Wind farms are a source of concern for local residents because of the noise emitted by the blades. They fear that this infrasound will harm their health.
- Wind turbines emit low-intensity sounds, which can disturb local residents.
- Some highlight effects on their health, such as sleep disorders.
- WHO and ANSES conclude that there is a lack of scientific evidence.
Every wind farm installation project raises concerns. Almost systematically, people oppose it for fear of effects on their health, particularly because of the noise that the devices emit. In The Conversationtwo researchers, Anne-Sophie Evrard and David Ecotière, take stock of the health risks linked to these sounds.
How much noise do wind turbines make?
“Compared to many other sources of environmental noise, whether man-made or natural, the noise levels generated by a wind farm are very moderate, they warn. Outside a resident’s home, they rarely exceed 40 dBA, the equivalent of the noise level in a quiet office.” But this noise can be felt louder than it is: as wind turbines are often located in rural areas, with low background noise, the perception of noise can be louder than its reality.
Wind turbines also emit infrasound: “low-frequency (20-200 Hz, audible) or infrasonic (frequencies below 20 Hz, generally considered inaudible) components that propagate over greater distances than sounds of higher frequencies”. These noises are predominant in wind farms according to the authors, but according to their conclusions, they remain ““very far below” human perception thresholds.
Residents bothered by noise from wind turbines
However, many people report being bothered by these noises.Most available studies have found a significant positive association between wind turbine noise levels and the percentage of people very annoyed, observe the authors. Furthermore, at an equivalent noise level, the noise generated by wind turbines can be perceived as more annoying than that coming from other sources of noise (particularly transport), due to certain acoustic characteristics of the sound signal.” Other, non-acoustic factors can also have an influence. Researchers cite the visual nuisance of the park or the feelings of local residents towards it.
Lack of scientific data on the health effects of wind farms
From a scientific point of view, the effects of wind turbine noise on human health are difficult to demonstrate. First, few studies have been devoted to the potential consequences on “sleep disturbances, cardiovascular disease, metabolic or endocrine systems, cognition or mental health”. “WHO therefore stresses that the evidence regarding the effects of wind noise on health is either non-existent or of low quality”indicate the French researchers.
As for ANSES, the National Agency for Food, Environmental and Occupational Health Safety, its last opinion dates back to 2017: it concluded at that time that “the lack of sufficient scientific argument in favour of the existence of health effects linked to these emissions and the lack of studies on the subject”.
In 2021, however, the French courts recognized the existence of wind turbine syndrome. Residents near a wind farm explained that they had been suffering from various symptoms since the installation of the machines: headaches, nausea, sleep disorders, etc. Exasperated, they decided to move: they claim that their symptoms disappeared after that. The operators of the park were ordered to pay them compensation.
