Infrared – the boomerang of the energies
| “I feel what you can not hear.” Thus, residents of wind power plants often describe their complaints, caused by low-frequency noise (infrared). But what is the cause of infrared, what impact does it have on people, what standards regulate the permissible sound emissions, and what is the state of science on these issues? A “The Energy Question” contribution by Dr. med Thomas Carl Stiller.
Inaudible but biophysiologically effective sound is not science fiction but an increasing threat to health. First, a few physical bases: sound is the pressure change in a medium such as air and spreads wavy around the source. The deeper the frequency, the more sound is transported in the air. Very low frequencies are also transmitted through closed buildings. As a result of acoustic reflections and superimpositions, it can then lead to excessively high sound pressure values. In general, sounds and noises are described by frequency, sound color and volume. The human ear can hear frequencies approximately in the range of 20,000 Hz, ie, vibrations per second (high tones) to 20 Hz (low tones). The sound range above a frequency of 20. 000 Hz is referred to as ultrasound, below 200 Hz as low-frequency sound, below 20 Hz as ultrasound. Both infrasound and ultrasound are no longer perceived by the ear, but the body has a subtle perception for infrasound, and some people are particularly sensitive to low-frequency sound.
In nature, low-frequency vibrations are ubiquitous. For example, the sea noise is transmitted over several hundred kilometers in the atmosphere, some migratory birds orient themselves. The sound pressure of natural noises in the infrared range, however, is quite evenly distributed over the different frequencies and is not perceived as disturbing by humans. The infrared of wind turbines is still measurable for several kilometers (1) .
On the other hand, humans are often exposed to technically generated ultrasound in their immediate surroundings. In residential areas, in the age of energy efficiency regulations for new buildings, air heat pumps are increasingly used as energy sources, which are cheaper to purchase than many other heating systems. In operation, however, they are often annoying for the neighbors, if the compressors are too loud and run too long. Even more problematic are wind power plants, in particular the modern large plants, which are mostly placed in front of villages and settlements at a small distance from the housing development. A pressure wave is generated every time a rotor blade is passed in front of the mast, many people perceive this as periodic “wummering”, sometimes also at a distance of several kilometers.
The consequences of technically generated infrared are only gradually understood. About 10 – 30 percent of the population is sensitive to infrared radiation. These people, in Germany several million, develop numerous symptoms, which we learn to physicians gradually. The low-frequency oscillations from compressors and wind power plants cause stress reactions in these people, which manifest themselves in sleep disorders, concentration disorders, nausea, tinnitus, dysphagia, dizziness, cardiac arrhythmia, fatigue, depression and anxiety disorders, earaches and permanent hearing impairments. From a physiological point of view, there is damage to the hair cells of the cortical organ of the auditory canal and to permanent irritation in cerebral arteries such as the almond nucleus (amygdala, anxiety center) (2) .
Those affected can not escape the effects of health and harassment. They are often ineffective for a long period of time. A neurobiological habituation of sensitive persons on technical infrasonic is not known. Often it is falsely asserted that the symptoms have to do with the personal attitude of the concerned against the infrasonic sources, a positive attitude against today’s energy policy thus to protect from infrasound symptoms. Unfortunately, this is not observed in medical practice, the symptoms are all sensitive. Numerous international studies have been carried out over the last few years, but in Germany this research is still very little developed and almost unknown at the political level.
If the symptoms occur, however, those affected can hardly react. Those who live in a residential area affected by low-frequency noise and infrared radiation can not usually move away so easily if, for example, they have to sell their house, which has lost a lot of value due to wind power plants nearby.
Who can still provide performance in today’s working world if he can not sleep by means of an infrared load and finds no peace in the house (4) ? How long can those affected compensate for this healthily and financially? Infrared-sensitive people are in a tragic dilemma: their complaints are not taken seriously and legally they do not go further because of the lack of immission control regulations.
The acoustician Steven Cooper, together with a wind farm operator in Australia, investigated the effects of infrared on the local population. Local residents near a wind park complained about the above complaints. But they did not have the wind farm directly in front of them. Cooper had her symptoms recorded at an exact time and checked the correlation with the activity of the wind power plants: the symptoms were strongest when the wind power plants were particularly active (5) .
In Dänemark haben Informationen über Missbildungen und Fehlgeburten auf einer Nerzfarm, in deren Nähe nachträglich Windkraftanlagen gebaut wurden, sowie gehäufte Berichte von Krankheitssymptomen von Menschen in der Nähe von Windkraftanlagen zu einem Ausbaustopp geführt, der genutzt wird, um die Zusammenhänge näher zu untersuchen. Auch hierzulande wird umweltmedizinisch das Thema Infraschall schon länger ernst genommen(6).
All previously valid protection standards, such as the Technische Anleitung (TA) noise and the DIN 45680, are based on the assumption that only such sound can damage the ear (7) . Other forms of the perception of sound remain outside. The measurement regulations are also not helpful, since only sound above 8 Hz is measured, although modern instruments can also detect frequencies of <1 Hz and the infrared range in the range 1 – 8 Hz causes particularly severe health impairments. The prescribed sound measurements also average individual frequency peaks. They are based on the decibel A filter, which follows the human auditory curve in the audible sound range and measures on many different frequencies rather than linear and narrow band, As would be appropriate to avoid health hazards in the infrasonic range. Furthermore, often obsolete measuring systems and microphones that do not measure accurately enough in the infrasonic range are still permitted within the scope of the currently valid regulations for measurement. As a result, the measurement of the sound phenomena that are harmful to human beings does not escape below 20 Hz. Since these measurement regulations are the basis for approval procedures for technical systems, they must be adapted to the state of the art. If the standards and regulations for the approval procedures of technical installations were at the level of the international state of knowledge, this would have direct effects: the measurement regulations for sound pressure corresponded to the state of the art, the limit values for infrasonic pressure would be set lower,
If technical sources of infrared radiation are not removed quickly and sustainably enough by wind turbines, the public’s complaints will develop into a health boomerang of energy sources. A new national disease with cases like diabetes and cancer is to be expected. It is high time for the politicians to meet their protection obligation for humans and nature and to initiate the most important measures from the point of view of preventive medicine: an immediate dismantling of wind power, greater minimum distances between man and wind power plants, Modern measurement regulations in the corresponding DIN standards and stricter protective regulations directed at sound physics and biology.
(1) Lars Ceranna, Gernot Hartmann & Manfred Henger; “The inaudible sound of wind turbines – infrared measurements on a wind turbine north of Hanover, Federal Institute for Geosciences and Natural Resources (BGR), Unit B3.11, Seismology, 2004
(2) AN Salt, JT Lichtenhan; “Perception-based protection from low-frequency sound may not be enough”; InterNoise 2012. http://oto2.wustl.edu/cochlea . AN Salt, JT Lichtenhan; “How does wind turbine noise affect people?”, 2014.
(3) Alves-Pereira M, Castelo Branco NA; Prog. Biophys. Mol. Biol. 2007 Jan-Apr 93 (1-3): 256-79. Epub 2006 Aug 4; “Vibroacoustic disease: biological effects of infrasound and low-frequency noise elucidated by mechanotransduction cellular signaling”.
(5) Steven Cooper; “Cape Bridgewater Wind Farm”; 44.5100.R7: MSC; Prepared for: Energy Pacific (Vic) Pty Ltd, Level 11, 474 Flinders Street, Melbourne VIC 3000, Date: 26th Nov, 2014.
(6) Robert Koch Institute; “Infrasonic and low-frequency sound – a topic for environmental health protection in Germany?”, Communication from the Commission “Methods and quality assurance in environmental medicine”. Position paper of the doctors for immission control ( www.aefis.de )
(7) Standards: DIN 45680, 45401, 45651; Technical guidance noise (TA noise). “Acoustics – Attenuation of sound in outdoor propagation – Part 2: General calculation method”. DIN EN 61260: 2003-03; “Electroacoustics – Band filters for octaves and fractions of octaves”; DIN EN 61400-11; “Wind energy installations, Part 11: Sound-measurement methods, acoustics, electroacoustics”; “Standard frequencies for measurements” (retracted), “Octave filters for electroacoustic measurements” (withdrawn).