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Tim Stuart 00 353 (0)XXXXXX XXXXXXX, Co. Meath, Ireland. XXXXXXXnet Friday, 21 February 2014 Wind Submissions, Planning Section, Department of the Environment, Community and Local Government, Custom House, Dublin 1. Email: [email protected] Submission on the proposed revisions to the Wind Energy Development Guidelines Noise There are a number of perspectives on noise. There is the Physical Vibration in the medium that conveys noise. This is very amenable to scientific investigation. Scientific analysis of the physical vibration focuses on two particular aspects of noise: amplitude or intensity, measured in decibels (Db), and frequency measured in cycles per second (Hz). There is the Stimulations within the Ear to the physical vibration. There are hairs attached to hair cells in the ear that vibrate in sympathy with the frequency of the physical vibrations and with an amplitude that is a function of the amplitude and frequency of the physical vibration. There are two distinct sets of hair cells, inner and outer, that respond in different ways to different frequencies, the outer hair cells being more responsive to lower frequencies including infrasound frequencies. The motion of these hairs excite their adjacent nerves cells (approximately 25,000 of them) that send signals to the brain. Research on animals and the comparison of the anatomy of the ears of these animals with the ears of humans result in a reasonable understanding of the stimulations within the ear. However, ethical considerations limit scientific experiments on the human ear and difficulties with definition, control and non-linearity of variables limit inferences that can be drawn from what experiments can be carried out. There is the Processing within the Brain of the neural signals from the stimulation within the ear. The nerves cells adjacent to both the inner and outer hair cells connect to the same region of the brain (within the cochlear nucleus of the brainstem) but to different functional areas within this region. These two areas are connected through two different branching networks of connections to both auditory and to a broad spectrum of non-auditory areas of the brain. The consequences of these processes are not transitory: for example, research by Akira Ishii et al. has shown when fatigued volunteers were exposed to the sound of a metronome for 30 minutes while continuing to perform a fatiguing task on day 1, that on day 2 the metronome sound on its own induced symptoms of fatigue. The current state of the art tools available to science to explore the brain enable 3-dimensional imaging of the active areas of the brain in controlled circumstances by detecting the electrical and magnetic effects of brain activity. While the technical ingenuity of the design of these tools is impressive, they are quite limited. For example, using these tools would not enable a direct causal Page 1 of 6 link to be established between the inputs to (“1”, “+” “1”,”=”) and output from (“2”) a basic electronic calculator. There is the Perception of Noise. Having been processed and interlinked through a hierarchy of functional levels within the brain, integrated information received from multiple stimuli is combined in the generation of perception. One particular singular aspect of perception is loudness. The International Organization for Standardization (ISO) develop and publish International Standards, including the standard “ISO 226:2003: Acoustics - Normal equal-loudness-level contours.” that forms the basis of the dB(A) measure of loudness. On their web-site they state: “This International Standard specifies combinations of sound pressure levels and frequencies of pure continuous tones which are perceived as equally loud by human listeners. The specifications are based on the following conditions: the sound field in the absence of the listener consists of a free progressive plane wave; the source of sound is directly in front of the listener; the sound signals are pure tones; the sound pressure level is measured at the position where the centre of the listener's head would be, but in the absence of the listener; listening is binaural; the listeners are otologically normal persons in the age range from 18 years to 25 years inclusive. The normal equal-loudness-level contour is the equal-loudness-level contour that represents the average judgment of otologically normal persons within the age limits from 18 years to 25 years inclusive An otologically normal person is a person in a normal state of health who is free from all signs or symptoms of ear disease and from obstructing wax in the ear canals, and who has no history of undue exposure to noise, exposure to potentially ototoxic drugs or familial hearing loss.” The role that ultrasound plays in various mental processes is not well understood, but it is clear that it is not available to perception and is thus excluded from the dB(A) measure of loudness. There is the Attention to Noise. Attention selects among the many and various stimuli that are available to perception. Consciousness and the nature and force of stimuli play roles in directing attention. Consciousness operates in a range of purposefulness between focussed intent and dormancy: towards either end of this range, stimuli that are not supportive of the purpose of consciousness exert greater force on attention. Stimuli present themselves in a range between pleasing and displeasing: those stimuli towards either end of this range present themselves with greater force than those towards the centre of the range. Stimuli may force themselves on attention in conflict with the purpose of consciousness. There are wide ranges of reaction to and ability to cope with this conflict among the population at large. Limits of scientific understanding of noise There is limited scientific understanding of the interface within the ear between the physical characteristics of noise and the neural system. The adage used until recently “What you can’t hear can’t affect you.” is now discredited by research demonstrating that sounds that can’t be heard (perceived) do in fact resonate within the ear and stimulate the nervous system. This change in understanding must serve as a clear warning to us. Our current understanding of noise “from the ear in” is limited. In our guidelines we must err on the side of caution. The scientific understanding of the effects within the neural system is at a primitive stage, particularly in establishing cause and effect relationships. Evolution does not equip us to receive stimuli that have no effect. This and the fact that stimulation from ultrasound does not affect perception and as a consequence does not directly impinge on consciousness leads to the conclusion that is has other unconscious effects. As of now, the scientific understanding of what these effects are is limited. The Page 2 of 6 limitations on our understanding of what these and other effects are must not be taken as evidence that there are no such effects. We must acknowledge our ignorance of the effects of noise within the neural system and act accordingly. Again, in our guidelines we must err on the side of caution. The dB(A) measure of loudness is a well-defined scientifically based measure. However, it has limitations. It is a measure based on a particular subset of the population. It is based on controlled circumstances where a singular relationship in space between the participants and the sound source is fixed. It is based on sounds of a single frequency, one frequency at a time. It is a measure that is normalised: the actual response of the individual participants is subsumed into an average. It is a measure of sounds as they are perceived. It is a measure where the attention of the participants is focussed on the sound that they are listening to. The measure is thus not representative of the population as a whole: in particular, it is not representative of children, whose development is susceptible to disturbance by intercipient noise. It bears little or no relationship to peoples’ experience of noise in general and in particular to their experience of noise from wind turbines. In its definition it avoids any measure of variation among individual. It is a measure of perception only: it makes no attempt to measure the effects of sounds other than on perception and as a consequence gives no measure at all for sounds that are not perceived. It provides no measure of the effects of noise on attention – the aspect of sound that is of greatest significance for consciousness and that scientist openly state is little understood. The dB(A) measure of loudness is one of a family of such measures all of which suffer from a similar set of limitations. These limitations are one particular reflection of the limitations of current scientific understanding of noise from the ear in. The Marshall Day report The Sustainable Energy Authority of Ireland (SEAI) commissioned Marshall Day to compile a report to form one of its inputs into the review of the Wind Energy Development Guidelines. The report “Examination of the significance of noise in relation to onshore wind farms” - has as its stated objective to: “...obtain evidence upon which to evaluate the appropriateness of the Wind Energy Development Guidelines in relation to noise impacts and if considered necessary suggest changes.” Given that the commissioned Marshall Day report is a major source of information for the process of reviewing the Wind Energy Development Guidelines it is appropriate to comment on the report in this submission. In section “3.4 Special characteristics”. The report refers to Amplitude modulation which it describes as “a sound which noticeably fluctuates in loudness over time” and impulsiveness which it describes as “transient sound having a peak level of short duration, typically less than 100 milliseconds.” The report states “neither impulsiveness nor amplitude modulation have widely accepted metrics that are field proven and are shown to correlate with peoples subjective impression of the sound. This, in turn, prohibits the development of prediction tools and regulations.” While it is not feasible to regulate that which cannot be measured, it is certainly not acceptable that the guidelines ignore issues that impinge on the people simply because they cannot be measured. The impracticality of specifying measurable regulations for these characteristics is a further indication that in the regulations we should err on the side of caution. Also in this section, Infrasound is describes as “noise at frequencies below the normal range of human hearing, i.e. <20 Hz”. In the context of infrasound the report cites a 2010 public statement from the Australian National Health and Medical Research Council (NHMRC) as follows “There is no published scientific evidence to positively link wind turbines with direct health impacts”. A public statement dated July 2010 on the NHMRC web site states “there is currently insufficient published Page 3 of 6 scientific evidence to positively link wind turbines with adverse health effects” (emphasis added). A PDF file of the public statement accessible from the website states “there is no published scientific evidence to support adverse effects of wind turbines on health”. This latter statement is clearly at odds with the facts. There are many published scientific reports reporting lower overall quality of life, physical quality of life, and environmental quality of life of individuals residing in the proximity of wind farms, such as those reports identified in appendix G of the Marshall Day report: Item 1. Nissenbaum et al. 2012 “The adverse event reports of sleep disturbance and ill health by those living close to IWTs are supported.” Item 6. Hanning, CD.,Evans, A., (2012) British Medical Journal “A large body of evidence now exists to suggest that wind turbines disturb sleep and impair health at distances and external noise levels that are permitted in most jurisdictions, including the United Kingdom.” Finally on the matter of the NHMRC public statement, the evidence in the statement was current in 2009. As indicated above the effects of noise from the ear in is poorly understood. Because of this and because the tools currently available to scientists to research these effects are primitive in relation to the research required there is little direct causal evidence relating noise from wind turbines to the plentiful of anecdotal evidence of the ill-effects of this noise. As stated by Hanning, CD., and Evans, A., (2012) in the British Medical Journal contribution referenced above “experts contend that the quantity, consistency, and ubiquity of the complaints constitute epidemiological evidence of a strong link between wind turbine noise, ill health, and disruption of sleep.” The absence of direct causal evidence in the Marshall Day report must be understood in the context of the limitations of the scientific understanding and of the abundance of the anecdotal evidence and must not be read as “no evidence”. The report makes no reference to attention to noise. Experience of noise The variation in the effects of what people hear is illustrated by comparison of the effects of hearing the noise of wind turbines at even low dB(A) levels with the effects of listening to music at the same level. Many people have experienced the “flight or fight” adrenaline rush associated with a noise that goes bump in the night. What we hear has a great variety of effects on our moods, emotions, focus, sense of well-being and many other physiological, psychological and behavioural effects. For many people, the noise from wind turbines can have considerable negative effects in these areas. In the quiet of the night, to a student with intent focussed on the complexity of a concept of study or to any individual trying to sleep, the effect of the sound of a dripping tap at a level of loudness just above the hearing threshold can range from irritating to infuriating. It is within the control of a household to fix a dripping tap. It is not within their control to quieten a wind turbine that elicits similar effects: this lack of control can exasperate residents to the point of distress. The seeming life sentence to residents of one or more wind turbines in their locality can exacerbate persistently over many years these negative effects. For individuals whose attention is particularly sensitive to noise such as individuals suffering from any of the autistic spectrum disorders, and to the families of these individuals, the absence of any reference to attention to noise in the considerations for the planning guidelines is unacceptable. We judge democracies by how well they treat their minorities. Ignoring this minority is reprehensible. Page 4 of 6 Guidelines The power rating of wind turbines has been growing in recent years and looks set to continue growing. The spectrum of noise generated shows a downward shift in frequencies with increased turbine power: lower frequency noise travels further. On larger turbines the blade tips travel further and faster resulting in greater wear and accretion on the blades which in turn results in the increase in noise with turbine age occurring more rapidly. Newer larger turbines are, by definition, not tried and tested in real life situations: there may be other as yet unknown effects of larger turbines. The guidelines should reflect this possibility and err on the side of caution. We Irish are now establishing Wind Energy Development Guidelines for ourselves. Due to the limits of the scientific understanding of the effects of noise on people, the mistaken assumptions made because of this in the past, the difficulties in measuring physical characteristics of noise, and the lack of field experience of newer larger turbines, when drawing up our guidelines we should err on the side of caution. Ireland is among the best positioned countries in the world to harness wind energy. There are wind farm locations in the country sufficient to at least meet our renewable energy needs that are sufficiently removed from noise sensitive properties to eliminate the possibility of ill-effects of wind turbines on the residents closest to the wind farms. The guidelines should acknowledge this fact, should not limit themselves to best international practice and should represent an appropriate Irish solution to an Irish problem. The residences of many households have not been constructed with attenuation of turbine noise in mind. Many people desiring a healthy personal environment leave windows open day and night for ventilation purposes. Many people consider their garden to be their “room outside”. Many parents urge their children to ”go out and play”. Where noise is concerned the distinction between indoor and outdoor living is somewhat artificial, particularly for rural residents, the group most likely to be affected by wind turbine noise. An outdoor noise limit of 30 dB(A) attributable to one or more wind turbines, suggested as being appropriate for indoors in the draft guidelines, should be applied in order to restrict noise from wind turbines at noise sensitive properties. Measurements of wind turbine noise at a noise sensitive property requires specialist skills, expensive equipment and a significant commitment of time. These are not available to most residents. Engagement with planning enforcement agencies requires a significant commitment of time and confident communication skills. These are not available to many residents. The commitment, resources and motivation of planning enforcement agencies across the country is variable. A simple, easily understood and effective planning regulation is the setback distance. The setback distance should be such that in all but exceptional circumstances the outdoor noise limit at noise sensitive properties will not be exceeded. In general, the noise from a wind turbine at a particular distance from the turbine increases with both turbine height and turbine rated power. While currently the typical number of blades on a turbine is 3 it is desirable to have additional blades as they harness additional energy: it is probable that technological advances will enable attachment of additional blades and additional blades will result in noisier turbines as well as higher flicker rates. As a consequence of these considerations the setback distance should be a function of both height and rated power of turbines. I have neither the tools nor the skills to determine the parameters of this function but it should be a simple function, such as 2 meters for every 1 meter in turbine height plus 4 meters for every 10 kilowatts of turbine rated power, but with a minimum setback distance of 800 meters. Page 5 of 6 Concluding comments I make this submission holding the conviction that humanity must stop treating the atmosphere as a dump for its unwanted gasses, greenhouse gasses in particular, and as an advocate of renewable energy particularly here in Ireland which, as mentioned above, is among the best positioned countries in the world to harness wind energy. Submitted by Tim Stuart Page 6 of 6