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NHMRC Draft Information Paper: Evidence on Wind Farms and Human Health submission

ID: 
4
Personal Details
First Name: 
Fiona
Last Name: 
Crichton
Questions
Q5. Is there additional evidence on whether it is plausible that noise, shadow flicker and electromagnetic radiation (of the type and at the levels produced by wind farms) might affect healthy functioning of the human body?: 

When people report symptoms attributed to environmental factors or new technologies it is important to rule out whether there may be a direct pathogenic link between the factor of concern, and health effects, but also to be aware that there are a number of pathways by which people may experience physical symptoms which they ascribe to the factor of concern, without there being any such direct link. In the case of wind farms, evidence does not support a direct link between adverse health effects and exposure to audible or sub-audible wind farm sound.

Whilst wind farms have been operating in many countries for over twenty years, claims that wind turbines cause health effects are much more recent. Epidemiological evidence has shown that symptom reporting tends to occur in areas where there has been targeted negative publicity about wind farms (Chapman, St George, Waller, & Cakic, 2013) which indicates that the dissemination of information is playing a determinative role in reported symptomatic experiences. Misinformation that exposure to a benign agent may cause health problems can trigger a nocebo response in the presence of that agent. A nocebo response occurs when the expectation of adverse health effects leads to increased symptom reporting. This happens because symptom expectations guide the detection and interpretation of common physiological symptoms, including normal somatic arousal caused by hyper-vigilance and elevated anxiety.

To test the potential for expectations formed by accessing information disseminated through the media, particularly the internet, to determine subjective health assessment during exposure to both audible and sub-audible wind farm sound, my colleagues and I have conducted a series of experiments. The only reliable method to test whether exposure to negative information may be providing a pathway for symptom reporting is experimentally, where exposure to information can be controlled. Given that it has been alleged that people who have hitherto been healthy have experienced acute adverse effects as a result of exposure to wind farm sound, rather than as a result of pre-existing health conditions, it was important that participants in our experiments were healthy volunteers.  Results of the first two experiments have been written up, subjected to rigorous peer review, and published in Health Psychology, which is the official scientific publication of the American Psychological Association’s Division 38 (Health Psychology).  Health Psychology has an ISI Impact Factor of 3.9 and a ranking of 12 out of 114 journals in the category Psychology – Clinical.

Experiment One: Crichton, F., Dodd, G., Schmid, G., Gamble, G., & Petrie, K. J. (2013, March 11). Can Expectations Produce Symptoms From Infrasound Associated With Wind Turbines? Health Psychology. Advance online publication, doi: 10.1037/a0031760

Abstract

Objective: The development of new wind farms in many parts of the world has been thwarted by public concern that sub-audible sound (infrasound) generated by wind turbines causes adverse health effects.  Although the scientific evidence does not support a direct pathophysiological link between infrasound and health complaints, there is a body of information available through the media, particularly the internet, suggesting a link between infrasound exposure and health effects. This study tested the potential for such information to create symptom expectations, thereby providing a possible pathway for symptom reporting.

Design: A sham controlled double blind provocation study, in which participants were exposed to ten minutes of infrasound and ten minutes of sham infrasound, was conducted. Fifty-four participants were randomised to high or low expectancy groups, and presented audiovisual information, integrating material from the internet, designed to invoke either high or low expectations that exposure to infrasound causes specified symptoms.

Results: High expectancy participants reported significant increases, from pre-exposure assessment, in the number and intensity of symptoms experienced during exposure to both infrasound and sham infrasound. There were no symptomatic changes in the low expectancy group.

Conclusion: Healthy volunteers, when given information about the expected physiological effect of infrasound, reported symptoms which aligned with that information, during exposure to both infrasound and sham infrasound. Symptom expectations were created by viewing information readily available on the internet, indicating the potential for symptom expectations to be created outside of the laboratory, in real world settings.  Results suggest psychological expectations could explain the link between wind turbine exposure and health complaints.

 

 

Experiment Two: (Crichton, F., Dodd, G., Schmid, G., Gamble, G., Cundy, T., & Petrie, K. J. (2013, November 25). The Power of Positive and Negative Expectations to Influence Reported Symptoms and Mood During Exposure to Wind Farm Sound. Health Psychology. Advance online publication. doi: 10.1037/hea0000037)

Abstract

 Objective: Wind farm developments have been hampered by claims that sound from wind turbines causes symptoms and negative health reports in nearby residents. As scientific reviews have failed to identify a plausible link between wind turbine sound, and health effects, psychological expectations have been proposed as an explanation for health complaints. Building on recent work showing negative expectations can create symptoms from wind turbines we investigated whether positive expectations can produce the opposite effect, in terms of a reduction in symptoms and improvements in reported health.

 Method: 60 participants were randomised to either positive or negative expectation groups and subsequently exposed to audible wind farm sound and infrasound. Prior to exposure, negative expectation participants watched a DVD incorporating television footage about health effects said to be caused by infrasound produced by wind turbines. In contrast, positive expectation participants viewed a DVD which outlined the possible therapeutic effects of infrasound exposure.

Results:  During exposure to audible windfarm sound and infrasound, symptoms and mood were strongly influenced by the type of expectations. Negative expectation participants experienced a significant increase in symptoms and a significant deterioration in mood, whilst positive expectation participants reported a significant decrease in symptoms and a significant improvement in mood. Conclusion:  The study demonstrates that expectations can influence symptom and mood reports in both positive and negative directions.  The results suggest that if expectations about infrasound are framed in more neutral or benign ways then it is likely reports of symptoms or negative effects could be nullified.

 

The full text to these articles can be accessed through the following links

Experiment One

http://psycnet.apa.org/index.cfm?fa=search.displayRecord&id=71801C47-ACD...

 

Experiment Two

http://psycnet.apa.org/index.cfm?fa=search.displayRecord&id=71801C47-ACD...

Page reviewed: 11 February, 2015