Title: Secondary School Cohort Study of Mobile Phone Use and Neurocognitive and Behavioural Outcomes
Funder: Department of Health and Social Care

Abstract: Background: In the UK, 70-80% of 11-12 year olds own a mobile phone. Children s potential sensitivity to radiofrequency (RF) exposures from mobile phones, highlighted by the Stewart Report in 2000, remains a key area of scientific uncertainty. The latest World Health Organisation (WHO) RF Agenda highlights this gap, ranking prospective cohort studies of children and adolescents , including neurocognitive and behavioural outcomes, as highest priority research need . Aims: This proposal is to conduct a 3 year secondary school-based cohort study to investigate prospectively whether mobile phone use is associated with neurocognitive and behavioural outcomes. Specifically, the aim is to discern whether any observed associations are likely due to exposure to RF fields from phones, all RF sources (e.g. DECT phones, WLAN), or from the brain-training that may occur from frequent use of technology. Research plan: The study will establish and follow a cohort of 2,500 school children in year 7 (ages 11-12 years) from ~25 schools in outer London for a period of 2 years. Parents will be asked to give consent and complete a questionnaire. Baseline data collection will take place via an internet mediated assessment conducted in each school. The assessment will include standardised neurocognitive tests, validated behavioural screening scales, and a questionnaire on mobile phone use, use of other RF sources, lifestyle and potential confounders e.g. video gaming. Traffic data from network operators will be requested annually augmented by data collected via the Xmobisense app. These data will enable more accurate RF exposure metrics to be derived than those based on usage alone, to help differentiate possible brain training from any effects of RF fields. A validation study will be conducted on ~200 children to collect personal RF exposure measurements to allow differentiation of mobile phone exposures from other RF sources, identify exposure-relevant behaviours and enhance and validate exposure assessment in the main cohort. Follow-up assessment in schools will take place in year 9 (age 14 years). Epidemiological analyses of mobile phone use and changes in neurocognitive and behavioural outcomes, i.e., follow-up assessment vs. baseline assessment, will be undertaken. Research team: Dr Mireille Toledano will take overall responsibility for the study based at Imperial College London, and will oversee, together with Professor Paul Elliott, Director of the MRC-HPA Centre for Environment and Health, all epidemiological aspects of the study. Both Dr Toledano and Prof Elliott have long standing expertise in EMF epidemiology and bring added value and experience to this study from having successfully led the set-up of the UK COSMOS cohort of 105,000 adult mobile phone users. Professor Michael Thomas, Director of the Centre for Education Neuroscience, and Dr Iroise Dumontheil both at Birkbeck University, provide expertise in neurocognitive development, including extensive experience designing and conducting in-school research on children. Professor Martin R&ouml;&ouml;sli, head of the Environmental Exposures and Health unit at the Swiss Tropical Public Health Institute is an internationally renowned expert in personal EMF exposure assessment, currently leading the HERMES study on mobile phone use amongst adolescents in Switzerland. Potential impact on policy/users: This research will generate a rich and unique dataset with which to address current gaps in, and the limitations of, available evidence and directly responds to WHO research needs. Research outputs on mobile phone use, total personal RF exposures, and potential associated health risks will enable review of current UK health policy precautionary advice regarding children s mobile phone use, which has not been updated for over a decade. With an improved understanding of UK childrens RF exposure in different frequency bands, specific ways to reduce exposure levels may be identified to provide targeted advice to parents and children as appropriate.

Lay abstract: In the UK, 70-80% of 11-12 year olds own a mobile phone. Scientists remain uncertain as to whether children s developing brains might be more vulnerable than adults to radio wave exposures to the head from mobile phones. This 3 year study will follow a group of 2,500 secondary school children to investigate whether children s use of mobile phones and/or other technologies that use radio waves e.g. portable landline phones and wireless internet, might affect their neurocognitive or behavioural development e.g. memory, problem solving skills. The study will be conducted in year 7 children (ages 11-12 years) from ~25 schools across outer London, with follow-up in year 9 (ages 13-14 years). Before commencing, approval will be obtained from an NHS research ethics committee. Parents will give consent and complete a questionnaire. Children will undertake a computer assessment conducted at their school, including questions assessing: how fast and accurately they can solve problems and recall images; behavioural problems e.g. hyperactivity; and use of mobile phones, other radio frequency (RF) technologies and lifestyle. Information on phone usage will also be obtained via mobile phone companies and from smartphone apps. All data will be stored in accordance with Data Protection laws and no individually-identifying information will be published. This collaborative research will be carried out at Imperial College London led by Dr Mireille Toledano. Dr Toledano together with Professor Paul Elliott provide expertise in RF health research, having successfully set-up the UK COSMOS study of 105,000 adult mobile phone users. Professor Michael Thomas and Dr Iroise Dumontheil both at Birkbeck University, provide expertise in neurocognitive development and in-school research. Professor Martin R&ouml;&ouml;sli at the Swiss Tropical Public Health Institute, is an internationally renowned expert in personal measurement of RF exposures. This research will enable review of current UK health policy precautionary advice to limit children s mobile phone use, which has not been updated for over a decade. With an improved understanding of UK childrens RF exposures from mobile phones and other RF technologies, specific ways to reduce exposure levels may be identified to provide targeted advice to parents and children as appropriate.

Research activity codes: 2.2 FACTORS RELATING TO PHYSICAL ENVIRONMENT
Health categories: MENTAL HEALTH;NEUROLOGICAL