On the Impact of Infrasound and Low Frequency Noise on Public Health – Two Cases of Residential Exposure
Abstract: Noise exposure is known to cause hearing loss and a variety of disturbances, such as annoyance, hypertension and loss of sleep. It is generally accepted that these situations are caused by the acoustical events processed by the auditory system. However, there are acoustical events that are not necessarily processed by the auditory system, but that nevertheless cause harm. Infrasound and low frequency noise (ILFN, <500Hz) are acoustical phenomena that can impact the human body causing irreversible organic damage to the organism, but that do not cause classical hearing impairment. Acoustical environments are normally composed of all types of acoustical events: those that are processed by the auditory system, and those that are not. It is generally assumed that acoustical phenomena not captured by the human auditory system are not harmful. This is reflected by current noise assessment procedures that merely require the quantification of the acoustical phenomena that are audible to human hearing (hence the dBA unit). Thus, studies investigating the effects ofnoise exposure on public health that do not take into account the entire spectrum of acoustical energy are misleading and may, in fact, be scientifically unsound. Two cases of in-home ILFN are described. …
Case Report 2: Family R. lives on a horse- and bull-breeding farm, located in a zoned, rural agricultural area, 1 hour north of Lisbon. Family R. consists of mother, father, 12-year-old son, and 8-year-old daughter. In November 2006, 4 wind turbines (2MW each) were installed around Family R.’s farm, at approximately 322m, 540m, 580m and 643m from the residential home. The distance to the stables is less than to the residential house. …
The wind turbines installed around Family R.’s home began operation in November 2006. In March 2007, the parents received a letter from the school inquiring about the reason for the sharp decrease in the memory and attention skills of the 12-year-old child, and the overwhelming tiredness he exhibited during physical education classes. The school questioned the parents if the boy was getting enough hours of sleep during the night.
The entire family has already received the typical vibroacoustic disease diagnostic tests, including echocardiograms which did not disclose any significant thickening of cardiovascular structures. Tissue fragments have been removed from the farm animals that have been scheduled for slaughter, and will be submitted to the light and electron microscopy analyses that this team usually conducts on ILFN-exposed tissue fragments. These procedures will be repeated every 6 months, and follow-up reports will ensue.
Revista Lusófona de Ciencias e Tecnologias da Saúde, 2007; (4) 2: 186-200
Direcção de Radiologia da Escola Superior de Saúde Ribeiro Sanches, Lisboa, Portugal.
Departamento de Ciencias da Saúde, Universidade Lusófona, Lisboa, Portugal.
Nuno A. A. Castelo Branco
Centro de Performance Humana, Alverca, Portugal.
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Family with Wind Turbines in Close Proximity to Home: Follow-Up of the Case Presented in 2007
In 2007, at the 2nd International Conference on Wind Turbine (WT) Noise, held in Lyon, France, low frequency noise (<500 Hz, LFN)–induced pathology, consistent with vibroacoustic disease (VAD), was shown to be emerging in the R. Family, exposed to residential LFN generated by 4 WTs installed in close proximity (300-700 m) to their home. Herein, a follow-up is provided.
The wife and 2 children no longer reside within that home. Mr. R., however, must remain to care for the thoroughbred Lusitanian horses and bulls that he trains and breeds for bullfights. In addition to the continued deterioration of Mr. R’s health and well-being, his financial situation is aggravated by the condition now appearing in his horses during the first year of life. Between 2000 and 2006, 13 healthy thoroughbred Lusitanian horses were born and raised on Mr. R’s property. All horses (N=4) born or raised after 2007 developed asymmetric flexural limb deformities. WTs began operations in November 2006. No other changes (constructions, industries, etc) were introduced into the area during this time.
Tissue analyses of the defected tendons were performed and revealed the classical features of LFN-induced biological responses: thickening of blood vessel walls due to proliferation of collagen in the absence of an inflammatory process.
14th International Meeting on Low Frequency Noise and Vibration and Its Control, Aalborg, Denmark, 9-11 June 2010
Nuno A. A. Castelo Branco
Luis Amaral Dias
Centro da Performance Humana, Alverca, Portugal
Teresa Costa e Curto
João Pedro da Costa Pereira
Sociedade Hípica Portuguesa, Campo Grande, Lisboa, Portugal
Luisa Mendes Jorge
Júlio Cavaco Faísca
Faculty of Veterinary Medicine, Universidade Técnica de Lisboa, Lisbon, Portugal
José Martins dos Santos
Instituto Superior de Ciências da Saúde Egas Moniz, CiiEM, Almada, Portugal
Universidade Lusófona–ERISA, Lisboa, Portugal