The Health Canada study into possible human health effects from wind turbine sound is designed to identify the source of both real and imagined problems from both the objectivity of science and the subjectivity of interviews with persons living near commercial wind farms.
Health Canada acknowledges that lowfrequency sound can increase the pressure of sound “disproportionately” and can cause a “rattling” of light objects within some receptor homes.
It also acknowledges that distance from turbines is only one of several factors influencing the effects of sound. Other factors, it says, include type of turbine, intervening structures, existing background sound levels, wind speed and direction, topography and meteorological conditions.
All such things are likely to be assessed as part of the study of about a dozen communities.
The federal ministry has yet to reveal which wind farm areas are among the eight to 12 communities to be studied, and specifically whether it would include the Melancthon Wind Farm, the first commercial-scale one in Ontario.
It does say, however, that it has selected 2,000 homes that are closer than 600 metres to turbines. Melancthon Phase 1 has some that are reported to be within 300 metres. The design for Phase 2 called for setbacks of at least 450 metres. Since then, Ontario has set a criterion of a 550-metre setback from non-participating receptor homes.
Possibly because low-frequency sound travels farther that audible ones, the study will include homes within 10 kilometres of turbines.
The study is to be headed by two Health Canada scientists – David Michaud PhD and Katya Feder PhD – but there are 22 other research scientists, medical doctors and epidemiologists including professional personnel from Statistics Canada, Natural Resources Canada, and Public Health Agency of Canada, among other agencies.
As well, there are five international advisers, from Japan, the Netherlands and Australia.
“The study aims to assess the data for evidence that living in areas with higher calculated wind turbine sound levels is associated with: impairments in sleep, as measured with actimetry; over-activated stress system, as measured by both cortisol concentrations in hair samples and elevated diastolic and systolic blood pressure and heart rate; and impairments in perceived stress, quality of life and self-reported sleep quality,” the research design report reads in part.
Subjects will wear a waterproof wrist monitor for seven days. The measured sleep disturbances and blood-pressure changes will be synchronized with the operations of the wind turbines.
They will participate in a 30-35 minute interview in which their smoking and drinking habits will be explored, as well as their various reactions to turbines.
The release of the methodology more or less coincides with a Global Wind Energy Council (GWEC) report that shows worldwide installed wind energy capacity increasing by 19 per cent in 2012 to 282,000 MW.
“Canada remains a global wind energy leader as it experienced the 9th largest increase in installed capacity in 2012 (936 MW). Both China and the United States, the world’s wind energy leaders, installed more than 13,000 MW of new capacity in 2012,” GWEC’s February 2013 report says.
It also coincides more or less with an Oraclepoll survey, conducted in January 2013, that showed 69% of Ontario residents in favour of wind energy, and also a Quebec public opinion poll published by Le Devoir that showed 79% in favour in that province.
The margin of error for the Oraclepoll survey of 1,000 adults is said to be plus or minus 3.1%, 19 times out of 20.
But it also coincides with a call by Dufferin County Council for the province to impose a moratorium on wind farm development pending the outcome of the federal study.
The study will be centred on the effects of sound, ultrasound (20-200 hz) and infrasound (1-20 hz), according to a just-released research design.
Health Canada says there is a knowledge gap in the area of low-frequency sound – which is generally inaudible to the human ear.
“Some public concern has been expressed about the potential health impacts of wind turbine sound (WTS). The health effects reported by individuals living in communities in close proximity to wind turbines are poorly understood due to limited scientific research in this area,” Health Canada acknowledges in its summary.
Whether or not the outcome of the study satisfies all factions for and against turbines remains to be seen, but the in-depth pioneering study is likely to be welcomed by governments globally.
Last July, Health Canada said the study results “are expected to be published in 2014.”
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