Frequently Asked Questions

What are the health problems?

Chronic severe sleep disturbance is the most commonly reported health problem. This is caused by:

  • The audible noise keeping people awake, and
  • Repetitive waking in a panicked state for no obvious reason and then being unable to get back to sleep for hours
  • Children’s sleep disturbance from a variety of causes including night terrors, sore ears, and headaches on nights when the turbines are operating and the wind is blowing in specific directions.

Other symptoms include:

  • Nausea
  • Vertigo
  • Dizziness
  • Painful ear pressure
  • Tinnitus (ringing in the ears)
  • Balance problems
  • Unusual body vibrations in the chest, the abdomen and sometimes the upper lip
  • Extreme noise sensitivity, known as hyperacusis
  • Severe headaches in children and adults
  • Migraines
  • Problems with memory and specific cognitive tasks such as mental arithmetic and multitasking
  • Specific language development problems in young children
  • Worsening diabetes
  • Psychiatric illness is marked and is occurring in people with no previous history of these problems. This includes:
    • severe depression
    • anxiety, and
    • exacerbations of previously well-controlled post traumatic stress disorder (PTSD)
  • Cardiovascular problems being reported include:
    • newly diagnosed high blood pressure, or
    • exacerbation of previously well-controlled high blood pressure
    • previously stable angina becoming unstable
    • arrythmias and tachycardias

While not common, there have been occasional reports of unusual conditions caused by adrenaline surges:

  • Acute hypertensive crisis, and
  • Tako tsubo heart attacks

Interestingly, after subsequent history taking and clinical investigation by the residents’ treating doctors, none of the usual known causes of these episodes were identified as being the cause. Animal studies have shown adrenaline and cortisol are released with exposure to infrasound experimentally.

Further Reading

What is the incidence and prevalence of the reported health problems in populations living near wind turbines?

In short, we don’t know yet. The proper independent comprehensive epidemiological research has not yet been done anywhere in the world, despite these problems being reported for many years, especially in Europe and the UK. Population studies recently conducted in Australia found for example that over 50% of households living within 5km of Waterloo wind development were reporting they were moderately to severely impacted by the noise.

What we do know, however, is that once symptoms are noted, they progress in time, worsening with ongoing exposure. The only way symptoms improve is for people to leave the vicinity of the operating wind turbines. We also know that over time, with ongoing exposure, people previously unaffected start to develop symptoms.

What are the patterns of symptom onset?

Some people are affected immediately and these people include those with a previous history of motion sickness, but this is uncommon. Others, often in the same household, may take months before they notice anything. It appears that some people may never be affected.

A common pattern is that people start to feel non-specifically unwell, or tired, and then they go away or the turbines are turned off for a period of time (at least 24 – 48 hours, but more commonly at least a week), and they start feeling better and more rested with improved sleep. Then they come home again and notice that the problems recur. Once this happens a few times it often becomes clearer to them that their symptoms are related to operating wind turbines.

The longer the period of cumulative exposure, the longer it takes for the symptoms to resolve when away from the turbines.

How far away do the health problems extend?

In Australia, in multiple locations, there are reports of the characteristic pattern of sleep disturbance and the body vibrations occurring at distances at least out to 10km, particularly with larger, taller wind turbines. Similar reports are emerging from the UK and the US, some even suggesting that further distances are involved.

With respect to audible noise, Dr Steve Robinson’s survey at Gloucester revealed that mining noise was disturbing people at night out to 10km away. A recent survey from the Tara Gas field has reported that CSG field compressor noise at night is disturbing people out to 15km away.

Variables that affect the distance at which health problems are reported

There are, however, many variables that can affect this distance and very little truly independent acoustic and clinical data has been collected to help predict it. These variables include the following with respect to wind turbines:

  • Height of turbine
  • Length of blade
  • Power generating capacity of the turbine
  • Individual noise sensitivity
  • Direction of prevailing winds
  • Turbine configuration in relation to the residence
    • turbines in a line with the home downwind at the end of the line can result in a cumulative effect. This appears to result in more rapidly progressive symptoms and worse severity of those symptoms
  • Terrain
    • sound energy appears to travel down/along valleys. Turbines on hills result in sound energy being perceived further away when compared to flat land
  • Weather, including things such as:
    • temperature inversion where cold air acts like a blanket to keep soundwaves along the ground
    • presence of snow or water between turbines and residences, and
    • cloud cover, which is similar to temperature inversion effect in concentrating sound energy at ground level

Can only one wind turbine cause health problems?

The field research commissioned by the US government Department of Energy in 1981, reported by Neil Kelley in 1985 showed that a single wind turbine emitting infrasound and low frequency noise could result in symptoms of annoyance in the occupants of homes 3km away.

Can sound energy from multiple turbines interact?

The acoustic emissions from multiple turbines can interact and if the sound waves reinforce each other they can result in interference patterns and greater peaks and troughs of sound energy. Perceptions of large fluctuations in air pressure or air turbulence like a ‘wake effect’ have also been reported. It is thought that these interference patterns are responsible for the reports some residents and workers have given of experiencing strong physical forces which have knocked them to their knees, felt like a ‘punch in the chest’ or resulted in symptoms of an acute hypertensive crisis.

Are some groups in the population more vulnerable than others?

While far more investigation is required in this area, it appears from empirical research involving direct resident interviews by individuals such as Dr Pierpont (Paediatrician), Dr Daniel Shepherd (Psychologist) and Dr Bob Thorne (Pscyhoacoustician), that some groups are more vulnerable, and develop symptoms earlier. This includes:

  • People with a previous history of motion sickness
  • The elderly
  • Younger children
  • People who are more noise sensitive, such as people with autism, and
  • People with previous eardrum surgery, who appear to be susceptible to some of the ear symptoms

What is the severity of the health problems?

It varies between individuals. Some people are not affected. However for those who are, the following may apply.

  • Some people are eventually so badly affected that they are unable to stay in their own homes and are forced to abandon them. Sometimes they go to live in a shed or a caravan. In other cases they have to rely on friends and relatives, or buy property elsewhere if they can afford to just walk away from their home
  • Others are trapped and unable to move, as they have nowhere to go and no financial resources with which to start over again. They may also be unable to sell their home, which is their major or sole financial asset
  • Sometimes family members become separated, when some are unable to live in the family home because of serious ill health

It is consistently reported that those who have developed symptoms get worse over time. They do not “get used to it”.

What factors affect the severity of the symptoms?

It is consistently reported that:

  • Symptoms are dependent on wind direction and weather conditions at the time, regardless of the source of the noise

It also appears that in the case of wind turbines:

  • There is both a downwind and an upwind effect
  • Days with low lying cloud can be bad
  • Days and nights where there is little wind on the ground, but the turbines are turning with ridge-top wind can be bad
  • Windy rainy days do not appear to be as much of a problem, and
  • Where residents report a perception of vibration, especially through the ground, their symptoms appear to progress more rapidly
    Perceptions of vibration include:

    • the perception of vibrations in their pillows when they are lying down
    • from watching a glass of water ripple, or
    • feeling the vibrations in the structure of their home.

Once again, far more work is needed to measure and quantify both the symptoms and the exposure dose of sound and vibration energy over time.

Do the symptoms change over time?

For those people who develop symptoms, they consistently worsen with continued exposure to operating wind turbines. There is no evidence to support the assertion that people will “get used to it”.

Some people report that when they are subsequently exposed to other sources of low frequency noise (from large compressors for example), they also get many of the identical symptoms they experience when near wind turbines. This is consistent with what acousticians have known for some time about people becoming sensitised to low frequency sound from other sources.

What is causing the reported health problems?

The noise we can hear

We know that wind turbines can be noisy, especially at night when the background noise in the country is very quiet. We also know that night time noise from any source, which keeps people awake or wakes them up, causes serious health problems if it occurs over a long period of time because of the adverse effect on restorative sleep which is vital for maintenance of physical and mental health in the longer term.

This is partly why noise regulations exist. It is also why there are regulations about safe working hours in various professions (pilots, medical trainees, truck drivers), to ensure that workers in these groups get sufficient restorative sleep.

At present, only audible noise (dBA) is being measured by regulatory authorities. This means that infrasound, low frequency sound and vibration energy are not being measured inside the homes of affected residents, anywhere in the world. In addition, dBA is only being measured outside people’s homes, but not inside where they are sleeping and waking up repetitively. This will not detect or accurately measure the dose and frequencies below 200 Hz.

The sound and vibration energy we can’t hear

We know that wind turbines emit both infrasound and low frequency noise as well as audible noise. Low frequency sound energy is measured using dBC, and infrasound is measured by dBG and by dBlinear. Special equipment, microphones and techniques known as ‘narrow band analysis’ are required to accurately measure these parts of the sound spectrum, in enough detail to detect the true peaks of the soundwaves. Otherwise averages rather than peaks of pulsations of sound energy are being measured, and it is the peaks of sound energy which our ears hear.

Many of the more pronounced symptoms and health problems such as painful ear pressure reported by people when they are exposed to operating wind turbines have also been reported in people exposed in experimental situations to low frequency noise and infrasound, but generally for shorter exposure times at higher “doses”. This suggests that the sound energy being experienced by the residents and workers both inside and outside buildings is much greater at times than has been documented and measured, and may be because of the cumulative effect of multiple wind turbines.

Important research from Acousticians

Acousticians working independently of the wind industry have recently started to measure infrasound and low frequency sound and vibration inside and outside homes to try and work out exactly what is making people so unwell.

Robert Rand and Steven Ambrose have recently documented measurements inside a home in Falmouth, near a couple of modern upwind bladed wind turbines, where a resident had become very unwell with the characteristic pattern and range of symptoms. After twenty minutes exposure, they too became unwell. The levels of infrasound measured by them were greater than levels found by Professor Alec Salt to adversely affect the outer hair cells of the inner ear, thought by some international researchers to be one explanation for the cause of many of the symptoms being reported.

Rand and Ambrose also found that the proportion of infrasound and low frequency noise inside this home was much greater inside the home compared to outside. They liken the effect to being like “living in a drum”, where:

  • The infrasound and low frequency noise component is amplified inside the home, and
  • The audible noise in the higher frequencies from the wind turbines outside the home is attenuated or blocked by the insulation and building materials from penetrating inside the home

The end result is that the proportion of infrasound and low frequency noise this resident was exposed to inside her home was significantly greater than outside the home.

The recent discovery of old research from 1985 commissioned by the US government Department of Energy has revealed that a team of researchers from various universities and research institutes including NASA determined that residents 3km away from a downwind bladed turbine were being adversely affected by the wind turbine infrasound and low frequency noise, which was causing resonance and amplification of those frequencies inside their homes, at levels of perception well below the threshold of hearing at those individual frequencies. Their research is consistent with findings from Harvey Hubbard, who had investigated the same building resonance phenomena resulting from noise from other sources.

What are the actual acoustic emissions which people are exposed to in their homes and their workplaces?

We have little information. Nowhere in the world is this being measured reliably and consistently inside people’s dwellings, by regulatory authorities acting in the best interests of the residents, or by independent acousticians, and being made publicly available. Some acousticians in the USA and Australia have been conducting these measurements. Some of them have developed symptoms themselves.

Do the symptoms correlate with exposure to operating turbines?

Where people are becoming unwell, they consistently report that their symptoms are worse with particular wind directions and weather conditions, and do not occur all the time.

After a while, some people can reliably predict which way the wind is blowing and whether or not the turbines are operating, without even seeing the turbines. They can tell simply on the basis of the symptoms they are experiencing inside their home.

Robert Rand and Steven Ambrose described what it was like to develop the symptoms themselves. They were able to demonstrate that this correlated with operating wind turbines and elevated levels of infrasound and low frequency sound coming from those turbines, inside the home at Falmouth.

Professor Con Doolan and his co-researcher’s findings show that a resident’s symptoms correlated directly with the measured acoustic low frequencies and the beginnings of a dose response curve was able to be developed for that person’s data. Unfortunately the developer chose not to cooperate with on – off testing, which would have determined whether the sound energy did indeed come from the wind turbines.

What is a safe setback distance between wind turbines and homes?

We don’t yet know, and it will vary with terrain. People are reporting symptoms such as the body vibrations and the waking up at night in a panicked state out to 10km from operating wind turbines. This is why the Waubra Foundation have recommended a precautionary setback distance of 10km until the proper research is done.

With respect to other sources of industrial ILFN, there is so little data that it is hard to predict, however CSG noise is disturbing people’s sleep out to 15km away and coal mining noise in the upper Hunter region was measured out to 10km from the noise source.

What makes the symptoms go away?

Apart from the turbines ceasing to operate, the only thing which people report works is to leave the area where the turbines are operating and move at least 10km away. Some people have had to move even further away to obtain relief.

Do the reported health problems go away completely when people leave?

Unfortunately it does appear that some people may develop permanent problems, which do not completely resolve despite the fact that they have moved away, sometimes for some years. These include specifically:

  • Tinnitus
  • Hyperacusis (extreme noise sensitivity), and
  • Memory dysfunction

Professor Mariana Alves Pereira’s work in Portugal also indicates that infrasound and low frequency noise can cause permanent changes to the structure of collagen in the body from exposure to infrasound, low frequency noise and vibration.

There are very limited case reports suggesting this may be an issue in people and animals exposed to wind turbines. This effect has been noted for example in thickened cardiac valves in residents in Germany who have chronic exposure to wind turbines. The same pathology has been reported in Taiwanese aviation workers.

Again, more research is required.