Documents > Noise, health > Alec N. Salt - Wind Turbines are Hazardous to Human Health

Alec N. Salt, Ph.D., Cochlear Fluids Research Laboratory, Washington University in St. Louis.

Wind Turbines are Hazardous to Human Health

Overview of The Problem

Wind turbines such as those currently being constructed in rural areas generate high levels of infrasound noise. This is very low frequency noise (sound waves of less than 20 cycles per second) that you cannot hear. Even though you cannot hear the sound, it is easily detected by the ear at the levels that are produced and can have effects on the body that profoundly disturb some individuals.

The situation is somewhat similar to ultraviolet (UV) light and the eye. We cannot see ultraviolet light but we all understand that it can affect us profoundly, causing sunburn, photokeratitis (also known as snow blindness or welder's flash) and cataracts. For UV light, there are simple ways that the damaging effects can be avoided using sunscreens and eye protection.

For infrasound exposure in your home, there is currently NO WAY TO PROTECT YOURSELF. Although double glazing and door seals will reduce the levels of the sounds you can hear, they have little influence on the infrasound level in the home. Infrasound is a slowly-changing pressure wave, that can only be blocked by completely sealing the house, making it airtight. In practice this cannot be performed due to building codes and the risk of suffocation.

The effects of wind turbine infrasound build up slowly on people. For most, there are no effects while in the vicinity of wind turbines for short periods (such as the workday) and when higher levels of other sounds (i.e. sound you can hear) are present. The problem arises when people try and sleep in their homes in the presence of wind turbine noise. The audible sounds are reduced by the house structure, so the room may be fairly quiet, but the sound becomes dominated by the infrasound that the person cannot hear. The infrasound is detected by the ear and has subtle influences on the body that we are only just beginning to understand. It can cause dysequilibrium (like sea-sickness, but not induced by movement), tinnitus, a sensation of fullness in the ear and worst of all, disturb sleep, probably by stimulation of subconscious neural pathways to the brain. People undergo repeated arousals from sleep (brief partial awakenings that are not remembered) and repeated awakenings when sleeping in such an environment that leave the individual stressed and unrefreshed. Sleep disturbance over a prolonged period is known to be extremely hazardous to health, causing mental changes, high blood pressure, diabetes and increased mortality.

In many cases, these health effects have been significant enough to force people to abandon their homes. In a few cases the homes have been “bought out” by the wind turbine companies (and the owners typically "silenced" by non-disclosure agreements, otherwise known as "gag" orders), but in others the home is abandoned and is difficult to sell to another family. Properties located in the vicinity of wind turbines are becoming increasingly difficult to sell. Recent epidemiological studies suggest that significant disturbances of sleep and mental health occur for people living in homes up to 5 kilometers away from the wind turbines. This is because infrasound is capable of traveling greater distances than the sound you normally hear (which is why elephants and whales use it to communicate).

The wind turbine companies and most politicians are turning a deaf ear to this problem, and continue to promulgate false and debunked arguments that no problem exists. In this collection of pages we consider in detail some of these issues in which we have scientific expertise.

Specific Issues Considered

• Industrial Wind Turbines Generate Infrasound
• The Ear Detects Infrasound at Levels that are not Heard
• Infrasounds you Cannot Hear Can Affect you
• Why Wind Turbine Sound Measurements using the dB(A) Scale (A-weighted) are Misleading
• Why it is Difficult to Demonstrate the Infrasound Generated by Wind Turbines
• 550 Meter (or lower) Setbacks are Insane!