Extensive research has been conducted into possible health effects of exposure to electromagnetic fields, including many types of radio signals. The WHO states that the scientific knowledge in this area is now more extensive than for most chemicals. The consensus of many expert reviews by independent public health agencies is that there are no established health hazards from exposure below the international recommendations. In May 2011 radiofrequency (RF) electromagnetic fields were classified as possibly carcinogenic to humans (Group 2B), a category used when a causal association is considered credible, but when chance, bias or confounding cannot be ruled out with reasonable confidence. The WHO has identified areas for continuing research to support future health risk assessments. Information on new research publications is available from the EMF-PORTAL.
A CLOSER LOOK
A large number of studies have been performed over the last two decades to assess whether mobile phones pose a potential health risk. According to the WHO, no adverse health effects have been established as being caused by mobile phone use. Some epidemiological studies have suggested an increased risk among subjects with the highest 10% of cumulative hours of reported mobile phone use, but study limitations prevent a causal interpretation. Wireless devices are designed to comply with safety guidelines when operating at their maximum power. In normal use, mobile phones automatically reduce the transmitted power to the minimum possible while maintaining good call quality. If individuals are concerned, they can choose to limit their exposure by limiting the length of calls, or using ‘hands-free’ devices to keep mobile phones away from the head and body.
Mobile and wireless communications networks use radio signals to provide a range of voice, video and other data services to subscribers and devices such as smart meters. In order to support higher data rates and improved in-building coverage, small cells are increasingly being deployed. The WHO has concluded that considering the very low exposure levels and research results collected to date, there is no convincing scientific evidence that the weak radio signals from base stations and wireless networks cause adverse health effects. Access to areas close to base station antennas (the rectangular panels at the top of the mast that transmit the radio signals) where exposure guidelines may be exceeded is restricted to authorised personnel. At ground level, radio signals are typically hundreds of times below the safety guidelines and similar to those from broadcast transmitters or Wi-Fi access points. Thus, there is no scientific basis for planning restrictions on antenna siting.
The GSMA booklet Mobile Communications and Health, available in multiple languages, provides clear answers to many of the common questions on this topic. A sampling of these questions is posted below.
I’ve read that mobile phones can cause cancer. Is this true?
There are no established health risks from the radio signals used by mobile phones. Some studies have suggested increased brain cancer risk for long-term users but there are limitations to the studies and a lack of evidence of cancer increase in national health registries. Due to these uncertainties, the WHO recommends that research should continue.
I live close to a base station. Am I at risk?
The consensus scientific view is that there are no health risks from living near a base station. Recent measurement surveys show that exposures to base station radio signals range from 0.002 per cent to two per cent of the levels of international exposure guidelines, depending on a variety of factors such as the proximity to the antenna and the surrounding environment. This is lower or comparable to RF exposures from radio or television broadcast transmitters.
Do mobile networks affect birds, animals or plants such as trees?
In 1999, the WHO International EMF Project, the ICNIRP and the German Federal Office for Radiation Protection (BfS) hosted a seminar on the effects of electromagnetic fields in the environment. A review produced after the seminar concluded that: ‘Overall, it appears that the human EMF exposure limits recommended by the International Commission on Non-Ionizing Radiation (ICNIRP, 1998) would also be protective of the environment.’
Can mobile phones cause explosions at petrol stations?
There is no established link between radio signals from mobile phones and petrol station fires according to a 2005 report for the Australian Transport Safety Bureau. The report concluded that of 243 incidents reported globally between 1993 and 2004, ‘… experts have subsequently revealed that not one of the incidents was associated with telecommunication equipment. Instead, many of the fires were ignited by the discharge of static electricity from the human body.’ There may be hazards associated with the distraction of using a mobile phone while operating a petrol pump and the GSMA recommends that mobile phone users respect the prohibitions of the fuel companies, and follow any relevant advice given in their mobile phone user guides.
Can long term use of a mobile phone affect hearing?
The scientific committee advising the European Commission has concluded that the listening habits of most users of personal music players (and mobile phones including a music playing function) are unlikely to cause harm. However, some people may put their hearing at risk because they set the volume control very high or listen to music at high levels for many hours per day. Mobile phone users can limit the risk of hearing damage by keeping the handset volume down, avoiding prolonged, continuous listening and making calls away from background noise.
Why are there so many restrictions on using mobile phones in hospitals?
At short range, the radio signal from a mobile phone may cause interference with electronic medical devices. At distances greater than one to two metres, the possibility is substantially reduced. It is possible for mobile phones to be used in designated areas of hospitals, but you should obey any warning signs and the instructions of hospital staff. If you use electrical medical equipment in your home, we recommend that you seek the advice of your doctor or equipment supplier.