A mobile phone must be connected to a mobile phone base station in order to transmit phone calls and transfer data. This connection is made by radio waves. Engineers refer to the way in which these connections are made as high-frequency electromagnetic fields and radio waves form a part of these fields. A call or another data transmission is captured by the mobile phone antenna that has the best connection with the transmitting mobile phone. The antenna conducts the data via radio or cable connections to a switching centre. This makes a connection with the receiver through an appropriate mobile phone antenna.

The mobile phone network is comprised of lots of individual mobile phone cells whose size depends on the density of the base stations. The density of the network has to increase in line with the number of people phoning from a particular place. The quality of the connection is not the only parameter that increases as a result of a short distance between the mobile phone and the base station. The transmission power of the mobile phone is minimised and hence the strength of the radio waves is reduced. Telefónica O₂ Germany ensures that power is kept to a minimum by the high number of 25,500 base stations.

The radio waves used for mobile telephony are part of the electromagnetic environment which also includes light and heat radiation. Radio waves have been used for technological applications for more than 100 years, including the transmission of radio and TV broadcasts. Radio waves are known as non-ionising radiation. Their biological effect differs fundamentally from ionising radiation, such as UV light or X-rays.

The World Health Organisation and expert committees like the German Radiation Commission (SSK) run by the Federal Ministry of the Environment have recommended limits for electromagnetic radiation relating to mobile phones on the basis of existing research. All transmission installations of O₂ and all equipment sold by us operate at levels significantly below these binding standards.

The radio waves of a mobile phone are partly taken up by tissue and converted into heat. The amount of energy that the body absorbs in this process is known as the specific absorption rate, SAR for short. The maximum permitted SAR value which a person is permitted to absorb when making a phone call is defined by the European Directive EN 50360. This directive specifies the volume of energy that the head is permitted to absorb when a mobile phone is held to a person's ear during a call. In practice,    SAR values are significantly below the permitted limits. The reason is that mobile phones automatically regulate their transmission powers and minimise them as necessary. In UMTS mode, mobile phones implement this regulation of transmission power particularly quickly and effectively.

Scientists have been carrying out investigations for more than 50 years in order to assess whether electromagnetic waves might exert an influence on the health of human beings. O₂ funds research into mobile telephony health and makes a proactive contribution to placing the results of the research in the public domain. We have spent some two million euros on providing finance for the German Mobile Phone Research Programme (Deutsches Mobilfunk Forschungsprogramm, DMF) since 2001. The programme was initiated by the Federal Ministry of the Environment (BMU) and implemented and coordinated by the Federal Agency for Radiation Protection (Bundesamt für Strahlenschutz, BfS). Important results were presented in conjunction with the World Health Organisation (WHO) in June 2008. The Federal Environmental Minister at the time, Sigmar Gabriel, made the following statement at the time:

"This broadly based research programme has not provided corroborating evidence confirming the fears about possible health hazards held by certain sections of the population. We now know much more about the protection provided by limits. However, we will be continuing to carry out further strategic research where a need is perceived to gain further clarification. This is particularly the case for children, who are very sensitive, and relates to the long-term effects experienced by children and adults alike."

After the German Mobile Phone Research Programme was concluded, the German mobile phone operators decided in June 2008 to continue the voluntary commitment and provide support for further research projects on potential long-term effects of using mobile phones. In 2009 O₂ provided the research community radio (Forschungsgemeinschaft Funk e.V.) with 127,822 Euro and the Federal Agency for Radiation Protection (Bundesamt für Strahlenschutz) with 83,334 Euro. From 2009 to 2011, we will contribute funding to the tune of 250,000 euros.

Various committees carry out regular evaluations on the status of the extensive research being carried out. The following statements have been taken from the assessments formulated by the committees. The relevant reports can be downloaded by clicking on the links provided to the Internet addresses:

International Commission on Non-Ionizing Radiation Protection (ICNIRP, 2009):

"..., it is the opinion of ICNIRP that the scientific literature published since the 1998 guidelines has provided no evidence of any adverse effects below the basic restrictions and does not necessitate an immediate revision of its guidance on limiting exposure to high frequency electromagnetic fields. ... Therefore, ICNIRP reconfirms the 1998 basic restrictions in the frequency range 100 kHz - 300 GHz until further notice."

Source: Statement on the Guidelines for limiting exposure to time-varying electric, magnetic and electromagnetic fields (up to 300 GHz):

http://www.icnirp.de/documents/StatementEMF.pdf

Radiation Protection Commission (2008):

"The studies carried out have not been able to provide hard evidence for the hypothesis that "electrosensitivity" actually exists in the form of significantly enhanced sensitivity to or the ability to perceive electromagnetic fields on the part of the persons investigated. No evidence was established indicating that electromagnetic fields are causally linked with non-specific health ailments."

Source: German Mobile Phone Research Programme - Statement by the Radiation Protection Commission:

http://www.ssk.de/de/werke/2008/volltext/ssk0804.pdf

World Health Organisation (2006):

"If we analyse the very low field strengths and the body of research results currently available, it is not possible to identify any convincing evidence that the weak HF signals of base stations and wireless networks exert a deleterious effect on human health:"

Source: Fact Sheet 304

http://www.who.int/ionizing_radiation/pub_meet/factsheets/bs_fs_304_german.pdf

Radiation Commission (2006):

"The Radiation Protection Commission (SSK) has established by an appraisal of the scientific literature prior to 2006 that recent literature has neither provided any evidence for a scientifically well-founded suspicion of a genotoxicity effect exerted by HF fields nor any scientifically evidence-based suspicion for HF fields exerting an influence on gene regulation. The results of the available studies therefore provide no evidence for assuming that high-frequency electromagnetic fields exert an influence on the genome likely to present a hazard to human health or for calling the currently valid limits into question."

Source: Effect of high-frequency fields on the genome: Genotxicity and gene regulation, adopted at the 213th meeting of the Radiation Protection Commission (SSK) on 5/6 December 2006

http://www.ssk.de/de/werke/2006/volltext/ssk0620.pdf