The smartphone has become indispensable in everyday life for most of us. We always carry it with us to make phone calls and surf the Internet. We write WhatsApp messages, send photos and check out the latest posts on Facebook. High-performance cellular networks are needed to meet these demands. But how is it possible that you can make phone calls around the world and log on to the Internet from almost anywhere?
Smartphones use high-frequency electromagnetic radio waves to transmit data and speech. They enable the transmission of information from your phone to the nearest phone mast (base station). Speech and data are digitalized and converted into radio waves. These radio waves that are produced when you make a call with your smartphone at your ear are commonly known as smartphone radiation.
According to the website of the German Federal Office for Radiation Protection (BfS)*, most smartphones transmit in GSM (Global System for Mobile Communication), UTMS (Universal Mobile Telecommunications System) and LTE-Standard (Long Term Evolution). GSM is known as the mobile communications standard of the 2nd generation (2G), UMTS as the 3rd generation and LTE as the 4th generation. The difference is primarily in the transmission speeds, increasing from generation to generation.
To ensure comprehensive coverage of networks, all mobile phone masts and base stations are required to be equipped with GSM as well as UMTS and LTE technology. Speech and data are transmitted from phones to the surrounding base stations, which route the signals to the recipient. The three cellular networks use the following frequency ranges:
- GSM: 900 and 1,800 MHz
- UMTS: 1,900–2,170 MHz
- LTE: 800 and 2,600 MHz
The expansion of cellular networks to other frequency bands is planned. The LTE successor 5G is already in the pipeline and will reach frequencies in the high GHz range in the coming years. The expansion and new building of additional base stations is required by the rapid rise of smartphone usage as well as the increasing demand for bandwidth, because each station can only handle a limited data volume. Each base station for mobile communications has a transmitter and reception facility. The number of base stations required depends on the number of calls, which means urban areas have more stations than sparsely populated areas.
Measures to protect the population from health hazards due to electric and magnetic fields from low-frequency and DC systems are set in the 26th Ordinance on the Implementation of the Federal Emissions Control Act (26th BImSchV) Limiting emission values.
The SAR value (specific absorption rate) is used as the basis for defining limiting emission values in this area. It is a measure for the absorption of electromagnetic fields in a body or material. The absorption of electromagnetic energy always results in the heating of a body. Consequently, the limiting emission values for smartphones are only based on the thermal effect of electromagnetic radiation.
Other influences of radiation, such as the possible damage to a cell genome or similar matters, are not considered. There are currently no long-term studies concerning these effects.
The maximum levels recommended for the protection of health are:
- 08 Watts per kilogram (W/kg) averaged over the whole body
- 2 W/kg locally averaged over body parts such as the head
Quote from the recommendation of the BfS for calling with your smartphone: “According to the current state of scientific knowledge, internationally established maximum levels are sufficient to protect us against proven health risks. However, uncertainties still exist in the risk assessment, which could not completely be eliminated by the German Mobile Telecommunication Research Program. Such measures especially concern:
- Possible health risks of long-term exposure to high-frequency electromagnetic fields due to calling using smartphones in adults (intensive smartphone use for more than 10 years)
- The question whether the use of smartphones by children could affect their health
For these reasons, BfS considers preventive health care (precautionary measures) still to be necessary: The exposure to electromagnetic fields should be as low as possible.”
Smartphones provide many advantages, and it is a question of using this technology responsibly. Each person should decide for himself which protection measures he deems appropriate. According to the recommendations of the German Federal Office for Radiation Protection, you should pay attention to a low SAR value when buying a smartphone. A list of the SAR values of mobile devices from different manufacturers is published on the BfS website.
If possible, using a landline should be preferred over a mobile phone. Phone calls with a mobile phone should be as short as possible and ideally with a headset or hands-free system in a car, so the smartphone radiation is not aimed directly at your head. In case of bad reception, you should preferably not make any calls, because your smartphone must transmit the call with increased performance, consequently causing increased exposure to electromagnetic fields. Some individual smartphone manufacturers even explicitly state in the operating instructions of their devices that a headset or the loudspeaker should be used when calling, to ensure sufficient distance from your ear and thus keep the effects of smartphone radiation to a minimum.
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