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29/04/2007 - The SAGE Report


The Stakeholder Advisory Group on ELF EMFs (SAGE) was set up in 2004 by the Department of Health to explore the implications and to make practical recommendations for a precautionary approach to power frequency electric and magnetic fields. It is funded equally by The Department of Health, the National Grid Company and the Charity CHILDREN with LEUKAEMIA. The participants only receive out-of-pocket expenses and no allowanace for time, which makes it difficult for many people who want a more precautionary stance to attend and do the background work. It is fine for industry and Government people but is now also becoming hard for academics to continue to take part as universities now require "full economic costing" to be charged for academics outside work activities.

SAGE has a range of Stakeholders, including Powerwatch. This is the first SAGE Interim Report. Further detailed work is still to be done on Powerlines, electricity substations and mains voltage distribution cables and EMFs in electric trains. It is the result of a great deal of hard work.

We have a copy of the Report and of the Supporting Papers on this website for you to download. We also host Brenda Short's Legal Supporting Document and the Trentham powerline health effects survey results. The links are at the bottom of this article.


Finally the first interim SAGE report is out, and has covered some very important areas of ELF EMF exposure to varying degrees of detail. For homes in the UK that have high background magnetic field levels, about one-third come from high-voltage overhead powerlines, one-third from faulty house wiring and equipment in the house and about one-third from electricity substations and mains voltage cables under the street (yet to be dealt with by SAGE). We will cover the first two below, with a description of what was covered, what was recommended, and our brief take on both for each section. Powerwatch was a member of SAGE and we will be reporting more here in the next week or so.

EMFs in the house - House Wiring and equipment

What was covered

Mainly magnetic fields from wiring, though we also discussed electric fields at some length and and also EMFs from appliances and electrical equipment.

Ideally, power-frequency EMFs in our homes should be as low as possible. In the UK the average typical background level of magnetic fields is about 0.04 microtesla; however it is estimated that about one-third of our background exposure at home to EMFs to higher levels fields above 0.3 microtesla comes from house wiring and electrical equipment and appliances.

You can purchase the Powerwatch Handbook (by Alasdair & Jean Philips, see below) which we believe is an inexpensive practical, informative guide to how to spot electromagnetic field problems and what you can do about them.

Magnetic Fields

To keep magnetic fields to the lowest possible levels, SAGE recommends that the "go" and "return" currents are always forced to travel close together in the same cable. This causes the magnetic fields that they produce to mainly cancel each other out. Most UK houses, at present, have the electric power sockets wired in what is known as a "ring circuit". The wires start at the consumer (fuse) box and travel around the house from socket to socket and end up back at the same consumer box. The circuit wires are connected at both ends to the electricity supply.

This method was done to allow the circuit to be able to supply the most power for the least use of copper cable. This was particularly useful when many pieces of high-power equipment or appliances were to be used (e.g. electric heaters, kettles, etc). However most of the electrical and electronic equipment that we use nowadays consumes much less power and so the technique is not so necessary.

The problem comes when poor connections occur, as a result of an aging or damaged circuit. This happens surprisingly often. Usually all the equipment continues to work, but the current now may be coming from one end of the circuit and returning to the other end. This effectively puts most of the house into single-turn transformer loop and can increase the resulting magnetic fields by up to several hundred fold.

To avoid this problem, SAGE is recommending that in the future all power circuits should be wired as "radial" circuits. The probable exception to this is likely to be having a separate final ring-circuit for the kitchen where loads are often still quite high.

Radial circuits start at the consumer (fuse) box and end at the last socket. If they develop any fault, equipment usually stops working and so indicates the need for an electrician to investigate and repair the problem. One ring-circuit can be replace by one, or more usually two, radial circuits. Very slightly more wire may be needed and, ideally though not essentially, another 20 amp circuit-breaker in the consumer box. The additional cost to wire the power circuits in homes in this way is very small and the cost-benefit analysis showed that this would be a very worthwhile change in practice. Radial systems are the normal way of wiring in most European countries.

Electric Fields

SAGE also discussed electric fields as these have also, though less often, been linked to an increase in adverse health effects. Ideally, mains frequency electric fields inside the house should be zero. When UK houses were first wired in the 1900s and up until about 1940 the wires were usually run in earthed metal pipes (conduits) which kept the electric fields to virtually zero. This is still the case in most commercial buildings and large apartment blocks where cables usually run in earthed conduits or trunking. However, since the introduction of modern PVC cables in the 1950s, most residential houses end up being a "spider's web" of wires, especially for the lighting circuits. This has resulted in residential electric fields rising from typically a few volts per metre to several tens and often hundreds of volts per metre. This can be avoided if modern electrcally shielded cables are used.

As these shielded (and often also fireproof) cables are significantly more expensive than standard PVC twin & earth cable, SAGE is not recommending a general change for building wioring to use shielded cable. However, where people are concerned about electric fields and wish to minimise them, SAGE recommends, and is supportive of the use of, electrically screened cabling. Such extra precaution would need to be paid for by the concerned individuals. In Sweden, the Government gives out grants to ES diagnosed people to enable electric fields to be reduced in this manner; however SAGE is not recommending that grants are made available from UK public finds for this work. SAGE recognition of, and support for, the use of screened mains wiring is particularly important for the increasing numbers of people who have developed Electrical Sensitivity Syndrome as it will mean that electricians will be more willing to carry out the work.

It is hoped, and expected, that the change to radial circuits and the permitted use of screend cable for normal wiring where required, will be made in the IET On Site Guide. These do not require changes to the IET / BS 5750 UK Wiring Regulations.


SAGE discussed the design of equipment to minimise the EMFs they produce. It was generally agreed the the lower the fields the better, but the manufacturers associations did not want this to be an additional design requirement at this time as they already have many Standards to comply with. If, at a later stage, the government wants "low EMFs" to be s design requirement, then the way forward would be to develop a new British (and then internationsl) design standard.

There was discussion about the very high levels of electric fields that users are exposed to from "double insulated" equipment that does not have an Earth connection. Garden equipment such as hedge cutters and lots of modern electronic equipment with mains adaptors, such as laptop PCs running from the mains, come into this category. This needs more work. EMFields can supply "Earthing Leads" for laptop PCs to remove this problem. Further work is needed on this topic.

However, there was general agreement within SAGE that better public information about EMFs and health and the typical levels given off by different sorts of electrical equipment should be made available so that people can more easily choose to avoid unecessary exposure if they want to. Easy examples would be not to sit or sleep close to a traditional mains-adapter transformer, or not to locate a bed close to the central heating pump or a electrical off-peak storage radiator.

The Powerwatch detailed article on house wiring for low EMFs is available for downloading via the article library.

High Voltage Overhead Powerlines

SAGE recommends that a new information booklet is prepared and made available to the general public about the reported health effects of power-frequency EMFs. The Powerwatch Handbook (see bottom of article for details), available from EMFields and all good booksellers, already does this in an informative way and offers many helpful practical tips for you to reduce your EMF exposure and that of your loved ones.

SAGE also recommends that some powerlines that are not currently "reverse-phased" to minimise magnetic fields are now reconnected to achieve this. This recommendation mostly applies to the smallest types of pylon line (the 132 kV distribution lines, quite commonly located close to houses) as most of the National Grid's 275 and 400 kV large transmission lines are already connected this way. There are about 20,000 houses within 60 metres of National Grid's high-voltage overhead powerlines and there are about 40,000 houses within 30 metres of 132 kV lines.

Moratorium on new building close to powerlines

Most importantly, SAGE also urges the Government to consider implementing a moratorium on new building within 60 metres of high-voltage electricity transmission lines and 30 metres from 132 kV electricity distribution lines. This is not a 'firm recomendation' as the UK electricity supply industry and the UK Regulator (Ofgem) did not feel able to back a firm recommendation for this change at the present time. They believe that such a decision would have to be a political one that took into account public opinion.

Powerwatch is very disappointed with this slightly weak "urge" instead of a firm recommendation to act. The extra cost (mainly in compensation) would have had a very small effect on electricity prices compared with the already significant increases in energy costs that are ocurring year-on-year.

Although it was agreed in two plenary SAGE meetings that we would consider childhood leukaemia plus other adverse health effects - i.e. all the other effects (headaches, adult leukaemias and brain tumours, miscarriage, Motor Neurone Disease, etc.) that have been repeatedly reported in the scientific literature, the electrical supply industry and the electricity Regulator refused to accept, at this point in time, the effect they have on the cost benefit analysis calculations.

Trentham Environmental Action Group have carried out two local surveys in Stoke on Trent, UK. You can see their summarised results here.

SAGE work shows that the raw CBA goes from about a Cost:Benefit ratio of about 20:1 (for childhood leukaemia alone) to a C:B ratio of about 1:50 (taking into account all the other documented health risks) - i.e. it becomes VERY worthwhile to implement the 60 metre distance moratorium on new building and new powerlines on simple cost benefit calculations alone.

Powerwatch's view

However, all in all, SAGE was a very worthwile process and has significantly moved forward the debate on what we should do regarding power-frequency EMFs and public health. Powerwatch is pleased to have taken part in the SAGE process to date although it has taken quite a lot of our time and resources to participate.

ur formal short final comments printed in the SAGE report are:

Powerwatch believes that SAGE plenary discussions reached agreement that implementation of a 60 metre "no new build" corridor should be firmly recommended to Government. We believe that sleight-of-hand actions by certain participants influenced this being significantly weakened to an information booklet and re-phasing of some lines, which is a wholly inadequate course of action from our perspective.

Some participants seemed to fail to understand that a precautionary approach can only be taken before scientific certainty is reached. Other adverse health effects (CL+) were left out of the SAGE conclusions despite being adopted by two plenary meetings and having significant scientific support.

Powerwatch appreciated the co-operative way that the members of the workgroup on house-wiring and equipment functioned and agree with its final recommendations.

Our Contributing Paper [to be placed on this site very soon] by Brenda Short on legal liability outlines the duties of the Secretary of State and GEMA (corporate body to OFGEM) under Electricity Act 1989 to protect the public from dangers arising from electricity generation, transmission, distribution and supply. It examines how UK & EU law, existing planning, EIA and pollution control legislation (e.g. statutory nuisance, waste, contaminated land, Pollution Prevention Control) might apply to EMFs and corona ions from powerlines. It suggests other offences that might arise (e.g. public nuisance). Civil liability (e.g. nuisance, negligence, trespass), citizen's redress including judicial review and the Human Rights Act 1998. Most of this important information is missing from the SAGE Report.

The Powerwatch Handbook, Alasdair and Jean Philips, Piatkus Books 2005, ISBN 0-7499-2686-4. The authors' Royalties are paid directly to the UK Charity CHILDREN with LEUKAEMIA. It is available from good bookshops and from EMFields (see link below).

EMFields - Powerwatch (EMFields) Publications (including the Powerwatch Handbook) and equipment
Powerwatch Legal Issues (April 2007) - Powerwatch Legal Issues Paper by Brenda Short
RICS Press Statement (27 April 2007) - Royal Institution of Chartered Surveyors (RICS) calls for new legislation (27 April 2007)
CwL Press Statement (27 April 2007) - CHILDREN with LEUKAEMIA Press Response to the SAGE Report (27 April 2007)
SAGE First Report (April 2007) - SAGE First Interim Report (2007) (2 MB)
Trentham Powerline Survey (2006) - Trentham Powerline Health Survey (2006) (32 KB)
SAGE website - Main official SAGE information website

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