This is part 3 of my series on Chapman’s 17 health reviews. In this part I’ll take a closer look at the main underlying studies that his reviews use to establish their points.
Chapman’s most recently-published review (Massachusetts) correctly lists just 4 peer-reviewed journal-published studies (actual studies, as opposed to a review) on wind turbines and health (a fifth, Nissembaum, was published later). Yep, just 4. They are:
Of the 17 reviews most of them at least refer to either 3 or 4 of these studies (depending on when the review was written) and a number of the 17 reviews use these studies as their central resource. If anyone is going to write about wind turbines and health it is almost inevitable that these studies get referenced. In short, they are central to the industry’s claims that wind turbines are not a health concern. Given their importance part 3 of this series will take a closer look at them.I’m pretty familiar with the first 3 of these studies and have used them as references myself. Chapman’s 17 reviews and their outsized reliance on these 4 studies gave me an opportunity to review them again, plus review Shepherd’s study for the first time. I’ll say at the outset that all of these studies are competent within their scope (with some reservations on van den Berg – see below). They all went out into the field and surveyed neighbors of wind turbines, something that many governments and the industry seem incapable of doing. They all fairly represented the results of their surveys. They all found that wind turbines create, at a minimum, substantial annoyance for the neighbors. And by annoyance, they meant enough annoyance to be a health concern, like prolonged disturbed sleep. None of these studies dismisses health concerns.
So how do Chapman’s reviews use them to claim there’s no health concerns? Well, as part 2 of this series documented, quite a few of the 17 don’t actually say that except in Chapman’s imagination. But many of the 17 reviews interpret these studies in ways that are simply not honest, and others stretch their applicability way beyond reason. I won’t go through (thankfully!) how each review treats them. Still at the risk of getting tedious I’ll go through each of the 4 studies, summarize what it said and what its limitations were, and show how it has been misinterpreted to suit the industry’s narrative.
All of these studies are cross-sectional – they mailed out a questionnaire that sampled a population at a point in time (as opposed to longitudinal, which samples the same population over a period of time). The first three sampled just the population close to the turbines while Shepherd additionally sampled a control group. None of them measured the turbine noise the neighbors were experiencing, instead calculating the noise based upon the turbines’ noise power levels and distance.
All of these studies found that wind turbine noise was a significant annoyance to the neighbors. All of them used the medical definition of annoyance, where it can lead to stress which in turn can lead to health problems. All of them reported sleep disturbance. All of them reported no other health issues, except those related to stress and/or sleep disturbance. None of them visited any residences nor gathered any medical data, other than what was in the questionnaire. They all at least tried to hide their specific interest in wind turbine noise, probably with varying effectiveness – read through the questions in van den Berg’s Appendix A and see what you think. None of them even hints at nocebo, one of Chapman’s favorites.
531 home-grown questionnaires were sent out to every household within 5 selected mostly flat areas in Sweden with a calculated wind-turbine noise level of more than 30 dbA, of which 351 were returned (68.4%). The questionnaire had 4 sections mostly on living conditions and concentrating on annoyance, with one section on chronic health conditions and general well-being. This study could best be characterized as an exploratory effort, attempting to see just how widespread the complaints were. Pedersen: “The aims of this study were to evaluate the prevalence of annoyance due to wind turbine noise and to study dose–response relationships.”
From the conclusion: “A significant dose–response relationship between calculated A-weighted SPL from wind turbines and noise annoyance was found. The prevalence of noise annoyance was higher than what was expected from the calculated dose.” This widely-produced chart came from this study:She proposed several answers for the disparity: “intrusive sound characteristics and/or attitudinal visual impacts” but had no answers, calling for more studies.
The only mention of health in this study is buried in one sentence: “No statistically significant differences in variables related to noise sensitivity, attitude, or health were found between the different sound categories.”
This study was a follow-on to the earlier one using selected areas with differing terrain (urban/rural, flat/hilly) to see if the extraordinary level of annoyance discovered by the first study was affected by the surroundings. 1309 same-as-before questionnaires were sent out to every household in 7 selected areas with calculated noise levels above 30dbA, of which 754 were returned (57.6%). Pedersen: “Objectives: To evaluate the prevalence of perception and annoyance due to wind turbine noise among people living near the turbines, and to study relationships between noise and perception/annoyance, with focus on differences between living environments.”
A main message: “The risk for being annoyed by wind turbine noise increases with increasing A-weighted sound pressure levels. Dose-response relationships at noise levels as low as these have not earlier been derived [from other noise sources].”
This study mentions health effects more than the first one did. Recall that this study is one of the prime sources for the industry’s assertion that wind turbines have no health effects. As you read through these quotes ask yourself how well they support that assertion. And perhaps as you read through these you will come to some appreciation of why many of those reviews include the word “direct” in their conclusions.
“Annoyance was further associated with lowered sleep quality and negative emotions. This, together with reduced restoration possibilities may adversely affect health.”
“A-weighted SPL was not correlated to any of the health factors or factors of wellbeing asked for in the questionnaire. However, noise annoyance was associated with sleep quality and negative emotions.”
“Annoyance is an adverse heath effect.”
“In our study no adverse health effects other than annoyance could be directly connected to wind turbine noise.”
1948 questionnaires were sent out to randomly-selected names in selected areas within 2.5 km of a “modern” turbine (>500kw) in the Netherlands, of which 725 were returned (37.2%). The questionnaires used Pedersen’s as a base, adding some questions regarding health. More promisingly part of the questionnaire was a validated instrument: The General Health Questionnaire.
In addition to the expanded section on health, van den Berg also studied attitudes towards wind turbines, annoyance due to visual effects (as opposed to noise) and annoyance differences of benefitters vs others. Pedersen had also studied attitude and visual influences and found that, unsurprisingly, there was a correlation among them. Van den Berg examined this in more detail.
Some of his conclusions are:
- Of the exposures from wind turbines, noise was the most annoying.
- Benefiting economically from wind turbines, not having wind turbines visible from the dwelling…decreased the probability of being annoyed by wind turbine sound.
- Although the presence of background sound from road traffic made wind turbine sound less noticeable, higher levels of background sound did not reduce the probability of being annoyed.
- Annoyance with wind turbine noise was associated with a negative attitude towards wind turbines in general and the impact of wind turbines on the landscape.
- Annoyance with wind turbine noise was associated with psychological distress, stress, difficulties to fall asleep and sleep interruption.
- There is no indication that the sound from wind turbines had an effect on respondents’ health, except for the interruption of sleep.
Let’s Pause Here…
so we can look at how the industry has twisted these 3 studies to suit their purposes. The narratives the industry has built include:
- There is no evidence of direct health effects of wind turbines.
- Opponents are just jealous and that causes annoyance.
- Opponents just don’t like the looks of them and that causes annoyance.
- Opponents have a bad attitude and that causes annoyance.
- Waiting in line at the post office is an annoyance, so what’s the big deal?
We’ll look at each of these in turn, and see what the studies really say.
No Direct Effects
This is true – these studies found no indication of health effects from turbines, except for annoyance and sleep disturbance. The industry tries to get around the health implications of that by using the word “direct”, as in Colby 2009: “There is no evidence that the audible or sub-audible sounds emitted by wind turbines have any direct adverse physiological effects.” or King: “The review concludes that while some people living near wind turbines report symptoms such as dizziness, headaches, and sleep disturbance, the scientific evidence available to date does not demonstrate a direct causal link between wind turbine noise and adverse health effects.” Nuclear weapons don’t directly cause death either, if you parse it carefully enough.
This comes entirely from van den Berg (as Pedersen didn’t study benefitters): “This lack of annoyance [among benefitters] may be the result of several factors: e.g. the ‘benefitters’ have a more positive view on wind farms, they have an actual benefit and they have a measure of control on the turbines.” The first two factors (positive view and actual benefit) certainly fit into that narrative. And then we come to the third – control. WHOOPS! What’s this about control? “Respondents that benefit will more usually have control: most or all of them have taken part in the decision to put up the turbines and they can stop them if they want. One respondent remarked that if a turbine close by caused too much noise for him or his neighbour, he stopped the turbine.” Most unfortunately, van den Berg didn’t ask the benefitters if they had control of the turbine, nor did he go back to find out. This is huge. It invalidates all the responses from benefitters, which constituted 14% of his respondents, including a large part of the closest. Unfortunately, van den Berg continued to include the benefitters in his analysis, although partially recognizing the problem by splitting out the benefitters to rerun some of the numbers. He should have just admitted that he screwed up by not asking and thrown all of them out from the beginning. And since the benefitters generally lived in the noisiest locations you can guess how their inclusion would impact the results, making the turbines seem more benign than they are.
Don’t Like the Looks
All three studies noted that seeing a turbine added to the annoyance it caused. The industry has taken this unsurprising result and turned it around, implying that looks are the primary cause of the annoyance. All of the studies, however, are quite explicit: the noise is the primary driver. Van den Berg: “Sound was found to be the most annoying of the exposures.” And they recognize that there’s an alternative explanation: maybe the noise is blocked at the same time the view is. Van den Berg: “When the sight of the wind farm is blocked, than the sound may be (partly) blocked too, leading to lower sound levels. This may explain the lower levels of annoyance.” And recall that the noise levels were calculated, not measured, so any blockage would have gone undetected.
A anti-turbine attitude is correlated with annoyance, and the industry implies that the attitude leads to the annoyance. The studies are again quite explicit: they don’t know which causes which. Van den Berg: “The study design does not allow conclusions on what is the cause and what is the effect.” Let me ask: is it more likely that the noise and annoyance caused the attitude, or that they let their previously existing bad attitude cause the annoyance. In fact there is ample testimony that the turbines were initially welcomed by the neighbors, until the noise, i.e. the Lindgrens (starts at 57:30).
No Big Deal
When Pedersen and van den Berg talk of annoyance, they mean enough to cause health issues, whether through prolonged stress or sleep disturbance. Pedersen: “Annoyance is an adverse heath effect.“
Turbine Sizes. These were relatively early studies, done when turbine sizes were much smaller than currently. The 5 areas in Pedersen’s first study had a total of 16 turbines with a total capacity of 8250 kw, for an average of 515 kw. The 7 areas in Pedersen’s second study had a total of 28 turbines with a total capacity of 14060 kw, for an even lower average of 502 kw. It wasn’t until the van den Berg study that turbines even close to current sizes appeared regularly, and even then many of them were smaller. He doesn’t provide actual counts, but extracting what I could it looked like maybe 25% of the turbines were larger than 1500 kw. Today 3000 kw seems to be the norm. And with increasing size comes higher capacity factors (and more constant noise) and a downward shift in the noise spectrum (low frequencies are more bothersome and harder to filter). The annoyance numbers in Sweden were bad enough, one has to wonder how much worse they would be with modern turbines.
For the turbine group, 2 questionnaires each were sent to all 56 houses within 2km of a portion of the turbines in the Makara Valley, NZ. 39 of them were returned (34.8%). These questionnaires were based on a validated instrument, the WHOQOL-BREF. While the first 3 studies concentrated on annoyance, Shepherd concentrated on quality of life. About 500 questionnaires were also sent to houses in a control area that differed only by its distance from any turbine and 158 of them were returned. The individual distances of the homes from a turbine were not calculated or measured, nor was each home’s noise level. Previous measurements indicated that the noise levels at these homes ranged up to 54dbA, depending on conditions. In place of distance/noise metrics, this study compared all the homes in the turbine group with all the homes in the control group.
Shepherd’s results are illuminating. The WHOQOL survey produces measures of physical , psychological and social QOL. While there were no significant differences in the social and psychological (psych was almost significant) QOL measures, there were significant degradations in the turbine group’s physical QOL and environmental QOL. There was also a significant reduction in sleep satisfaction ratings. Out of the 39 turbine group responses, 23 rated the noise to be extremely annoying.
Shepherd: “Statistically significant differences were noted in some HRQOL domain scores, with residents living within 2 km of a turbine installation reporting lower overall quality of life, physical quality of life, and environmental quality of life. Those exposed to turbine noise also reported significantly lower sleep quality, and rated their environment as less restful. Our data suggest that wind farm noise can negatively impact facets of HRQOL.”
One thing that was not different between the groups was their overall self-reported health.
To date the industry hasn’t tried to use Shepherd’s study to build any convenient narratives. In fact they don’t seem to have responded much at all to it. Perhaps they’re hoping nobody important will ever read it. While you can quibble about certain aspects of it (like the small number of responders, but then even with that small number statistical significance was found) I think it is a pretty solid piece of work.
A Quick Summary
Recall that the industry uses these 4 studies as the foundation for their claim that wind turbines have no health effects. It is true that none of these studies found any overall health effects, except for stress and sleep issues. But it is also true that none of these studies concentrated on finding health issues, and none of them even hinted that turbines were totally safe. The first 3 concentrated on annoyance and Shepherd on quality of life. The industry has warped the findings of the first 3 studies to suit their interests. In spite of the unanimous findings of these studies that turbine noise does represent a health hazard the industry claims the opposite. And the government accepts this claim, throwing precaution to the wind. And the neighbors continue to suffer.