Mobile phone radiation and health
The effect of mobile phone radiation on human health is the subject
of recent interest and study, as a result of the enormous increase in mobile
phone usage throughout the world (as of November 2011, there were
more than 5.981 billion subscriptions worldwide[1]).
Mobile phones use electromagnetic radiation in
the microwave
range. Other digital wireless
systems, such as data communication networks, produce similar
radiation.The WHO has classified mobile phone radiation on the IARC scale into Group 2B - possibly carcinogenic. That means that there "could be some risk" of carcinogenicity, so additional research into the long-term, heavy use of mobile phones needs to be conducted.[2] Some national radiation advisory authorities[3] have recommended measures to minimize exposure to their citizens as a precautionary approach.
Effects
Many scientific studies have investigated possible health
symptoms of mobile phone radiation. These studies are occasionally reviewed by some
scientific committees to assess overall risks. A recent assessment was
published in 2007 by the European Commission Scientific
Committee on Emerging and Newly Identified Health Risks (SCENIHR).[4]
It concludes that the three lines of evidence, viz. animal, in vitro,
and epidemiological studies, indicate that "exposure to RF fields is
unlikely to lead to an increase in cancer in humans"
Blood–brain barrier effects
Swedish researchers from Lund University (Salford, Brun, Persson, Eberhardt, and Malmgren) have studied the effects of microwave radiation on the rat brain. They found a leakage of albumin into the brain via a permeated blood–brain barrier.[12][13] This confirms earlier work on the blood–brain barrier by Allan Frey, Oscar and Hawkins, and Albert and Kerns.[14] Other groups have not confirmed these findings in in vitro cell studies[15] or whole animal studies.[16]Cancer
In 2006 a large Danish study about the connection between mobile phone use and cancer incidence was published. It followed over 420,000 Danish citizens for 20 years and showed no increased risk of cancer.[17] The German Federal Office for Radiation Protection (Bundesamt für Strahlenschutz) considers this report inconclusive.[18]The following studies of long time exposure have been published:
- The 13 nation INTERPHONE project – the largest study of its kind ever undertaken – has now been published and did not find a solid link between mobile phones and brain tumours.[19]
The authors reported the following conclusion:
Overall, no increase in risk of glioma or meningioma was observed with use of mobile phones. There were suggestions of an increased risk of glioma at the highest exposure levels, but biases and error prevent a causal interpretation. The possible effects of long-term heavy use of mobile phones require further investigation.
In the press release[21] accompanying the release of the paper, Dr. Christopher Wild, Director of the International Agency for Research on Cancer (IARC) said:
An increased risk of brain cancer is not established from the data from Interphone. However, observations at the highest level of cumulative call time and the changing patterns of mobile phone use since the period studied by Interphone, particularly in young people, mean that further investigation of mobile phone use and brain cancer risk is merited.
A number of independent health and government authorities have commented on this important study including The Australian Centre for Radiofrequency Bioeffects Research (ACRBR) which said in a statement that:[22]
Until now there have been concerns that mobile phones were causing increases in brain tumours. Interphone is both large and rigorous enough to address this claim, and it has not provided any convincing scientific evidence of an association between mobile phone use and the development of glioma or meningioma. While the study demonstrates some weak evidence of an association with the highest tenth of cumulative call time (but only in those who started mobile phone use most recently), the authors conclude that biases and errors limit the strength of any conclusions in this group. It now seems clear that if there was an effect of mobile phone use on brain tumour risks in adults, this is likely to be too small to be detectable by even a large multinational study of the size of Interphone.
The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA)which said in a statement that:
On the basis of current understanding of the relationship between brain cancer and use of mobile phones, including the recently published data from the INTERPHONE study, ARPANSA:
concludes that currently available data do not warrant any general recommendation to limit use of mobile phones in the adult population,
continues to inform those concerned about potential health effects that they may limit their exposure by reducing call time, by making calls where reception is good, by using hands-free devices or speaker options, or by texting; and
recommends that, due to the lack of any data relating to children and long term use of mobile phones, parents encourage their children to limit their exposure by reducing call time, by making calls where reception is good, by using hands-free devices or speaker options, or by texting.
The Cancer Council Australia said in a statement that it cautiously welcomed the results of the largest international study to date into mobile phone use, which has found no evidence that normal use of mobile phones, for a period up to 12 years, can cause brain cancer.
Chief Executive Officer, Professor Ian Olver, said findings from the Interphone study, conducted across 13 countries including Australia, were consistent with other research that had failed to find a link between mobile phones and cancer.
This supports previous research showing mobile phones don’t damage cell DNA, meaning they can’t cause the type of genetic mutations that develop into cancer,” Professor Olver said.
However, it has been suggested that electromagnetic fields associated with mobile phones may play a role in speeding up the development of an existing cancer. The Interphone study found no evidence to support this theory.
- A Danish study (2004) that took place over 10 years found no evidence to support a link. However, this study has been criticized for collecting data from subscriptions and not necessarily from actual users. It is known that some subscribers do not use the phones themselves but provide them for family members to use. That this happens is supported by the observation that only 61% of a small sample of the subscribers reported use of mobile phones when responding to a questionnaire.[17][23]
- A Swedish study (2005) that draws the conclusion that "the data do not support the hypothesis that mobile phone use is related to an increased risk of glioma or meningioma."[24]
- A British study (2005) that draws the conclusion that "The study suggests that there is no substantial risk of acoustic neuroma in the first decade after starting mobile phone use. However, an increase in risk after longer term use or after a longer lag period could not be ruled out."[25]
- A German study (2006) that states "In conclusion, no overall increased risk of glioma or meningioma was observed among these cellular phone users; however, for long-term cellular phone users, results need to be confirmed before firm conclusions can be drawn."[26]
- A joint study conducted in northern Europe that draws the conclusion that "Although our results overall do not indicate an increased risk of glioma in relation to mobile phone use, the possible risk in the most heavily exposed part of the brain with long-term use needs to be explored further before firm conclusions can be drawn."[27]
- A Swedish scientific team at the Karolinska Institute conducted an epidemiological study (2004) that suggested that regular use of a mobile phone over a decade or more was associated with an increased risk of acoustic neuroma, a type of benign brain tumor. The increase was not noted in those who had used phones for fewer than 10 years.[28]
- The INTERPHONE study group from Japan published the results of a study of brain tumour risk and mobile phone use. They used a new approach: determining the SAR inside a tumour by calculating the radio frequency field absorption in the exact tumour location. Cases examined included glioma, meningioma, and pituitary adenoma. They reported that the overall odds ratio (OR) was not increased and that there was no significant trend towards an increasing OR in relation to exposure, as measured by SAR.[29]
- Cell phone users had an increased risk of malignant gliomas.
- Link between cell phone use and a higher rate of acoustic neuromas.
- Tumors are more likely to occur on the side of the head that the cell handset is used.
- One hour of cell phone use per day significantly increases tumor risk after ten years or more.
- A self-published and non-peer reviewed meta-study by Dr. Vini Khurana, an Australian neurosurgeon, presented what it termed "increasing body of evidence ... for a link between mobile phone usage and certain brain tumours" and that it "is anticipated that this danger has far broader public health ramifications than asbestos and smoking".[32] This was criticised as ‘… an unbalanced analysis of the literature, which is also selective in support of the author’s claims.’[33]
In a time trends study in Europe, conducted by the Institute of Cancer Epidemiology in Copenhagen, no significant increase in brain tumors among cell phone users was found between the years of 1998 and 2003. "The lack of a trend change in incidence from 1998 to 2003 suggests that the induction period relating mobile phone use to brain tumors exceeds 5–10 years, the increased risk in this population is too small to be observed, the increased risk is restricted to subgroups of brain tumors or mobile phone users, or there is no increased risk."[36]
On 31 May 2011 the International Agency for Research on Cancer classified radiofrequency electromagnetic fields as possibly carcinogenic to humans (Group 2B). The IARC assessed and evaluated available literature and studies about the carcinogenicity of radiofrequency electromagnetic fields (RF-EMF), and found the evidence to be "limited for carcinogenicity of RF-EMF, based on positive associations between glioma and acoustic neuroma and exposure". The conclusion of the IARC was mainly based on the INTERPHONE study, which found an increased risk for glioma in the highest category of heavy users (30 minutes per day over a 10‐year period), although no increased risk was found at lower exposure and other studies could not back up the findings. The evidence for other types of cancer was found to be "inadequate". Some members of the Working Group opposed the conclusions and considered the current evidence in humans still as “inadequate”, citing inconsistencies between the assessed studies.[2][37]
Researchers at the National Cancer Institute found that while cell phone use increased substantially over the period 1992 to 2008 (from nearly zero to almost 100 percent of the population), the U.S. trends in glioma incidence did not mirror that increase.[1]
Cognitive effects
A 2009 study examined the effects of exposure to radiofrequency radiation (RFR) emitted by standard GSM cell phones on the cognitive functions of humans. The study confirmed longer (slower) response times to a spatial working memory task when exposed to RFR from a standard GSM cellular phone placed next to the head of male subjects, and showed that longer duration of exposure to RFR may increase the effects on performance. Right-handed subjects exposed to RFR on the left side of their head on average had significantly longer response times when compared to exposure to the right side and sham-exposure.[38]Sleep and EEG effects
Sleep, EEG and waking rCBF have been studied in relation to RF exposure for a decade now, and the majority of papers published to date have found some form of effect. While a Finnish study failed to find any effect on sleep or other cognitive function from pulsed RF exposure,[48] most other papers have found significant effects on sleep.[49][50][51][52][53][54] Two of these papers found the effect was only present when the exposure was pulsed (amplitude modulated), and one early paper actually found that sleep quality (measured by the amount of participants' broken sleep) actually improved.While some papers were inconclusive or inconsistent,[55][56] a number of studies have now demonstrated reversible EEG and rCBF alterations from exposure to pulsed RF exposure.[57][58][59][60] German research from 2006 found that statistically significant EEG changes could be consistently found, but only in a relatively low proportion of study participants (12 - 30%).[61]
Behavioral effects
A study on mice suggested that cell phone use during pregnancy may cause behavioral problems for their offspring that resemble the effects of ADHD.[62]Safety standards and licensing
In order to protect the population living around base stations and users of mobile handsets, governments and regulatory bodies adopt safety standards, which translate to limits on exposure levels below a certain value. There are many proposed national and international standards, but that of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) is the most respected one, and has been adopted so far by more than 80 countries. For radio stations, ICNIRP proposes two safety levels: one for occupational exposure, another one for the general population. Currently there are efforts underway to harmonise the different standards in existence.[76]Radio base licensing procedures have been established in the majority of urban spaces regulated either at municipal/county, provincial/state or national level. Mobile telephone service providers are, in many regions, required to obtain construction licenses, provide certification of antenna emission levels and assure compliance to ICNIRP standards and/or to other environmental legislation.
Many governmental bodies also require that competing telecommunication companies try to achieve sharing of towers so as to decrease environmental and cosmetic impact. This issue is an influential factor of rejection of installation of new antennas and towers in communities.
The safety standards in the U.S. are set by the Federal Communications Commission (FCC). The FCC has based its standards primarily on those standards established by the Institute of Electrical and Electronics Engineers (IEEE), specifically Subcommittee 4 of the "International Committee on Electromagnetic Safety".
Switzerland has set safety limits lower than the ICNIRP limits for certain "sensitive areas" (classrooms, for example).[77]
On 1 September 2012, India set electromagnetic frequency exposure limit for all mobile phone base stations to 1/10th of the existing ICNIRP exposure level. Telecom Enforcement Resource & Monitoring (TERM) cells will audit the self certification provided by the mobile network operators.[78]
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