We live in fearful times.

The forces of irrationality and nonscience are alive and well in Australia right now. A member of the South Australian Parliament is apparently trying to introduce legislation banning the chemical spraying of the population by the vapour trails behind high-flying jet aircraft. I'm not sure how this rates against the 1897 attempt by the Indiana legislature to pass a law allowing squaring of the circle which coincidentally would have set the value of π to be 3.2, but it would be fun watching the debate. I'm reminded of when someone told me that the NSW Parliament would have to legislate against any sea level rise due to global warming or they would risk a voter backlash from people with expensive, low-lying waterfront properties.

In Queensland the politicians aren't quite as mad, but the state government has recently revoked the compulsory fluoridation of water and is now allowing individual local councils to decide whether they want fluoride in their water supplies. Fluoridation is up there with vaccination as an extremely cost-effective public health initiative, but it's hard to counter stories about people being poisoned by toxic waste from the aluminium industry which was used by the Nazis to control the minds of concentration camp inmates. It is useless pointing out that Queensland has a very significant aluminium extraction and refining industry which doesn't seem to be harming the participants or that the effect of fluoride on the rate of dental decay was discovered by observing populations with varying amounts of naturally-occurring fluoride in streams and creeks. Almost as useless as pointing out to an anti-vaccination campaigner that a single ripe pear has about 600 times as much formaldehyde in it as even the most deadly vaccine and that vaccines don't measurably raise the level of formaldehyde which is naturally in the body. Scary stories win over boring old scientific facts any day.

I recently drove past a large wind farm that was established to balance out the electricity consumption of Sydney's desalination plant. One interesting objection to the desalination plant was that taking salt water from the Pacific Ocean, extracting about five per cent of the water content and pumping the remaining brine back into the ocean would cause an enormous pollution problem by increasing the salinity of the Pacific. I had no answer to this, other than to back away slowly.

Professor Simon Chapman from Sydney University has recently turned his attention from tobacco to investigate the health problems supposedly related to proximity to electricity generating turbines. (There are economic and climate change denial objectors as well, but they are far less vocal than those claiming health dangers.) One amazing fact is that he has collected a list of almost 300 health problems falling under the rubric of "wind farm syndrome", which if all were true would make living near one of these giant propellers possibly the most dangerous thing anybody could do. Residents of Chernobyl and Fukushima would be grateful that they lived near badly designed and maintained nuclear reactors rather than wind farms.

Recent research by Professor Chapman and also by a team at the University of Auckland has thrown interesting light on the health claims surrounding wind farms, and it has general applicability to other health scares. Both studies found that objection and reported problems were not homogeneous across all wind farm installations and people claiming problems, but are related to publicity and preconception.

Professor Chapman looked at the 49 installations in Australia and found only 18 that had generated health or noise complaints. Only 120 people living within five kilometres of turbines had complained, and 81 of these had been related to five installations that have been specifically targeted by opposition groups. This is similar to the situations with both vaccination and fluoridation, where there are pockets of strong opposition clustered around the locations of high-profile activist groups, with the rest of the country paying little or no attention.

The Auckland study is perhaps more relevant to other health scares as it set out to find if bad publicity could affect symptom expectations. A randomised trial using both real and sham infrasound revealed that people with high expectations of something going wrong responded significantly to both real and sham noise, but those with no preconceived opinion showed no reaction at all.

Wind farm objectors can (and probably will) point out flaws in both studies – small sample sizes, Professor Chapman's readily-identified potential bias, what is "sham" infrasound (echoing the complaints about research showing the uselessness of acupuncture) and so on, but even with these flaws there is good indication of a nocebo effect caused by adverse publicity. If people think something is bad for them they will react badly to it.

Now I'm off to have a gluten-free breakfast with permeate-free milk and no GM grains.

References:

Spatio-temporal differences in the history of health and noise complaints about Australian wind farms: evidence for the psychogenic, "communicated disease" hypothesis. Chapman, Simon; St.George, Alexis; Waller, Karen; Cakic, Vince. Sydney University Research Papers and Publications. Public Health, March 14, 2013.

Can Expectations Produce Symptoms From Infrasound Associated With Wind Turbines? Crichton, Fiona; Dodd, George; Schmid, Gian; Gamble, Greg; Petrie, Keith J. Health Psychology,  March 11, 2013

This article was published as the Naked Skeptic column in the May 2013 edition of Australasian Science