We believe the following 8 research questions are the immediate priority:
What is the maximum distance over which the adverse health effects (especially sleep disturbance) are being reported and perceived by the residents, from the different sized turbines and other sources of industrial Infrasound and Low Frequency Noise (ILFN) in the different terrains and different acoustic environments?
This is essential information for planning purposes, in order to site industrial wind turbines or any other industrial facility safely, so the penetrating infrasound and low frequency sound waves will not harm the health of neighbours.
Which sound and vibration frequencies at what doses are involved in the sleep disturbance episodes, particularly those which involve people waking up repetitively in a panicked state?
We think this is a vital key to understanding why people’s health deteriorates from chronic sleep deprivation and chronic stress, both of which are known to be extremely damaging for health. Direct investigation with in-home sleep studies and concurrent full spectrum sound and vibration monitoring are long overdue. We think this needs to be done in a variety of locations with different noise sources also being measured (eg acoustic pollution from gas fired power stations, CSG field compressors, and mining operations)
What proportion of the population is being affected?
Three population surveys conducted in Australia carried out by Wang, Morris and Schneider suggest that the numbers of affected households are much greater than previously thought, especially with the larger wind turbines. Figures well over 50% of households reporting a negative effect on sleep in these surveys at distances out to 5km or greater from 2MW turbines or larger, indicate that there are problems both with regulation of the noise pollution and with the standards themselves, which do not mandate measurement of infrasound or low frequency noise.
Mining noise and vibration has been reported out to between 5 – 10km in quiet rural areas at night from the Upper Hunter region, and CSG field compressors have been reported to affect neighbours sleep out to 15 km.
What exposure ‘doses’ of sound and vibration energy are people actually receiving, from upwind turbines, at the different frequencies, and which frequencies and exposure doses correlate directly with symptoms?
Currently there is almost no data of exposures inside homes and workplaces, relating to upwind turbines, and it is clear from the progression of people’s symptoms that there is a cumulative effect with ongoing exposure. The recent discovery of old research from the USA in 1985 relating to the impact of acoustic emissions from a single downwind turbine clearly identified nearly 30 years ago that infrasound and low frequency noise from the turbine was causing resonance within the building and that was directly causing the reported annoyance symptoms of the affected residents, and that people became “sensitised” or “conditioned” over time ie the impacts were known to be cumulative.
What are the longitudinal adverse health effects over time?
Which conditions are not reversible with cessation of exposure, i.e. which are leading to permanent damage to health?
What are the impacts on particularly vulnerable groups, such as babies and children, and the elderly and chronically ill, or those with preexisting conditions which make them more vulnerable?
What are the neurophysiological and neuroendocrine connections between ILFN exposure, vestibular dysfunction, repetitive physiological stress and the development of PTSD and other psychiatric disorders?