There are some indications of an increased risk of glioma for those who reported the highest 10% of cumulative hours of cell phone use, although there was no consistent trend of increasing risk with greater duration of use. The international pooled analysis of data gathered from 13 participating countries found no increased risk of glioma or meningioma with mobile phone use of more than 10 years. The largest retrospective case-control study to date on adults, Interphone, coordinated by the International Agency for Research on Cancer (IARC), was designed to determine whether there are links between use of mobile phones and head and neck cancers in adults. Several large multinational epidemiological studies have been completed or are ongoing, including case-control studies and prospective cohort studies examining a number of health endpoints in adults. However, results of animal studies consistently show no increased cancer risk for long-term exposure to radiofrequency fields. However, because many cancers are not detectable until many years after the interactions that led to the tumour, and since mobile phones were not widely used until the early 1990s, epidemiological studies at present can only assess those cancers that become evident within shorter time periods. Long-term effectsĮpidemiological research examining potential long-term risks from radiofrequency exposure has mostly looked for an association between brain tumours and mobile phone use. Further, research has not been able to provide support for a causal relationship between exposure to electromagnetic fields and self-reported symptoms, or “electromagnetic hypersensitivity”. To date, research does not suggest any consistent evidence of adverse health effects from exposure to radiofrequency fields at levels below those that cause tissue heating.
At the frequencies used by mobile phones, most of the energy is absorbed by the skin and other superficial tissues, resulting in negligible temperature rise in the brain or any other organs of the body.Ī number of studies have investigated the effects of radiofrequency fields on brain electrical activity, cognitive function, sleep, heart rate and blood pressure in volunteers. Tissue heating is the principal mechanism of interaction between radiofrequency energy and the human body. To date, no adverse health effects have been established as being caused by mobile phone use. Are there any health effects?Ī large number of studies have been performed over the last two decades to assess whether mobile phones pose a potential health risk. Mobile phones are often prohibited in hospitals and on airplanes, as the radiofrequency signals may interfere with certain electro-medical devices and navigation systems. The use of commercial devices for reducing radiofrequency field exposure has not been shown to be effective. Using the phone in areas of good reception also decreases exposure as it allows the phone to transmit at reduced power. In addition to using "hands-free" devices, which keep mobile phones away from the head and body during phone calls, exposure is also reduced by limiting the number and length of calls. A person using a mobile phone 30–40 cm away from their body – for example when text messaging, accessing the Internet, or using a “hands free” device – will therefore have a much lower exposure to radiofrequency fields than someone holding the handset against their head. The power (and hence the radiofrequency exposure to a user) falls off rapidly with increasing distance from the handset. The handset only transmits power when it is turned on. Mobile phones are low-powered radiofrequency transmitters, operating at frequencies between 4 MHz with peak powers in the range of 0.1 to 2 watts. Radiofrequency waves are electromagnetic fields, and unlike ionizing radiation such as X-rays or gamma rays, can neither break chemical bonds nor cause ionization in the human body. Mobile phones communicate by transmitting radio waves through a network of fixed antennas called base stations. Given the large number of mobile phone users, it is important to investigate, understand and monitor any potential public health impact.
In some parts of the world, mobile phones are the most reliable or the only phones available. In 2014, there is an estimated 6.9 billion subscriptions globally. In many countries, over half the population use mobile phones and the market is growing rapidly. Mobile or cellular phones are now an integral part of modern telecommunications.