Facts About Mobile Phones And Base Stations
The use of mobile phones has increased dramatically in South Africa and throughout the world. Questions are asked about how this technology works and specifically about the health and safety aspects of mobile phones and the supporting network of base stations.
There is a vast amount of information available globally, in all forms of media, on every aspect of mobile telecommunication services and the technology. This information includes published papers on research studies conducted over the past 50 years and testing on the bio-effects of radio frequency emissions.
SACTA recognises the prime importance of all health, safety and technology issues related to the use of mobile phones, as well as the need for presentation of factual information on these issues in an easily accessible form for the public. SACTA is committed to ensuring the continued safety of the public and has prepared the following information in order to answer your questions.
In addition to the questions and answers below, detailed information for both mobile phones and base stations can be accessed from the following international sources:
How does a mobile phone work?
When a person talks on a mobile phone, it transmits to a nearby base station antenna. Your mobile phone transmits and receives low power, electromagnetic radio signals - also called (RF) radio frequency emission that allows the sound of your voice or other data to be conveyed to another user. Your mobile phone generates power to an average level of 0.25 Watts. However, while you are in the midst of a conversation, it will transmit only the minimum power required to maintain the call, which, in most urban areas, is about 0.0625 Watts. This automatic power adjustment feature helps to lengthen the life of the mobile phone battery and reduces interference with other users.
What is radio frequency emission?
Radio frequency (RF) emissions are electromagnetic waves that transport energy as they travel through space and time. The RF emission provides the support media for the transportation of information between end users. The communication relies upon electromagnetic waves travelling from and toward the base station and mobile phone.
The electromagnetic spectrum and non-ionising radiation
The electromagnetic spectrum covers an enormous range of frequencies extending from the slow magnetic field variations associated with power lines up to the gamma rays attributable to radioactivity and beyond. The electromagnetic waves associated with mobile technology fall into the "non-ionising" portion of the electromagnetic spectrum. This means the waves are not capable of breaking chemical bonds in biological structures or removing electrons (ionisation) from constituent atoms. In this respect, the RF emissions are very different, and should not be confused with the ionising radiation produced by x-rays and atomic processes such as gamma rays.
Electromagnetic spectrum and exactly where the RF of mobile telecommunication equipment slots in - CLICK HERE.
How do base stations function?
A base station provides radio coverage to people using cell phones in its specific surrounding geographical area. The base station houses a sensitive receiver and low power transmitter and is merely one of many that are required to provide cellular telephony in an extended area. The transmitter inside the base station produces a radio signal at a frequency of about 900 MHz and at an average output power of 20 Watts.
The antenna's function is to focus the radio waves in a particular direction (generally away from the supporting structure). Independent measurements at ground level show that the radio transmissions near base stations are typically many hundreds of times below the international guidelines set for RF safety.
What are the RF guidelines?
The South African Department of Health provides the necessary safety guidelines for all emission throughout the electromagnetic spectrum. In particular, the RF safety guidelines, endorsed by the Department of Health in South Africa were developed by the International Commission on Non-Ionising Radiation Protection otherwise known as ICNIRP. The ICNIRP guidelines were internationally endorsed by the European Commission in July 1999 and subsequently by the UK government in May 2000. The World Health Organisation (WHO) and the South African Department of Health also endorse the use of ICNIRP as a suitable safety standard for RF exposure. It should be noted that ICNIRP sets the safety levels that govern both public and occupational exposure.
Do mobile phones and base stations comply with these guidelines?
Mobile telecommunication equipment is designed, manufactured and tested according to the relevant international safety and specification standards and guidelines.
Is there any evidence of an adverse health risk from the use of mobile phones?
The health and safety aspects of electromagnetic energy have been the subject of intensive study for more than half a century. The preponderance of scientific evidence indicates that there are no adverse health effects from the use of wireless phones. Periodic reviews by numerous government agencies, international health organisations and scientific bodies support the observation that the radio signals from mobile phones and other portable communications devices pose no health risk.
The base of scientific knowledge related to RF emissions continues to expand with a significant amount of research now being conducted under the directorship of the World Health Organisation (WHO).
What about base stations?
Claims that base stations are harmful to health are not borne out by established scientific opinion. The World Health Organisation's position is that the radio frequency fields around base stations are typically a fraction of the safety guidelines and therefore do not constitute a health risk.
What the experts are saying?
The following are selected quotes highlighting the views of a number of government agencies, expert scientific groups, research organizations and international standard-setting bodies on the question of RF safety.
" Validated scientific evidence supports the conclusion that neither mobile phones nor their associated base stations, if they comply with current maximum exposure guidelines-as they appear to do-present a health hazard."
UK House of Commons, Science and Technology Committee Press Release, September 22, 1999
"... NRPB concludes that the totality of the evidence available does not suggest that the use of mobile phones have any detrimental effect on human health."
UK National Radiological Protection Board (NRPB) Response Statement, National and International Exposure Standards for Electric and Magnetic Fields, July 1998
"The exposure limits set by Safety Code 6 [Canada's RF exposure guidelines] are similar to other national and international standards. All countries use the same biomedical data and the same general approach to setting safety guidelines. Differences in interpreting the biological effects under certain exposure conditions sometimes result in small differences in the exposure limits that are recommended. These minor differences will not affect a person's health. Canada's exposure limits are among the safest guidelines in the world."
Health Canada, Safety of Exposure to Radiofrequency Fields, Frequently Asked Questions, February 1998
" There is no substantive evidence that adverse health effects, including cancer, can occur in people exposed to levels at or below the limits on whole body average SAR recommended by INIRC (IRPA/INIRC 1988) or at or below the ICNIRP limits for localised SAR set out in this document".
International Commission on Non-Ionising Radiation Protection. Health issues relating to the Use of hand-held Radiotelephones and Base Transmitters," Health Physics, Volume 70, Number 4, pp 587-593, April 1996.
" Current scientific evidence indicates that exposure to low levels to RF fields, such as those emitted by mobile phones and their base stations, is unlikely to induce or promote cancers."
"... guidelines have been developed to protect everyone in the population ..."
"... scientific evidence does not indicate any need for RF-absorbing covers or other ‘absorbing devices' on mobile phones."
WHO International EMF Project, Fact Sheet Number 193, Electromagnetic Fields and Public Health, June 2000
"... there is no convincing evidence that exposure to RF shortens the life span of humans, induces or promotes cancer."
WHO International EMF Project, Fact Sheet Number 183, Electromagnetic Fields and Public Health, May 1998
" Current scientific evidence indicates that exposure to RF fields, such as those emitted by mobile phones and their base stations, is unlikely to induce or promote cancers."
World Health Organisation : Fact Sheet N° 193: June 2000
"Considering the very low exposure levels and research results collected to date, there is no convincing scientific evidence that the weak RF signals from base stations and wireless networks cause adverse health effects."
WHO International EMF Project, Fact Sheet Number 304, Base Stations and Wireless Networks, May 2006
"The epidemiological evidence currently available does not suggest that RF (radio frequency) exposure causes cancer. This conclusion is compatible with the balance of biological evidence, which suggests that RF fields below guidelines do not cause mutation, initiate or promote tumour formation."
" The balance of evidence indicates there is no general risk to health of people living near to base stations where the exposures are only small fractions of the guidelines"
Conclusions of the UK Independent Expert Group on Mobile Phones - Stewart Commission Report: 11 May 2000
" The chance of health problems occurring among people living and working below base stations as a result of exposure to electromagnetic fields originating from the antennas is, in the Committee's opinion, negligible. The field strengths are always considerably less than the exposure limits."
Report on ‘GSM base stations’ (2000/16) published by the Health Council of the Netherlands.
What about these new products that offer to protect consumers from radio-frequency emissions of their mobile phones? Do they work?
Most importantly, mobile phones conform to strict international safety guidelines. Given compliance with these requirements, use of any of these products would not make any material difference in the safe use of the phone.
What does the World Health Organisation say about the need for phone shields or “RF absorbing devices”?
In a June 2000 Fact Sheet, the World Health Organisation commented that: “Scientific evidence does not indicate any need for RF-absorbing covers or other “absorbing devices” on mobile phones. They cannot be justified on health grounds and the effectiveness of many such devices in reducing RF exposure is unproven.”
What are the interference effects attributable to mobile phones?
Electromagnetic interference is not a new phenomenon and is well understood, manageable and usually preventable. Almost every electrical device can be susceptible to electrical interference of some kind but following simple guidance will ensure that the interference effect from a mobile phone is minimized.
The digital signals used by mobile phones can cause a buzzing sound in some designs of audio system. This is a natural consequence of the digital signals used by the mobile phone system. The interference effect is not in any way harmful, but if it should occur, it is recommended that one simply move the phone away from the device being affected.
Can I use a mobile phone in hospital?
With respect to the use of mobile technology in the vicinity of medical facilities one should seek advisement from the particular hospital administration.
Can I use a mobile phone at petrol stations?
The risk of a mobile phone generating a spark is much the same as that for any other electrical equipment found at petrol stations. However because of the extremely remote risk of a spark being caused by a cell phone the Health and Safety Executive recommends not using mobile phones at petrol stations.
Why can’t I use a mobile phone on an aircraft?
It is the policy of airline administrations worldwide to prohibit the use of mobile phones on airplanes in order to remove any risk of interference with sensitive avionic equipment.
Do mobile phones interfere with the electrical systems of cars?
A vehicle’s components are typically built and tested to withstand exposure to radio frequency fields stronger than those emitted by mobile phones. It is most unlikely that a mobile phone will interfere with the proper operation of a car’s electrical systems.
Can a person wearing a hearing aid also use a mobile phone?
Hearing aid interference comes from many sources, such as fluorescent lights, computers and other electronic devices including mobile phones. Some hearing aids now on the market are immune to mobile phone interference and new compatibility standards are currently being developed.
What solutions exist if a hearing aid user suffers from interference?
There are several things that can be done which may improve the situation:
- If possible use the mobile phone at the non aided ear;
- Use a different, more immune hearing aid;
- Use a hands free accessory. Different accessories can be coupled to the hearing aid by either using the Microphone or T-Coil position.
Would a different aid help?
Some hearing aids have higher levels of immunity to interference than others do. In general smaller aids worn in the ear have higher immunity, than those worn behind the ear. It is important for the user to try a new aid with a mobile phone to confirm in advance that it is compatible. It is also important to remember that the power level of the phone’s transmitter changes with geographic location.
If pacemaker users are concerned about interaction with their phones, what should they do?
We suggest the following steps:
- Do not hold your phone to your chest;
- Consult with your physician;
- Refer to your pacemaker product literature for information.