Resource Documents: Noise (492 items)
Documents presented here are not the product of nor are they necessarily endorsed by National Wind Watch. These resource documents are provided to assist anyone wishing to research the issue of industrial wind power and the impacts of its development. The information should be evaluated by each reader to come to their own conclusions about the many areas of debate.
Author: Kenny, Pamela
Would I say this?:
Hundreds of thousands of people around the world live near and work at operating wind turbines without health effects. Wind energy enjoys considerable public support, but wind energy detractors have publicized their concerns that the sounds emitted from wind turbines cause adverse health effects. These allegations of health-related impacts are not supported by science. Studies show no evidence for direct human health effects from wind turbines.
It is certainly not me talking.
It is the claim of the American Wind Energy Association (AWEA), the national trade association for the U.S. wind industry. Wind power developers and their lobby groups around the world are shouting the same message – that the noise and vibration (infrasound, sound pressure, and low frequency noise) produced by large-scale wind turbines produce no direct health effects.
In reality, their claim is a lie. There is an ocean of documented evidence to support the assertions of anti-wind campaigners that the noise and vibration from wind turbines causes a range of health problems in significant numbers of people. If you search for just a couple of hours online, you can find personal stories by the thousand, and also numerous highly technical research papers by eminent medics and scientists detailing, amongst others, these symptoms:
- Chronic sleep deprivation
- Sleep disturbance
- Increased blood pressure
- Increased blood sugar (dangerous for diabetics)
- Poor concentration and memory
- Headaches and migraines
- Dizziness, unsteadiness, ear pain and vertigo
- Vibration in the body, particularly the chest
- Sensations of pressure or fullness in the ear
- Annoyance, anger and aggression
- Increase in agitation by those with Autistic Spectrum Disorder, and ADD/ADHD
Some of these symptoms can be attributed to sleep deprivation. It is increasingly clear from peer- reviewed medical papers that night noise interrupting sleep has an adverse effect on both cardiovascular health and stress levels. Interrupted sleep can also have serious effects on daytime concentration leading, potentially, to increased risk of industrial accidents and road traffic collisions. As these problems are likely to occur at locations remote from the cause of the interrupted sleep they are difficult to attribute to their actual cause. Dr. Christopher Hanning, a now-retired Consultant in Sleep Disorders Medicine to the University Hospitals of Leicester NHS Trust, writes:
In the short term … deprivation of sleep results in daytime fatigue and sleepiness, poor concentration and memory function. Accident risks increase. In the longer term, sleep deprivation is linked to depression, weight gain, diabetes, high blood pressure and heart disease.
I do not pretend to be an expert in the effects of noise, but I do know that in over 30 years as a GP I have seen countless patients presenting with the effects of insomnia, and shift workers in particular suffer far more than the general population with the effects of disturbed sleep. What I find astonishing is that the noise regulations for the wind industry permit MORE noise to be generated by the turbines at night than during the day. This is completely contrary to noise pollution legislation, World Health Organisation (WHO) guidelines – and common sense.
Other symptoms listed above are likely to be a response to exposure to infrasound (sound with a frequency of less than 20 Hz) and low frequency noise (sound with a frequency of less than 200 Hz) produced by the turbines. Both low frequency noise and infrasound occur naturally in the environment (for instance, from household appliances and machinery in the case of low frequency noise, and ocean waves in the case of infrasound). In periods when the wind is blustery, large wind turbines generate both very low frequency sounds and infrasound which can travel much greater distances than audible sound. These sounds are not audible to the human ear, but our brains certainly detect them and some susceptible people suffer some of the unpleasant symptoms I have listed, such as tinnitus, ear pain and vertigo. If you feel up to reading some technical, but very interesting, research on this subject, take a look at “Wind-Turbine Noise. What Audiologists Should Know” by Punch, James and Pabst, published in the American publication Audiology Today in 2010.
Other reasons why people experience health impacts from wind turbines include the swishing or thumping of the blades, which is highly annoying as the frequency and loudness varies with changes in wind speed and local atmospheric conditions. This is not at all like the sound of a passing train, aeroplane or tractor which moves on rapidly to be replaced by less intrusive background sounds. The noise of wind turbines has been likened to a “passing train that never passes” which may explain why it is prone to cause sleep disruption.
Some of those with heightened sensitivity to specific repetitive stimuli, such as those with Autistic Spectrum Disorder, Attention Deficit Disorder or Attention Deficit Hyperactivity Disorder (ADD/ADHD), can be seriously affected by the noise. Consultant clinical psychologist Dr. Susan Stebbings, from the Lincolnshire Partnership NHS Trust, said more research was needed into wind turbine noise and these disorders:
Because it is clear from our clinical knowledge of the condition of autism that the sensory difficulties individuals can have are possibly going to be impacted on by the presence of such large sensory objects in their environment.
Indeed, there is at least one case on record of a wind farm application being turned down because of the proven impact on children with autism.
Then there is shadow flicker or strobing which occurs when the rotating blades periodically cast shadows through the windows of properties. This can be truly unpleasant to live with and can trigger migraine and – much more rarely – epileptic fits in those suffering from photosensitive epilepsy. At night, the red warning lights on the tops of some turbines can cause blade glint and strobing effects, so it is not just a daytime phenomenon.
Then there is the effect of stress. If you live in a tranquil rural area like ours, where the daytime and night time noise levels are almost always very low, you may well suffer varying levels of stress from the imposition of industrial-scale wind turbines into the landscape. The stress can occur long before the turbines are erected: during the planning process; during the noise and disruption of the construction; when you see the turbines for the first time and cannot believe the scale of them; and, then, during their operation when your sleep is disrupted and other physical and mental symptoms present themselves.
The effects of wind turbine noise have been known for several years now. In February 2007, a Plymouth GP, Dr. Amanda Harry, published a report “Wind Turbines, Noise and Health”. The report documents her contacts with 39 people living between 300 metres and 2 kilometres from the nearest turbine of a wind farm. She discovered symptoms such as those I have outlined experienced by people living up to 1.6 kilometres from the wind farms.
The wind industry has repeatedly tried to discredit Dr. Harry’s report, and another – published in 2009 – by a leading American Pediatrician Dr. Nina Pierpont, who coined the phrase “Wind Turbine Syndrome” to cover the range of health problems she investigated over five years in the US, the UK, Italy, Ireland and Canada. The global wind industry also spends vast sums attempting to discredit scientifically sound research studies, and the papers of experts in the physiology of the ear that prove infrasound can have adverse effects despite it not being audible.
It is true that both Dr. Harry’s and Dr. Pierpont’s research is largely anecdotal and does not reach the high standards needed for statistical validity. However, that also applied to reports on the association between lung cancer and smoking, and asbestos and asbestosis, in the early days.
We have now reached the stage in the debate when there can be no reasonable doubt that industrial wind turbines – whether singly or in wind farms – generate sufficient noise to disturb the sleep and impair the health of those living nearby. In fact, our own Government has long been fully aware of the problems, as demonstrated in a 2008 Economic Affairs Committee Memorandum by Mr Peter Hadden, which concludes that:
onshore wind turbines built within 2km of homes offer no benefits and should not be part of a plan to provide the UK with a viable, secure, predictable supply of electricity. Indeed, onshore wind turbines ensure an unpredictable energy supply, by the very nature of the wind, with a long list of adverse impacts that diminish their supposed usefulness. Other renewables, such as solar and hydropower, offer more options and more predictability, especially combined with the still necessary (and technologically advancing) conventional sources of energy.
I find it unbelievable that the wind industry is permitted to inflict health nuisance such as sleep disturbance, stress, and headaches on our communities – let alone more serious health issues such as depression, and heart and diabetes problems. To suggest, as the wind industry does, that there is “no problem” when faced with the huge body of evidence from around the world is perverse.
What sums up this entire problem for me is the quote below. It is by Dr. Noel Kerin of the Occupational and Environmental Medical Association of Canada. He was attending the First International Symposium on Adverse Health Effects and Industrial Wind Turbines, held in Canada in October 2010. He was shocked by the overwhelming evidence on the harmful effects of wind turbines:
First we had tobacco, then asbestos, and urea formaldehyde, and now wind turbines. Don’t we ever learn? Our public health system should be screaming the precautionary principle. The very people who are sworn to protect us have abandoned the public.
My extensive reading into the harmful effects of wind turbines leaves me in no doubt that, to protect our community, we need to oppose the erection of three 125 metre turbines on Berry Fen.* Quite aside from the damage to our beautiful landscape, our tranquillity, our tourism industry, and wildlife, this wind farm would have serious implications for the health of many who live and work here for the entire 25-year life of the wind farm, and well beyond.
Pamela Kenny, MB BS, MRCS LRCP, FIMC RCSEd
Dr. Pamela Kenny was a founder of the current Haddenham and Stretham GP surgeries in 1986. She retired from practice there in 2006, but continued to work in Cottenham and St Ives and is a Trustee of the emergency medical service MAGPAS. Dr. Kenny has always had an interest in how lifestyle factors affect patient’s health, and continues to do so in the interests of the community. She has immense sympathy with anyone who might be affected by any form of flicker as she has always suffered from flicker-induced migraine. She also has the kind of hearing that is super-sensitive to both high and very low sound.
*There is still time to object to the planning application [the deadline has been extended to 3rd September 2014]. You do not have to write a long letter – just a couple of points outlining why you object – and every single person in your household should write individually as the number of objections will make a difference. Whichever method you choose, please include your name and full postal address, and the Planning Application Number 14/00728/ESF:
- Send your objection by email to firstname.lastname@example.org
- Or write to: Mrs Penny Mills, Planning Officer, East Cambs District Council, The Grange, Nutholt Lane, Ely, CB7 4EE
- Or drop off to the following addresses: Simon Monk, Dunelm House, 4d The Borough, Aldreth; and Ian Munford, 4 Orchard Way, Haddenham.
Author: Krahé, Detlef; Schreckenberg, Dirk; Ebner, Fabian; Eulitz, Christian; and Möhler, Ulrich
This feasibility study evaluated the state of knowledge about the effects of infrasound on human beings, the identification of infrasound sources and the potential concerns in Germany due to infrasound. Furthermore, a study design was developed for a noise impact study concerning infrasound immissions. Based on these findings, recommendations for the further development of regulations on immission control were made. The study led to the following conclusions:
- The literature review does not present a coherent picture about the determination and assessment of low frequency sounds. Especially in Germany, there are just a few studies that deal with infrasound. A database was created for further research projects.
- Survey tools that allow for an initial acoustic description and classification were developed for the acoustic identification and assessment of potential infrasound sources.
- The surveys of the immission control authorities of the Länder (German states) and the evaluation of Internet communication on infrasound show a somewhat higher level of noise pollution in Southern Germany. Above all, noise pollution from air-conditioning systems and biogas facilities were mentioned. In the official practice, the Technical Instructions on Noise Abatement and DIN 45680 generally apply in cases of conflicts concerning infrasound.
- A study design was developed for an interdisciplinary field study and the essential survey contents and sources were defined.
- The DIN 45680 Measurement and Assessment of Low Frequency Noise Immissions in the Neighbourhood can be used for the assessment of low frequency noise (<100 Hz). The international standard ISO 7196 Acoustics – Frequency-Weighting Characteristic for Infrasound Measurements was especially created for the measurement of infrasound immissions (<20 Hz). The research findings indicate that these standards have deficits with regards to the assessment of infrasound and should be further developed. The current revision of DIN 45680 shows a path for how inconsistencies in the area of low frequency sounds can be rectified.
—June 2014, Umweltbundesamt (Federal Environmental Agency, Germany)
Download original document: “Machbarkeitsstudie zu Wirkungen von Infraschall: Entwicklung von Untersuchungsdesigns für die Ermittlung der Auswirkungen von Infraschall auf den Menschen durch unterschiedliche Quellen”
Author: Fox Islands Wind Neighbors
It is a sad spectacle for the citizens of the State of Maine (and more than that for the Fox Islands Wind Neighbors, the “Neighbors”) to see the Department of Environmental Protection (the “DEP”), the state agency charged with the responsibility to protect us from environmental harm, align itself with Fox Islands Wind, LLC (“FIW”) to grant a de facto exemption from the Noise Rule and then responding in court with claims that it has the absolute right to do so without judicial oversight. It is even worse that the Commissioner responsible for this was in a highly compromised position, having been employed as an industry lobbyist for the very same law firm asking for such special treatment weeks before she issued the Condition Compliance Order (the “CCO”) at issue in this appeal.
A. Issues about Excessive Noise in Connection with the Licensing of the Project.
B. Noise Complaints Following Commencement of Operations.
C. DEP’s Finding of Non-Compliance and FIW’s Refusal to Cooperate.
D. Events Leading to the Challenged Condition Compliance Order.
I. The Superior Court correctly ruled that it had jurisdiction over the petition for review and that the neighbors have standing.
II. The Superior Court correctly ruled that the CCO is unlawful.
III. The Superior Court erred by dismissing the neighbors’ First Amendment retaliation claim.
For the reasons stated above, the Neighbors respectfully request this Court to affirm the decision of the Superior Court that the CCO is invalid as a product of arbitrary and capricious action, without substantial evidence to support it, and an abuse of discretion and hold that the Neighbors have established a valid First Amendment retaliation claim under Rule 80C, with allowance for an award of attorney’s fees or, in the alternative, that they have set forth a plausible claim under Section 1983 of First Amendment retaliation that may proceed on as an independent claim. The Neighbors further request that the matter be remanded back to the Superior Court so that the matter can be remanded to the DEP with detailed instructions on the parameters of a valid CCO.
Dated: August 5, 2014
Rufus E. Brown, Esq.
BROWN & BURKE
Attorney for the Fox Islands Wind Neighbors and the Individual Petitioners
Author: Waubra Foundation
Emission of Sound and Vibration
Note: ILFN = infrasound and low-frequency noise.
1. Wind turbine blades produce airborne pressure waves (correctly called sound but which, when unwanted, is called noise) and ground-borne surface motion (vibration).
2. Recent measurements have indicated that turbines generate vibrations even when shut down, presumably from the wind causing the flexing of large blades and the tower structure, and that this vibration (when turbines are shut down) can be measured at significant distances.
3. The airborne energy manifests as sound across a range of frequencies from infrasonic (0–20 Hertz [Hz]) up through low-frequency sound (generally said to be below 200 Hz), and into the higher audible frequency range above 200 Hz. (Hertz is the variation in a particular changing level of sound pressure, as the rate of cycles [or period] per second).
4. Sound at 100 Hz is audible at sound levels of around 27dB (decibels) for an average person, whilst the level of sound required for average audibility rises quite quickly below frequencies of, say, 25 Hz. Sensation, being non-auditory but bodily recognition of airborne pressure waves, occurs at lower pressure levels of infrasonic frequencies than can be heard. At infrasonic frequencies the “sounds,” i.e., pressure waves, exist and may be detected by the body and brain as pressure pulses or sensations, but via different mechanisms than the perception of audible noise.
5. Periodic pressure pulses are created by each turbine blade passing the supporting pylon. This is an inherent consequence of the design of horizontal axis wind turbines. These energy pulses increase with increasing blade length, as does the power generating capacity. People living near turbines have described the effect of these pulses on their homes as “like living inside a drum”.
6. Larger turbines produce a greater percentage of their total sound emissions as low-frequency noise and infrasound than do smaller turbines. Therefore replacing a number of small turbines with a lesser number of larger turbines, whilst keeping the total power output of a wind project constant, will increase the total ILFN emitted by the development. This effect will be compounded by increased wake interference, unless the turbines have also been repositioned further apart in accordance with the spacing specifications for the larger turbines. Wake interference results in turbulent air flow into adjacent turbines, with a consequent loss of efficiency, and increased ILFN generation.
7. If estimated sound contours have been used in seeking planning permits, then replacing the permitted turbines with larger turbines will significantly increase the persistence of the wake turbulence, and thereby the sound emitted by adjacent turbines (and the proportion of ILFN emitted) will be significantly above the predicted contours. This is what occurred at the Waubra development, and will occur when a lesser number of larger turbines are used to maintain the generating capacity of the development, as occurred at Macarthur (both projects being in Western Victoria).
1. Infrasound is common in our world, but most natural infrasound is irregular and random, or is caused by a transient event (e.g. earthquakes). Some frequency bands below 20 Hz have been shown experimentally to cause a physiological stress response in humans at below audible levels. Industrial machinery noises are often regular and repetitive, as is the case with wind farm noise emissions, across the audible and infrasonic frequency spectrum.
2. Infrasonic pulsations travel much larger distances than audible noise and easily penetrate normal building materials, and once inside can resonate building elements (i.e., increase in impact inside rooms).
3. Infrasonic pulsations from a single 4 MW wind turbine were measured 10km from their source by NASA researcher William Willshire in 1985. Recent data collected by acoustician Les Huson in Australia and in the United Kingdom at onshore and offshore wind developments has shown that attenuation (reduction in sound level with increasing distance from the source) can be much less than the 3dB per doubling of distance found by Willshire in 1985.
4. Some acoustic pressure pulsations are relatively harmless and indeed even pleasant to the body, including waves on a beach. Organ music at frequencies just below 20 Hz generates “feelings” in people that can be either pleasant or unpleasant, and has been designed to produce emotive effects. Once it is understood that different frequencies can have very different effects on humans, it is easy to understand the importance of accurate acoustic measurement.
5. Dr Neil Kelley and his colleagues from NASA demonstrated in the 1980’s that wind turbine–generated energy pulses and noise in the infrasonic and low-frequency bands, which then penetrated and resonated inside the residents’ living structures, directly caused the range of symptoms described as “annoyance” by acousticians and some researchers. A more accurate general descriptor would be mild, serious or intolerable “impacts”.
6. Residents and their treating medical practitioners know these symptoms and sensations include repetitive sleep disturbance, feelings of intense anxiety, nausea, vertigo, headaches, and other distressing symptoms including body vibration. American Paediatrician Dr Nina Pierpont gave this constellation of symptoms the name “wind turbine syndrome” in 2009. Dr Geoff Leventhall, a British acoustician who was one of two peer reviewers of the NHMRC’s 2010 Rapid Review, has accepted these symptoms and sensations as “annoyance” symptoms, which he attributes to a stress effect, known to him to be caused by exposure to environmental noise, one source of which is wind turbine noise.
Wake Interference and Turbulence
1. Historically it was accepted that wind turbines should be no less than 5–8 rotor diameters apart, depending on the direction and consistency of the prevailing wind, with the higher separation being for turbines in line with the major wind direction. This was accepted industry practice and, as an example, was explicitly specified in the 2002 NSW SEDA handbook. The purpose of this specification is to minimise turbulent air entering the blades of an adjacent turbine. As noted above, turbulent air is associated with increased sound levels and infrasonic pulsations.
2. If a significant proportion of the wind blows at a right angle (90°) from the major direction used for turbine layout it follows that turbine spacing should be 7 or 8 rotor diameters in both directions. It should be noted that the 7–8 rotor diameters number is a compromise between ensuring smooth air inflow to all turbines (and hence less noise and vibration) and packing as many turbines as possible into the project area. Research conducted at Johns Hopkins University in 2012 showed that the best design for efficient energy extraction suggests wind turbines should be 15 rotor diameters apart.
3. It is increasingly evident that some projects are not laid out in accordance with accepted specifications to reduce turbulence, which in turn significantly increases acoustic emissions including audible noise and infrasonic pressure pulses. The consequences of increased turbulent air entering upwind-bladed wind turbines resulting in increased generation of impulsive infrasonic pressure waves and low-frequency noise were known to the industry in 1989. Recent projects with turbines positioned inappropriately too close together should not have been given final approval by the responsible authorities.
4. Yawing (side to side movement of the blades caused by minor wind direction changes) is also known to increase wake interference.
Transmission of Energy Pulses
1. Information on the different attenuative and penetrative properties of infrasound and audible sound are discussed above.
2. Topography, wind speed, wind direction, wind shear, and ambient temperature will also have an impact on noise emissions and how that sound travels.
Noise Guidelines for Turbines
1. Many acoustic consultants and senior acousticians have known that wind turbines produce pulsatile ILFN as the blades pass the tower. It was common knowledge in the 1980’s, from research conducted by Dr Neil Kelley  and NASA researchers such as Harvey Hubbard, that the pulsatile infrasound generated by a single downwind-bladed wind turbine and other sources of ILFN such as military aircraft and gas fired turbines penetrated buildings, amplified and resonated inside the building structures, and directly caused “annoyance” symptoms including repetitive sleep disturbance.
2. Long-term sleep disturbance and chronic stress symptoms (accepted as “annoyance” symptoms), are well known to medical practitioners and clinical researchers to damage human health. Dr Kelley was quoted in 2013 as advising that the conclusions from his research in the 1980’s were equally relevant to modern turbine designs, and this seems to have been confirmed in the preliminary results of acoustic measurements commissioned by Pacific Hydro and conducted by acoustician Steven Cooper at the Cape Bridgewater (Victoria) development.
3. The New Zealand and Australian Noise Standards for wind projects were written by the then uninformed planning authorities. They were based on the UK ETSU 97 standard, also an uninformed document.[20,21]
4. Despite information being available from the Kelley research in 1985 specifying recommended exposure levels of ILFN which should not be exceeded, the respective Australian guidelines only specified limits for audible, filtered, sound levels expressed as dBA outside homes; so there are no recommended limits or requirements to forecast, or to measure, ILFN levels or vibration inside homes neighbouring wind projects.
5. Permitted sound levels across most Australian States for all industrial equipment are background noise levels plus 5dBA or 35dBA whichever is less, whereas for wind turbines they are background plus 5dBA or 40dBA whichever is more. There is no scientific evidence or reason for this difference. An increase of 5dBA represents an approximate doubling of the sound level. Most rural environments have a background noise level of 18dBA to 25dBA, approximately averaging 22dBA at night. This represents a huge increase in audible sound. Increases of 10dBA at night are long known by acoustic consultants to raise complaints, and increases of 15–20dB are associated with widespread complaints and legal action. Averaging measured levels of sound across too-wide frequency bands also allows the hiding of sound pressure (level) peaks to which the ear responds, understating the true extent of facility noise emission levels.
6. World Health Organisation (WHO) Night Noise Guidelines for Europe quoted the 1999 WHO Community Noise Guidelines: “If negative effects on sleep are to be avoided the equivalent sound pressure level should not exceed 30 dBA indoors for continuous noise”. Cities have a higher background noise than country areas. Denmark limits indoor noise from industrial sources, including wind turbines, to a maximum of 20 dBA at night.
7. The currently permitted outdoor noise level in New Zealand and some Australian states has been ameliorated somewhat by the addition of a deduction of 5dBA from the 40dBA limit to allow for especially quiet environments.
8. History has shown that these Australian guidelines were based on ETSU 97 from the UK, and were expressly designed to encourage development of the wind industry, not to protect the health of rural residents from wind turbine noise. Predictably, because the Kelley criteria limiting exposure to impulsive ILFN were ignored, these guidelines have turned out to be completely unsafe.
9. It is therefore necessary to predict and measure sound pressure levels across the full spectrum of frequencies in order to predict and control sound energy impacts on project neighbours.
Compliance with Permitted Noise Conditions
There are several problems associated with validating compliance.
1. Compliance is generally carried out by an acoustician or acoustics consultancy, paid directly by the owner or operator of the project. In one case a wind turbine manufacturer has contracted the acousticians directly, making the results even more questionable.
2. Compliance is of utmost importance to all parties with a financial interest in the development, but it is critical to families that neighbour the projects.
3. There are many ways that data measurements can be rigged (faux compliance): measuring instruments placed under trees or too close to buildings; waiting for optimum weather and wind conditions; not measuring for long enough continuously, recording in octave bands that are too broad and other averaging techniques. Operators may also reduce operational noise by reducing power output (with blade angle changes and slowed rotation) to reduce the noise during the monitoring period. Operators may also refuse to provide wind turbine facility operating data from test periods, claiming that it is “commercial in confidence”, thus making it impossible to verify actual operating conditions.
4. It would therefore be both appropriate and necessary for all projects to have their compliance independently audited.
5. Sufferers will not escape disturbance to their sleep and damage to their health even if a project is properly compliant with its permit conditions and noise guidelines, as preliminary findings of the acoustic survey commissioned by Pacific Hydro, conducted by Steven Cooper, have recently demonstrated.
6. A compliant project may still cause damage to neighbours for numerous reasons. First, the standard refers to dBA only and thereby omits reference to ILFN; and second, even with regard to audible noise, the standard refers to a maximum of 40dBA outdoors, whereas every other form of industrial or other noise in country and city is limited to 35dBA maximum. There is no technical basis for such an aberration, and it is clearly (intended or not) discriminatory. Third, in quiet rural environments, even 35dBA will be intrusive and loud if the background level is below 25dBA, which is not uncommon. The ear responds to the peaks of sound levels, not the averages. The wind turbine noise standards all refer only to averages, and exclude ILFN, and do not account for the human response, so cannot protect people from predictable serious harm to their health.
23. http://waubrafoundation.org.au/resources/who-night-noise-guidelines-for-europe/ – See p 110 for background to 30dBA inside bedrooms – sourced from the 1999 WHO Community Noise document, which can be accessed at http://waubrafoundation.org.au/resources/who-guidelines-for-community-noise-2/
24. http://waubrafoundation.org.au/resources/sa-epa-resonate-infrasound-levels-near-windfarms-other-environments/ – See p 9 for the Danish LFN criteria indoors overnight
25. http://waubrafoundation.org.au/2013/explicit-warning-notice/ – See footnote number 10