- How a mobile phone works
A mobile phone is an electronic communications device that enables communication in two directions simultaneously. It uses radiofrequency (RF) signals/energy to transmit and receive voice and data and communicates by transmitting the radio waves through a network of fixed antennas called base stations. Mobile communications systems require the use of a number of base stations located throughout a service area as each base station will serve a specific geographical area called a cell.
When a user makes a call, the mobile phone communicates with a nearby base station and while the user moves about, he/she will be ‘handed over’ to other base stations, which may have a better signal strength. The location of base stations is determined generally by two different needs; to provide adequate coverage and adequate capacity. Increase in capacity of a network in a particular area will increase the number of installations of the base stations. This is the main reason why in densely populated areas like towns and cities, the base stations are closer together.
- Radiofrequency radiation?
Radio frequency (RF) radiation is the transfer of energy by radio waves. It lies in the frequency range 3 kilohertz (kHz) to 300 gigahertz (GHz). RF radiation is non-ionizing radiation, meaning that that it does not have insufficient energy to remove an electron from an atom or molecule (ionization). This is as opposed to ionizing radiation that has sufficient energy to remove an electron from an atom or molecule such as the gamma rays and X-rays.
A mobile phone emits non-ionizing radiation (NIR). NIR does not have sufficient energy to cause ionization in living matter. It causes some heating effect, but usually not enough to cause any kind of long-term damage to human tissue.
Of the entire electromagnetic spectrum, radiofrequency energy, visible light and microwave radiation are considered non-ionizing while gamma rays and x-rays are ionizing radiation
- Health concerns around mobile phone usage
The health concerns usually reported that are related to mobile phone usage include; elevated risk of cancer, headaches, changes in brain activity, reaction times and sleep patterns among others.
The substantial amount of research carried out by recognized institutions like the World Health Organisation (WHO), the International Agency for Research on Cancer (IARC) and Health Protection Agency (HPA) with regard to the probable health risks has no found so far any link between mobile phones and their base stations, and an elevated risk of cancer.
The biological effects of non-ionising radiation, backed by evidenced scientific research is surface heating in direct line of sight over a prolonged exposure period. However, non-ionising radiation does not have insufficient energy to remove an electron from an atom or molecule (ionization).
However, health experts still recognize how critical the public concerns are, and thus studies are still on going to fully assess the potential long-term effects of communications developments.
- Possible health risks and effects associated with mobile phone use
A number of health risks and effects have been reported with mobile phone use. However, experts have not found convincing evidence that the radiation from mobile phones and their base stations causes adverse health effects to human. However, health experts still recognize how critical the public concerns are, and thus studies are still on going to fully assess the potential long-term effects of communications developments.
It is noteworthy that the consistent health risk associated with mobile phone use is distracted driving and vehicle accidents and the lack of concentration.
- Exposure levels from mobile phones
RF exposure levels are directly proportional to the actual power of a mobile phone during a call as well as sending/receiving data. A mobile phone’s output power is significantly lower than maximum output power due to adaptive power control (a feature of a radio transmitter that automatically minimizes the power for just enough to get a good quality connection).
Factors that can change the output power of a mobile phone and intensify exposure include; user movement, technology, phone usage, user location among others. Mobile phone calls made in areas where there are many base stations at relatively short distances from each other such as trading centers, use lower power output than mobile phones calls made in areas with larger distances between base stations such as in rural areas.
- Typical power of a mobile phone
The typical power output of a mobile phone ranges from 10 to 100 milliwatts (mW) which considers the operation of adaptive power control. It is noteworthy, that the mobile power may be higher in rural areas.
- How to reduce exposure from a mobile phone
Mobile phones are designed to operate automatically at low power which minimizes exposure. However, the World Health Organisation (WHO) has outlined additional steps that can further reduce exposure. These include; using hands-free device to keep the phone away from the head and body during calls, limiting the call duration, making calls in areas with good reception, among others.
- Mobile phones emit less with good network signal
A mobile phone in use will operate at low power when near a base station, emitting less and offering a good signal quality.
- Mobile phones and Specific Absorption Rate
Specific Absorption Rate (SAR) is the amount of RF energy from the phone absorbed by the user’s body it is measured in watts per kilogram (W/kg). When talking to someone on mobile phone, the RF energy is partly absorbed in the head. If a headset is used and the mobile is away from the head (e.g. in one’s pocket), the energy will be absorbed by the body part close to where the mobile phone.
The International Commission on Non- Ionising Radiation Protection (ICNIRP), a body of independent science experts addressing the important issues of possible adverse effects on human health of exposure to non-ionising radiation, recommends an SAR not more than 2W/kg for all mobile phones.
- Mobile phone exposure limit guidelines
The exposure limits for mobile phone users are given in terms of Specific Absorption Rate (SAR). The ICNIRP has developed guidelines for exposure limits based on a detailed assessment of the available scientific evidence.
- The role of UCC in ensuring that mobile phones are safe.
The UCC type approves/accepts all mobile devices imported in Uganda before they are deployed for use. The type approval/acceptance process assesses the conformity of the devices to the national and international technical specifications and standards. UCC also requires that mobile devices comply with the radio emissions standards and safety limits of Specific Absorption Rate (SAR) prescribed by the International Commission for Non-Ionising Radiation Protection (ICNIRP) limits and standards and recommended by the International Telecommunications Union (ITU).
- Does a phone shield is a protective device and reduces exposure?
There is also no reliable evidence or scientific proof that protective shields reduce exposure. However, while such devices are placed on the phone, the phone’s automatic power control makes it work harder and transmit more power, increasing heat and reducing battery life and reduce signal quality.
UCC does not recommend the use of any protective devices other than the approved hands-free accessories.
- Are children at greater risk from mobile phone use?
The World Health Organisation (WHO) notes that studies into the long health effects do not indicate that children may be more vulnerable to RF emissions from mobile phones than adults. The current guidelines to limit exposure are designed to protect people of all ages against the known harmful effects of exposure to RF.
Nonetheless, parents may wish to administer precautions to further lower their children’s exposure while using mobile phones by; reducing call time and phone use, make calls where there is good signal, use hands-free or speaker options or texts.
- Should people stop using mobile phones?
To date, science has not linked health problems to mobile phone use. Mobile phone use comes with advantages like time saving and lifesaving. However, lifestyle choices can cause risk as a result of mobile phone use such as; driving while using your phone like texting.
- Where to get information related to mobile phones and safety.
UCC is available to provide more information on any inquiries or questions regarding mobile phones and safety. For more information, you may contact;
The Executive Director,
Uganda Communications Commission,
Plot 42-44, Spring Road, Bugolobi,
P.O. Box 7376, Kampala (U)
Toll Free line: 0800222777
Office Numbers: 0414339000/0312339000
Face Book: Uganda Communications Commission