By Dan Reid, The Observer, www.theobserver.ca 9 January 2011
Over the past few months, I have read with interest the comments on the proposed Silcote Corners wind farm near Meaford, Ont., and others around the province.
What I have found particularly intriguing is the consistent and almost automatic dismissal of the health impacts on people colocated with the turbines. I have listened to people arbitrarily dismiss health issues as being psychosomatic or; regurgitate the popular excuse of the lack of scientific evidence.
With respect, I would suggest that whether these projects involve wind turbines really is inconsequential. The core issue would be the same if we were considering placement of a new manufacturing plant, an industrial complex of some type, an airport or a multi-lane highway.
The fundamental problem is environmental noise. Wind turbines are just the instrument.
To anyone who suggests we lack data regarding the impact(s) of environmental noise on human health, I would offer the following: Every year there are international conferences on this subject, some focused on certain types of environmental noise (i. e. low frequency noise). There are numerous journals published on the subject.
These publications catalogue a continuously growing collection of peer-reviewed experiments and studies by subject-matter experts, medical professionals and academics on the human impact of environmental noise.
Given the quality and depth of these resources, we are exceedingly well equipped to act in situations where humans are at risk, regardless of the source of the noise. And there is a well-established regulatory environment intended to minimize the risk of exposure.
The Province of Ontario has noise restrictions that must be met by any developer. Those requirements are summarized in a publication called ‘Sound Levels for Stationary Sources’ NPC-232.
This publication stipulates that no installation shall exceed a maximum noise level of 40 decibels during the evening and 45 during the day.
Science tells us that loudness of 40-45 decibels is equivalent to the noise level in a library. That statement is often touted by wind farm proponents and it is absolutely true.
Unfortunately, by itself, that fact is also totally irrelevant. The ambient noise in rural environments such as Silcote Corners is from 25- 30 decibels, since it is not influenced by other background noises of traffic, industry and the like.
So the question becomes, how disruptive is noise of 40-45 decibels from an industrial complex (such as the wind farm) when it is located in a natural environment with an ambient noise level of 25- 30 decibels (or 15-20 decibels less)?
Again, science informs us that when the volume of any noise is increased by three decibels that noise becomes noticeable. Increases of five decibels are loud enough to be considered annoying. Increases of 10 decibels represent a doubling of volume to the human ear.
Therefore, 40 decibels is twice as loud as 30 decibels to humans. That degree of increase changes a sound from noticeable to intolerable. Consequently, if we place our “library” in an environment where the natural volume is only half as loud, the “library” will be the noisiest thing in the neighbourhood.
What we also know from science is that human hearing is very subjective. What some find annoying doesn’t bother others. Therefore, doubling the level of ambient noise in an environment such as Silcote won’t be an issue for everyone.
However, to assume that it won’t be dangerous to anyone would be naive. Those who find the noise increase intolerable have the greatest risk of negative health impacts.
Science is clear regarding the health implications, citing increased headaches, possible nausea and sleep deprivation as the most common symptoms. Prolonged exposure increases stress and the risk of depression, anxiety and cardiovascular disease. The sad reality is that, if the noise is permanent, the cure is to move away.
As an interesting aside, the Vestas wind turbines destined for Silcote Corners have a sound power rating between 95 decibels and 103 decibels per turbine, depending on wind velocity. When they are clustered together there is an incremental increase in the sound power as each turbine is added. As a result, in accordance with the Green Energy Act, to meet NPC-232 requirements wind turbines are “set back” 550 metres from a receptor.
The fact that the 95+ decibel noise will dissipate to a level of 40 or 45 decibels at a distance of 550 metres is only based on a mathematical (albeit scientific) formula. There is no requirement for measurement, validation or monitoring unless there are noise complaints after the fact.
Obviously, however, the closer to the turbine you are the louder the noise. So, to those folks who’ve relinquished their rights to setbacks and choose to use their property as a site for multiple turbines, best of luck! In Germany, if a wind farm is built in an environment characterized by a 35 decibel ambient noise level, the setback from any receptor is 1.5 km.
Unfortunately, all of this only focuses on part of the issue of environmental noise – that is, the part we can hear. The other part is low frequency noise and infrasound. We know from scientific research that low frequency and infrasound noise behaves differently in that it does not decrease over distance. That partially explains why elephants and whales use low frequency noise to communicate over great distances through the ground and oceans.
We also understand that solid structures such as houses can actually amplify the sound through vibration. That means it won’t be blocked by going inside and shutting doors and windows. Only a portion of low frequency noise is audible. Infrasound, defined as less than 20 Hz, is below the hearing threshold of humans. It will only be “felt” through inner ears and body sensations. Thus the volume in decibels is irrelevant because you don’t hear it. Increased volumes of infrasound will however, speed the body reaction.
We know from science that every organ in the human body can resonate or vibrate from exposure to low frequency noise. As examples; low frequency noise of 50 Herz stimulates vibration in the chest cavity; at 30 Hz abdominal organs can do the same; at 17 Hz vision can be blurred due to vibration of optic nerves.
The science concerning the risk of exposure for humans is explicit. It has been acquired from years of occupational studies, military experiments and the life experience of individuals in neighbourhoods co-located with industrial factories.
The emission of low frequency noise from wind turbines is also well-recognized. Over the course of the decade from 1980 to 1990 NASA researched this specific problem and its efforts led to a fundamental redesign of turbines. Low frequency noise emissions have improved, but have not been eliminated. Unfortunately, with current industry standards on wind turbines, manufacturers are not required to specify low frequency noise emissions.
Moreover, the standards used are well known to understate the low frequency component. The Japanese, at the end of 2009, curtailed installations of wind farms and initiated a four-year epidemiological study on people living near turbines to understand the issue of cell damage in the human body due to low frequency noise exposure.
To perpetuate the debate on health issues and wind turbines is at best unproductive and at worst dangerous to the future health of all of those living near turbines. Those who dismiss the concern as illegitimate only demonstrate how hopelessly uninformed they are.
We have the science, the expertise and the intelligence to tackle the issue head on if we define it in the appropriate framework. It is not about a wind turbine. It’s about protecting the health of the people in our community against the negative impact of environmental noise, whether they can hear it or not and irrespective of the source.
We need municipal politicians to use the knowledge we have, take the next steps beyond a moratorium and construct bylaws to get the sources of environmental noise away from inhabitants. We need to take that expertise and add it to a collective political voice that demonstrates we are prepared to take control of the development of our communities.
We do not need more health surveys to add to the portfolio of examples of human victims suffering from what science has already explained.
Dan Reid is a retired director with Bell Canada. He lives in Sydenham Township in the municipality of Meaford.
URL to article: https://www.wind-watch.org/news/2011/01/10/health-effects-of-turbines-we-already-know/