Thank you to all our participants for taking part in the 2010 and 2012 COSMOS questionnaires.

The first COSMOS Pilot follow-up questionnaire is now available. A small sample of our participants have been invited to pilot this vital questionnaire and our remaining participants will be invited to take part soon in 2017.

If you would like to learn more about the data collected so far or remind yourself about COSMOS first, please read on.

The Study

Key details of the study are shown below. For more in-depth information about the COSMOS study please read our Participant Information Booklet or visit our Science section.
What is COSMOS?
COSMOS (cohort study of mobile phone use and health) is an international cohort study investigating possible health effects from long term use of mobile phones and other wireless technologies. The aim of the study is to carry out long-term health monitoring of a large group of people so that we can identify if there are any possible health issues linked to using mobile phones and other wireless technologies over a long period of time.
Who is behind the study?
In the UK, the study is run by the COSMOS team at MRC-PHE Centre for Environment and Health, Department of Epidemiology and Biostatistics, Imperial College, London, and funded by the Department of Health. COSMOS also receives support from industry in the form of mobile phone use data provided by network operators. Click here to find out more about how the study is funded. Our team is also joined by five partner teams across Europe in the Netherlands, Denmark, Sweden, Finland and France who make up the international COSMOS team.
How many people are taking part?
Today, COSMOS has close to 105,000 participants in the UK alone. And while we make up the biggest portion of the international cohort, there are more than 300,000 people taking part across Europe.
Why is this research being done?
Mobile phones have only been widely used for a relatively short time, and there are questions about the possible long-term health effects associated with this new technology. As a result, many health agencies worldwide have endorsed the need for this kind of study, including the World Health Organisation (WHO). Through COSMOS, we will be able to resolve the current uncertainties about the possibility of long-term health effects caused by mobile phone technology. For more detailed information about the research background to the study please click here.
How does it work?
In 2010 and 2012, we invited members of the public to fill out a questionnaire about themselves and their health. This baseline questionnaire will be followed up at regular intervals by further questionnaires to monitor changes in participants’ health and use of mobile phones and other wireless technology. The questionnaire also gathers information on a range of other important factors which need to be accounted for. This includes information such as sleep quality and reproductive health, indoor and outdoor environmental factors such as air pollution and traffic noise, and measures of lifestyle, social factors and demographics. We will also link the data we gather from questionnaires to participants’ health registry records and mobile phone traffic data (provided that separate consent has been given). This data linkage is vital to provide us with objective measures of health and mobile phone use.
What have we learned so far?
COSMOS is a long-term study, and we will need to wait a number of years for the research to be completed. However, results will be made available throughout the course of the study, and we are already learning about the make-up, health and behaviour of our participants (including statistics on location, gender, health and well-being and mobile phone use) as well as more general findings about best practice for the conduct of similar studies which will benefit the wider scientific community.
If you’re interested in reading more about these findings, both the UK and international COSMOS teams have already published papers about COSMOS - click here for a full list.
How are you keeping participants’ personal data safe?
Participants’ privacy, and the appropriate use and protection of participants’ data are paramount. Imperial College will ensure the research complies fully with the requirements of the Data Protection Act 1998 and has sought advice from the Information Commissioner to ensure it does. All individually identifiable data (such as name and address) is dealt with in the strictest confidence. Individually identifiable data is stored separately from health and mobile phone use information to preserve confidentiality. In the short-term, participant data may be held by service providers contracted by Imperial College, but these service providers will be legally bound by non-disclosure agreements and strict data security requirements. All participant data will be stored long-term on a secure computer network at Imperial College. The results of this study will be published following independent review, but no individually identifiable data will ever be published.

Data may be shared with members of the international COSMOS consortium in other countries across Europe or with other researchers. However, no individually-identifying data will ever be passed to international COSMOS partners or any other researchers. Imperial College may share with contracted service providers limited data e.g. name, address, sex as required. These service providers will be legally bound by non-disclosure agreements and strict data security requirements and will only be able to use these data for the purposes of the COSMOS Study.
Can I join the COSMOS study?
Thank you for your interest, but we are no longer recruiting participants for COSMOS. Please do check back regularly for the latest study news.

The Phone Usage App

The COSMOS Phone Usage App (XMobiSense) is now available to download directly onto your phone from the international COSMOS website.
If you are a UK COSMOS participant with an Android smartphone (e.g. Samsung, Moto, LG etc.) you can help by installing the app on your phone for a short period (at least 2 weeks). Please visit the international COSMOS website for instructions, and take care to select the UK version of the app.
The app is an important addition to the study as it allows us to collect important phone usage information we cannot obtain from network operators (e.g. use of speaker phone or other hands-free kits, which side of the head voice calls are made on, and the amount of data uploaded or downloaded, including whether this occurs over the mobile phone network or over a WiFi network).
The app does not collect any personally identifiable information such as phone numbers, the content of calls or messages, websites visited or any other personal information. The app does not reduce battery life and, only when WiFi connection is available, it will upload data to a secure server at Imperial College.

The Science (in brief)

Key details of the science informing the study are shown below. For more in-depth information about the evidence base and research agenda driving COSMOS please visit our Science page.

Mobile phones and other wireless technologies (e.g. tablets, laptops, cordless phones) are sources of electromagnetic fields (EMF). It is exposure to these electromagnetic fields when using a mobile phone that is the main scientific interest in this study. Electromagnetic fields can arise from natural sources (such as lightning, or from the Earth’s magnetic field) but it is EMF from man-made sources that we are interested in.
Mobile phones and EMF
Mobile phones make use of EMF by converting your voice or text into an electrical signal, which is then transmitted as radio waves and converted back into sound or text. However, to send a long-distance radio signal takes a lot more power than most phones are able to provide, and alone, a phone is only able to transmit a short distance. To get around this problem, mobile phone masts are used to pick up the weak signal and relay it onwards across a network of masts until it gets to its destination – all in a matter of milliseconds.
The electromagnetic spectrum
There are many different types of EMF, ranging from mostly harmless low frequency waves (non-ionizing radiation) to dangerous high frequency waves (ionizing radiation) that can damage cells and DNA. The frequency (measured in Hertz (Hz)) of radiation, is the number of waves that travel through a certain point in a given length of time. Depending on the frequency, these waves can be hundreds of metres long or smaller than an atom. However, even high frequency radiation has many uses, such as for medical X-Rays or nuclear power, as illustrated in the diagram below.
Mobile phones belong in the radio frequency (radio wave) part of the spectrum, which we primarily use for communications (e.g. TV and radio).
Ionizing and non-ionizing radiation
Ionizing radiation includes gamma rays, X-rays, and ultraviolet rays. These rays can break chemical bonds between atoms to produce ions – hence the term ‘ionizing’. Scientific evidence is clear that exposure to ionising radiation can cause cancer, with risk to health depending on the dose of ionising radiation received. Risks from low doses are actually small and ionising radiation is widely used in cancer therapy.
Non-ionising radiation includes radiowaves, microwaves, infrared and visible light. This type of radiation cannot break chemical bonds, but can cause heating.
Potential risks
We know that when we are exposed to radio frequency waves, some of the transmitted energy is absorbed into our heads and bodies. As there is still no clear answer as to whether there are any possible health effects from non-ionising radiation, studies that are investigating this area, such as COSMOS, are hugely important.

The Team

Professor Paul Elliot Professor Paul Elliott
Dr Mireille Toledano Dr Mireille Toledano
Professor Paul Elliott
Principal Investigator for COSMOS and Head of the Department of Epidemiology and Biostatistics at Imperial College.
“It’s hugely important for people to continue to take part in this study, for the health of both this generation and future generations, so we can categorically answer whether mobile phone use has a long-term effect on health.”
Dr Mireille Toledano
Co-Principal Investigator for COSMOS and Senior Lecturer in Epidemiology at Imperial College.
“When it comes to mobile phones and health, there are still gaps in our knowledge and uncertainties we need to address. We can only do this by monitoring the health of a large number of users over a long period of time – COSMOS will build up a valuable picture as to whether or not there are any links in the longer term.”
Dr Milagros Ruiz
Research Associate in Epidemiology and Biostatistics
“It is wonderful to be part of a large-scale study of great benefit to the health of society.”
Rohan Alexander
Database Manager for COSMOS
“With over 100,000 people taking part in the study, it takes a lot of work to keep on top of all the information coming in. My job involves managing participant data, making sure it is stored securely, linking health and mobile phone records with our questionnaire data, and translating the raw survey data into something the research team are able to analyse.”
Rosi Hirst
Research Administrator for COSMOS
“I take care of the day-to-day running of the study so the rest of the team can focus on the research itself. Everything from updating the website, to purchasing equipment, organising meetings and booking travel falls to me. I also act as the main point of contact for the study for participants, so if you have any questions feel free to ask me!
Mark Ellis
Research Assistant for COSMOS
“It has been exciting to contribute to this important research by helping to finalise the COSMOS follow-up questionnaire. I’m thankful for all our participants’ time spent contributing to the study, and I am looking forward to helping with our analysis of the results.”

Please Update Your Personal Details

Perhaps you’ve moved address or got a new mobile number? We need to know changes like these, so that we can follow your health and mobile usage over the long-term.
To provide up-to-date details please email us at or call Freephone 0800 0270 270 and we will update your records. It is crucial that we have current information for all our participants, so please do let us know whenever your details change.
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