What are the health concerns about mobile phones?
Mobile phone use in the UK has risen rapidly over the past two decades, with the number of mobile connections currently standing at in excess of 81 million (2012).
Mobile telephony uses a radio wave network. Mobile phones are small radio transmitters and receivers, typically with a range of a few miles. To send or receive calls, a handset must be within range of a transmitter mast. When a call is made within range of a mast, the mast relays the call to a switching centre, either by underground cable or by microwave, which routes it to the correct destination. If the destination is a mobile phone, it too must be in range of a mast.
There are concerns that the radiofrequency (RF) emissions from mobile phone handsets and masts (which also frequently emit microwaves) are damaging to human health, particularly to children.
With widespread mobile phone use less than 20 years old, scientific knowledge about the health effects is limited.
Mobile phone handsets are low-powered RF transmitters, emitting maximum powers in the range of 0.2 to 0.6 watts. It is known that RF radiation of this intensity, at frequencies of between 800 and 1800 MHz, can penetrate human tissue to a depth of around one cm, producing a heating effect.
The intensity of the waves produced by handsets is too low to produce a dangerous level of heating, as determined by the National Radiological Protection Board (NRPB). Also, studies have shown that the intensity of RF radiation emitted by handsets falls off dramatically outside the immediate proximity of the phone.
However, the NRPB's safety guidelines only relate to the known biological consequences of excess heating and some believe that there may be other effects. It has been suggested that mobile phones can interfere with the bodies' natural electrical fields and even be linked to brain cancer.
Current scientific evidence does not support the cancer hypothesis, although a 1997 study on genetically-engineered mice found that RF fields similar to those produced by mobile phones increased the incidence of lymphoma in animals within 0.65 m of the transmitting antenna. A large number of studies, under the auspices of the World Health Organisation, are underway to determine whether there is any cancer risk for humans.
Some scientists and users have reported other effects of using mobile phones, including changes in brain activity, reaction times, and sleep patterns. Electromagnetic fields produced by handsets are also said to have the potential to interfere with the functioning of some medical devices, including pacemakers, implantable defibrillators, and certain hearing aids.
In March 1999, Tessa Jowell, then Minister for Public Health, commissioned an Independent Expert Group on Mobile Phones, chaired by Sir William Stewart, to assess the current state of research into the possible health risks from mobile phones and to make suggestions for future action.
The Stewart Report concluded that mobile phone use does not threaten public health, but in view of a lack of definitive evidence, it recommended adherence to the precautionary principle.
However, the Report also said that RF may have "subtle effects" on the brain, reinforcing the suspicions of those who maintain that mobile phones have athermal effects. The WHO also said that there were gaps in existing knowledge, particularly in relation to long-term effects. But neither Stewart nor the WHO called for any specific corrective measures.
Sir William, moreover, caused controversy in September 2001 when he called for children's use of mobile phones to be restricted, because of their thinner skulls. Research from the University of Utah later suggested that children absorbed up to 50 per cent more RF from handsets than adults.
Following public health scandals such as BSE, the public has been cautious about Government and scientific reassurances. The Stewart Report said that while there may be no evidence of health effects, the anxiety about mobile phone masts was actually generating health problems in some people who lived near them.
In 2005 several further reports into the possible health effects of mobile phones were published both in the UK and abroad, including from the US Food and Drug Administration, the BMA, and the French Agency for Environmental Health. All concluded that although adverse health effects had not yet been proven, scientific research should continue.
Similar conclusions were reached in reports published in 2007 by the European Commission's Scientific Committee on Emerging & Newly Identified Health Risks (SCENIHR) and by the UK Mobile Telecommunications and Health Research (MTHR) programme progress report.
In June 2008, MTHR announced that a new £3.1 million study was to follow on from the pilot study into possible health effects associated with long term mobile phone use. This international cohort study (COSMOS) is a long term project currently funded for the first five years.
A different kind of health concern related to mobile phone use was raised in October 2008 by the British Association of Dermatologists who reported that a new allergic skin disorder had been discovered. According to BAD, people who spend long periods of time on their mobile phone may develop an allergic reaction to the phone's nickel surface, resulting in "mobile phone dermatitis".
An updated fact sheet published by the World Health Organisation in May 2010 on mobile phone use and public health reported that a large number of studies had been carried out over the past two decades and that "to date no adverse health effects have been established."
However, in May 2011, the WHO/International Agency for Research on Cancer (IARC) classified radiofrequency electromagnetic fields as possibly carcinogenic to humans (Group 2B), based on an increased risk for glioma, a malignant type of brain cancer, associated with wireless phone use. The chairman of the Working Group, Dr Jonathan Samet, said that although the evidence was still accumulating, it was strong enough to support the conclusion that there could be some risk and therefore "a close watch" should be kept for a link between cell phones and cancer risk.
The UK COSMOS study, which has been funded by the MTHR, jointly supported by the Department of Health and by industry, announced in February 2012 that any UK resident aged 18 or over who uses a mobile phone could now participate. The study involves the long-term health monitoring of a large group of people in order to try and identify any possible health issues linked to mobile phone usage over a long period of time.
There are now over 81 million mobile connections in the UK.
Over 4.8 million customers now access mobile broadband services via a laptop and dongle.
28 per cent of UK adults use their mobile phones for internet access.
Mobile Operators Association - 2012
"Given the potential consequences for public health of this classification and findings, it is important that additional research be conducted into the long-term, heavy use of mobile phones. Pending the availability of such information, it is important to take pragmatic measures to reduce exposure such as hands-free devices or texting. "
IARC Director Christopher Wild, responding to the classification of radiofrequency electromagnetic fields as possibly carcinogenic to humans (Group 2B) – May 2011.
"Many reviews have concluded that there is no convincing evidence to date that mobile phones are harmful to health.
"However, regarding longer-term use, the evidence base necessary to allow us to make firm judgements has not yet been accumulated. There are still significant uncertainties that can only be resolved by monitoring the health of a large cohort of phone users over a long period of time."
COSMOS – 2012
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