Many view wind turbines as a great way to produce clean energy. However, some think that wind farms adversely affect the health of those living nearby them. These concerns include effects of infrasound, electromagnetic radiation, shadow flicker, and blade glint. But are they relevant? The Australian National Health and Medical Research Council published a report of studies that have found no substantial evidence that turbines pose any health risk. Here’s what the report says regarding those health allegations.
Infrasound is sound generally inaudible to the human ear. The World Health Organization states there is no reliable evidence that sounds below the hearing threshold produce physiological or psychological effects. Based on information in the accompanying table, noise levels from wind turbines have been assessed as negligible. That is, they appear to be no different from the noise found in other everyday situations.
Electromagnetic radiation is also a concern, but the Australian Wind Energy Association says the closeness of the electrical cables counters the electromagnetic field, as shielding does with metal armor.
Shadow flicker is the flicking on and off of the turbine’s shadow as the blades rotate. The primary concern here is that the flickering will cause epileptic seizures, though the report says the risk is very low.
Blade glint happens when sunlight reflects off turbine blades and into a person’s eye. However, all major wind turbine blade manufacturers coat their blades with a low reflectivity treatment that prevents reflective glint from the surface of the blade. Therefore, the NHMRC considers the risk of blade glint low as well.
Others complain of annoyance, anxiety, hearing loss, and interference with sleep, speech and learning. However there is no published scientific evidence to support such adverse effects of turbines on health. Some argue symptoms come from stress, which can result when people worry about their health. Another study shows people who benefit economically from wind turbines are less likely to report annoyance, despite exposure to similar sound levels.
Still, because evidence to health risk is limited, the report recommends authorities take a precautionary approach and continue to monitor research outcomes.
Australian National Health and Medical Research Council www.nhmrc.gov.au
Filed Under: Uncategorized
John Harrison says
Another comment: The article mentions that host families do not make complaints. Well, some do. Please see the following, part of the public record and dated August 24th, 2010.
Allen Haas, a farmer the Town of Malone, Fond du Lac County filed these comments with the Wisconsin Public Service Commission, docket # 1-AC-231.
His father was the landowner who signed on with the developers. Allen Haas then bought the property from his dad. He says his dad can’t get over what the turbines have done to his life and to the entire community.
I have three wind turbines on my property and get $4,000 for each one.
It`s been 2 years now with the turbines and everyone in the community is irritable and short, they snap back. The best of friends for 35 years, but everyone just snaps.
People are not really mad directly at the wind turbines or even know what they are mad about, they`re just mad, aggressive.
The closest one to my house is 3,000 feet away – way too close.
You don’t get sleep at night because they roar like at an airport. I get shadow flicker in my house, but down in the village of Johnsburg where those are about another 1,500 feet away from the turbines – oh probably 4,500 feet total those blades are throwing shadows right over all the house roof tops in entire village …..that`s really bad.
All of our tv’s got knocked out too. I can only get local channels when the turbine is turned in a certain direction. 97% of the time, we got no reception. There is no mitigation either.
I go to the doctor and now I’m on a lot of different medications. I’ve been to the hospital a couple of times in the past two years with chest pains. And they just can’t figure out what it is, but now we`re all being diagnosed with wind turbine syndrome.
And I sure got it.. It definitely causes depression. Memory loss is the worse issue. I see it so bad in myself and especially my parents who are older. But they at the point where they just don`t care anymore because there`s nothing they can do anyhow.
My dad is a totally different person since these things went up. He stays in bed all day now. Even if he does get up to eat, he just goes back to bed. There is no will anymore. I ask the doctor- how are they doing this to us? He just says he doesn’t know..
WE energies called today and they are going to be spraying for weeds, so I asked if there were any more plans for windmills? They said, they don’t know. I told em… “This area is completely destroyed, it would make more sense to just put a few up around here as opposed to destroying the rest of the state.”
I got turbines and the money doesn’t pay off in the end. I`ve gotta spend more on cutting around those things and all them cables. It has destroyed my farmland.
I feel really bad for the folks who don`t have contracts cause they`re still all stuck. Even if a realtor wants to sell a place, the first question a buyer asks is if there are windmills in the area. They just hang up.
They should be paying everyone around who is affected, that way – everyone who wants to move could get out and move. So many want to move and leave, but they can’t sell their property. The developers deny devaluation, but it`s real… the ones without contracts lost half the value of their property and can’t move because they have no money, still trying to pay off their homes. At least if you got contracts and enough windmills, you can move out.
It turned out to be a real shocker. This whole thing is not right, it should not be done in small communities, but you know, these are just simple country folk who do just don`t say anything. Even if it`s bad, they just go along with it cause what else are they supposed to do?
If I could write out a check from all the money they gave me and give it back, wake up tomorrow morning and all the turbines be gone, that’d be the best thing that ever happened to me.
I affirm that these comments are true and correct to the best of my knowledge and belief.
John Harrison says
Recently, on behalf of the Ontario Government the Chief Medical Officer for Health (CMOH) issued a review of the health impacts of wind turbines. It can be found at:
The Ontario Government is rail-roading wind energy into rural Ontario, having passed a law removing local government from any decision-making in the process. As expected, the CMOH (an Ontario employee) review vindicated the government position. The following is my response to that review:
Response to the CMOH Report on Adverse Health Effects from Wind Turbine Operation
On May, 20th 2010, Dr. Arlene King, Chief Medical Officer of Health (CMOH) for Ontario, released a report on the adverse health effects of wind turbine operation. In my opinion, the CMOH report is flawed.
The CMOH report concludes as follows:
a) Some people living near wind turbines report symptoms such as dizziness, headaches and sleep disturbance;
b) The scientific evidence to date does not demonstrate a direct causal link between wind turbine noise and adverse health effects.
c) The sound level from wind turbines at common residential setbacks is not sufficient to cause hearing impairment or other direct health impacts, although some people may find it annoying. It has been suggested that annoyance may be a reaction to the characteristic “swishing” or fluctuating nature of wind turbine sound rather than to the intensity of the sound.
d) Other concluding statements are referred to below.
Contrary to the statements of CMOH are the findings of the World Health Organization which acknowledges the relationship between annoyance and other health effects and recognizes noise as an “environmental health hazard”.
The adverse health effects are indirect in character: annoyance, sleeplessness and disturbed sleep lead to stress, head-aches, inability to concentrate, depression, a sense of worthlessness and anger
The CMOH’s report and the earlier report sponsored by the Canadian and American Wind Energy Authorities are skirting the issue. Claiming there are no direct health impacts when they know full well there are health impacts that are indirect in nature is a way to support the agenda of the provincial government and the wind industry.
Unfortunately it is not unusual for organizations to minimize or hide findings in order to support their agendas – especially where large amounts of money are concerned. Tobacco companies are a prime example.
It is fact that more than one hundred people living near wind turbines in Ontario have reported adverse health effects. Over a dozen families in Ontario have abandoned their homes because they could not take the noise.
In some cases, wind energy developers have purchased the properties but at what price we do not know because of associated gag orders.
Dr. King has misquoted from field studies of annoyance due to wind turbine noise. The CMOH report includes the statement: “The sound was annoying only to a small percentage of the exposed people; approximately 4 to 10% were very annoyed at sound levels between 35 and 45 dBA.”
After reviewing the original publications we find the following: The authors broke down the responses to turbine noise from the surveys (586 non-participants in the Netherlands and 1095 mostly non-participants in Sweden) into five categories: do not notice; notice but not annoyed; slightly annoyed; rather annoyed; and very annoyed. The survey population was grouped by the noise level at their homes: 30 to 35 dBA, 35 to 40 dBA etc.
The authors add together “rather annoyed” and “very annoyed” when determining annoyance from turbine noise. Figure 2 of the 2009 publication by Dr. Pedersen and colleagues shows very clearly that the fraction of respondents annoyed was 20% and 25% in the ranges 35 to 40 dBA and 40 to 45dBA respectively for the Dutch survey and was 9% and 29% for the two ranges in the Swedish survey. As in any survey, there is uncertainty; the authors put the uncertainty at about 5% in the above percentages.
For reference, the noise limit regulation for Ontario is 40 dBA for wind speeds up to 22 km/h with the possibility of rising to 51 dBA for wind speeds up to 36 km/h. Dr. King is quite correct in writing that annoyance due to transportation noise at the same level is very much smaller, about 3%.
A major criticism of the CMOH report is that no attempt was made to meet with those in Ontario who are suffering adverse health impacts. It would have been very easy for Dr. King to have asked the local medical officers of health to talk with those in their communities who have registered complaints and to have visited their homes to experience the night-time noise that causes the annoyance and sleep disturbance. After all, these medical officers are first and foremost doctors.
Another major criticism is that no attempt was made to investigate whether the real noise levels at the homes of those suffering were above or below the regulation noise limit. The Ministry of the Environment has been overwhelmed by complaints of excess turbine noise and has reacted by claiming that there is no protocol for measuring noise levels at homes.
This is nonsense. Acoustics consultants have been performing noise audits in all sorts of situations and environments for years. Consultants have indeed performed noise audits of turbine noise. One audit performed by a very experienced company on behalf of a major developer showed noise levels at an Ontario home above the Ontario noise limit for all wind speeds above 10 km/h and at times 25 dBA above the 40 dBA limit. The CMOH report accepts this state of affairs.
Until audits in response to complaints can be made routinely, there should be a moratorium on all new development.
In writing the report, Dr. King does not seem to know what the Ministry of the Environment is allowing in its regulations. For instance, in the report we read that a complete blade has been thrown 150 metres, a blade fragment 500 metres and sizeable ice fragments 100 metres. Later: The risk of injury is minimized with setbacks of 200 to 500 metres. However, Technical Bulletin Six issued by MOE on March 1, 2010 allows a setback of hub-height plus 10 metres (i.e. 90 metres) from public roads and a setback of hub-height (i.e. 80 metres) from property lines. A proponent can even apply to reduce the setback from a property line, over the objection of the neighbour.
Again, in the report we read that the minimum setback from a receptor is 550 metres. Until Technical Bulletin Six this was true. Now, a participating receptor is no longer subject to this minimum setback. This is regardless of the fact that the participating receptor may have a family and that the 550 metre setback was put in as a mild effort to avoid adverse health effects.
Yet again, we read in the report that setbacks now extend beyond 550 metres with an increased number of turbines, with an example of 950 metres for five 107 dBA turbines within a 3 km radius of the receptor. In fact, the MOE regulations that accompanied the Green Energy Act allow the developer to hire a consultant and use the old October 2008 noise and setback regulations, subject to the minimum 550 metres for non-participating receptors.
The CMOH report finishes with un-supported statements that allegation of adverse health impacts may diminish if there were more community engagement, fairness and equity. As if these things will change the noise intrusion and resulting annoyance and sleep disturbance!
For a more detailed critique of the CMOH report please see the website of the Society for Wind Vigilance at http://windvigilance.com/CMOH_Analysis.aspx
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Stella, ON K0H 2S0
John Harrison says
The standard sound propagation model ISO 9613-2 shows that one modern up-wind turbine generates a sound pressure level at 400 metres of 40 dBA. 10 such turbines at the same distance adds 10 dBA (10 log 10 for those checking the numbers) for a total of 50 dBA. The International Standards Organization recommends 25 dBA in a bedroom. The World Health Organization recommends 30 dBA in a bedroom. The above model is subject to a 3 dBA uncertainty which should be added for caution (are engineers not supposed to err on the side of caution?). Turbines generate amplitude modulated sound which is perceived to be particularly annoying. There should be a 5 dBA penalty for this. The above model does not account for turbulent inflow noise which adds considerably to the low frequency component and hence annoyance of turbine noise. Finally, ambient noise in rural areas is between 25 – 30 dBA at night-time when, world-wide, turbines cause annoyance and sleep deprivation.
I can only assume that your numbers were fed to you by lobbyists for the wind energy industry!
I will comment separately on the health issue.