SAGE stands for Stakeholder Advisory Group on Extremely Low Frequency Electric and Magnetic Fields (EMFs). It is a UK group set up in 2004 to consider possible precautionary measures in relation to EMFs.
SAGE is made up from stakeholders representing a broad spectrum of views, including campaign groups, relevant industries, and the Government. It brings together many areas of expertise, including those with significant expertise in scientific and policy-making disciplines, as well as voices representing sections of the public. SAGE is funded equally by Government, the electricity industry, and the charity CHILDREN with LEUKAEMIA.
Over the course of the last 30 years there has been a growing understanding of the effects of electric fields (EF) and magnetic fields (MF) on people. Together EFs and MFs are known as electric and magnetic fields, EMFs. SAGE is concerned only with "extremely low frequency" EMFs, such as produced by electrical power, and future uses of "EMFs" in this Assessment refer to just these frequencies.
Well-understood effects, found at significantly higher exposure levels, are covered adequately by existing guidelines, which in the UK are set by Government on the recommendations of the Health Protection Agency. The Stakeholder Advisory Group on ELF EMFs - SAGE - was formed in 2004 to consider possible practical precautionary measures to address the possibility of health effects at lower levels, and to give advice to Government.
SAGE Phase 1
In 2004 the UK changed from its previous UK-specific exposure guidelines to international guidelines (specifically, the 1998 International Commission on Non-Ionizing Radiation Protection, ICNIRP, Guidelines in the terms of the 1999 EU Recommendation), which set electric and magnetic field levels (e.g. a magnetic-field reference level for power frequencies of 100 µT) above which members of the public should not usually be exposed. This represented a modest tightening of the guidelines for members of the public. However this left open the question of how to respond to the body of science concerning effects on people at lower levels such as 0.4 µT (the level which is associated with a doubling in incidence of childhood leukaemia). This question is controversial for several reasons, and it involves levels which can be found in some homes, from their wiring circuits and from the cables supplying them, from appliances and equipment, and in homes that are near to power lines.
The Stakeholder Advisory Group on ELF EMFs was set up in November 2004 to involve all key stakeholders to address this question. This group process deliberately set out to change the dynamic and type of relationships that had existed between stakeholders over the preceding 20 or so years, which had been characterised by incessant conflict and "standing on opposing sides at inquiries". The state of relations between stakeholders at the start of this process was therefore not good. Although it would be wrong to claim that all relationships are now ideal or that SAGE delivers all participants- desired outcomes, significant progress has been made towards better communication over the process as a whole since then and continues to be made. The aim of the process was agreed by stakeholders in November 2004 as:
"To bring together the range of stakeholders to identify and explore the implications for a precautionary approach to ELF EMF (electric and magnetic fields) and make practical recommendations for precautionary measures".
The SAGE process published its "First Interim Assessment" in April 2007.
SAGE Phase 2
The second phase of SAGE's work covered EMFs caused by electricity distribution networks (e.g. 11 kV lines, underground street cables, substations, etc) and it also considered the difficult issue of how different people and groups approach and interpret the available scientific evidence.
The SAGE Second Interim Assessment
(1 MB file), published in June 2010, covers the work conducted by SAGE since 2008. Most of the documentation for the second phase can be found at the SAGE website.
The following is mostly extracted from the Executive Summary of the SAGE-2 report.
"Distribution" covers a number of aspects: the power lines at intermediate voltages which distribute electricity from where it leaves the high-voltage long-distance transmission system; substations and transformers, which reduce the voltage and allow switching of circuits; and the final distribution circuits at 230 V which supply the power to homes. Of these, it is EMFs from the final distribution circuits that affect the greatest number of people.
The Second Interim Assessment focussed on measures that are practical and easy for Government to take forward, rather than radical new measures or any major changes to regulation or current practice. Furthermore, the recommendations put forward are all low-cost options. SAGE consider it important therefore that Government take forward the actions SAGE recommend; SAGE do not want these recommendations to languish by default. Where possible SAGE has been specific about what action needs to be taken and who within Government needs to take it.
Where SAGE has identified existing practices that are beneficial in EMF terms, it
recommends that Government communicate clearly and specifically to the relevant authorities that EMFs are an additional reason for continuing this practice. This includes, for the electricity industry, practices to do with balancing loads on circuits, identifying and repairing broken neutral conductors, disconnecting redundant cables, siting new substations away from homes, and use of compact designs for new substations; for the gas and water industries, practices to do with use of plastic pipes; and for the electrical installation industry, practices to do with installations in multi-occupancy buildings. SAGE-2 gives full details of all of these in the Assessment.
Finally, in order to create the greater awareness of and sensitivity to EMF issues that SAGE feels will be the most productive way forward on EMFs from electricity distribution, we recommend more information for the public, and a package of training for electricity industry staff. Again, we understand that the industry will be willing to embrace this; Government must retain the final responsibility for authorising this work, but it should be easy to achieve.
SAGE considers it should be realistic for Government to respond to the SAGE-2 recommendations within six months, ie by the end of November 2010, and urges them to do so as this would reflect the importance of the issues covered and the work that has gone into producing these recommendations.
Arising from our discussions of the science underlying this area, we have identified the following areas that we believe should be explored further as they will better inform the creation of policy:
- how appropriate risk-management policies are chosen, including health-economics considerations such as cost-benefit analyses
- how, and more importantly why, different countries have responded with different policies to the same scientific evidence
- the communication of these issues
SAGE makes the following recommendations for precautionary measures concerning
- 12 measures which are already existing best practice for other reasons
- 7 new measures
- 11 measures which are available to consumers in specific circumstances
- 5 measures where further investigation is required
Note: "DNOs" are the Distribution Network Operators (the regional electricity network companies)
Net currents in distribution circuits:
- DNOs make reasonably practicable effort to balance loads on three-phase final distribution circuits
- DNOs assist customers who take a three-phase supply to balance loads to the extent reasonably practicable
- DNOs investigate and repair broken neutrals
- Disconnect redundant cables, when they are assessed as genuinely redundant, and when work is being done on the circuit anyway
- Use plastic gas and water pipes for new build
- Insert plastic sections in metal gas and water pipes when work is being done anyway
Wiring in multi-occupancy buildings:
- Site plant rooms away from occupied rooms
- Use separate-neutral-and-earth cables for risers
- Use compact risers
- DNOs make reasonably practicable effort for heavily loaded double-circuit intermediate-voltage lines to have optimal phasing and loads balanced between the two circuits
Final distribution substations:
- Reasonably practicable efforts be made to site substations distant from homes etc
- New substations to have compact design where reasonably practicable
- Use compact designs when refurbishing substations where reasonably practicable
- Arrange components in the substation in the lowest-exposure layout reasonably practicable
- DNOs to consider instances of substations producing elevated exposures when requested and, where practically feasible, to offer options for reducing the exposures at the consumer-s choice and cost
- DNOs to record instances of substations producing particularly high exposures so that EMF issues can be factored in to future maintenance decisions for that substation
Training and response:
- Information for the public
- DNOs to investigate instances of high EMF exposures when notified of them
- Develop awareness within DNOs, by training of relevant staff, of how elevated exposures can be an indication of system problems (but recognising that development of a workable training package is needed first)
SAGE asks Government to:
- reconfirm that Government does indeed want SAGE to continue
- say whether there are particular policy issues that Government wants SAGE to consider (to complement SAGE-s own thinking about what it should look at next)
- confirm that Government will consider seriously whatever advice may emerge from SAGE in future
We look forward to a positive response from Government.
Alasdair Philips represents Powerwatch as a member of the SAGE process.