Appendix E
Electric and magnetic fields
1 Introduction to EMF
Electric and magnetic fields (EMF) are part of the natural environment and are present in the Earth’s
core and the atmosphere. EMF is also produced wherever electricity or electrical equipment is in
use. Power lines, electrical wiring, household appliances and electrical equipment all produce EMF.
EMF is sometimes incorrectly referred to as electromagnetic radiation.
The electric field is proportional to the voltage (which can be considered as the pressure with which
electricity is pushed through the wires). The magnetic field is proportional to the current; that is, to
the amount of electricity flowing through the wires.
Both electric and magnetic fields on the electricity network are also dependent on elements such as
conductor heights, cable depths and phase separations.
All fields decrease rapidly as you move away from the source. Generally, the smaller the object or
closer the conductors producing the field, the more rapidly the field will decrease as you move
away from the source.
At extremely low frequencies such as power frequencies, electric and magnetic fields do not
normally radiate from their source. They merely exist in the space surrounding their source, and
the strengths of the fields decrease rapidly with distance from their source. On the other hand, at
much higher frequencies such as radio frequencies, energy is radiated away from the source and
can be detected at great distance. Other familiar examples of radiating fields are television signals,
microwaves and sunlight. It is for this reason that power frequency EMF is described as ‘fields’ and
not ‘radiation’.
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2 Nature and sources of EMF
2.1 Voltage and current
Electricity is characterised by ‘voltage’ and ‘current’.
Voltage can be considered the pressure with which electricity is pushed through a wire (measured
in ‘volts’). The higher the ‘push’ on electricity, the further it can travel. Electricity leaves the power
station where it is generated at voltages up to 500,000 Volts to enable it to cover long distances to
where it is required by customers. As it gets closer to homes and businesses where it is used,
electricity is progressively reduced to lower voltages by substations across the electricity network.
Current is basically the amount of electricity flowing through cables/wires, or the rate the electric
charge is flowing (measured in ‘amps’).
Power systems are designed so that the voltage is held relatively constant over time while the
current rises and falls with the demand for power from customers.
The current flowing in a power line is not directly related to the voltage so a high voltage power
line can operate at the same current as a low voltage power line.
The power actually transmitted by a wire is related to both its voltage and current.
Currents and voltages associated with electrical power are generally ‘alternating’. The direction of
the current changes 50 times per second in Australia (and Europe) and this system is described as
operating at a frequency of 50 Hertz (Hz). (In North America and some other countries, an operating
frequency of 60Hz is used).
2.2 Power frequency electric and magnetic fields
All alternating electric currents generate electric and magnetic fields, which are collectively known
as ‘EMF’ (sometimes this is incorrectly referred to as electromagnetic radiation).
2.2.1 Electric fields
The electric charge on an object creates an electric field, which is proportional to the voltage. The
strength of the electric field reduces as distance from the charged object increases.
The units commonly used to describe electric field strength are volts per metre (V/m) or kiloVolts
(1,000 Volts) per metre (kV/m). In a uniform field 1 kV/m means there is a voltage difference of 1 kV
between two points one metre apart.
Electric fields are shielded by most objects, including trees, buildings and even human skin and
their strength reduces rapidly as you move away from the source.
Although electric fields were the primary focus of scientific attention in the health issue more than
twenty years ago, today most interest and research centres on magnetic fields.
2.2.2 Magnetic fields
Whenever an electric charge moves (i.e. whenever an electric current flows) a magnetic field is
created. Magnetic fields are often described in terms of their flux density which is commonly
measured in units of Tesla (T)or Gauss (G) where:
1,000 mG = 1 G.
10,000 G = 1 T
1 G = 100 microT (µT)
1 microT = 10 mG
1 µT = 10mG
As the electric current increases in a cable/wire, the strength of the magnetic field will also increase.
For example, the magnetic field produced by a 240V electric heater with a 2,000 watt element will
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be twice as strong as the field produced by a 1,000 watt element. However, the electric field from
both heaters will be the same because the voltages are the same. Electric driven appliances such as
hairdryers and shavers produce high magnetic fields within close proximity when operating.
Like electric fields the strength of magnetic fields drops off quickly as you move away from the
source.
While electric fields can be shielded quite easily, magnetic fields pass through most materials.
2.2.3 Field characteristics
At extremely low frequencies such as power frequencies, electric and magnetic fields do not
normally radiate from their source. They merely exist in the space surrounding their source, and
the strengths of the fields decrease rapidly with distance from their source. On the other hand, at
much higher frequencies such as radio frequencies, energy is radiated away from the source and
can be detected at great distance. Other familiar examples of radiating fields are television signals,
microwaves and sunlight. It is for this reason that power frequency EMF is described as ‘fields’ and
not ‘radiation’.
2.2.4 Magnetic field sources and comparative field strengths
Because power frequency magnetic fields are created whenever electricity flows, they are not
something unique to power lines. They occur wherever an electric current flows in a conductor or
wire. As the Gibbs Report put it:
“Transmission lines are by no means the only source of extremely low frequency electric
fields and magnetic fields. Such fields are pervasive and indeed ubiquitous. They are created
by distribution lines, residential wiring and current induced in gas and water pipes and
telephone lines and ground return currents which flow when residential wiring is earthed. In
addition, electrical appliances in the home, office, workplace, shopping centre or hospital,
and electric trains and other systems of electrical transportation all create electric and
magnetic fields.” [5.2.14]
To provide an idea of the relative strengths of magnetic fields in Australia, the following table
shows typical magnetic field strengths at normal user distances from appliances and under power
lines. It should be noted that as a result of variations in the design of electrical appliances and
loadings on power lines, the levels of magnetic fields can vary. The table is based on a consistent
set of measurements undertaken by power authorities in Australia using similar techniques and
protocols to overseas measurements. Because of the difference in appliance design and voltages
overseas, resulting in differing currents, there can often be different magnetic field levels shown in
overseas publications. See Figure A below.
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Figure A – table showing typical magnetic field measurements around common home
electrical appliances and electricity network infrastructure
Appliance measurements taken at normal user distance (Source: ARPANSA)
(a)
Electric appliances in the home
Typically, the electric field due to common household appliances can reach 10 - 200 volts per metre
(0.01 - 0.2 kV/m) in the region very close to the appliance. This field decreases rapidly with distance.
The magnitude of magnetic fields also decreases very rapidly with distance. As can be seen from
the above table, in the vicinity of the user, a magnetic field range up to 70 mG or possibly higher
may typically exist (depending on the appliance type). At the surface of the appliance, the magnetic
field strength is likely to be much higher.
Magnetic fields found in rooms of homes typically are between 0.5 and 5 mG. However, in some
instances, the magnetic fields may be higher, depending upon the wiring in the house, the earthing
system and the appliances in use at the time. Wide variations can occur from house to house and
from room to room.
(b)
Power lines
EMF from power lines also decreases with distance from the line, but not at the same rate as with
electric appliances.
The strength of fields from transmission lines is influenced by the height/depth of conductors
above/below the ground, the geometric configuration of the conductors, the electric phasing of the
circuits, direction of current flow, and distance from the line. Magnetic field strength will depend
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primarily on the current/electrical load on the line whilst electric field strength will depend on the
line voltage.
Electric field strengths from power lines can be substantially reduced by shielding. Trees, tall
fences, buildings and most other large structures provide shielding from electric fields. The
presence of these structures can, therefore, have a significant effect on the electric fields to which
people are exposed. By contrast, magnetic fields are modified or influenced only by structures
containing large amounts of ferrous or other special metals.
Electric fields associated with underground cables are shielded by the ground.
(c)
Relative field strengths
The magnetic field strengths in the home in the vicinity of operating electrical equipment can be
within the range of field levels associated with power lines. Magnetic fields in the workplace
(including offices) associated with the use of electrical equipment can be higher than the field levels
associated with power lines. Also, exposure to magnetic fields occurs as a result of proximity to
underground cables and the power usage of commercial, social, cultural and sporting facilities.
2.3 EMF from existing and proposed power lines around the
route of the Botany Bay Cable Project
This section is intended to illustrate the electric and magnetic field profiles associated with the
proposed cables, possible overhead alternatives, as well as existing distribution lines in the area.
For reasons discussed below, the profiles are indicative only.
40
35
Magnetic field, mG
30
25
A
20
C
15
B
10
5
0
0
2
4
6
8
10
12
14
16
18
20
Distance from centerline, m
Note:
‘Magnetic field’ represents the magnetic field at 1m above the ground
Curve A Proposed underground double 132kV circuit (92MVA per circuit – reverse
phasing).
Curve B Typical 11kV overhead construction (assuming 1.9MVA (100A) load – see below).
Curve C Typical 415V overhead construction (assuming 0.1MVA (150A) load – see below).
Figure B- Typical magnetic fields from the proposed cable and well as existing distribution
lines in the area.
The magnetic field is proportional to electric load. The electrical load varies continually with time of
day, type of season and from year to year. The situation is further complicated by changes in load
growth patterns or system requirements which may alter load flows on the network.
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Generally, the magnetic field decreases with the square of the distance from the conductors. For
overhead lines, the vertical position of the conductors varies with temperature which in turn, is
dependent on a number of factors such as electrical load, ambient temperature and wind velocity
as well as line layout and design. These considerations, together with the variable nature of the
ground in both longitudinal and traverse directions combined with further assumptions regarding
conductor stringing data, actual and equivalent span, soil resistivity, solar radiation intensity and
lateral wind velocity mean that the magnetic field is indicative only.
Typical magnetic fields are shown in Figure A.
EnergyAustralia has carried out a load flow study to determine the expected load for the new
cables from the time of commissioning to 2011. Loads were based on summer peak loads.
The replacement of Feeders 908 & 909 is part of a network of feeders supplying power and on
occasions maintenance is required on feeders to ensure their reliability. During this period of time
the adjacent feeders are designed to share their load to maintain power supply to the area.
Conditions considered.
1.
Normal system. Each feeder supplying 92 MVA
2.
Two other feeders out of service for maintenance or fault (each feeder 165 MVA).
3.
Fault on one of the two new feeders. One feeder at 200 MVA.
Condition 2 & 3 would only be in the event of maintenance or fault and it would not be expected to
be more than 1% of their life expectancy.
The modelling of EMF for these circuits was based on 92 MVA, which is at the top end of
expectations based on the peak summer demand. Power demand overnight is less than 50% of this
figure; hence exposure over 24 hours would be considerably less than outlined in modelling.
Beyond 2011 the loading of the proposed cables will decrease in power transfer after a new feeder
is installed within the Sydney CBD, which is expected in 2012. The load after this date will drop then
increases to 92MVA over a period of time and is subject to the surrounding area load growth.
These calculations for the proposed 132kV circuits have been verified by an independent report
prepared for EnergyAustralia by Magshield Products (Aust.) International Pty. Ltd. (see attachment
2).
The magnetic fields for the existing 415V and 11kV power lines are based on a typical average load
of 100A for 11kV and 150A for 415V. Typically the 415V network is not balanced. This is due to
single phase services being supplied along the length of the power line. As loads vary, so does the
imbalance. To model all possible system unbalances would be an impossibility therefore the 415V
overhead construction has been modelled as a balanced 3 phase system. This will result in an
underestimation of the magnetic field.
The magnetic fields for distribution power lines (11kV and 415V) are further complicated by the fact
that the load is continually supplied (to substations and houses) along the length of the line.
Therefore the magnetic field (produced from the power line) will generally decrease towards the
end of the power line. While 11kV and 415V distribution circuits usually have a capacity of 400A, a
value of 100A and 150A is considered typical.
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3 Introduction to health
debate
EnergyAustralia is aware of concerns in the community and some scientists regarding the
possibility of adverse health effects from exposure to EMF. In recent years, scientific research has
focussed on magnetic fields rather than electric fields, and the remainder of this section reflects
that focus.
Scientific discussion regarding the issue dates back to the late 1960s with the introduction of ultra
high voltage transmission systems. Concerns were raised that the high electric fields might have
health implications for utility workers.
In 1972 general health effects such as headache and fatigue were reported in switchyard workers
exposed to high electric fields in the former Soviet Union. Subsequent studies attributed these
symptoms to aspects of the work environment other than EMF.
Public concern was heightened by an American study in 1979 which suggested a link between
exposure to estimated magnetic fields from street distribution lines and transformers and
childhood cancer. This was a turning point in the issue as it was the beginning of the transition
from electric fields to magnetic fields as the source of concern. There has been much research since
that time. The scientific literature is both complex and voluminous and covers a wide spectrum of
science.
All of the research has been extensively reviewed by Australian and international inquiries and
expert panels established for the purpose of trying to determine whether or not human exposure to
EMF is related to adverse health effects.
There is scientific consensus that health effects have not been established, but that the possibility
cannot be ruled out. Some scientists argue that there is a need for ongoing high quality scientific
research in order to give better answers to the questions which have been raised. Others hold the
view that no further research is required and that EMF should not be regarded as a risk to health.
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4 Scientific overview
The first studies into possible health effects from EMF in the early 1970s were interested mainly in
electric fields, and it was not until almost the end of that decade that the focus changed. An
epidemiological study of childhood cancer cases in Denver, Colorado (Wertheimer and Leeper
1979) first raised the possibility that there could be a relationship between magnetic fields and
cancer. Although this study was relatively unsophisticated by today’s epidemiological standards, it
created interest in the scientific and broader community, and led to the redirection of research
efforts towards magnetic fields.
Since that first study, over 25,000 papers have been published on EMF - dealing with both
epidemiological and laboratory (in-vitro and in-vivo) studies. As outlined in Section 6.1 of this
Appendix E, answering the question - does EMF cause cancer? is not a simple task. It is certainly
now realised that research into EMF and health is an extremely complex and multi-disciplinary
area. Many disciplines are involved - from biology, physics and chemistry to medicine, biophysics
and epidemiology. Also, the diseases of most interest to researchers are very rare in the population
at large which further complicates the situation.
It is well accepted by scientists that no study considered in isolation will provide a meaningful
answer to the question of whether or not EMF can contribute to adverse health effects. In order to
make an informed conclusion from all of the research, it is necessary to consider the science in its
totality. Over many years, governments and regulatory agencies around the world have
commissioned independent scientific review panels to provide such an overall assessment.
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5 Reports and findings of
independent review panels
and inquiries
EnergyAustralia is of the view that any policy or regulatory actions proposed regarding EMF should
be based on the totality of the science and not on the results of a single research project or the
opinion of any single scientist irrespective of his or her standing. The considered conclusions of
independent authoritative reviews of the body of science by groups of expert scientists or official
inquiries or panels established for the purpose are an essential guide for health authorities and
other policy decision makers when dealing with the issue.
Since 1977, over 100 reviews of EMF science have been conducted by scientific panels, public
health organisations, or governmental bodies. Representative key conclusions from reviews
undertaken since 1999 are presented in attachment 1.
Australia’s regulator ARPANSA advises that “On balance, the scientific evidence does not indicate
that exposure to 50 Hz EMFs found around the home, the office or near power lines is a hazard to
human health.”
And, “the majority of scientists and Australian radiation health authorities in particular, do not
regard chronic exposure to 50 Hz electric and magnetic fields at the levels commonly found in the
environment as a proven health risk. Moreover, the evidence we have is inconclusive and does not
allow health authorities to decide whether there is a specific magnetic field level above which
chronic exposure is dangerous or compromises human health.”
Other information and conclusions can be found from ARPANSA’s web site at
www.arpansa.gov.au.
In the light of this and other independent reviews, the various findings and conclusions relating to
the state of the EMF science reached in the Gibbs Report in 1991 (see Section 6 of this Appendix E)
are as relevant today as they were at the time they were published.
In particular, the conclusions of these various international scientific and medical bodies provide a
comprehensive and sound review of the science on the EMF health issue and ought to be
considered as a sound basis for policy decision making.
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6 Public policy considerations
6.1 EnergyAustralia’s position
EnergyAustralia’s position on EMF has been adopted in the light of authoritative reviews having
concluded that no adverse health effects from exposure to EMF have been established, but
recognising that there is, within the community, some genuine public concern about the issue
which must be addressed.
The following is EnergyAustralia’s position on EMF, which largely reflects the policy of the energy
industry representative body, the Energy Networks Association:
•
to provide balanced, accurate information to our employees and customers, including
electric and magnetic field measurements and advice
•
take reasonable steps to limit field exposures from new facilities by locating and operating
our electrical installations prudently within the latest Australian health guidelines
•
closely monitor engineering and scientific research, overseas policy development and
major reviews of scientific, medical and engineering research regarding electric and
magnetic fields and health
•
cooperate fully with any bodies established by governments in Australia to investigate and
report about power frequency electric and magnetic fields.
6.2 Gibbs report
On 28 May 1990 the Minister for Minerals and Energy for the State of New South Wales (the
Minister) authorised former Chief Justice of Australia The Right Honourable Sir Harry Gibbs
G.C.M.G., A.C., K.B.E. to conduct an inquiry into community needs and high voltage transmission
line development in the State of New South Wales. On 3 July 1990 the Minister wrote Sir Harry
Gibbs a letter which included the following paragraph:
“Without in any way limiting or restricting the nature of the terms of reference of your
Inquiry, I would like to request that you specifically include in your investigations the
question of electromagnetic fields and their relationship to health.” [1.1.4]
On 28 February 1991 Sir Harry Gibbs delivered to the Minister a report (the Gibbs Report) which
included chapters dealing with matters which are central to EMF and the installation of power lines.
The findings and recommendations contained in the Gibbs Report regarding EMF and health are as
relevant today as they were in 1991, and these are adopted and relied upon by EnergyAustralia.
6.3 The challenge of dealing with uncertain science
The uncertain state of the science regarding EMF has presented significant challenges for decision
makers. As the Texas PUC Review put it:
“Policy Issues and Options
The current status of scientific evidence regarding EMF health effects is unclear. There is no
definitive indication that EMF exposure can affect health, and there are no data that establish
convincingly that it does not. In fact, as is often the case in situations involving very low
probability cause/effect relationships, it may not ever be possible to prove an effect or the
lack of an effect.
With respect to the EMF health effects issue, state legislatures find themselves in a quandary.
Acceptance of false positive conclusions may result in a significant expenditure of taxpayers’
money and divert attention from efforts to seek the true source of any increased risk. By
contrast, not acting on false negative conclusions is likely to be interpreted by the public as
irresponsible disregard for citizens’ safety. Therefore, it seems reasonable to expect
legislatures to actively support efforts to resolve the conflict.
Regulatory agencies normally address scientific uncertainty, such as the EMF health effects
question, through procedural mechanisms similar to those used in the courts and
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legislatures. The details of the mechanisms vary considerably depending on the nature of
the regulatory agency and its legislative charter. Political pressures to ‘do something’ about
the EMF issue may result directly or indirectly in the search for regulatory relief, especially if
no action is achieved at the judicial or legislative levels.
In at least 17 states, legislative or administrative agencies have formally considered the
possibility of health effects as a result of EMF exposure. Responses range from dismissal of
the question due to lack of evidence (Wyoming) to codification of formal EMF limits in
transmission lines (Florida). Courts and legislatures are actively considering actions in
several states.
Different responses and their rationales are tied to different views of what constitutes the key
problem in the EMF debate. There have been at least four different ways to define the EMF
‘problem’, each with distinctive views of the scientific evidence, of the proper role for science
to play, and of the proper perception of risk. More importantly, each definition carries a
policy prescription along with it. In the absence of a conclusive body of scientific findings
that would provide a firm grounding for deciding which of the four ways of constructing the
problem is the most appropriate, one is left to decide largely on the basis of pre-existing
beliefs and values that each of us brings to the EMF issue.
In this instance, the values of experts alone may provide too narrow a basis for legitimating
one definition of the problem over others. Recognizing this limitation, the Committee
recommends that, until science can provide a clearer path, state officials should engage the
public in open discussions of both the evidence to date and the public values that influence
its interpretation.
Professor Granger Morgan of Carnegie Mellon University in the United States has written widely on
the issue of public policy in the context of EMF. As he wrote in an essay for a book (Carpenter &
Ayrapetyan, 1994) on the issue:
“In the face of possible risk and incomplete evidence many (including myself) believe that
the wise strategy is to exercise prudence. Search for low-cost steps that could get people out
of fields, especially new fields, and then adopt them. At the same time, do not go off the
deep end. On a per capita basis, do not spend large amounts of money or incur great
inconvenience until the evidence is clearer than it now is.
In our private lives when we face a possible but uncertain risk we exercise such prudence all
the time. For example, many of us eat a bit more fibre, broccoli, and cauliflower and a bit
less fat and charbroiled meat than we once did. We know that these dietary changes offer no
assurance of protection from cancer, but there is some evidence that they might help. The
changes do not cost much. You can get used to them. So, it seems prudent to make some
adjustments. In public life we have rather greater difficulty exercising prudence. Our
regulatory and legal systems want to classify everything unambiguously as either safe or
hazardous. Indeed, a US. Federal Appeals Court judge once told me, ‘no matter how
incomplete the scientific evidence, present me with the case and I will decide’.
Creating certainty by fiat in the face of serious scientific uncertainty is not a wise way to
organize a society. Understanding this, a variety of groups and individuals have begun to
develop strategies for exercising prudence on the subject of power - frequency fields.”
The Gibbs Report dealt with this aspect of the health issue as follows:
“It then becomes a question of policy what action should be taken to avert a possible risk to
public health when it cannot be said either that it is probable that the risk exists or in what
circumstances a risk; if one exists, arises. A suggestion has been made in the United States
that a policy of prudent avoidance should be adopted.” [5.11.6]
“It would not be prudent, but foolish, to make radical or expensive changes to existing lines
until further scientific studies have resolved the doubts. On the other hand, when new lines
are being constructed, it may be prudent to do whatever can be done without undue
inconvenience and at modest expense to avert the possible risk; remembering that if that is
not done and future research establishes the existence of a real risk to health, serious
problems may arise which can be remedied only at great cost.” [5.11.9]
The policy recommendation contained in the Gibbs Report formed the basis of the policy
subsequently adopted by EnergyAustralia and the Australian electricity supply industry.
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6.4 Energy Networks Association policy response
6.4.1 Background
The Energy Networks Association (ENA) is the peak national body representing gas and electricity
distribution businesses throughout Australia. The owners of electricity transmission networks are
Associate Members and as such, are full and active participants in ENA asset management policy
issues such as electric and magnetic fields.
ENA is committed to taking a leadership role on relevant environmental issues including power
frequency EMF. ENA and its members are committed to the health and safety of the community
including their own employees.
Adverse health effects from EMF have not been established, but there remains a lack of scientific
consensus about whether or not they can occur, particularly in the area of childhood leukaemia.
Because of this lack of scientific consensus, the question of whether EMF can cause adverse health
effects is important both for the Australian community and the electricity supply industry. ENA
recognises that there is concern within the Australian community about EMF and is committed to
addressing it by the implementation of appropriate policies and practices.
ENA is committed to a responsible resolution of the issue where government, the community and
the electricity supply industry have reached public policy consensus consistent with the science.
6.4.2 ENA policy statement
This policy was originally approved as an industry policy statement by the ESAA (Electricity Supply
Association of Australia) Board on 15 June 2001 and was reconfirmed by the EMF Committee of
ENA on 30 March 2006:
1. ENA recommends to members of the energy supply industry that, within Australian health
guidelines, they design and operate their electricity generation, transmission and distribution
1
systems prudently.
2. ENA will closely monitor engineering and scientific research, including reviews by scientific
panels, and overseas policy development.
3. ENA will communicate openly with all stakeholders including assisting its members in
conducting community and employee education programs, distributing information material
including newsletters, brochures, booklets and the like, liaising with the media and responding to
enquiries from members of the public.
4. ENA will cooperate fully with any bodies established by governments in Australia to investigate
and report about power frequency electric and magnetic fields.
1
Prudence embraces a range of actions which it is sensible to take, having regard to the current
state of scientific uncertainty. Such actions could include monitoring research; sponsoring research;
continually reviewing policies in the light of the most up to date research findings (with particular
emphasis on the findings of scientific review panels); providing awareness training for electricity
supply business employees and keeping them informed; sharing information freely with the
community; measuring fields levels and practising prudent avoidance when designing and siting
new transmission and distribution facilities.
Prudent avoidance has been defined in an Australian context by the former Chief Justice of the
High Court of Australia, Sir Harry Gibbs as “doing what can be done without undue inconvenience
and at modest expense to avert the possible risk to health from exposure to new high voltage
transmission facilities. In practical terms, this means designing new transmission and distribution
facilities having regard to their capacity to produce EMF, and siting them having regard to the
proximity of houses, schools and the like.”
6.5 NHMRC interim guidelines
As part of our commitment to operate within Australian health recommendations, EnergyAustralia
and the electricity industry generally have complied with interim guidelines developed by the
National Health and Medical Research Council (NHMRC) on limits of exposure to 50/60 Hz electric
and magnetic fields.
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These guidelines covering both residential and workplace exposures were published in November
1989 to prevent immediate health effects resulting from exposure to EMF.
These interim guidelines are outlined in more detail in Section 7.1 of this Appendix E.
6.6 Draft ARPANSA standard
In December 2006 the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) – the
national health authority now responsible for this area – released a draft new standard for EMF
exposure taking into account the latest scientific research. This new draft standard relates to EMF of
extremely low frequency (ELF) such as those found around an electricity network.
Following public comment this new standard is expected to be finalised and implemented in 200708. The exposure guidelines for the draft standard are outlined in Section 7 of this Appendix E.
This Standard sets limits on the exposure to ELF fields for persons in the occupational and general
public settings (see Section 7.2 of this Appendix E). These limits are designed to prevent
established biological effects which could lead to adverse health outcomes due to induced electric
currents within the body and are set at a level that includes a safety margin.
Regarding the issue of potential health effects at levels below the limits specified in the Standard,
these are dealt with in Section 5.7e and Annex 6 of the draft standard. Excerpts from these sections
are reproduced below:
Section 5.7(e)
Minimising, as appropriate, ELF and/or static electric and magnetic field exposure provided this can
be readily achieved without undue inconvenience and at reasonable expense. Any such
precautionary measures should follow good engineering and risk minimisation practice. Planning
practice and relevant codes of practice should also be followed. Precautionary measures should be
proportional to the risk. (eg. where children are involved). Important principles underlying
appropriate precautionary measures are discussed in Annex 6. The incorporation of arbitrary
additional prescriptive safety factors beyond the exposure limits of this Standard is not supported.
Annex 6: Application of the precautionary approach to ELF fields
With respect to ELF fields, acute effects due to induced currents in the body (such as electrostimulation) occur, and the limits are designed to provide protection against these effects. At levels
of ELF exposure below the limits, the risk of any effect is low, but some uncertainty exists, and a
precautionary approach could be applied (WHO 2000). A precautionary approach would be
supplementary to the limits of the standard, as it strives to widen the margin of safety by
promoting measures to keep exposure at levels even lower than the limits set in the standard.
This Standard already contains elements of precaution; for example, limits for the general public
are lower than the occupational group, and there is special treatment of pregnant workers.
However, a precautionary approach implies more than just adopting measures so as not to exceed
the prescribed limits; it entails taking additional steps to provide a greater margin of safety by
promoting measures to keep exposure lower than the limits (Foster, Vecchia & Repacholi 2000).
The reports of Commission of the European Communities (2000), WHO (2002) and NRPB (2004)
considered application of the precautionary approach.
An application of the precautionary approach is encapsulated in clause 5.7 (e) of this Standard:
“Minimising, as appropriate, ELF and/or static electric and magnetic field exposure provided this
can be readily achieved without undue inconvenience and at reasonable expense. Any such
precautionary measures should follow good engineering and risk minimisation practice. Planning
practice and relevant codes of practice should also be followed. Precautionary measures should be
proportional to the risk. (Eg. Additional precautions may be considered appropriate). The
incorporation of arbitrary additional safety factors beyond the exposure limits of this Standard is
not supported.”
In the occupational setting where the limits are higher, measures to keep exposure lower than the
limits are encouraged through the mandatory application of risk management process outlined in
Section 5.1. The measures that are applied so as to not exceed an ELF limit, and those measures
used to keep exposure somewhat lower than a limit often differ only in degree.
Electric and magnetic fields – Appendix E of Environmental Assessment - EnergyAustralia
Page 13
While a precautionary approach is an attractive concept in some parts of the community, care is
required in its application (Cross 1996). The chief difficulty is the lack of evidence that any
additional measures will offer any more protection against unknown risks, than that provided by
just keeping within the prescribed general public ELF limits. It is also important that the
introduction of a particular measure does not inadvertently introduce an additional untoward effect
in a different area. The consumer and society must ultimately meet costs, both direct and indirect.
Further scientific research should provide data that helps reduce the degree of uncertainty about
the effects of exposure to ELF. Hence the Standard and Codes of Practice will need review in the
light of new scientific evidence.
Codes of Practice also have an important educational role, which can help reduce individual
exposure, both public and occupational, to ELF fields. They do this by identifying potential areas of
ELF exposure, and giving advice on measures that individuals can take to reduce their exposure.
Precautionary measures: cost-benefit approach
If magnetic fields are a cause of childhood leukaemia, the chief uncertainties in assessing the risk
are:
•
uncertainty as to the relevant aspect or metric of exposure. Long-term time weighted
average exposure in the home has been used in epidemiology partly for pragmatic reasons
and may be a marker for some other aspect of exposure
•
uncertainty as to exposure-response relationship. If long-term average is indeed the correct
metric, it is not known whether there is a threshold (at 0.4 µT or any other value) or a
smooth function, and if a smooth function, what shape
•
uncertainty as to the aetiologically relevant period and duration-response relationship.
In view of these uncertainties, it is recommended that:
•
a working assumption that measures that reduce any aspect of average exposure across
the population would indeed reduce the risk if there is one
•
recognition that any specific measure that reduces exposure is unlikely to reduce precisely
the relevant aspect of exposure - this extra uncertainty must be included in any cost-benefit
analysis.
The traditional means of deciding whether a particular project should be undertaken is to conduct a
cost-benefit analysis. Opponents of this approach cite questions of equity (poorer communities and
individuals and less willing/able to pay for mitigation) and problems related to the process of
assigning a monetary value to life and health. However a transparent cost-benefit analysis does
provide a platform for negotiations between stakeholders.
Various options are given in the following table and some relevant factors are provided. In the
analysis the costs of taking a precautionary approach should be considered at the level of the
society as a whole and all costs should be included, whether borne by industry, taxpayers or
others.
If the aim of the exercise is to eliminate the role of magnetic fields as an agent in the aetiology of
childhood leukaemia then the following factors will apply to the analysis:
•
childhood leukaemia is a relatively rare disease
•
taking the epidemiological evidence at face value, only a small fraction of the population is
exposed at the levels associated with a significantly increased risk
•
there are many uncertainties as to whether any intervention would be effective or not,
including the uncertainty as to whether magnetic fields are causal or not and the
uncertainty as to which aspect of exposure is the relevant one to reduce.
In view of these factors, and even after fully allowing for the legitimate desire by society to err on
the safe side, it seems likely that only very low-cost measures will be justified.
6.7 Prudent avoidance guidelines (1998)
At the 23d Annual Conference of the Australasian Radiation Protection Society Inc held at Ballarat
in Victoria in October 1998, Mr Kevin Nuttall presented a scientific paper which he had authored
Electric and magnetic fields – Appendix E of Environmental Assessment - EnergyAustralia
Page 14
with Mr P J Flanagan and Mr G Melik. The paper was entitled “Prudent Avoidance Guidelines for
Power Frequency Magnetic Fields”. The abstract of the paper states:
“This paper provides practical guidance 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 prudently be 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 other policies of individual electricity utilities.”
It is suggested that these guidelines are consistent with the principles in the Gibbs and Peach Panel
Reports and provide a useful tool when implementing a policy of prudent avoidance.
Electric and magnetic fields – Appendix E of Environmental Assessment - EnergyAustralia
Page 15
7 Prudent avoidance options
The paper written by K Nuttall, et al, entitled ‘Prudent Avoidance Guidelines for Power Frequency
Magnetic Fields’ outlines a range of general measures which might be prudently applied. The
guidelines state:
“The application of prudent avoidance in the design and construction of new electrical
facilities is a process of assessing the extent to which people may be exposed to fields
produced by them and considering what “low cost” and “no cost” measures might be taken
to reduce such exposure within acceptable constraints.”
Measures which may be taken can be categorised under distance, conductor configuration, phase
arrangement, split phasing, current reduction, and in very limited cases, undergrounding, which
per se, does not always result in a reduction in exposure to magnetic fields.
Undergrounding has been chosen as the construction method for the Botany Bay Cable Project for
technical issues and also in view of the fact that the cables are being installed to replace existing
underground cables, albeit along a different route.
In the context of undergrounding being the construction method, the following are the prudent
avoidance methods proposed for the Botany Bay Cable Project:
7.1 Distance
The most common method of reducing peoples’ exposure to EMF is through the selection of the
positioning of cables/power lines.
In addition to technical and construction issues, the proposed route was chosen with consideration
of a range of neighbouring properties:
•
Captain Cook Drive, Girl Guides Hall
•
Captain Cook Drive, Scout Hall
•
Captain Cook Drive, Pre school
•
Bunnerong Rd, La Perouse School
•
Bunnerong Rd, Dental Clinic
•
Bunnerong Rd, No 85 Scouts Hall
•
Bunnerong Rd, Women’s Athletic Field
•
Bunnerong Rd, NSW Women’s Sports Centre
•
Bunnerong Rd, Houses close to Bunnerong Rd
•
Bunnerong Rd (Abbe Receveur Pl), Houses close to Bunnerong Rd
The circuits are generally positioned within the road reserve or areas of low public occupancy.
7.2 Phase arrangement
For double circuit lines, it is possible to arrange each three phase circuit with a different reverse
phase arrangement, such that some cancellation of magnetic fields occurs. This is usually a
relatively low cost option in the case of new lines. The effectiveness of this measure can be seen by
comparing curves A and B, and C and D in Figure B.
The proposed cables will utilise a reverse phase arrangement that produces the lowest magnetic
field.
7.3 Conductor configuration
Different arrangements of phasing can produce different magnetic field strengths for the same line
current.
Electric and magnetic fields – Appendix E of Environmental Assessment - EnergyAustralia
Page 16
In general, triangular arrangements tend to provide more field cancellation than horizontal
arrangements, with lower resultant field strengths.
A triangular ‘trefoil’ cable arrangement has been selected for the Botany Bay Cable Project.
7.4 Current reduction
A reduction in electrical current will generally reduce magnetic field strengths. The reduction in
field strength is approximately proportional to the reduction in current. For a given load
requirement, the only way to reduce the current is to increase the voltage. The choice of voltage for
this project is the highest voltage that EnergyAustralia’s network allows.
100
90
80
A
Magnetic field, mG
70
B
60
50
C
40
D
30
20
10
0
0
2
4
6
8
10
12
14
16
18
20
Distance from centerline, m
Notes:
‘Magnetic field’ represents the magnetic field at 1m above the ground
‘Distance’ represents the distance measured horizontally from the centreline of the power line.
Curve A Underground double 132kV circuit, conduit, trefoil formation (92MVA per circuit –
normal phasing).
Curve B Underground double 132kV circuit, conduit, trefoil formation (92MVA per circuit –
reverse phasing).
Curve C Underground double 132kV circuit, direct buried, trefoil formation (92MVA per
circuit – normal phasing).
Curve D Underground double 132kV circuit, direct buried, trefoil formation (92MVA per
circuit – reverse phasing).
Figure C- Comparison of the effectiveness of underground construction options in relation to
EMF mitigation
Electric and magnetic fields – Appendix E of Environmental Assessment - EnergyAustralia
Page 17
8 Exposure guidelines
8.1 The NHMRC guidelines
In November 1989, the (Australian) National Health and Medical Research Council (NHMRC)
adopted and published interim guidelines for public and occupational exposure to EMF (the
guidelines). These are identical to the interim guidelines adopted earlier that year by the
International Radiation Protection Association (IRPA).
See Figure D below.
8.2 Draft ARPANSA standard
In December 2006, the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) – the
national health authority now responsible for this area – released a draft new standard for EMF
exposure taking into account the latest scientific research.
Following public comment this new standard is expected to be finalised and implemented in 200708.
See Figure D below.
8.3 International guidelines or standards
In March 1998, the International Commission on Non-Ionizing Radiation Protection (ICNIRP)
published its revised electric and magnetic field exposure guidelines for the general public and
workers. The revisions span frequencies from static to radio frequency fields and result from expert
consultation world-wide.
Previous ICNIRP guidelines were issued in 1988 (RF), 1990 (50/60-Hz) and in 1994 (static fields). The
1998 guidelines supersede all of this earlier work. Their purpose is “to establish guidelines for
limiting EMF exposure that will provide protection against known adverse health effects.” They are
not intended to protect against potential long-term health effects such as cancer, because “ICNIRP
concluded that available data are insufficient to provide a basis for setting exposure restrictions.”
The other prominent international standard was released by the Institute of Electrical and
Electronics Engineers (IEEE) in 2002.
The IEEE C95.6 standard is the most up-to-date international reference and has been written as a
standard rather than a guideline as is the case with the ICNIRP document. See Figure D below.
PUBLIC magnetic field limits
NHMRC
ARPANSA
IEEE
ICNIRP
Normal
controlled activity
limbs
Up to 24 hours
NA
NA
NA
1,000
1,000
3,000
NA
NA
9,040
NA
758,000
NA
1,000
NA
NA
NA
Few hours/day
10,000
NA
NA
NA
ARPANSA
IEEE
ICNIRP
NA
NA
5,000
15,000
27,100
NA
5,000
NA
NA
18,000
NA
NA
5,000
50,000
250,000
NA
NA
NA
NA
NA
758,000
NA
NA
NA
OCCUPATIONAL magnetic field limits
NHMRC
Normal
controlled activity
(head)
controlled activity
(other)
Whole working day
2 hours/day
limbs
Figure D – table of Australian and international magnetic field exposure limits
Electric and magnetic fields – Appendix E of Environmental Assessment - EnergyAustralia
Page 18
9 Conclusions
9.1 General
Considering the currently available information on EMF worldwide, the following conclusions may
be drawn:
•
The body of scientific literature on the issue is both complex and voluminous, and public
policy initiatives should be based on independent and authoritative reviews and reports.
•
Adverse health effects from human exposure to EMF has not been established, but the
possibility cannot be ruled out.
•
Conventional science cannot guarantee absolute safety for exposure to environmental
factors such as EMF.
•
If a risk to human health is established, it is likely to be a small risk.
•
There is no basis to establish human exposure limits for EMF other than those which
presently exist, and, in particular there is no scientific basis to support exposure limits
below 10mG as a prudent avoidance measure.
•
EnergyAustralia should continue to act prudently in relation to the issue. This includes
implementing prudent avoidance measures in accordance with the principles established
by the Gibbs and Peach Panel Reports and in this regard, the prudent avoidance principles
referred to in Section 7 of this Appendix E.
9.2 Consideration of prudent avoidance principles
Taking into account the above considerations, the application of prudent avoidance principles has
been a key element in determining the final positioning of the cables for the Botany Bay Cable
Project.
The final cable route design has been prepared with regard to the following issues:
•
Distance - the final positioning of the cable has been determined with consideration of the
location of properties along the route and generally within the road reserve or areas of low
public occupancy).
•
Phase arrangement – The proposed cables will utilise a reverse phase arrangement that
produces the lowest magnetic field.
•
Conductor configuration - a triangular or ‘trefoil’ conductor arrangement has been
selected for the Botany Bay Cable Project to assist with reduction in field strengths.
Undergrounding can sometimes be considered a prudent avoidance option, but it has been
selected as the preferred construction method for technical reasons and in view of the fact that the
project is being carried out to replace existing underground cables
9.3 Compliance with health guidelines
For the Botany Bay Cable Project, the proposed cables will comply with all relevant local and
international health guidelines or standards for public exposure:
•
The NHMRC interim guidelines (1989)
•
Draft ARPANSA’s draft EMF standard (2006)
•
International Commission on Non-Ionizing Radiation Protection (ICNIRP) (1998)
•
Institute of Electrical and Electronics Engineers (IEEE) C95.6 (2002).
Electric and magnetic fields – Appendix E of Environmental Assessment - EnergyAustralia
Page 19
9.4 EMF calculations
EnergyAustralia has performed modelling on the expected EMF outcomes once the proposed
cables are in operation (see Figure C). Calculations, which have been independently verified (see
attachment 2), compared a range of underground 132kV construction methods and configurations.
This modelling confirms the effectiveness of the prudent avoidance measures adopted by
EnergyAustralia for the project to nominate a reverse phase arrangement with the 132kV cables
installed in triangular formation.
Electric and magnetic fields – Appendix E of Environmental Assessment - EnergyAustralia
Page 20
10 References
Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) (2006). Draft Radiation
Protection Standard for Exposure Limits to Electric and Magnetic Fields 0 Hz - 3 kHz. Public
Consultation Draft 7 December 2006.
Carnegie Mellon University. Department of Engineering and Public Policy (1995). Fields from
electric power. What are they? What do we know about possible health risks? What can be done?
Pittsburgh, Pennsylvania: 1995.
Electricity Supply Association of Australia Limited (ESAA) (1991). ESAA policy statement on electric
and magnetic fields. Adopted by the ESAA Board on 19 July 1991. (With: EMF policy advice,
November 1994).
Energy Networks Association (ENA) (2006). ENA Policy Statement on Electric and Magnetic Fields.
Originally adopted by the ESAA Board on 19 July 1991 and reconfirmed by the ENA EMF
Committee on 30 March 2006.
Gibbs, Sir Harry (1991). Inquiry into community needs and high voltage transmission line
development. Report to the NSW Minister for Minerals and Energy. Sydney, NSW: Department of
Minerals and Energy, February 1991.
International Commission on Non-Ionizing Radiation Protection (ICNIRP) (1993). Press release 12
May 1993.
IRPA/INIRC (1990). International Radiation Protection Association, International Non~lonizing
Radiation Committee, Interim guidelines on limits of exposure to 50/60 Hz electric and magnetic
fields. Health Physics 58(1): 113-122.
Measurements taken by Australian power authorities, 1995, as set out in Electricity Supply
Association of Australia Limited (ESAA) brochure. “Electric & magnetic fields. What we know”.
Brisbane, Qld: Reel Image, 1995.
Morgan M. Granger (1994). Power frequency electric and magnetic fields: Issues of risk
management and risk communication. In: Biological effects Of electric and magnetic fields:
Beneficial and harmful effects. Volume 2. Edited by D.O. Carpenter and S. Ayrapetyan. New York:
Academic Press, 1994. (p. 297-319).
National Health and Medical Research Council (NHMRC) (1989). Interim guidelines on limits of
exposure to 50/60 Hz electric and magnetic fields (1989). Melbourne, Victoria: Australian Radiation
Laboratory for NI-IMRC, December, 1989. (Radiation Health Series No. 30).
Nuttall, K, Flanagan P. 1, Melik G. (1998). Prudent Avoidance Guidelines for Power Frequency
Magnetic Fields - paper presented at 23d Annual Conference of the Australasian Radiation
Protection Society Inc.
Peach H.G., Bonwick W.J. and Wyse T. (1992). Report of the Panel on Electromagnetic Fields and
Health to the Victorian Government (Peach Panel Report). Melbourne, Victoria: September, 1992. 2
volumes: Report; Appendices.
Repacholi M. (1991). 50/60 Hz standards and guidelines. Australian Radiation Protection Society
(ARPS) Tutorial Workshop: 50Hz Fields and Health, Sydney, 3-4 October, 1991; Radiation Protection
in Australia 9(4): 116-123.
Wertheimer N. and Leeper E. (1979). Electrical wiring configurations and childhood cancer.
American Journal of Epidemiology 109(3): 273-284.
Electric and magnetic fields – Appendix E of Environmental Assessment - EnergyAustralia
Page 21
Attachment 1 – Reviews of
EMF science conducted by
scientific panels, public
health organisations, or
governmental bodies
Since 1977, 134 reviews of EMF science have been conducted by scientific panels, public health
organisations, or governmental bodies. These reviews are listed below. (Reviews by individuals or
other entities are not listed.) Representative key conclusions from each review are also presented
below.
134 2005 British Columbia (Canada) Centre for Disease Control - Health Concerns of Power
Frequency Electric and Magnetic Fields
“Epidemiological studies (study of the various factors influencing the occurrence of disease in a
defined human population) have not established an association between exposure to the fields the
development of cancer in adults. The evidence associating cancer in children with exposure to
powerfrequency EMF's is considered inconclusive for higher field exposures and not established
for lower field exposures. Therefore the available scientific evidence to date does not support the
assumption that adverse health effects from exposure to these fields at levels normally
encountered in our homes, schools and offices pose a risk to human health.” [p. 1]
133 2005 American Conference of Governmental Industrial Hygienists - Threshold Limit Values
for Physical Agents in the Work Environment
“At this time, there is insufficient information on human responses and possible health effects of
magnetic fields in the frequency range of 1 Hz to 30kHz to permit the establishment of a TLV for
time-weighted average exposures.” [p. 146]
132 2005 Australian Radiation Advisory Committee (State of Victoria) - Annual Report for the
year ending September 2005
“The additional evidence reviewed by the Committee concerning health effects of power frequency
has supported the Committee’s position that overall, there is insufficient evidence to conclude that
exposure to power frequency electric and magnetic fields, normally encountered in the
environment, causes adverse health effects in humans.” [p. 24]
131 2005 Health Council of the Netherlands Electromagnetic Fields Committee Electromagnetic Fields: Annual Update 2005
“All things considered, the evidence of DNA damage in the REFLEX study is weak. The Committee
also emphasizes the fact that this is in vitro research, i.e. research on cells that are in an unnatural
situation. For example, cells derived from tissues or organs do not have the opportunity to interact.
It is highly questionable whether cells react in the same way under such circumstances as they
would in a natural situation. If effects are, in fact, identified in such in vitro research, it is still
questionable whether they will also occur in vivo and if so, whether they can then give rise to
health effects.” [p.119]
130 2005 Canadian Federal-Provincial-Territorial Radiation Protection Committee - Health
Effects and Exposure Guidelines Related to Extremely Low Frequency Electric and Magnetic
Fields
“Based on the available scientific evidence to date, the Federal Provincial Territorial Radiation
Protection Committee (FPTRPC) concludes that adverse health effects from exposure to powerfrequency EMFs, at levels normally encountered in homes, schools and offices, have not been
established.” [p.268]
Electric and magnetic fields – Appendix E of Environmental Assessment - EnergyAustralia
Page 22
129 2004 U.K. National Radiological Protection Board - Review of the Scientific Evidence for
Limiting Exposure to Electromagnetic Fields (0-300 GHz)
“In the view of the NRPB, the epidemiological evidence that time-weighted average exposure to
power frequency magnetic fields above 0.4 μ T [4 mG] is associated with a small absolute raised
risk of leukaemia in children is, at present, an observation for which there is no sound scientific
explanation.There is no clear evidence of a carcinogenic effect of ELF EMFs in adults and no
plausible biological explanation of the association can be obtained from experiments with animals
or from cellular and molecular studies.” [p. 15]
128 2004 Institution of Electrical Engineers Policy Advisory Group on the Biological Effects of
Low Level Electromagnetic Fields - The Possible Harmful Biological Effects of Low Level
Electromagnetic Fields of Frequencies up to 300 GHz – IEE Position Statement – May 2004
“The Institution of Electrical Engineers Policy Advisory Group on the Biological Effects of low-level
Electromagnetic Fields (the “Group”) has concluded that the balance of scientific evidence does not
indicate that harmful effects occur in humans due to low-level electromagnetic field exposure. This
conclusion is the same as that reached in its previous position statements, the last being in May
2002 and has not been changed by the peer-reviewed literature of the past two years.” [p.1]
127 2004 American Conference of Governmental Industrial Hygienists - TLVs and BEIs
“At this time, there is insufficient information on human responses and possible health effects of
magnetic fields in the frequency range of 1 Hz to 30kHz to permit the establishment of a TLV for
time-weighted average exposures.” [p. 142]
126 2004 Connecticut Department of Public Health Division of Environmental Epidemiology &
Occupational Health - Electromagnetic Fields (EMF): Health Concerns
“Despite extensive research over the past 20 years, the health risk caused by EMF exposure
remains an open question. Two national research organizations have looked at the studies and
have concluded that there is not strong evidence suggesting that EMF exposures pose a health risk.
However, some studies have shown a weak link between household EMF exposure and a small
increased risk of childhood leukemia at average exposures above 3 mG. For cancers other than
childhood leukemia, none of the studies provide evidence of an association.” [p. 2]
125 2003 Florida Department of Environmental Protection - 2003 Annual Report on EMF
Research
“Over the last six years a number of scientific and governmental organizations have reviewed EMF
health effects research. … The conclusion of the reviewing scientific committees is that there is no
consistent, significant link between cancer and power line EMFs.” [pp. 2-3]
124 2003 Australian Radiation Protection and Nuclear Safety Agency - The Controversy Over
Electromagnetic Fields and Possible Adverse Health Effects
“On balance, the scientific evidence does not indicate that exposure to 50 Hz EMFs found around
the home, the office or near power lines is a hazard to human health.” [p. 4]
123 2003 International Commission on Non-Ionizing Radiation Protection - Exposure to Static
and Low Frequency Electromagnetic Fields, Biological Effects and Health Consequences (0-100
kHz)
“In the absence of evidence from cellular or animal studies, and given the methodological
uncertainties and in many cases inconsistencies of the existing epidemiological literature, there is
no chronic disease outcome for which anaetiological relation to EMF exposure can be regarded as
established.” [p. 479]
122 2003 Health Council of the Netherlands Electromagnetic Fields Committee Electromagnetic Fields: Annual Update 2003
“What are the ramif ications of this [IARC] conclusion? Firstly, the Committee emphasizes that this
does not mean that ELF magnetic fields are actually carcinogenic, simply that they might be. … The
Committee, like the IARC itself, points out that there is no evidence to support the existence of a
causal relationship here. Nor has research yet uncovered any evidence that a causal relationship
might exist.” [pp. 75-76]
121 2003 American Conference of Governmental Industrial Hygienists - TLVs and BEIs
Electric and magnetic fields – Appendix E of Environmental Assessment - EnergyAustralia
Page 23
“At this time, there is insufficient information on human responses and possible health effects of
magnetic fields in the frequency range of 1 Hz to 30kHz to permit the establishment of a TLV for the
time-weighted average exposures.” [p. 144]
120 2003 Australian Radiation Advisory Committee (State of Victoria) - Annual Report of the
Radiation Advisory Committee for the year ending September 2003
“The additional evidence concerning health effects of electromagnetic fields reviewed by the
Committee during the past year has not been sufficiently compelling to alter the Committee’s
position concerning the issue. That is that, overall, there is insufficient evidence to come to a firm
conclusion regarding possible health effects from exposure to power frequency electric and
magnetic fields.” [p. 20]
119 2002 U.S. National Institutes of Health U.S. National Institute of Environmental Health
Sciences - EMF Questions & Answers: Electric and Magnetic Fields Associated with the Use of
Electric Power
“Over the past 25 years, research has addressed the question of whether exposure to powerfrequency EMF might adversely affect human health. For most health outcomes, there is no
evidence that EMF exposures have advers eeffects. There is some evidence from epidemiology
studies that exposure to power-frequency EMF is associated with an increased risk for childhood
leukemia. This association is difficult to interpret in the absence of reproducible laboratory evidence
or a scientific explanation that links magnetic fields with childhood leukemia.” [p. 57]
118 2002 Institution of Electrical Engineers Policy Advisory Group on the Biological Effects of
Low Level Electromagnetic Fields - The Possible Harmful Biological Effects of Low Level
Electromagnetic Fields of Frequencies up to 300 GHz
“The Institution of Electrical Engineers Policy Advisory Group on the Biological Effects of Low Level
Electromagnetic Fields has concluded that there is still no convincing scientific evidence that shows
harmful effects of low-level electromagnetic fields on humans.” [p.1]
117 2002 Minnesota State Interagency Working Group on EMF Issues - A White Paper On
Electric and Magnetic Field (EMF) Policy and Mitigation Options
“The Minnesota Department of Health concludes that the current body of evidence is insufficient to
establish a cause and effect relationship between EMF and adverse health effects.” [p. 36]
116 2002 Australian Radiation Protection and Nuclear Safety Agency - Electricity and Health
“The scientific evidence does not firmly establish that exposure to 50 Hz electric and magnetic
fields found around the home, the office or near powerlines is a hazard to human health. In view of
the epidemiological studies, however, the possibility remains that intense and prolonged exposures
to magnetic fields may increase the risk of leukaemia in children. If exposure to higher-than-normal
magnetic fields does actually cause leukaemia at the level indicated in the Doll report, then, on
average, there would be one extra case in Australia every two years. The evidence does not allow
health authorities to decide whether there is a specific magnetic field level above which continuous
exposure is dangerous or compromises human health.” [p. 4]
115 2002 Italy - Ministries of Environment, Health & Telecommunications International
Evaluation Committee to Investigate the Health Risks of Exposure to Electric, Magnetic and
Electromagnetic Fields - Statement of the International Evaluation Committee
“Reviews of current scientific information have all indicated that, while there are gaps in knowledge
requiring further research before better health risk assessments can be made, there have not been
any adverse health consequences confirmed from EMF exposures below the ICNIRP (1998)
guideline limits.” [p. 2]
114 2002 American Conference of Governmental Industrial Hygienists - TLVs and BEIs
“At this time, there is insufficient information on human responses and possible health effects of
magnetic fields in the frequency range of 1 Hz to 30kHz to permit the establishment of a TLV for
time-weighted average exposures.” [p. 144]
113 2002 California Department of Health Services California EMF Program - An Evaluation of
the Possible Risks from Electric and Magnetic Fields (EMFs) from Power Lines, Internal Wiring,
Electrical Occupations and Appliances
“To one degree or another all three of the DHS scientists are inclined to believe that EMFs can
cause some degree of increased risk of childhood leukemia, adult brain cancer, Lou Gehrig’s
Disease, and miscarriage. They strongly believe that EMFs do not increase the risk of birth defects,
Electric and magnetic fields – Appendix E of Environmental Assessment - EnergyAustralia
Page 24
or low birth weight. They strongly believe that EMFs are not universal carcinogens, since there are
a number of cancer types that are not associated with EMFexposure. To one degree or another they
are inclined to believe that EMFs do not cause an increased risk of breast cancer, heart disease,
Alzheimer’sDisease, depression, or symptoms attributed by some to a sensitivity to EMFs.
However, all three scientists had judgments that were close to the dividing line between believing
and not believing that EMFs cause some degree of increased risk of suicide, or for adult leukemia,
two of the scientists are close to the dividing line between believing or not believing and one was
prone to believe that EMFs cause some degree of increased risk.” [p. 3]
112 2002 Australian Radiation Advisory Committee (State of Victoria) - Annual Report of the
Radiation Advisory Committee
“The additional evidence concerning health effects of electromagnetic fields reviewed by the
Committee during the past year has not been sufficiently compelling to alter the Committee’s
position concerning the issue. That is that, overall, there is insufficient evidence to come to a firm
conclusion regarding possible health effects from exposure to power frequency electric and
magnetic fields.” [p. 25]
111 2001 Florida Department of Environmental Protection - 2001 Annual Report on EMF
Research
“We seem to be approaching a time when some aspects of EMF exposure maybe deemed a slight
risk, but we are still lacking knowledge of EMF impact mechanisms and adequate scientific proof to
allow a valid estimate of risk to the public and the knowledge to set a regulatory standard to
manage the risk.” [p. 5]
110 2001 World Health Organization - Electromagnetic Fields and Public Health: Extremely low
frequency fields and cancer
“There is no consistent evidence that exposure to ELF fields experienced in ourliving environment
causes direct damage to biological molecules, including DNA. Since it seems unlikely that ELF
fields could initiate cancer, a large number of investigations have been conducted to determine if
ELF exposure can influence cancer promotion or co-promotion. Results from animal studies
conducted so far suggest that ELF fields do not initiate or promote cancer. However, two recent
pooled analyses of epidemiological studies provide insight into the epidemiological evidence that
played a pivotal role in the IARC evaluation. These studies suggest that, in a population exposed to
average magnetic fields in excess of 0.3 to 0.4 μT, twice as many children might develop leukaemia
compared to a population with lower exposures. In spite ofthe large number data base, some
uncertainty remains as to whether magnetic field exposure or some other factor(s) might have
accounted for the increased leukaemia incidence.” [p. 3]
109 2001 Australian Radiation Advisory Committee (State of Victoria) - Annual Report of the
Radiation Advisory Committee
“The additional evidence concerning health effects of electromagnetic fields reviewed by the
Committee during the past year has not been sufficiently compelling to alter the Committee’s
position concerning the issue. That is that, overall, there is insufficient evidence to come to a firm
conclusion regarding possible health effects from exposure to power frequency electric and
magnetic fields.” [p. 22]
108 2001 International Commission on Non-Ionizing Radiation Protection, Standing Committee
on Epidemiology - Review of the Epidemiologic Literature on EMF and Health
“In the absence of experimental evidence and given the methodological uncertainties in the
epidemiologic literature, there is no chronic disease for which an etiological relation to EMF can be
regarded as established. … Among all the outcomes evaluated in epidemiologic studies of EMF,
childhood leukemia in relation to postnatal exposures above 0.4 μT is the one for which there is
most evidence of an association. … On the basis of epidemiologic findings, evidence shows an
association of amyotrophic lateral sclerosis with occupational EMF exposure although confounding
is a potential explanation. Breast cancer, cardiovascular disease, and suicide, and depression
remain unresolved.” [p. 911]
107 2001 U.K. National Radiological Protection Board Advisory Group on Non-Ionizing
Radiation - ELF Electromagnetic Fields and Neurodegenerative Disease
“There is no good ground for thinking that exposure to extremely low frequency electromagnetic
fields can cause Parkinson’s disease and only very weak evidence to suggest that it could cause
Alzheimer’s disease.” [p. 21]
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106 2001 European Commission Directorate-General Health and Consumer Protection
Scientific Committee on Toxicity, Ecotoxicity and the Environment - Opinion on Possible
Effects of Electromagnetic Fields (EMF), Radiofrequency Fields (RF) and Microwave Radiation
on Human Health
“Combined analysis of the epidemiological studies on the association between exposures to ELF
and childhood leukaemia have strengthened the evidence of an association. However, given some
inconsistencies in exposure measurements and the absence of other criteria commonly used in
assessing causality (particularly a plausible explanation of underlying biological mechanisms, see
above), the association does not meet adequate criteria forbeing causal. Thus, the overall evidence
for 50/60 Hz magnetic fields to produce childhood leukaemia must be regarded as being limited. …
There is no convincing suggestion of any other carcinogenic effect of ELF on either children or
adults.” [p. 10]
105 2001 German Commission on Radiological Protection Commission on Radiological
Protection - Limit values and precautionary measures to protect the public against
electromagnetic fields
“Since 1998, various results of studies involving animal experiments looking at a possible
carcinogenic effect of low-frequency fields have been published. These results are mostly negative
and tend to argue against the existence of a risk. … The link found in the epidemiological studies
with the occurrence of leukaemia in children is insufficient with respect to the lack of evidence of
carcinogenic effects in adults or a plausible explanation of the experiments carried out on animals
and isolated cells, to warrant the unequivocal conclusion that the fields in question cause
leukaemia in children.” [Pt. 3.2.1]
104 2001 International Agency for Research on CancerWorking Group on the Evaluation of
Carcinogenic Risks to Humans - Non-Ionizing Radiation, Part 1: Static and Extremely LowFrequency (ELF) Electric and Magnetic Fields
“There is limited evidence in humans for the carcinogenicity of extremely low frequency magnetic
fields in relation to childhood leukaemia. There is inadequate evidence in humans for the
carcinogenicity of extremely low frequency magnetic fields in relation to all other cancers. There is
inadequate evidence in humans for the carcinogenicity of static electric or magnetic fieldsand
extremely low-frequency electric fields. There is inadequate evidence in experimental animals for
the carcinogenicity of extremely low-frequency magnetic fields. No data relevant to the
carcinogenicity of static electric or magnetic fields and extremely low-frequency electric fields in
experimental animals were available. Extremely low-frequency magnetic fields are possible
carcinogens to humans (Group 2B).” [p. 338]
103 2001 American Conference of Governmental Industrial Hygienists - TLVs and BEIs
“At this time, there is insufficient information on human responses and possible health effects of
magnetic fields in the frequency range of 1 Hz to 30kHz to permit the establishment of a TLV for the
time-weighted average exposures.” [p. 142]
102 2001 Health Council of the Netherlands Electromagnetic Fields Committee Electromagnetic Fields: Annual Update 2001
“[R]ecent meta-analysis show a consistent association between relatively high measured or
calculated magnetic field strengths and an increased risk of childhood leukaemia. However, from an
epidemiological point of view, an association with a relative risk of smaller than 2 is to be
considered as weak.… The committee would emphasize that there is no known mechanism that
could account for the association referred to above. Because the association is weak and without a
reasonable biological explanation, it is not unlikely thatit could also be explained by chance or by
an artifact. The committee therefore sees no reason to modify its earlier conclusion that the
association is not likely to be indicative of a causal relationship. It therefore remains the
committee’s belief that it is not likely that children (or adults) living near tohigh-voltage power lines
are at risk through exposure to electromagnetic fields generated by those lines.” [p. 41]
101 2001 U.K. National Radiological Protection Board Report of an Advisory Group on NonIonising Radiation - ELF Electromagnetic Fields and the Risk of Cancer
“Laboratory experiments have provided no good evidence that extremely low frequency
electromagnetic fields are capable of producing cancer, nor do human epidemiological studies
suggest that they cause cancer in general. There is, however, some epidemiologic evidence that
prolonged exposure to higher levels of power frequency magnetic fields is associated with a small
risk of leukaemia in children. … In the absence of clear evidence of a carcinogenic effect in adults,
or of plausible explanation from experiments on animals or isolated cells, the epidemiological
Electric and magnetic fields – Appendix E of Environmental Assessment - EnergyAustralia
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evidence is currently not strong enough to justify a firm conclusion that such fields cause
leukaemia in children. Unless however, further research indicates that the finding is due to chance
or some currently unrecognized artifact, the possibility remains that intense and prolonged
exposures to magnetic fields can increase the risk of leukaemia in children.” [p. 164]
100 2000 Swedish Council for Work Life Research Health Risks of EMF - Electromagnetic
hypersensitivity and health risks from electric and magnetic fields. Research review and
evaluation.
“Extremely low frequency magnetic fields, i.e. between 1 and 300 Hz, are regarded as possible
carcinogenic factors, primarily based on the results of epidemiological studies. This evaluation is
based on studies of leukemia in children living close to power lines, and studies of primarily
chronic lymphatic leukemia among adults who in their work are exposed to elevated magnetic field
levels. Concerning other cancer forms, scientific data are currently insufficient for any conclusions
to be drawn. For neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), and
diseases in the cardiovascular system, some indications for effects of occupational exposure to
extremely low frequency magnetic fields exist, but these indications are currently insufficient for
conclusions.” [p. 3]
99 2000 Virginia Department of Health Division of Health Hazards Control - Monitoring of
Ongoing Research on the Health Effects of High Voltage Transmission Lines (Final Report)
“Based on the review and analysis of the exhaustive literature review and other research projects
completed under the EMF-RAPID program, the Virginia Department of Health is of the opinion that
there is no conclusive and convincing evidence that exposure to extremely low frequency EMF
emanated from nearby high voltage transmission lines in causally associated with an increased
incidence of cancer or other detrimental health effects in humans.”[p. 20]
98 2000 Australian Department of Health and Community Services Radiation Advisory
Committee of Victoria - Annual Report of the Radiation Advisory Committee for the year
ending September 2000
“The additional evidence concerning health effects of electromagnetic fields reviewed by the
Committee during the past year has not been sufficiently compelling to alter the Committee’s
position concerning the issue. That is that, overall, there is insufficient evidence to come to a firm
conclusion regarding possible health effects from exposure to power frequency electric and
magnetic fields.” [p. 21]
97 2000 Health Council of the Netherlands ELF Electromagnetic Fields Committee - Exposure
to electromagnetic fields (0 Hz – 10 MHz)
“The concern that is regularly voiced over supposed dangers of exposure to ELF EM fields is, in
virtually every case, based on outcomes of the epidemiological research. The Committee finds that
the quality of that research has improved substantially in recent years. However, it has not yet led
to unequivocal, scientifically reliable conclusions. … Based on the totality of the results from
epidemiological research, and taking into consideration the strengths and weaknesses of the
different studies, the Committee believes that there is a reasonably consistent association between
the occurrence of leukemia in children and residence near overhead power lines (both high voltage
and distribution lines). As has already been indicated, however, the date does not point directly to a
causal link with exposure to ELF EM fields.”[p. 41, 43]
96 2000 American Conference of Governmental Industrial Hygienists - TLVs and BEIs
“At this time, there is insufficient information on human responses and possible health effects of
magnetic fields in the frequency range of 1 Hz to 30kHz to permit the establishment of a TLV for the
time-weighted average exposures.” [p. 147]
95 1999 U.S. National Institute of Environmental Health Sciences U.S. National Institutes of
Health - Health Effects from Exposure to Power-Line Frequency Electric and Magnetic Fields
“The NIEHS believes that the probability that ELF-EMF exposure is truly a health hazard is currently
small. The weak epidemiological associations and lack of any laboratory support for these
associations provide only marginal, scientific support that exposure to this agent is causing any
degree of harm. The NIEHS concludes that ELF-EMF exposure cannot be recognized as entirely safe
because of weak scientific evidence that exposure may pose a leukemia hazard. In our opinion, this
finding is insufficient to warrant aggressive regulatory concern.” [p. 36]
94 1999 Florida Department of Environmental Protection - 1999 Annual Report on EMF
Research
Electric and magnetic fields – Appendix E of Environmental Assessment - EnergyAustralia
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“The overall conclusion of the Department’s review of the literature and the material presented at
conferences is that here is still not conclusive scientific evidence of adverse health effects. There is
no justification to warrant revising our regulatory standards.” [p. 5]
93 1999 American Conference of Governmental Industrial Hygienists - TLVs and BEIs
“At this time, there is insufficient information on human responses and possible health effects of
magnetic fields in the frequency range of 1 Hz to 30kHz to permit the establishment of a TLV for the
time-weighted average exposures.” [p. 143]
92 1999 U.S. National Academy of Sciences National Research Council - Research on PowerFrequency Fields Completed Under the Energy Policy Act of 1992
“We conclude that no finding from the EMF-RAPID program are alters the conclusion of the
previous NRC review on the Possible Effects of Electromagnetic Fields on Biologic Systems (NRC
1997). In view of the negative outcomes of EMF-RAPID replication studies, it now appears even less
likely that MFs in the normal domestic or occupational environment produce important health
effects, including cancer.” [p. 8]
Electric and magnetic fields – Appendix E of Environmental Assessment - EnergyAustralia
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Attachment 2 – Computer
modelling and calculation of
magnetic fields from 132kV
(Aust) International Pty. Ltd.
Electric and magnetic fields – Appendix E of Environmental Assessment - EnergyAustralia
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