Evidence Base

Many reviews have concluded that there is no convincing evidence to date that mobile phones are harmful to health in the short term. However, the widespread use of mobile phones is a relatively recent phenomenon and it is possible that adverse health effects could emerge after ten years or more of prolonged use. The evidence base necessary to allow us to make firm judgments regarding use in the longer-term has not yet been accumulated, and this question can only resolved by monitoring the health of a large cohort of phone users over a long period of time.
IARC announcement
The current research agenda
Key reviews of research to date
IARC announcement
  • In May 2011 the International Agency for Research on Cancer (IARC) announced in a press release (1) that it had classified radiofrequency electromagnetic fields as possibly carcinogenic to humans (Group 2B).
  • The group reviewed the scientific literature and concluded that there was limited evidence of carcinogenicity among users of wireless telephones for glioma and acoustic neuroma, but inadequate evidence to draw conclusions for other types of cancers.
  • IARC concluded that a close watch should be kept for a link between mobile phones and cancer risk and that it is important that additional research be conducted into the long-term, heavy use of mobile phones.
  • A commentary on Mobile Phones and Cancer was also published in 2014, ‘Next Steps After the 2011 IARC Review’ (2), and the authors ‘made the call for more research’, recognising prospective cohort studies like COSMOS as essential for a valid assessment of exposure.
The current research agenda
  • In 2010, the World Health Organization (WHO) published a new research agenda for radiofrequency (RF) fields (3). This agenda sets out the priorities for health effects research relating to RF exposures, which include the use of mobile phones.
  • In terms of epidemiological research, the WHO agenda identifies the COSMOS study as one of the most important studies currently ongoing in this field, and the study continues to be classified as high priority in order to evaluate potential long-term risks of mobile phone use.
Key reviews of research to date
  • 2000 - The Stewart Report (4), a major report on mobile phones and health, was published by the UK Independent Expert Group on Mobile Phones.
  • 2005 – Following on from the Stewart Report, a further review of mobile phones and health was undertaken by the Advisory Group on Non-Ionizing Radiation (AGNIR) (5) and published by the National Radiological Protection Board (NRPB).
  • 2007 - The independent Mobile Telecommunications and Health Research programme (MTHR) (established in 2001 following the Stewart Report) published a report (6) describing research undertaken as part of its programme. None of the published research supported by MTHR demonstrates biological or adverse health effects produced by radiofrequency exposure from mobile phones.
  • 2009 - Reports reviewing mobile phones and health research were published by both The International Commission on Non-Ionizing Radiation Protection (ICNIRP) (7) and The Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) (8). The report by ICNIRP concluded that studies published to date do not demonstrate an increased risk for any head tumour. However, the Commission notes that the observation period for slow-growing tumours has been too short for the absence of associations reported so far to be considered conclusive.

The COSMOS Study

Details of UK COSMOS research, including the scientific method followed, can be found below, in addition to other useful information. Please click the headings to read more.
Study goals
COSMOS aims to carry out long-term health monitoring of a large cohort to identify any possible health risks linked to mobile phone usage and other wireless technologies.
Members of the public over the age of 18 were invited to complete a questionnaire about their health, well-being and mobile phone use in 2010 or 2012 for the collection of baseline data. Participants were also asked for permission to link their data to health registry records (via HSCIC) and mobile phone use data (via phone operators). These data will allow us to track our participants’ health and mobile phone use objectively throughout the study. Participants will also be followed up at regular intervals by further questionnaires to monitor changes in participants’ self-reported health, mobile phone use and other relevant factors which need to be accounted for. These factors include information relating to medical history, sleep quality and reproductive health, indoor and outdoor environmental factors such as air pollution and traffic noise, in addition to measures of lifestyle, social factors and demographics. The first follow-up questionnaire is planned for 2016.
Cohort size
Approximately 105,000 participants in the UK, recruited through electoral register mailing and via phone data providers.
COSMOS was commissioned by the Department of Health, and is currently funded solely by the Department of Health. Previously, the study was jointly funded by industry and government, via the independent Mobile Telecommunications & Health Research Programme (MTHR).
Related Studies

If you would like to read more about other studies which are investigating possible health risks associated with mobile phone use and radiofrequency fields, you may be interested in the following studies.

  • The MOBI-KIDS Project
    This case-control study spans 14 countries and is following approximately 3,000 young people aged 10-24 years old. This research is investigating a potential link between the risk of brain tumours and environmental factors such as the use of communications devices.
  • The INTERPHONE Study
    This case-control study spanned 13 countries and comprised approximately 14,000 participants aged 30-59 years. This research investigated a potential link between mobile phone use and the risk of certain brain tumours.
Find Out More

If you are interested in learning more about mobile phones, and health protection policy in the UK, below are some useful links.

UK Research Team

Professor Paul Elliott
Principal Investigator, Head of Department of Epidemiology and Biostatistics
Professor Paul Elliott, MBBS, PhD, FMedSci, trained in clinical medicine and epidemiology as a Wellcome Trust Clinical Fellow at St Mary's Hospital London and the London School of Hygiene & Tropical Medicine.
He studied for his PhD in Epidemiology on the INTERSALT Study under the mentorship of Professor Geoffrey Rose. He remained at the London School working as a lecturer, then senior lecturer and reader in epidemiology before becoming Head of the Environmental Epidemiology Unit at LSHTM 1990. In 1995 he was appointed to the Chair in Epidemiology and Public Health Medicine at Imperial College London. He heads what is now the Department of Epidemiology and Biostatistics in the School of Public Health. The Department has expanded significantly during recent years to encompass a wide-ranging programme of health research and extensive collaborations with honorary and visiting staff. Paul Elliott is also Director of the MRC-PHE Centre for Environment and Health which sits within the Department and includes the Small Area Health Statistics Unit (SAHSU). He is also an honorary consultant in public health medicine in the Directorate of Primary Care and Public Health of the Imperial College Healthcare NHS Trust and the academic lead for the Biobanking research theme for the Imperial NIHR Biomedical Research Centre. He was recently appointed as the Academic Health Sciences Centre's (AHSC) Director of Information Governance.
Dr Mireille B Toledano
Co-Principal Investigator, Senior Lecturer in Epidemiology
Dr Mireille Toledano is a senior lecturer in epidemiology at Imperial College London and an investigator of the MRC-HPA Centre for Environment and Health specialising in environmental and spatial epidemiology.
She was awarded her undergraduate degree from University College London, a Master's degree in environmental epidemiology from the London School of Hygiene and Tropical Medicine, and her PhD from Imperial College London. She is currently a Fellow of the Higher Education Academy and a co-author of the Oxford Handbook series ‘Epidemiology for Clinicians’. Much of her work to date has focused on early life environmental exposures, including leading the environment theme of the new UK-wide Life Study and collaborative projects with various birth cohorts across Europe, assessing exposure at individual level through questionnaire data, biomarkers, and global metabonomic profiling. She also has over 10 years expertise in spatial epidemiology and the use of routinely collected data and geographical information systems (GIS) for small area health studies at the SAHSU. Her work in this field has included studies of birth outcomes and water disinfection by-products, waste incineration, and air and noise pollution, as well as investigations of cancer trends and clustering, in particular for primary liver tumours. Her special interest is in the field of non-ionizing radiation epidemiology, having worked on several major projects including national studies of adult cancers near overhead power lines and childhood cancers in proximity to mobile phone base stations.

International Team

Denmark Study Centre: Danish Institute of Cancer Epidemiology Number of participants: around 30,000 Principal Investigator: Dr Aslak Poulsen Email: aslak@cancer.dk Website: www.cancer.dk/cosmos
Finland Study Centre: School of Public Health at Tampere University Number of participants: around 15,000 Principal Investigator: Professor Anssi Auvinen Email: anssi.auvinen@uta.fi
France Study Centre: International Agency for Research on Cancer (IARC) Number of participants: around 50,000 Principal Investigator: Dr Aslak Poulsen Email: deltouri@iarc.fr
The Netherlands Study Centre: Institute for Risk Assessment Sciences at Utrecht University Number of participants: around 90,000 Principal Investigator: Dr RoelVermuelen, Professor Hans Kromhout Email: h.kromhout@uu.nl
Sweden Study Centre: Karolinska Institute Number of participants: around 50,000 Principal Investigator: Dr Lena Hillert, Dr Maria Feychting, Professor Anders Ahlbom Email: cosmos@imm.ki.se Website: www.imm.ki.se/cosmos


Cohort profile: UK COSMOS – a UK cohort for study of environment and health
Sep 2015
Toledano MB, Smith RB, Chang I, Douglass M, Elliott P
International Journal of Epidemiology September 2015
How to Establish and Follow up a Large Prospective Cohort study in the 21st Century - Lessons from UK COSMOS
Jul 2015
Toledano MB, Smith RB, Brook JP, Douglass M, Elliott P
PLOS-ONE July 2015
Validation of exposure assessment and assessment of recruitment methods for a prospective cohort study of mobile phone users (COSMOS) in Finland: A pilot study
Mar 2011
Heinävaara S, Tokola K, Kurttio P, Auvinen A
Environmental Health, March 2011
An international prospective cohort study of mobile phone users and health (Cosmos): design considerations and enrolment
Feb 2011
Schüz J, Elliott P, Auvinen A, Kromhout H, Poulsen AH, Johansen C, Olsen JH, Hillert L, Feychting M, Fremling K, Toledano MB, et al.
Cancer Epidemiology, February 2011


There are currently no vacancies on the UK COSMOS team. Please check back later.


Press Release No. 208 - 31 May 2011.2
Commentary: Mobile Phones and Cancer: Next Steps After the 2011 IARC Review
WHO Research Agenda for Radiofrequency Fields.
Health Effects from Radiofrequency Electromagnetic Fields.
Mobile Telecommunications and Health Research Programme: report 2007.
Exposure to high frequency electromagnetic fields, biological effects and health consequences.
Health Effects of Exposure to EMF.
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