Wind farms
This brochure provides information about
noise generated by wind farms and its
possible effects on human health. The WA
Department of Health has examined the
current evidence on the impact of wind
farms on public health, and current
management strategies in Western
Australia for wind farm developments.
Noise
Noise, as defined by enHealth, is any
undesirable or unwanted soundi. Noise
perception depends on the sensitivity of the
individual, and factors such as the character
of the noise, attitude to the noise source
and degree of control over the sound.
Environmental noise (also known as noise
pollution) can be caused by air and road
transport and industrial, commercial and
domestic activities.
Sound pressure is the pressure felt by the
ear drums to register noise. This is
measured in decibels (dB). The table below
gives an indication of common noise
sources and their levels:
Source
Lowest normal audible level
Very quiet rural area
Rural area, distant traffic
Typical wind farm at 1km
Light wind in trees
Strong wind in trees
Normal conversation
Children playing
Footpath, busy street
dB(A)
0
20
30
35 - 40
40
50
60
70
80
The reception of sound by individuals
depends on existing background noise
levels, topography, distance and wind
speed and direction.
Sound frequency or pitch, is measured in
Hertz (Hz). It is generally accepted that
people hear frequencies between 20 to
20,000 Hz, although this varies with age
and environmental factors.
Infrasound is sound with a frequency less
than 20 Hz and is lower than the normal
frequency range for human hearing. It can
be produced by a variety of natural and man
made sources such as wind, breaking
waves, vehicles and air conditioning. People
who report detecting infrasound may
mention the non-specific symptoms of
stress and annoyance, including
headaches, nausea and loss of sleep.ii
However, these non-specific symptoms are
also symptoms of a number of other
physiological and psychological conditions.
Health and noise
The effects of environmental noise on
health are normally assessed in studies
carried out on large populations. Exposure
to environmental noise can have proven
impacts on amenity and health, including
sleep disturbance, annoyance; and in some
circumstances can put people at a greater
risk of cardiovascular disease and affect
cognitive development in children.iii
Wind farms and noise
Wind farms were generating 63% of
Western Australia’s renewable energy in
2009/10.iv
A wind farm can create noise from the:
•
construction
•
mechanics of the wind turbine
generators
•
movement of the rotor blades through
the air.
The movement of rotor blades causes the
distinctive ‘swish’ noise and is the most
noticeable source from wind farms.
Wind farm noise and health
The National Health and Medical Research
Council (NHMRC) states that there is
currently no published scientific evidence to
positively link wind turbines with adverse
health effects.v This is supported by a
review of the literature by Knopper and
Ollison in 2011vi, and the Chief Medical
Officer in Ontario, Canada.vii
Annoyance was also found to be dependant
on a person’s sensitivity to noise.
Annoyance can lead to such health effects
as headaches, stress and sleep
disturbance. The studies indicated that
these health effects were attributed to the
change in the environment, not directly from
wind farm noise itself.
Shadow flicker and blade glint are two other
features of wind turbines that have been
associated with health effects. The impact
of these has been found to be negligible.x
Some people are concerned that infrasound
can have an effect on their health. The
modern design of turbines produces very
low levels of infrasound, well below the
perception threshold.xi There is currently no
scientific evidence that infrasound – at the
levels received from wind farms – has an
impact on human health.xii The stress
associated with perceived impacts can in
itself be considered a health effect.
In June 2011, the Senate Community Affairs
References Committee recommended a
number of actions following its inquiry into
the social and economic impacts of wind
farms including:
•
Measures to calculate the impact of
low frequency noise.
Some people living near wind farms have
reported health effects such as sleep
disturbances, headache, tinnitus, nausea,
irritability and problems concentrating.
However, this has not been scientifically
proven to be caused by wind farm noise.
•
Expeditious response to complaints
through an independent arbitrator.
•
Further consideration be given to the
development of policy on separation
criteria between residences and
wind farms.
Scientific literature concludes that wind
farms can be a source of annoyance for
some people. Studies in The Netherlandsviii
and Swedenix found that annoyance was
strongly correlated with negative attitudes
towards the visual impact of the wind farms.
•
Further research into human health
and wind farms, regular reviews by
NHMRC and the National Acoustics
Laboratories assess noise impacts
from wind farms, including
infrasound.
The WA Department of Health supports the
ongoing review of research into the health
impacts of wind farms and consultation with
the health sector on development of wind
farm policy.
new wind farm developments should be
constructed and designed to ensure that
noise generated will not exceed the higher
of the following limits at surrounding noisesensitive premises:
•
35dB(A) at night in rural living areas, at
low wind speeds; or
•
5dB(A) above the background sound
level at higher wind speeds.
Resources
A number of guidelines and regulations
have been implemented in WA to ensure
that social and environmental impacts from
wind farms are managed effectively.
§
The WA Planning Commission (WAPC)
developed the Planning Bulletin 67,
Guidelines for Wind Farm Development
in 2004 for new wind farms. The
guidelines balance environmental, social
and economic benefits with
environmental, landscape and amenity
impacts, such as noise.
To minimise noise to surrounding
environments, the guidelines
recommended proposed developments
include buffer zones and set backs
determined on the basis of acoustical
studies. Proponents are encouraged to
undertake noise modelling to assist
planning authorities in determining the
acceptability of the proposal.
§
Environmental noise is regulated under
the Environmental Protection Act 1986
and the Environmental Protection
(Noise) Regulations 1997 which require
compliance with base noise levels.
§
Additional guidance on wind farm noise,
developed by the WA Environmental
Protection Authority in its Guidance No.8
– Environmental Noise, refers to the
South Australian Environmental
Protection Authority Wind Farms
Environmental Noise Guidelines 2003.
The WA noise regulations and the South
Australian guidelines together specify that
As wind farm noise increases with wind
speed, these criteria account for both low
and high wind conditions.
Nationally, the Environmental Protection
and Heritage Council advised on best
practice methods for assessing wind farm
developments, through the National Wind
Farm Development Guidelines (Draft). The
WA Department of Environment and
Conservation uses the method set out in
this document for assessing infrasound
noise emissions from wind farms.
Further information
•
NHMRC Wind turbines and health:
Rapid Review of the Evidence, July
2010.
•
The Western Australian Planning
Commission, Guidelines for Wind Farm
Development, Planning Bulletin 67, May
2004.
References
i
enHealth, The health effects of environmental noise
– other than hearing loss. 2004
ii
Health Protection Agency: Health Effects of Exposure to
Ultrasound and Infrasound, February 2010.
iii
World Health Organisation: The Burden of Disease from
Environmental Noise, 2011
iv
Government of Western Australia: Office of Energy.
v
NHMRC Wind turbines and health: Rapid Review of the
Evidence, July 2010.
vi
Knopper and Ollison: Health Effects and Wind Turbines:
A Review of the Literature. Environmental Health 2011
10:78
vii
Chief Medical Officer of Health (CMOH) Ontario: The
Potential Health Impact of Wind Turbines 2010.
viii
Pedersen E, van den Berg F, Bakker R, Bouma J:
Response to noise from modern wind farms in The
Netherlands. J Acoust Soc Am 2009, 126:634-64
ix
Pedersen E, Persson Waye K: Wind turbine noise,
annoyance and selfreported health and well-being in
different living environments. J Occup Environ Med 2007,
64:480-486.
x
Environmental Protection and Heritage Council: National
Wind Farm Development Guidelines – Draft. July 2010.
xi
Jakobsen J: Infrasound Emissions from Wind Turbines.
Journal of Low Frequency Noise, Vibration and Active
Control, 2005, 24(3): 145 – 155.
xii
Leventhall G: Infrasound from Wind Turbines: Fact,
Fiction or Deception, Canadian Acoustics, 2006, 34(2) 29 36