By: Rosemary Stephen PMed, (cert) EOH, IPM, Elements: Environmental Health Intelligence
Although windmills are a green form of renewable energy, complaints of a debilitating effect, called wind turbine syndrome, are surfacing wherever windmills are installed. In Japan, for instance, people started to complain about experiencing physical discomfort such has stiff shoulders, headaches, insomnia, and hand tremors soon after the installation of windmills [1]. Infrasounds [1F] emitted from the rotors of wind turbines have been identified as the cause of these symptoms [2]. This problem is not only affecting urban residential areas, but rural areas as well and the symptoms are so annoying that in the United States people are simply leaving their homes altogether just to move away from the noise and alleviate the symptoms [3].
Infrasound was first reported after the eruption of Krakatoa in 1883 when infrasound waves caused windows to shatter at a distance of more than one hundred miles away from the volcano. These waves can travel very long distances; measurements during the Krakatoa eruption indicated that infrasound waves circled the earth seven times [4]. Vladimir Gavreau and his assistant identified infrasounds in the 1960′s, after experiencing a silent but painful sensation in the ear drums as well as feeling ground vibrations even though no sounds were audible [5,6]. An experiment done in 1983 by Landstrom and al. on subjects with normal hearing and with sensoryneural deafness [2F] indicated that infrasonic frequencies are not only detected by the ear but also by the body [7].
Infrasonic noise is not unique to windmills. Natural events like hurricanes produce infrasound while whales, elephants, rhinoceroses, even giraffes and alligators use infrasound for long distance communication. Man-made products also produce infrasound, including industrial installations, low speed machinery, airplanes and traffic [8]. Infrasound penetrates housing and interferes with human health and induces various psychological disorders by disrupting sleep [9]. Infrasound is even suspected as the root cause of travel / motion sickness.
Infrasonic noise not only troubles dry land, it also adversely affects an aquatic setting. Infrasound in aquaculture tanks has been linked to physiological effects on fish; it lowers their growth rate and creates hormonal deficiencies [10]. Doctor Clark and al. explain in their study entitled “Physiological effects of infrasonic noise on captive fish” that the cause of infrasonic noise in an aquaculture environment can be traced to “Ground vibrations, pumps and other mechanical systems for cleaning, aerating and maintaining constant flows in the water can generate noise that is transmitted to the tanks by pipes, mounts, and airborne paths. Fluctuations in pressure and particle velocity can be further amplified by vibrations of the flexible tank walls” [11].
We have seen that infrasound emanates from a wide rage of natural and man-made sources. In our next blog, we will have a closer look at the physiological effects infrasound has on the human body.
Rosemary Stephen PMed, (cert) EOH, IPM (2010). Wind Turbine Syndrome, Part I Elements: Environmental Health Intelligence
End Notes:
[1F] Infrasounds : acoustic waves with very low frequencies. Infrasounds are audible to the human ear.
Infrasound Monitoring (2010) Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). (On-line) Available: http://www.ctbto.org/verification-regime/monitoring-technologies-how-they-work/infrasound-monitoring/page-2/. Cited 2010 Apr. 16.
[2F] Sensoryneural Deafness: Sensorineural deafness is decreased hearing or hearing loss that occurs from damage to the inner ear, the nerve that runs from the ear to the brain (auditory nerve), or the brain.
Sensorineural deafness (2010) Medline Plus. (On-line) Available: http://www.nlm.nih.gov/medlineplus/ency/article/003291.htm. Cited 2010 Apr 16.
References:
[1] Yoshida, N. and Yasuda, K. Wind power may have its own environmental problems (2009) Physorg.com. (On-line) Available: http://www.physorg.com/news166022416.html. Cited 2010 Apr 08.
[2] Ibid. Cited 2010 Apr 08.
[3] Pierpont, N. Wind Turbine Syndrome (2009) K-Selected Books. (On-line) Available: http://www.kselected.com/?page_id=6560. Cited 2010 Apr 08.
[4] Infrasound Monitoring (2010) Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). (On-line) Available: http://www.ctbto.org/verification-regime/monitoring-technologies-how-they-work/infrasound-monitoring/page-2/. Cited 2010 Apr. 16.
[5] Infrasound (2009) The free encyclopedia, Wikipedia. (On-line) Available: http://en.wikipedia.org/wiki/Infrasound. Cited 2009 Jul 31.
[6] Gavreau, V. Dr. Chapter 8, Deadly Sounds (1999) Lost science. (On-line) Available: http://www.hbci.com/~wenonah/history/gavreau.htm. Cited 2009 Jul 31.
[7] Infrasound (2009) The free encyclopedia, Wikipedia. (On-line) Available: http://en.wikipedia.org/wiki/Infrasound. Cited 2009 Jul 31.
[8] [10] Leventhall, G. What is infrasound? (2006) ScienceDirect. (On-line) Available: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TBN-4KJV20D-1&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=0ac7b15b5a05613c5898414c8da0c184. Cited 2009 Jul 30.
[9] Ilgakojis, P. An investigation of infrasonic in traffic flow noise (2009) WIT eLibrary, Wessex Institute. (On-line) Available: http://library.witpress.com/pages/PaperInfo.asp?PaperID=14629. Cited 2009 Jul 30.
[10] Clark, J.A. and al. Physiological effects of infrasonic noise on captive fish (1996) Acoustical Society of America Digital Library. (On-line) Available: http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JASMAN000100000004002709000005&idtype=cvips&gifs=yes. Cited 2009 Jul 30.
[11] Ibid. Cited 2009 Jul 30.
