Use of mobile phones and cordless phones is associated with increased risk for glioma and acoustic neuroma
Highlights
► In May 2011 radiofrequency electromagnetic fields from mobile phones were categorised as Group 2B, ‘possible’, human carcinogen by IARC at WHO. ► The IARC decision on mobile phones was based mainly on case-control studies from the Hardell group in Sweden and the IARC Interphone study. ► This article gives a comprehensive up-to-date review of the association between use of mobile and cordless phones and brain tumours. ► There is a consistent pattern of increased risk for glioma and acoustic neuroma associated with use of wireless phones. ► The current safety limits and reference levels are not adequate to protect public health and new public health standards and limits are needed.
Introduction
On 31 May 2011 the International Agency for Research on Cancer (IARC) at WHO categorised the radiofrequency electromagnetic fields (RF-EMF) from mobile phones, and from other devices that emit similar non-ionising electromagnetic fields, as a Group 2B, i.e., a ‘possible’, human carcinogen [1], [2]. Nine years earlier IARC had also classified extremely low frequency (ELF) magnetic field as Group 2B carcinogen [3].
The IARC evaluation of the carcinogenic effect of RF-EMF on humans took place during a 24–31 May 2011 meeting at Lyon in France. The Working Group consisted of 30 scientists representing four areas: ‘animal cancer studies’, ‘epidemiology’, ‘exposure’ and ‘mechanistic and other relevant data’. The expert groups initially prepared a written draft prior to the IARC meeting. Further work was done in the expert groups and a final agreement, sentence by sentence, was obtained during plenary sessions with all experts participating.
The IARC decision on mobile phones was based mainly on two sets of case-control human studies; the Hardell group of studies from Sweden and the IARC Interphone study. Both provided complementary and supportive results on positive associations between two types of brain tumours; glioma and acoustic neuroma, and exposure to RF-EMF from wireless phones.
The final IARC decision was confirmed by voting of 29 scientists (one not present). A large majority of participants voted to classify RF-EMF radiation as ‘possibly carcinogenic’ to humans, Group 2B. The decision was also based on occupational studies.
In this paper an up-to-date review of the evidence of an association between use of wireless phones and brain tumours is presented. The Nordic countries were among the first countries in the world to widely adopt wireless telecommunications technology. Analogue phones (NMT; Nordic Mobile Telephone System) were introduced in the early 1980s using both 450 and 900 Megahertz (MHz) frequencies. NMT 450 was used in Sweden from 1981 but closed down on 31 December 2007, NMT 900 operated during 1986–2000.
The digital system (GSM; Global System for Mobile Communication) using dual band, 900 and 1800 MHz, started to operate in 1991 and dominates now the market. The third generation of mobile phones, 3G or UMTS (Universal Mobile Telecommunication System), using 1900/2100 MHz RF fields has been introduced worldwide in recent years, in Sweden in 2003. Currently the fourth generation, 4G (Terrestrial 3G), operating at 800/2600 MHz and Trunked Radio Communication (TETRA 380–400 MHz) are being established in Sweden and elsewhere. Nowadays mobile phones are used more than landline phones in Sweden (http://www.pts.se/upload/Rapporter/Tele/2011/sv-telemarknad-halvar-2011-pts-er-2011-21.pdf). Worldwide, an estimate of 5.9 billion mobile phone subscriptions was reported at the end of 2011 by the International Telecommunication Union (ITU; http://www.itu.int/ITU-D/ict/facts/2011/material/ICTFactsFigures2011.pdf). Many users are children and adolescents, which is of special concern regarding potential health effects.
Desktop cordless phones (DECT) have been used in Sweden since 1988, first using analogue 800–900 MHz RF fields, but since early 1990s using a digital 1900 MHz system. The cordless phones are becoming more common than traditional landlines. Also these phones emit RF-EMF radiation similar to that of mobile phones. Thus, it is also necessary to consider the usage of cordless phones along with mobile phones, when human health risks are evaluated. It should be noted that the usual cordless base stations emit RF-EMF continuously. They are often installed in offices close to the person using a cordless phone handset or in homes even in bedrooms next to the head of a sleeping person.
The real increase in use and exposure to electromagnetic fields from wireless phones (mobile phones and cordless phones) in most countries has occurred since the end of the 1990s. When used they emit RF-EMFs. The GSM phones and to a lesser extent the cordless phones emit also ELF-EMF from the battery when used [4], [5]. The brain is the main target organ during use of the handheld phone [6]. Thus, fear of an increased risk for brain tumours has dominated the debate during the last one or two decades. While RF-EMFs do not have sufficient energy to break chemical bonds like ionising radiation, at least not directly, they can nevertheless have harmful effects on biological tissues. Plausible biological mechanisms for these effects include impairment of DNA repair mechanisms and epigenetic changes to DNA.
Primary brain tumours (central nervous system; CNS) constitute of a heterogeneous group of neoplasms divided into two major groups; malignant and benign. They are of different histological types depending on tissue of origin with different growth patterns, molecular markers, anatomical localisations, and age and gender distributions. The clinical appearance, treatment and prognosis are quite different depending on tumour type.
Ionising radiation is an established risk factor for primary brain tumours [7], but there are no well-established environmental causes. Higher socio-economic status tends to be related to higher incidence and some rare inherited cancer syndromes account for a small fraction of tumours [7]. Familial aggregation of glioma has been reported. In a large study 77% more glioma cases than expected were reported among family members [8].
The purpose of this article is to give a comprehensive review of the association between use of mobile and cordless phones and brain tumours, primarily based on the results of the major publications in this field. We include the Hardell group papers and the WHO Interphone study [9], [10], [11]. Also some additional analyses of the risk for brain tumours based on these results are given. Some early studies not part of these two major study groups are also included. More discussion of the results and responses, agreements and disagreements of the findings for the Hardell group and Interphone studies can be found elsewhere [12]. In addition, this review includes studies published after the IARC evaluation in May 2011.
Section snippets
Materials and methods
The PubMed database (www.ncbi.nlm.nih.gov) was used for an up-dated search of published studies in this area using mobile/cellular/cordless telephone and brain tumour/neoplasm/acoustic neuroma/meningioma/glioma as searching terms. Personal knowledge of published studies was also used in order to get as comprehensive a review as possible. All of the authors have long experience in this research area and have published the pioneer studies indicating an association between use of wireless phones
Brain tumours overall
The first study by Hardell et al. [15], [16] included cases and controls during 1994–1996 in parts of Sweden and was the first published study on this issue. Only living cases diagnosed during 1994–1996 were included. Two controls were selected to each case from the Population Registry. In total 209 (90%) of the cases and 425 (91%) of the controls that met the inclusion criteria answered the mailed questionnaire. Overall no association between mobile phone use and brain tumours was found. A
Discussion
The most comprehensive results on use of wireless phones and the association with brain tumours come from the Hardell group in Sweden and the international Interphone study. As pointed out by IARC [1] other studies as discussed above are too small with short latency times, usually in the range of at most 5 years. Both the Hardell group studies and Interphone give results for latency time of 10 years or more. Thus, a summary evaluation will mainly be based on results from these two study groups.
Conclusions
There is a consistent pattern of increased risk of glioma and acoustic neuroma associated with use of mobile phones and cordless phones. The epidemiological evidence comes mainly from two study centres, the Hardell group and the Interphone study group. In the same studies by the Hardell group and Interphone study group no consistent pattern of an increased risk was found for meningioma. These results strengthen the other findings, i.e., increased risk for glioma and acoustic neuroma, since a
Authors’ contributions
Lennart Hardell was responsible for drafting of the manuscript and Michael Carlberg made all statistical calculations. Michael Carlberg and Kjell Hansson Mild read and gave valuable comments on the manuscript. All authors have read and approved the final version. No conflicts of interest reported.
Acknowledgements
Supported by grants from Cancer-och Allergifonden, Cancerhjälpen, and Örebro University Hospital Cancer Fund.
References (96)
- et al.
Carcinogenicity of radiofrequency electromagnetic fields
Lancet Oncology
(2011) - et al.
Epidemiological evidence for an association between use of wireless phones and tumour diseases
Pathophysiology
(2009) - et al.
Case-control study of the association between the use of cellular and cordless telephones and malignant brain tumours diagnosed during 2000-2003
Environmental Research
(2006) - et al.
On the association between glioma, wireless phones, heredity and ionising radiation
Pathophysiology
(2012) - et al.
Electromagnetic fields and DNA damage
Pathophysiology
(2009) - et al.
Increased blood-brain barrier permeability in mammalian brain 7 days after exposure to the radiation from a GSM-900 mobile phone
Pathophysiology
(2009) - et al.
An international prospective cohort study of mobile phone users and health (Cosmos): design considerations and enrolment
Cancer Epidemiology
(2011) - et al.
Social inequality and incidence of and survival from cancer in a population-based study in Denmark, 1994-2003: background, aims, material and methods
European Journal of Cancer
(2008) - et al.
Incidence trends in the anatomic location of primary malignant brain tumours in the United States: 1992-2006
World Neurosurgery
(2012) - et al.
Environmental risk factors for sporadic acoustic neuroma (Interphone Study Group, Germany)
European Journal of Cancer
(2007)
Essential problems in the interpretation of epidemiologic evidence for an association between mobile phone use and brain tumours
Comptes Rendus Physique
Measurement of low frequency magnetic fields from digital cellular telephones
Bioelectromagnetics
Assessment of the magnetic field exposure due to the battery current of digital mobile phones
Health Physics
Distribution of RF energy emitted by mobile phones in anatomical structures of the brain
Physics in Medicine and Biology
Nervous system
Familial aggregation of glioma: a pooled analysis
American Journal of Epidemiology
Risk of brain tumours in relation to estimated RF dose from mobile phones: results from five Interphone countries
Occupational and Environmental Medicine
Re-analysis of risk for glioma in relation to mobile telephone use: comparison with the results of the Interphone international case-control study
International Journal of Epidemiology
Use of cellular telephones and the risk for brain tumours: a case-control study
International Journal of Oncology
Ionizing radiation, cellular telephones and the risk for brain tumours
European Journal of Cancer Prevention
Handheld cellular telephone use and risk of brain cancer
Journal of the American medical Association
Population-based studies on incidence, survival rates, and genetic alterations in astocytic and oligodendroglial gliomas. Review
Journal of Neuropathology and Experimental Neurology
Cellular-telephone use and brain tumours
New England Journal of Medicine
Brain tumours and salivary gland cancers among cellular telephone users
Epidemiology
Cellular and cordless telephones and the risk for brain tumours
European Journal of Cancer Prevention
Further aspects on cellular and cordless telephones and brain tumours
International Journal of Oncology
Case-control study on cellular and cordless telephones and the risk for acoustic neuroma or meningioma in patients diagnosed 2000-2003
Neuroepidemiology
Mobile phone use and the risk for malignant brain tumours: a case-control study on deceased cases and controls
Neuroepidemiology
Pooled analysis of two case-control studies on use of cellular and cordless telephones and the risk for malignant brain tumours diagnosed in 1997-2003
International Archives of Occupational Environmental Health
Pooled analysis of case-control studies on malignant brain tumours and the use of mobile and cordless phones including living and deceased subjects
International Journal of Oncology
Possible health effects related to the use of radiotelephones—recommendations of a European Commission Expert Group
Radiological Protection Bullentin
The INTERPHONE study: design, epidemiological methods, and description of the study population
European Journal of Epidemiology
Mild, methodological aspects of epidemiological studies on the use of mobile phones and their association with brain tumours
Open Environmental Sciences
Commentary: call me on my mobile phone..or better not?—a look at the INTERPHONE study results
International Journal of Epidemiology
Microwaves from mobile phones inhibit 53BP1 focus formation in human stem cells more strongly than in differentiated cells: possible mechanistic link to cancer
Environmental Health Perspectives
How to combine the use of different mobile and cordless telephones in epidemiological studies on brain tumours?
European Journal of Cancer Prevention
Use of cellular telephones and brain tumour risk in urban and rural areas
Occupational and Environmental Medicine
Location of gliomas in relation to mobile telephone use: a case-case and case-specular analysis
American Journal of Epidemiology
Pooled analysis of two case-control studies on the use of cellular and cordless telephones and the risk of benign brain tumours diagnosed during 1997-2003
International Journal of Oncology
Mobile phones, cordless phones and the risk for brain tumours
International Journal of Oncology
Handheld cellular telephones and risk of acoustic neuroma
Neurology
A case-case study of mobile phone use and acoustic neuroma risk in Japan
Bioelectromagnetics
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2021, Environment InternationalCitation Excerpt :Several expert panels performed updated reviews of this body of evidence (AGNIR 2012; ANSES, 2013; 2016; ARPANSA, 2014, CCARS, 2017; Demers et al. 2014; FDA 2020; HCN 2016; ICHENF, 2018; SCENIHR 2015; SSM 2013; 2014; 2015; 2016; 2018; 2019; 2020). Eleven meta-analyses addressing mobile phone use and head tumour risks were published since 2012 (Bortkiewicz et al. 2017; Choi et al. 2020; de Siqueira et al. 2017; Gong et al. 2014; Hardell et al. 2013; Lagorio and Röösli 2014; Prasad et al. 2017; Repacholi et al. 2012; Röösli et al. 2019; Wang and Guo 2016; Yang et al. 2017), often arriving at conflicting conclusions (Ioannidis 2018). None of these evidence syntheses complies in full with the recommendations for the conduct of systematic reviews in toxicology and environmental health research (COSTER) (Whaley et al. 2020), and only one protocol (Mao et al. 2013) of a meta-analysis later published in Chinese (Gong et al. 2014) was preregistered in PROSPERO.