WHO International EMF Project

International Advisory Committee Meeting 19-20 June 2008

National Collaborating Institute Report Radiation Protection Division of the UK Health Protection Agency

The Health Protection Agency (HPA) was formed in 2003 and brought together several organisations in order to provide an integrated approach to protecting UK . The HPA has a large network of approximately 3000 staff based at three major centres, and regionally and locally throughout . There is a small central office based in London. The Agency works closely with locally based colleagues employed within the devolved administrations of Wales, Scotland and Northern Ireland. The Centre for Infections at Colindale is the base for communicable disease surveillance and specialist microbiology. The Centre for Radiation, Chemical and Environmental Hazards (CRCE), is based at Chilton and the Centre for Emergency Preparedness and Response, focusing on applied microbiological research and emergency response, is based at Porton Down.

On 1 April 2005 the National Radiological Protection Board merged with the Health Protection Agency (HPA) forming its Radiation Protection Division (RPD). Together with the Chemical Hazards and Poisons Division of HPA it forms the Agency’s Centre for Radiation, Chemical and Environmental Hazards (CRCE). RPD carries out the Health Protection Agency’s work on ionising and non-ionising radiations. It undertakes research to advance knowledge about protection from the risks of these radiations; provides laboratory and technical services; runs training courses; provides expert information and has a significant advisory role in the UK.

Patient and Volunteer Exposures in MRI Revised advice on limiting the exposure of patients and volunteers to the static magnetic fields, time varying electromagnetic fields and acoustic noise from magnetic resonance imaging (MRI) will be published shortly by HPA. Previous advice was published in 1991 by the predecessor of RPD, the National Radiological Protection Board. More recently the International Commission on Non-Ionizing Radiation Protection (ICNIRP, 2004) has reviewed the science relevant to possible adverse health effects from such exposures and published its advice. Recognising the importance of global harmonisation, the HPA review takes account of the ICNIRP review and focuses on the ICNIRP recommendations, and particularly as to their possible application in the UK.

The new advice is being developed by a working group comprising RPD staff and external experts in the field of MRI and its applications. The group has reviewed published scientific data in the life and physical sciences about the possible adverse effects on people of exposure to MRI. The reviewers took into account the clear benefits to individual patients undergoing MRI examinations and the potential benefits from research involving volunteer exposures which can increase medical knowledge.

A draft document was made available for expert comment from June 2007 and for general consultation from October 2007. Input was sought input from all interested parties, including corporate and professional bodies and MRI equipment developers and users, particularly in respect of any potential problems in the development and use of MRI equipment were the ICNIRP 2004 guidelines on patient and volunteer exposure to be implemented in the UK.

The advice is expected to be published in Documents of the HPA within the next few months and the consultation document (now closed) remains available on the HPA website: http://www.hpa.org.uk/webw/HPAweb&Page&HPAwebAutoListName/Page/1204542909765?p=1 204542909765

UK ELF stakeholder group SAGE is the Stakeholder Advisory Group on ELF EMFs which has been set up by the Department of Health to explore the implications and make practical recommendations for a precautionary approach to power frequency electric and magnetic fields. SAGE has representation from public concern groups who advocate greater precaution as well as from the power supply industry, government departments and the Health Protection Agency. The SAGE website can be found at www.rkpartnership.co.uk.

SAGE published its first interim report on 27 April 2007. The report considered a wide range of possible health effects, and mitigation options such as the 'corridor option', in which no development would not occur within a certain distance of power lines, optimal phasing of lines to reduce electric and magnetic fields, the design and promotion of low magnetic field appliances and changes in wiring practice, and provision of information in the public domain.

HPA has given Health Ministers advice on the first interim assessment. The advice highlighted the recommendation issued in 2004, by the National Radiological Protection Board (NRPB - now the Radiation Protection Division of the HPA), to adopt in the UK the guidelines of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) for limiting exposures to ELF EMFs and confirmed that this advice remains extant. In addition, the uncertainties in the underlying evidence base led NRPB to recommend in its 2004 document that the Government should consider the need for further precautionary measures in respect of exposure of people to ELF EMFs. In doing so, it should note that the overall evidence for adverse effects of ELF EMFs on health at levels of exposure normally experienced by the general public is weak. The least weak evidence is for the exposure of children to power frequency magnetic fields and childhood leukaemia.

SAGE was not set up to review the scientific evidence relating to the health effects of ELF EMFs. Rather, it took as its starting point the NRPB advice to “consider the possible need for further precautionary measures….” However, SAGE identified two broad viewpoints on the science. In one, exposure to ELF EMFs is assumed to be a risk factor (possibly causal) for childhood leukaemia. This is termed by SAGE the “WHO/HPA” position, short-handed as CL. The other viewpoint allows for the possibility of a larger number of illnesses attributable to exposure to ELF EMF (e.g. adult leukaemia and brain tumours, miscarriage and amyotrophic lateral sclerosis). This viewpoint is short-handed as CL+, or the “ California” position in the SAGE report.

The scientific evidence, as reviewed by HPA, supports the view that precautionary measures should address solely the possible association with childhood leukaemia and not other more speculative health effects. HPA advises that it would be wise to err on the side of caution, but with a proportionate response. HPA supports precautionary measures that have a convincing evidence base to show that they will be successful in reducing exposure, are effective in providing reassurance to the public, and where the overall benefits outweigh the fiscal and social costs.

The full advice from HPA, including responses to the range of measures identified by SAGE can be found on the HPA website: http://www.hpa.org.uk/webw/HPAweb&HPAwebStandard/HPAweb_C/1204276682532?p=12078 97920036

Summary of EMF-related research ongoing at HPA-RPD Theoretical dosimetry studies Finite-Difference Time-Domain (FDTD) calculations of SAR from 50 MHz to 6 GHz in a series of child phantoms have been performed. The University of Florida (UF) Series B paediatric phantoms were developed for medical and radiation protection photon dosimetry. The series includes a 9-month male, a 4-year female, an 8-year female, an 11-year male and a 14-year male. They have been adapted to calculate electromagnetic fields in the body for plane wave exposure. A comparison has been made with the previous linearly scaled versions of NORMAN and NAOMI for calculations at 2 mm resolution. Further FDTD calculations were performed at resolutions of 1 and 0.7 mm above 900 MHz to elucidate the effects of grid resolution on SAR. The external electric fields required to produce the basic restriction for public exposure on whole-body averaged SAR have been calculated.

A study has been performed to identify uncertainties and problems in the practical application of the ICNIRP low frequency basic restriction on current density. This quantity should be averaged over a cross-section of 1 cm2 perpendicular to the current direction. There are difficulties in finding a square cm of spinal cord over which to average. The consequences of including neighbouring tissues in the averages has been investigated in the male and female voxel models NORMAN and NAOMI for applied uniform electric and magnetic fields at 50 Hz.

A contract for the Electrical Power Research Institute (EPRI) has been completed on calculations relating external fields to basic restrictions in the body between 65 MHz and 2 GHz. Exposure conditions included plane-wave irradiation in a variety of orientations and near-field exposure from half-wave dipole antennas. Whole-body SAR, localised SAR, ankle current values and spatially averaged fields were calculated for these exposure conditions. A paper has been published on calculated SAR distributions in the NORMAN voxel phantom due to the reflection of electromagnetic fields from a ground plane. The SAR calculations were performed for standing waves set up in the computational domain to investigate any problems this may cause regarding compliance with electromagnetic guidelines.

An intercomparison of head/eye thermal models with the Japanese institutes at NIT (Nagoya) and NICT (Tokyo) is underway. Anatomical models and parameter sets have been exchanged and differences discussed.

Experimental dosimetry studies There has been a rapid expansion in the use of wireless computer networks (WiFi) in the home, in businesses and in schools. This has led to expressions of concern about exposures to the radio signals from individuals, groups and the media. There are few published measurements of exposures and there is a lack of quantitative information that takes into account real usage conditions in classrooms. Such exposure-relevant conditions include the proportion of the time that a computer used by a child actually transmits during a lesson, how far the computer is from their body and the directional characteristics of the computer’s transmitting antenna. Against this background, HPA has initiated a project to systematically investigate the types of WiFi equipment which are in use in schools and elsewhere. It will produce measured exposure information, both for comparison with accepted guidelines on limiting exposures and for comparison with exposures from other sources, such as mobile phones. The project is timetabled over two years and includes a review of technical standards and existing exposure information, laboratory measurements of the electromagnetic fields from selected examples of WiFi equipment, analysis of the internal RF structure of computers and access points and subsequent computational modeling of SARs. It is also hoped to visit some schools to make measurements of cumulative transmit time from computers during lessons. The results of the project will provide an input to a wider health risk review. A press release on the study is available on the HPA website http://www.hpa.org.uk/webw/HPAweb&HPAwebStandard/HPAweb_C/1195733726123?p=11719 91026241

The phase-out of incandescent lamps by 2011 and their replacement by Compact Fluorescent Lamps (CFLs) may lead to concerns about EMF exposure. This is because, unlike incandescent lights, CFLs produce RF emissions in the 10s of kHz range. Some data have been published, but there is not yet consensus on the most appropriate method for assessing exposure. Most of the published data report spot measurements of electric field at certain distances and compare these with the ICNIRP reference levels, sometimes taking account of the harmonic content of the waveform. There is also a product standard being developed by IEC, which is based on measuring the current induced by the field in a head-sized metal sphere connected to ground. HPA is investigating various measurement approaches and instrumentation for CFLs with an aim of providing robust exposure information relating to typical lamps

Independent Advisory Group on Non-ionising Radiation Protection (AGNIR) Background AGNIR was set up in 1990. The terms of reference were to review work on the biological effects of non-ionising radiation relevant to human health and to advise on research priorities. The Group was reconstituted in 1999 as an independent advisory group and reported directly to the Board of NRPB; since April 2005 it reports to the sub-committee of the Board of the HPA that deals with radiation, chemical and environmental hazards. In addition to the work of the Advisory Group, subgroups address specific issues.

The Advisory Group has, to date, issued twelve major reports and a number of statements. The reports have mainly covered reviews of experimental and epidemiological studies, together with exposure data relevant to assessing possible health effects from exposures to electromagnetic fields (EMFs) and ultraviolet radiation (UVR). They have been a valuable input to NRPB, and now HPA, advice and have been used in the development of UK exposure guidelines as well as being widely circulated and used by the UK Government and the devolved administrations. The ongoing programme of work of AGNIR is summarised below and it is also given on the HPA web site: http://www.hpa.org.uk/webw/HPAweb&Page&HPAwebAutoListName/Page/1207821636407?p=1 207821636407

Static magnetic fields AGNIR was asked to conduct a review of any hazards from exposures to static fields and in particular of patients during magnetic resonance imaging (MRI) procedures and the report was published on 21 May 2008. This was a new topic for AGNIR to address and the Group benefited from the expertise of additional members from the MRI community in preparing the report. A workshop organised at HPA’s Chilton centre in 2004, in conjunction with the World Health Organization (WHO) and the International Commission on Non-Ionizing Radiation Protection (ICNIRP) also introduced useful background papers and expertise. AGNIR discusses sources and exposure levels in an opening chapter before reviewing the mechanisms for biological interaction and explaining how these could give rise to the effects observed. Studies covering effects observed in cells, animals and people are then addressed in separate chapters before conclusions and recommendations for further research are given. AGNIR concluded that • Transient sensory effects occur in some individuals exposed to static fields above about 2 T and that these effects relate at least in part to movement in the field. • No serious or permanent health effects have been found from human exposures at levels up to 8 T, but scientific investigation has been limited. • The effects of human exposure to fields above 8 T are unknown, but some cardiovascular and sensory effects would be expected to increase with greater field strength. The report is available on the HPA website: http://www.hpa.org.uk/webw/HPAweb&HPAwebStandard/HPAweb_C/1211184025666?p=11994 51989432

AGNIR also concluded that there is a pressing need for a well-conducted study of mortality and cancer incidence in workers with high occupational exposures to static magnetic fields, particularly those associated with medical MRI scanners. The HPA Board approved this recommendation, in principle, and the Agency will now examine the feasibility of such a study with specialists here and abroad, with the aim of launching such a study as soon as possible. The Agency will be setting up a Working Group under the Chairmanship of Board member Professor Andrew Hall. The Group will undertake a detailed review in order to advise the HPA Board on future research on possible long-term health consequences in people exposed to the static magnetic fields associated with Magnetic Resonance Imaging. Emphasis will be placed on identifying appropriate study groups and their exposures, the diseases of potential concern and the feasibility of future epidemiological investigations. The Group will report to the HPA Board within one year of commencement of the scoping study and a press release is available on the HPA website: http://www.hpa.org.uk/webw/HPAweb&HPAwebStandard/HPAweb_C/1211354081861?p=12041 86170287

Ultrasound and infrasound In September 2004 AGNIR was asked to undertake a review of ultrasound (frequencies>20kHz) and infrasound (frequencies<20Hz) relevant to any possible health effects. The AGNIR report is expected to review physical principles; sources and applications; and cellular, human and animal studies. The report will also summarise current advice on exposure guidelines but will not make recommendations for the UK. It is important for the HPA to draw on the expertise available in the UK and this is facilitated by having a formal Subgroup of AGNIR to review the information available.

Radiofrequency radiation The Independent Expert group on Mobile Phones (IEGMP) drew attention to concerns on this topic in its 2000 report and called for more research. Similar calls were raised in other countries around the same time, and also within Europe. The result has been a substantial programme of research supported by governments, industry and the . In recognising that research would proceed apace, IEGMP recommended that a further review of the science should be carried out within three years of its own report and AGNIR prepared such a review in 2003. At this time, many studies were in progress and, in particular, epidemiological research of mobile phone users was at an early stage. Hence, it was agreed in 2003 that AGNIR should produce a further review of studies relevant to concerns about health for publication in a few years time. The first phase of the UK’s Mobile Telecommunications and Health Research (MTHR) programme is now drawing to a close and a report on the bulk of the work has been published. The initial phases of work funded in other countries and by the EU are also largely complete, meaning that the time is right for AGNIR to begin its review. AGNIR has therefore been asked to perform a review of exposure to radiofrequency radiation and human health focusing particularly on those areas of the science where knowledge has been added since its last review. This work is expected to take 2-3 years and will become the main activity for AGNIR once the work on ultrasound and infrasound is concluded.

Power frequency fields AGNIR published a report on ELF electromagnetic fields and the risk of cancer in 2001. In the report it was concluded that laboratory experiments had provided no good evidence that extremely low frequency electromagnetic fields (EMFs) are capable of producing cancer, nor do human epidemiological studies suggest that they cause cancer in general. There is, however, some epidemiological evidence that prolonged exposure to higher levels of power frequency magnetic fields (50 hertz (Hz) in the UK) is associated with a raised risk of leukaemia in children (relative risk of approximately two). AGNIR continues to keep under review published research related to health concerns arising from exposure to power frequency electromagnetic fields. At present there is insufficient new information to justify the development of an update to the 2001 report, although it will be needed at some point in the future.

Some recent EMF-related publications from HPA-RPD AGNIR (2008). Static Magnetic Fields (2008). Report of the independent Advisory Group on Non- ionising Radiation. Documents of the HPA: RCE-6 http://www.hpa.org.uk/webw/HPAweb&HPAwebStandard/HPAweb_C/1211184025666?p=11994 51989432

Cooper TG, Mann SM, Blackwell RP and Allen SG (2007). Occupational exposure to electromagnetic fields at radio transmitter sites.. HPA-RPD-026 http://www.hpa.org.uk/webw/HPAweb&HPAwebStandard/HPAweb_C/1195733775298?p=11976 37096018

Dimbylow P (2008). Quandaries in the application of the ICNIRP low frequency basic restriction on current density. Phys Med Biol, 53(1):133-45.

Dimbylow P and Bolch W (2007). Whole-body-averaged SAR from 50 MHz to 4 GHz in the University of Florida child voxel phantoms. Phys Med Biol, 52(22):6639-49.

Dimbylow P (2007). SAR in the mother and foetus for RF plane wave irradiation. Phys Med Biol, 52(13):3791-802.

Findlay RP and Dimbylow PJ (2008). Calculated SAR distributions in a human voxel phantom due to the reflection of electromagnetic fields from a ground plane between 65 MHz and 2 GHz. Phys Med Biol, 53(9):2277-89.

Khalid M and Mann SM (2007). Exposure to EMFs from lightweight aviation transponders. HPA- RPD-031. http://www.hpa.org.uk/webw/HPAweb&HPAwebStandard/HPAweb_C/1195733855397?p=11976 37096018

Maslanyj MP, Mee TJ, Renew DC, Simpson J, Ansell P, Allen SG and Roman E (2007). Investigation of the sources of residential power frequency magnetic field exposure in the UK Childhood Cancer Study. J Radiol Prot, 27(1):41-58. Erratum in: J Radiol Prot, 27(2):207.

Mann S (2007). Rapporteur’s report: German Mobile Telecommunication Research Programme, International Workshop on Final Results of Dosimetry Projects, held on 25-26 July 2006 at Federal Office for Radiation Protection (BfS). Radiation Protection Dosimetry, 124(1), 2-5.

McKinlay AF et al (2007). Protection of patients and volunteers undergoing MRI procedures: A document for consultation. The MRI Patients and Volunteers Working group. http://www.hpa.org.uk/webw/HPAweb&Page&HPAwebAutoListName/Page/1204542909765?p=1 204542909765

Prepared by Simon Mann, Group Leader of EMF Dosimetry Physical Dosimetry Department Radiation Protection Division Health Protection Agency Chilton Oxfordshire OX11 0RQ [email protected]