Swedish scientist is an idol of the Czech anti-wind movement, but has not proven the harmfulness of wind turbine infrasound

If you have recently taken part in any debate about wind turbines or visited the websites and social media pages of wind turbine opponents, you are bound to have come across the name of Swedish professor Ken Mattsson. His research should be taken seriously, though not in the way anti-wind activists present it.

Ken Mattsson is an applied mathematics specialist at Uppsala University, where he works on computer modelling. The main focus of his research is infrasound – sound with a frequency so low that the human ear cannot detect it.

A video is circulating online in which Mattsson explains, during a 50-minute lecture , that current measurements of wind turbine noise are inadequate because they do not take low-frequency components into account, measuring only frequencies audible to the human ear. “No study has yet proven that infrasound from wind turbines is safe,” Mattsson states in his presentation.

Yet there is also no research that conclusively proves that infrasound from wind turbines harms human health. Ken Mattsson himself has no such research either, although he claims that he returns home with migraines after every wind turbine measurement and cannot sleep for several days.

Skylarks are the biggest enemy

Mattsson goes against the established scientific consensus. A 2014 review study, drawing on 60 peer-reviewed scientific articles, concludes that low-frequency sound and infrasound from wind turbines are unlikely to affect human health. A 2023 document by the Czech National Institute of Public Health reaches a similar conclusion. “There is no evidence that the low-frequency component has effects on residents different from normal sound, nor that infrasound below the hearing threshold could have any effects,” the document states.

And while Mattsson sounds the alarm in the aforementioned 50-minute lecture, he is far more restrained in his peer-reviewed articles published in academic journals. He does not write directly about the harmfulness of infrasound from wind turbines; rather, he urges that it be studied more.

“Professor Mattsson is certainly no crank. He is a scientist who deals with mathematics and differential equations describing the propagation of sound at low frequencies. Much of what he says makes sense, but there are quite a few things he embellishes to make his lecture engaging. He behaves a little like US President Donald Trump,” comments Aleš Jiráska, a noise and acoustics specialist at the National Reference Laboratory for Environmental Noise.

“When, for example, he says that no animal wants to live within five kilometres of a wind turbine, that is not true. I have been measuring wind turbine noise for 30 years, and skylarks interfere with my measurements. The worst enemy of wind turbine noise measurers is the Eurasian skylark. So Professor Mattsson cannot tell me that animals are fleeing from there when skylarks live there perfectly comfortably and could not care less about wind turbines,” Jiráska argues.

He does not conduct health research

“The main point is probably that Mattsson does not conduct any research into health effects; he only measures the propagation of infrasound in the landscape. But that says nothing about health effects,” says Petr Vidomus, an analyst at the Association for International Affairs and author of the study Against the wind, which examines the activities of wind turbine opponents. “The anti-wind movement operates in the same way climate sceptics once did – they take some ‘dissenting’ fringe scientist and recycle them over and over,” Vidomus adds.

Mattsson is frequently invoked by anti-wind organisations in many European countries. “They say: Let us first carry out more and more research into whether it is dangerous before we begin any construction of wind farms. They are trying to completely dilute the debate, and if we went along with it, nothing would ever be built here,” says Vidomus.

“The fact that someone is a scientist does not at all mean they cannot be bribed, or that one part of their research is rigorous and another is not,” warns Daniel Kortus, a scientist at the University of Chemistry and Technology, Prague, and founder of the Klimatomluva project.

“A current example of such a scientist is John Clauser. He won the Nobel Prize in quantum mechanics, but then readily allowed himself to be courted by the fossil fuel industry to say that climate change is not caused by humans,” says Kortus. “And the fact that Ken Mattsson works on the mechanics of sound and its modelling does not make him a medical expert who understands what affects human health and how,” the scientist adds.

Turbines face stricter limits than transport

Infrasound has a long wavelength, allowing it to travel long distances and pass through walls and other obstacles. In nature, infrasound is produced by volcanoes, thunderstorms, sea waves, earthquakes, as well as water and wind. Elephants, whales, hippos and other animals use it to communicate.

As for artificial sources of infrasound, wind turbines are far from the only ones. Low-frequency sound is also produced by hydroelectric dams, high-speed rail lines, aircraft and internal combustion engines, particularly diesel engines. The deep rumble that city residents hear at night – and probably no longer even notice – is caused by cars passing nearby and within the city. However, representatives of the Motorists for Themselves party do not protest against diesel engines, unlike against wind turbine noise.

“The number one noise issue is transport, where we have a daytime limit of 68 decibels and a night-time limit of 58 decibels,” says Jiráska. A wind turbine, by contrast, must comply with a daytime limit of 50 and a night-time limit of 40 decibels.

Detailed measurements are carried out in Czechia

Mattsson claims that infrasound from wind turbines is worse than naturally occurring infrasound because of its pulsating nature. He says that measuring noise levels using the A-weighting filter, which corresponds to the sensitivity of the human ear (and therefore gives less weight to low and very high frequencies), is inadequate.

“Mattsson suggests that A-weighting is a measurement system that works for higher frequencies but is less effective for low-frequency sources. I agree with that, but in Czechia we do not rely solely on the A-weighting filter; we also always examine the occurrence of so-called tonal components in frequency bands from 6 Hz to 20 kHz. However, Mattsson says there may be a problem even around one hertz. That is why we also carry out detailed spectrum measurements in the 0 to 500 Hz range,” says Jiráska.

It is legitimate to investigate the effects of infrasound from wind turbines on human health, as Mattsson calls for. At the same time, the limitations of such research must be taken into account. Studies based, for instance, on questionnaires may be distorted by the so-called nocebo effect (the opposite of the placebo effect, author’s note) – a situation in which people begin to experience real health problems because they expect them, are frightened by misinformation and so on. Subjective symptoms such as insomnia, headaches or stress may in such cases arise more from concerns than from infrasound itself.