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A paper has been published, believed to be the first of it's kind worldwide, which generally reflects the practice of prudent avoidance which has been adopted by the electricity supply industry in Australia.

PRUDENT AVOIDANCE GUIDELINES FOR POWER FREQUENCY MAGNETIC FIELDS. (1999) Authors: K. Nuttal, P.J. Flannagan, G. Mellik was presented at the 32nd Annual Conference of the Australasian Radiation Protection Society Inc., 11-15 October 1999 and published in that Society's Journal, RADIATION PROTECTION IN AUSTRALIA, December 1999, Volume 16, No3. A similar paper was also presented at the World Health Organisation's (WHO) conference on EMF, in Geneva in November 1998.
(WHO website; < http://www.who.int/peh-emf/ >)

OUR COMMENT ON THE DOCUMENT
Our organisation has been in contact with the authors suggesting that they include in the document the two very important sites of high EMF exposure:

(a) Corner residential blocks where power lines border two sides forming a right angle within where EMF may be unacceptably high within the dwelling. It has been determined that field values within the right angle on such a block can be up to 40% higher than values measured outside the same right angle.

(b) Medium rise buildings (of less than four stories) where high EMF values are generated by electrical equipment used for that building's requirements. (high-rise buildings are mentioned in the paper).

The authors have indicated that these points would be considered for inclusion, should the Paper be re-presented or updated in the future.

WELCOME INFORMATION
This long overdue document is greatly needed in today's highly electrified environment.
The authors are to be commended on this paper. It represents a valuable contribution to the information sought in relation to the EMF/EMR health issue.

The following is an example of the current lack of officially recognised material dealing with electromagnetic field radiation exposure on a level where it would have much positive impact.

MUNICIPAL COUNCIL INTEREST
A recent attempt was made to reduce EMF/R exposure at the domestic meter board site at the Building Code level. A Councillor, needing information on domestic electricity meter boxes and their EMR emissions in order to compile a resolution to Council was directed, by the authority he approached, to our voluntary organisation for assistance

The Sydney Metropolitan Council was presented with a resolution to have included in their building Code, a directive to avoid the placement of electricity meter boxes on residential buildings where a bedroom would be located. Proceedings called for the Environmental Officer's report to Council on the matter.

Unfortunately this report lacked the strength to convince Council to adopt the resolution. This was due to the limited amount of available information from any official source, (so noted in the report) on which the report to Council was based.

A successful outcome to this resolution may well have set a precedent for other councils to follow, a major step in reducing EMF/R exposure in the community.

The Guidelines will be welcomed by all interested stakeholders and includes those with a duty of care to the community such as, municipal councils, master-builders, owner-builders, electrical contractors, householders, educators of trade courses, employers and others.

Following is the abstract and the section on domestic meter boards and household wiring:
For the complete 12 page paper titled PRUDENT AVOIDANCE GUIDELINES FOR POWER FREQUENCY MAGNETIC FIELDS. (1999). Contact your local power authority for a copy - your inquiries give clear indication to the industry of the level of community interest in the EMF/EMR health issue.

ABSTRACT
In March 1991, following a wide ranging inquiry into community needs and high voltage power line development, Sir Harry Gibbs, an ex-Chief Justice of the High Court of Australia concluded that adverse health effects from power frequency electric and magnetic fields (EMFs) had not been established. He went on to find that there was some evidence that they might pose a risk to health. On this basis, he recommended a policy of prudent avoidance in the construction of new transmission lines. Since that time, a succession of inquiries in recommended prudent avoidance.

This paper provides practical guidelines to electricity transmission and distribution utilities and other interested stakeholders in the application of prudent avoidance to the design and siting of new electrical facilities. The paper provides background information and a range of general measures, which might be prudently applied. It is not the authors' intention to provide precise instructions for the application of prudent avoidance
But, rather, to provide a series of guiding principles, which may be applied to particular situations, having regard to the specific design practices and policies of individual electricity utilities.

Following here is the contents page of the paper and then the full text of the household/domestic prudent avoidance guidelines.

Whilst the primary focus of this paper is on utility installations, sources within customers' installations can also make a significant contribution to the overall magnetic field environment. Accordingly a brief selection of considerations, relevant to customer's installations, are provided in the following sections.

Supply conditions may vary from utility to utility, and if inconsistencies are evident, these conditions should take precedence.

Commercial/ Industrial Switchboards
In the case of large commercial/industrial switchboards, the busbars inside the switchboard can have an effect on field levels outside the switchboard. The following prudent avoidance measures may be available:

· Keeping the incoming line and associated meter panel and/or busbars away from frequented areas. This will also help avoid computer interference problems.
· Avoiding the use of separate conductor trays for the energised neutral wires. If separate trays are necessary, it is best to place them adjacent to low/no use areas.
· Locating switchboards away from high use areas if possible
· Locating workstations way from switchboards when laying out new or reorganised office areas. A distance of 4 to 5 metres is suggested to provide the additional benefit of avoiding computer VDU interference.
· Using energy efficient lift motors, air conditioning equipment and industrial motors and manufacturing equipment.

Domestic Meters and Wiring
Generally the principle source of magnetic fields associated with domestic meter boxes is the wires leading to the meter box. Accordingly prudent avoidance measures associated with meter boxes focus on the wiring rather than the box itself. The following prudent avoidance measures may be available:

In general, for new constructions, the layout of meters, switchboard and wiring may be planned in advance, giving consideration to the magnetic fields that they could produce.

· Locating the meter box in an area that is not adjacent to high use areas. Good locations would be at the garage, a closet, and storage room or at the back of a wardrobe. (Refer Figure 5). Bedroom and living room walls are better avoided to reduce fields in active use areas. Many authorities recommend the placement of meter boxes and switchboard in a back-to-back arrangement, with the meters outside and the switchboard inside the home for security of home and occupants. This arrangement usually places the switchboard in low-use areas (for the sake of appearance) and is consistent with prudent avoidance.
· Locating the main connecting wiring away from the high use areas in cases where meter location and switchboard location are separated by a significant distance, e.g., where meters are installed at the fence and the switchboard is located at (or in) the house. The connecting wiring should be run phases and neutral grouped together, and in a ceiling space rather than a wall space, for example.

· Using service wires of insulated twisted construction, as they produce significantly less fields than open wire (bare conductor) construction (Refer to Figure below)
· Minimising or avoiding situations where heavy current wiring, especially that of stoves and air-conditioning is placed in wall cavities within the house. This type of wiring is best located and grouped together in the ceiling. Close proximity of the phase wires and neutral helps to cancel the magnetic fields.
· In the case of two-way switches, running the neutral wire along the same path as the twin active wire connecting the two switches to provide a canceling effect on the magnetic fields.
· Using energy efficient equipment which will use less electricity and save money, as well as reducing the electrical load on the switchboard, thereby reducing magnetic fields. Large white goods such as refrigerators, dishwashers, washing machines and dryers are often sold with energy efficient model alternatives.

Methods of reducing magnetic fields
in the home

Note:
1. Insulated twisted pair service produces only 10% of the open wire service fields.

2. Moving the meter box 1 metre (as shown in the diagram) can reduce fields in the bedroom by 80%.

Earth Connections.
The Multiple Earthed Neutral (MEN) system is commonly used to connect a utility's neutral at a customer's switchboard. This neutral is earthed at the switchboard, sometimes via a metallic earth stake, and sometimes via a metallic water pipe. Depending on the condition of these earth connections, some fraction, or indeed, the majority of the neutral current may flow through a path other than via the utility's neutral. If this happens, then an earth connection or more commonly, a water pipe can become a substantial source of magnetic fields. In these situations, the supply wiring also becomes a source of significant magnetic field as the magnitudes of the active and neutral currents are not equal.

When considering options for earth connections, it is the responsibility of the owner/electrician to identify and implement appropriate actions.

If metallic water pipes are a source of magnetic fields, consideration could be given to installing a plastic joint at the entrance to the building's water system to prevent current from adjacent earths traveling along the pipe. In this case, the installation of a separate earth stake is mandatory for electrical safety considerations.

Conclusions.
The concept of prudent avoidance has been recommended as the most appropriate public policy response to health concerns associated with magnetic fields, Historically it has been difficult to scope because, by its very nature it cannot be defined in precise terms. Nevertheless, it is possible to adopt many specific measures which are consistent with the notion of doing what can be done at modest cost and without undue inconvenience to reduce people's exposure to magnetic fields. This paper has sought to clarify the concept of modest cost and to suggest a range of practical options or measures for transmission and distribution applications. The paper has also touched on a number of options which may be adopted by other stakeholders in this issue such as developers, builders, electricians and home and building owners.

Acknowledgements.
The authors wish to acknowledge the assistance given by many colleagues within the electricity supply industry in the development of this paper. References are available at end of original paper.