcinogenic to human beings’, is attributed to environmental factors and substances that show ‘limited epidemiological indications' in relation to cancer. According to the IARC, coffee and car exhaust fumes also belong to that group. In the case of 'limited indications' it is still possible that the relationship that was detected is only seeming, the results being potentially influenced by a coincidence or by bias. The degree of certainty when something is classified as ‘potentially carcinogenic to human beings’ is lower than this is the case for the classifications 1 (‘carcinogenic’) and 2A (‘probably carcinogenic’). When even less indications exist, a substance is considered ‘not classifiable’ (3). Finally, there is the classification 4, ‘probably not carcinogenic’.
The IARC insists on the necessity of further research and recommends meanwhile to reduce the exposure to mobile phone radiation by using an earpiece or by sending messages. Also read other tips further on this page.
What is it about?It is about mobile phones and to a lesser extent about wireless home telephones. Most studies focus on the use of mobile phones, given their widespread dissemination, their use close to the head and their relatively high transmitting power (1-2 W) compared to other wireless devices like baby monitors, WIFI adapters or Bluetooth headsets.
Good to knowThird generation mobile phones (UMTS) have smaller transmitting powers (0,1 W) than the second generation (GSM, 1-2 W). The exposure to radio waves produced by a DECT-phone is 5 times smaller than from a mobile phone.
What is it not about?It is not about other devices like WIFI, bluetooth of microwave ovens. These were not considered in the evaluation of the IARC. And it is not about transmission masts for mobile telephone communication. The IARC considers the research on the effects of these sources insufficient to draw conclusions.
Good to knowThe exposure to radio waves from transmission masts is more than 10,000 times smaller than the exposure when using mobile phones.
Can a mobile phone cause physical symptoms in electromagnetically sensitive people?
Electrical or electromagnetic hypersensitivity, EHS, is a set of symptoms that people spontaneously attribute to exposure to electromagnetic fields. The symptoms include fatigue, exhaustion, concentration problems, dizziness, nausea, heart palpitations and digestive disorders. These symptoms are attributed to exposure to the weak electromagnetic fields of electrical or wireless devices by those afflicted.
More than 40 high-quality provocation trials have been performed with ‘electromagnetically sensitive’ people. According to the SCENIHR, a relationship has been observed between the symptoms and exposure to electromagnetic fields only in a few studies. However, these results were neither statistically strong nor reproducible. The majority of the studies have found no association. This leads to the assumption that exposure to electromagnetic fields plays no role – or a very small role – in the existence of EHS. The SCENIHR assumes that the nocebo effect plays a role (a negative effect is caused by negative expectations).
May people sleep with a mobile phone on the bedside table?
Sleeping with a mobile phone on the bedside table can’t do any harm. A few studies have shown small changes in the electrical activity of the brain, in sleep quality and in the biochemistry of neurotransmitters while calling with a mobile phone. These studies generally focus on calling for a long time with a mobile phone set to maximum power and not on a mobile phone that is just lying next to you. According to the SCENIHR, the health significance of these changes is unknown and should be studied further.
Good to know
When a mobile phone is switched off it transmits nothing. When it is on stand-by the mobile phone only transmits a sort signal now and again to give its position in the network. It is only during a conversation that the mobile phone transmits constantly.
Is calling with a mobile telephone harmful for children?
The decision to buy a mobile phone for a child is often driven by security considerations. However it is recommended to take other factors into consideration too. Scientists do indeed agree that children should use mobile phones as little as possible. When calling on a mobile phone, the energy absorption in the head of a child is more important than in the head of an adult (2 times more important for the brain and 10 times more important for the skull marrow). The concern is also that the cumulative exposure of the current generation of children and adolescents in their adult lives will be much higher than that of the current adults. The recent classification of mobile phone radiation as possibly carcinogenic is an additional reason to be cautious.
Tips for sensible use
Some tips to reduce your exposure
So far, it has not been proven that the radiation from mobile phones is harmful to their users. But on the foundation of current scientific knowledge, health risks relating to long-term, frequent mobile phone use cannot be ruled out. Experts – including those on the Superior Health Council – advise everyone to limit their exposure to mobile phone radiation. The following simple tips will help you.
* Limit your calling time
Avoid unnecessary or excessively long telephone conversations with your mobile phone: the longer you call for, the longer you are exposed to radio waves. Because a mobile phone is held close to the head, a person making a call is exposed to a relatively large radiation level. Also, remember that the exposure is greatest during the first few seconds, when the phone is searching for a connection. For this reason, you should wait a moment before putting your mobile phone to your ear.
Avoid unnecessary or excessively long telephone conversations with your mobile phone: the longer you call for, the longer you are exposed to radio waves. Because a mobile phone is held close to the head, a person making a call is exposed to a relatively large radiation level. Also, remember that the exposure is greatest during the first few seconds, when the phone is searching for a connection. For this reason, you should wait a moment before putting your mobile phone to your ear.
Good to know
Devices that claim to reduce or negate radiation (such as ‘anti-radiation’ or ‘bio-protectors’) have not proven their effectiveness. On the contrary, an anti-radiation sticker or microchip you stick on your mobile phone can even have the reverse effect: the mobile phone will increase its power to guarantee the quality of the signal. The mobile phone battery will also drain more quickly.
* Use an earpiece When you use an earpiece the distance to your mobile phone is greater and therefore your exposure is less. If you don’t have an earpiece at hand you can call with the loudspeaker on.
Good to know
There are different earpieces (‘hands-free’ kits) on the market: wired and wireless. With which types is exposure less? Earpieces with wire do not transmit anything themselves, but they can pick up radio waves produced by a mobile phone and lead them to the head. Even then, exposure of the head is 10 to 30 times less with an earpiece with wire than when you hold the mobile phone to your ear. Using a ferrite filter (see photo) on the wire partly catches the radio waves and can further reduce exposure. You can buy a ferrite filter from your electrical retailer. A Bluetooth earpiece is wirelessly connected to your mobile phone so transmits radio waves. Exposure due to a Bluetooth earpiece is, however, very small: 300 - 1,000 times lower than a mobile phone. To sum up: if you want to reduce your exposure, using an earpiece (wired or wireless) is a good option.
* Send messages instead of calling
When you send a message exposure is much lower. After all, your mobile phone is kept at a distance from your body. Moreover, your mobile phone only sends a short signal.
* Send messages instead of calling
When you send a message exposure is much lower. After all, your mobile phone is kept at a distance from your body. Moreover, your mobile phone only sends a short signal.
* Preferably call in places with good reception
Your mobile phone automatically adjusts its transmitting power to ensure a good connection quality. In a vehicle, elevator, underground car park, or in a location where the network is less extensive, for example, you have poor reception and your mobile phone increases its power. This also increases the exposure. For that reason, keep an eye on the bars that indicate reception and give preference to places where the reception is optimum: the more bars, the better the reception.
Your mobile phone automatically adjusts its transmitting power to ensure a good connection quality. In a vehicle, elevator, underground car park, or in a location where the network is less extensive, for example, you have poor reception and your mobile phone increases its power. This also increases the exposure. For that reason, keep an eye on the bars that indicate reception and give preference to places where the reception is optimum: the more bars, the better the reception.
Good to know
In places with optimum reception, the transmitting power may be a thousand times smaller than the maximum power.
* Children and mobile phones
Discuss with your children the way that they are allowed to use their mobile phones (for example, sending messages is allowed, or playing, but call only when it is really necessary, preferably using the speakerphone).
istockphoto.com
* Choose a mobile phone with a lower SAR value
The SAR value is mentioned in the instructions for use for your phone or on the internet. The choice of mobile phone model is important, but the way you use the phone is much more important.
Good to know
The official limit value in Europe for the SAR of a mobile phone is 2 W/kg. The CE mark is proof that a mobile phone has been tested and complies with the European safety standards. In some countries an additional label is given to mobile telephones with a lower SAR value. To obtain the Swedish TCO label a mobile phone may have a maximum SAR of 0.8 W/kg. The German Blaue Engel quality mark requires 0.6 W/kg as the criterion to come into consideration for the quality mark.
* Using a mobile phone while driving is not a good idea
In conclusion, a practical tip: do not use your mobile phone while driving. Even with a hands-free set, your attention is distracted from traffic. The use of a mobile phone while driving significantly increases the risk of an accident: by 75% when the mobile phone is held in the hand, and by 24% with a hands-free device.
Federal Public Service (FPS) Health, Food Chain Safety and Environment
Eurostation II
Place Victor Horta, 40 box 10
1060 Brussels
Belgium
Eurostation II
Place Victor Horta, 40 box 10
1060 Brussels
Belgium
Contact Center: +32 (0)2 524.97.97
Published on 08/08/2011 – Page last updated on 08/08/2011
http://www.health.belgium.be/eportal/Environment/Electromagnetic_fields/Mobilephoneuse/index.htm?fodnlang=en#.UZJjdJWl0dI
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