Ed. Note: The health effects of industrial wind on local residents continues to attract mainstream research despite severe political incorrectness. It’s common sense: huge industrial machines moving in the open air have negative effects. For other posts at MasterResource on this subject, see here. This post complements yesterday’s on the nighttime amplification of noise.
“Wind turbines generate low-frequency noise (LFN, 20–200 Hz)…. [which causes] headaches, difficulty concentrating, irritability, fatigue, dizziness, tinnitus, aural pain sleep disturbances, and annoyance. Clinically, exposure to LFN from wind turbines may cause increased risk of epilepsy, cardiovascular effects, and coronary artery disease.”
“In order to reduce LFN transport from outdoors to indoors, we recommend that the windows should be kept closed, especially at nighttime because LFN is most noticeable at night. In addition, … residences in close proximity to wind turbines should be equipped with airtight windows.” (Nature, September 8, 2021)
Make no mistake: the obvious is becoming mainstream despite the protests of the mighty industrial-wind complex. The latest evidence on aerodynamic noise comes from Nature magazine [Scientific Reports volume 11: 17817 (2021)]: “Effects of Low-frequency Noise from Wind Turbines on Heart Rate Variability in Healthy Individuals.”
The Abstract follows:
Wind turbines generate low-frequency noise (LFN, 20–200 Hz), which poses health risks to nearby residents. This study aimed to assess heart rate variability (HRV) responses to LFN exposure and to evaluate the LFN exposure (dB, LAeq) inside households located near wind turbines.
Thirty subjects living within a 500 m radius of wind turbines were recruited. The field campaigns for LFN (LAeq) and HRV monitoring were carried out in July and December 2018. A generalized additive mixed model was employed to evaluate the relationship between HRV changes and LFN. The results suggested that the standard deviations of all the normal to normal R–R intervals were reduced significantly, by 3.39%, with a 95% CI = (0.15%, 6.52%) per 7.86 dB (LAeq) of LFN in the exposure range of 38.2–57.1 dB (LAeq).
The indoor LFN exposure (LAeq) ranged between 30.7 and 43.4 dB (LAeq) at a distance of 124–330 m from wind turbines. Moreover, households built with concrete and equipped with airtight windows showed the highest LFN difference of 13.7 dB between indoors and outdoors. In view of the adverse health impacts of LFN exposure, there should be regulations on the requisite distances of wind turbines from residential communities for health protection.
Introduction
Wind energy is used around the world as a source of clean energy. However, wind turbines generate low-frequency noise (LFN) in the range of 20–200 Hz. As many community complaints have centered around the LFN from wind turbines, it is important to evaluate the health impacts of LFN on residents near wind farms.
LFN exposure has been found to cause a variety of health conditions. Exposure to LFN from wind turbines results in headaches, difficulty concentrating, irritability, fatigue, dizziness, tinnitus, aural pain sleep disturbances, and annoyance. Clinically, exposure to LFN from wind turbines may cause increased risk of epilepsy, cardiovascular effects, and coronary artery disease.
It was also found that exposure to noise (including LFN) may have an impact on heart rate variability (HRV). HRV is the variation over time of the period between adjacent heartbeats, which is an indicator of the activities of the autonomic nervous system, consisting of the sympathetic nervous system (SNS) and parasympathetic nervous system (PNS). Autonomic imbalance usually represents a hyperactive SNS and a hypoactive PNS and results in reduced HRV.
An autonomic imbalance may increase the morbidity and mortality of cardiovascular diseases25. A review paper indicated that road traffic noise may overactivate the hypothalamic-pituitary-adrenocortical axis (HPA) and sympathetic-adrenal-medullar axis (SAM), increase the blood pressure and reduce HRV, and finally affect the cardiovascular system26. A recent study analyzing 658 measurements of HRV obtained from 10 healthy males (18–40 years old) indicated reductions in HRV due to environmental LFN exposure27. However, few studies have specifically examined the effect of LFN from wind turbines on HRV in healthy individuals; thus, this was the aim of this study.
In view of the adverse health impacts of noise exposure, many countries and international organizations have established regulations for noise control. These regulations are set for noise in the full spectrum of human hearing (20–20 k Hz). The Ministry of Environment of Finland set limits for wind farm noise of 45 dB (LAeq) during the day and 40 dB (LAeq) during the night.
In the United Kingdom, the fixed limit for turbine noise is 40 dB (LAeq) for the daytime and 43 dB (LAeq) for the nighttime. In the United States, noise levels of ≤ 55 dB (LAeq) are set for outdoors in residential areas, farms, and other outdoor areas as requisites for public health protection, and levels of 45 dB are set for indoor residential areas, hospitals, and schools.
In addition to the full noise spectrum, the Taiwan Environmental Protection Administration (EPA) also established regulations for LFN to avoid impacts on residents, since wind farms have been set up very close to residential communities. The LFN standards for wind turbines in the daytime (7 a.m.–7 p.m.) and evening (7 p.m.–10 p.m.) are 39 dB (LAeq) for environments requiring tranquility such as residential areas, 44 dB (LAeq) for mixed residential and commercial/industrial areas, and 47 dB (LAeq) for industrial areas; those at nighttime (10 p.m.–7 a.m.) are 36, 36, 41, and 44 dB (LAeq), respectively32. This study assessed the LFN in the indoor environments of households near wind turbines to evaluate whether the LFN levels meet the Taiwan EPA standards.
One of the most important factors influencing residential noise exposure from wind turbines is the distance of the wind turbine from the observer33. For example, at a distance of 120–500 m, the measured turbine noise levels decreased by 3–5 dB (LAeq), while at a distance of 1000 m the noise was reduced by 6–7 dB (LAeq). Hansen et al. reported variations in indoor LFN levels (15–45 dB (LAeq)) for two households (houses made of sandstone/concrete/iron or bricks with windows remaining closed or half open) at different distances from wind turbines.
This study assessed the indoor/outdoor differences in LFN exposure in several households located at varying distances from wind turbines. Our main focus was on the indoor LFN levels in several recruited households; we did not intend to conduct a comprehensive evaluation of the influential factors. These households serve the purpose of demonstrating the potential impacts of influential factors.
Besides distance from turbines, building materials also affect indoor LFN exposure. This work assessed the indoor LFN levels for several recruited households with different building materials and open/closed windows to illustrate their potential impacts. It is known that materials have different sound absorption coefficients.
The overall sound pressure level and spectrum of external noise change when transmitted to the interior of a building. Mid- and high-frequency noises are selectively attenuated by roofs and walls, causing the building structure to function like an LFN pass filter.
Outdoor to indoor noise reduction generally decreases with frequency, which is related to housing construction and room dimensions. Factors contributing to indoor/outdoor noise reduction also include structural resonances, room modes, and coupling between the air volume inside the residence and the stiffness of the walls, roofs, and ceilings. It is known that the appropriate choice of construction materials and designs can contribute to LFN exposure reduction for residents. Hence, these factors are not evaluated comprehensively in this study.
Taiwan is a small and highly populated island. Wind farms have been set up near residential communities, affecting the day-to-day lives of the residents. The hypothesis of this study is that LFN from wind turbines might affect HRV of residents. In order to verify the hypothesis of this study, we defined two objectives: to evaluate the LFN and HRV relationship with an intervention design and to assesses the actual LFN exposure of the community residents.
This investigation is the first in Asia examining the impact of LFN from wind turbines on the HRV of healthy residents. In addition, the variations in LFN exposure inside several residences constructed of different building materials are examined. The findings of this study would serve as a useful reference for Asian countries planning to launch or promote wind power generation.
Sherri Lange
I will say what all good mothers usually say when their child writes excellent articles like you do: “What don’t you write a book?”
As an engineering student in college we experimented with resonant frequencies of human bodies. The sir in the lungs / diaphragm resonate at 75 Hz. to 150 Hz., depending on the size of the chest cavity. Infrasound resonates the whole body.
In a local audio club meeting back in the 1990s, one member who tested subwoofers for audio magazines demonstrated his own “Subwoofer That Shook The World”, with eight expensive 15″ drivers capable of 10Hz, output. The original six driver version was featured in a magazine article:
https://web.archive.org/web/20151002181631/http://home.comcast.net/~infinitelybaffled/page1IB-NousaineIB1.html
Another club member, who was an audio consultant, found s small number of CDs with infrasound frequency content. They were of “music” that teenagers played in their “boombox” cars. That “music” drove several audio club members out of the house in minutes, including me — all nauseous from the infrasound — but at least 85% of the club members could tolerate it. I suppose the beer consumption helped.
If “music” with infrasound can be so painful to some people, I can’t imagine how bad the intermittent non-musical NOISE of a windmill would be.
In homes, the bass resonances within a room will rarely be below 20Hz. unless the room is exceptionally large. But the air in the entire interior of a home also has a resonant frequency, and that will be below 20Hz. So specific frequencies from a windmill can cause whole house resonances inside. Room or whole home resonances can only be tamed with unusually flexible walls (very rare) or massive quantities of large sound absorbers called “bass traps” (expensive and big).
From my article, on my climate science and energy blog, a few years ago:
U.S. MILITARY INFRASOUND WEAPONS EXPERIMENTS: Colonel John B. Alexander, headed a department that developed unorthodox weapons, including an infrasound weapon: Colonel Alexander said this about an experimental infrasound weapon, after it was rejected:
“There were some people who were physiologically affected. They were nauseous. They would get dizzy. There were some who had psychological issues, fear factors, inability to think, kinds of things. We found that some people are affected dramatically. Some people are affected a little bit, and others not at all. From a weapons perspective … ( we need to ) know exactly what the effects are going to be.”
The US military gave up on an infrasound weapons after 2000, because its effects on people were too random: Some targets were seriously debilitated; others not much.
Thanks, Richard Greene. Appreciate your commenting today as well. What Mr. Bradley adds is significant. Studies are accruing, and the obvious is indeed becoming mainstream.
Studies from Finland on ILFN distances for attenuation, dBA studies also; a long-term study was conducted in Sweden as early as 2012-2014, by Conny Larsson Uppsala University.
A colleague from Finland asserts that the results indicating further setbacks appear universal, but the proposal for a reduction of 5 dBA was unanimously rejected by the authorities.
Ove adds: “We now have more evidence and will put new pressure on them.”
Sherri:
I immediately assumed YOU wrote the article, but now I see the byline is Robert Bradley, so I must change my comment to:
Robert: You and Sherry should wrote a book on wind turbines, … the least reliable source of energy for an electric grid where reliability is the top priority. A suggested title: “Wind Turbines: Biden’s Building Back Baloney”
This subject is technical, so needs a lot or personal anecdotes from people who have suffered by living near windmills.
Not that I ever wrote a book. Animals known to be able to hear infrasound include cows, cuttlefish, ferret, goldfish, horses, octopi, pigeons, rock doves, squid, and whales.
Species such as alligators, elephants, giraffe, hippopotamus, okapi, and rhinoceros use infrasound frequencies in their communications.
Windmills would be losers even if they did not shred birds and bats, and make horrible noises.
Windmills belong in museums, not attached to an electric grid.
PS: dBA studies are worthless for infrasound They roll off the bass below 500Hz. dBC or a flat DB scale, are needed.
Sound ordinances are almost always in dBA because that scale correlates with hearing damage, which is NOT a problem with infrasound.
Even more important is to measure individual frequencies (one Hz. at a time) to catch peak SPLs,rather than a band of frequencies that smooths the peaks and troughs.
It seems that 25 years of me measuring room bass modes with sine wave test tones,scaring the wife and cat, for equalizing my homemade subwoofer designs, was useful knowledge for something else !