I study the biological response to acoustical stimuli, in particular, occupational and residential exposures to infrasound and low frequency noise exposure. Over the past 30 years, this has included acoustical measurements, cellular and tissues analyses, as well as clinical and epidemiological studies.
This chapter focuses on infrasonic (≤20 Hz) noise exposure as captured in and around homes locate... more This chapter focuses on infrasonic (≤20 Hz) noise exposure as captured in and around homes located in the vicinity of wind power plants. Despite persistent noise complaints by local residents, no satisfactory acoustical event has yet been identified to justify this troublesome (worldwide) situation. Continuous (days), high-resolution recordings—spectral segmentation of 1/36 of an octave and 1-second temporal increments—have been acquired in many homes across the world revealing the presence of wind turbine acoustic signatures. These consist of trains of airborne pressure pulses, identified in the frequency domain as harmonic series with the fundamental frequency equal to that of the blade-pass frequency of the wind turbine. This report documents three such cases (Portugal and Scotland). The highest peaks of the wind turbine acoustic signature (up to 25 dB over background noise) occurred within the 0.5–5 Hz window which is classically defined as below the human hearing threshold; and...
Vibroacoustic disease (VAD) is a systemic disease that results from long-term exposure to low-fre... more Vibroacoustic disease (VAD) is a systemic disease that results from long-term exposure to low-frequency noise (LFN). VAD can cause lesions in several organs. Noise-exposed individuals frequently present digestive symptoms, but only a few studies have attempted to evaluate gastrointestinal lesions. The aim of this study was to investigate the duodenal alterations in VAD, using an animal model of the disease. Adult Wistar rats were exposed to continuous LFN. After five, nine and thirteen weeks they were sacrificed. The duodenums were studied by light microscopy and scanning electron microscopy, and compared with those of animals kept in silence. Superficial erosions and widespread cell death with microvilli coalescence and fusion were observed, by light and electron microscopy. Erosion, cellular degeneration and death, and microvilli destruction, reflect noise-induced duodenal alterations in rats which may be equivalent to the ulcers and dyspeptic symptoms reported in human VAD patients.
Introduction. In 1980, research into the effects of low frequency noise (LFN, <500 Hz, includi... more Introduction. In 1980, research into the effects of low frequency noise (LFN, <500 Hz, including infrasound) -induced pathology began to be studied among a group of aircraft technicians. Vibroacoustic disease (VAD) has since been defined as the whole-body pathology caused by excessive exposure to LFN. In 1987, the first autopsy of a VAD patient was performed. Among the plethora of findings that laid the foundation of many concurrent avenues of research, was the enormous thickening of the pericardium (a thin sac, <0.5mm thickness, that surrounds the heart). Based on this finding, an echocardiography program was set up among an initial group of 10 technicians. This report exposes the chronological findings of echocardiography in VAD patients. Methods. The results of echocardiograms performed among aircraft technicians, commercial airline pilots and flight attendants, and populations exposed to environmental LFN are gathered and collectively discussed. Results. Echocardiograms of...
Introduction. Vibroacoustic disease (VAD) is the whole-body pathology caused by excessive exposur... more Introduction. Vibroacoustic disease (VAD) is the whole-body pathology caused by excessive exposure to LFN. For the past 25 years, it has been know that low frequency noise (LFN, <500 Hz, including infrasound) targets the respiratory system. In LFN-exposed rodents, the morphological changes of respiratory tract tissue partially explained some respiratory symptoms reported by VAD patients. However, many questions remain unanswered. Recently, some volunteer VAD patients underwent bronchoscopy in order to ascertain possible damage that could be associated with their respiratory complaints. Methods. Fourteen fully-informed and volunteer VAD patients were submitted to bronchoscopy, and biopsies were removed for analysis. Results. All patients exhibited small submucosal vascular-like lesions near the spurs, consisting of increased collagen and elastin fibres. Histology disclosed cilliary abnormalities, basal membrane hyperplasia, and thickening of vessel walls. In five patients, collage...
Previous studies show that exposure to low frequency noise (LFN) (< or =500 Hz, including infr... more Previous studies show that exposure to low frequency noise (LFN) (< or =500 Hz, including infrasound) produces irreversible lesions in Wistar rat respiratory epithelia. Recovery periods for LFN-induced lesions have thus become an object of interest. Changes in the respiratory epithelia of Wistar rats after continuous short-term exposure to LFN are described. Twelve rats were exposed to continuous LFN for 48 hrs, and 10 age-matched rats were kept in silence. Animals were treated in accordance with 86/609/CE. After exposure ceased, two rodents were sacrificed immediately, and another two after 6, 12, 24, 48 hrs, and 7 days of post-exposure silence. Respiratory epithelial fragments were prepared for light and scanning/transmission electron microscopy. Six hours after exposure, intense and irregular cellular tumefaction was visible and rosetta structures, formed by secretory cells (SC) centered on a brush cell (BC), were identifiable. Cilia were shorter and shaggy. BC microvilli tend...
foi definida como uma patologia induzida pelo ruído e caracterizada pelo crescimento anormal de c... more foi definida como uma patologia induzida pelo ruído e caracterizada pelo crescimento anormal de colagénio na ausência de processos inflamatórios. Descreve-se aqui uma revisão cronológica dos achados durante a investigação e as fases clínicas desta doença (para exposições ocuapacionais). Os exames médicos utilizados para diagnosticar a DVA são também descritos. Em 2008, a DVA foi pela primeira vez reconhecida pelo Ministério do Trabalho como a causa para a incapacidade para o trabalho de uma assistente de bordo da aviação comercial. É objectivo deste trabalho fornecer informação sobre a DVA a um público mais alargado. Palavras-chave: infrasons, ruído de baixa frequência, espectro acústico, ocupacional, ambiental
This chapter focuses on infrasonic (≤20 Hz) noise exposure as captured in and around homes locate... more This chapter focuses on infrasonic (≤20 Hz) noise exposure as captured in and around homes located in the vicinity of wind power plants. Despite persistent noise complaints by local residents, no satisfactory acoustical event has yet been identified to justify this troublesome (worldwide) situation. Continuous (days), high-resolution recordings—spectral segmentation of 1/36 of an octave and 1-second temporal increments—have been acquired in many homes across the world revealing the presence of wind turbine acoustic signatures. These consist of trains of airborne pressure pulses, identified in the frequency domain as harmonic series with the fundamental frequency equal to that of the blade-pass frequency of the wind turbine. This report documents three such cases (Portugal and Scotland). The highest peaks of the wind turbine acoustic signature (up to 25 dB over background noise) occurred within the 0.5–5 Hz window which is classically defined as below the human hearing threshold; and...
Vibroacoustic disease (VAD) is a systemic disease that results from long-term exposure to low-fre... more Vibroacoustic disease (VAD) is a systemic disease that results from long-term exposure to low-frequency noise (LFN). VAD can cause lesions in several organs. Noise-exposed individuals frequently present digestive symptoms, but only a few studies have attempted to evaluate gastrointestinal lesions. The aim of this study was to investigate the duodenal alterations in VAD, using an animal model of the disease. Adult Wistar rats were exposed to continuous LFN. After five, nine and thirteen weeks they were sacrificed. The duodenums were studied by light microscopy and scanning electron microscopy, and compared with those of animals kept in silence. Superficial erosions and widespread cell death with microvilli coalescence and fusion were observed, by light and electron microscopy. Erosion, cellular degeneration and death, and microvilli destruction, reflect noise-induced duodenal alterations in rats which may be equivalent to the ulcers and dyspeptic symptoms reported in human VAD patients.
Introduction. In 1980, research into the effects of low frequency noise (LFN, <500 Hz, includi... more Introduction. In 1980, research into the effects of low frequency noise (LFN, <500 Hz, including infrasound) -induced pathology began to be studied among a group of aircraft technicians. Vibroacoustic disease (VAD) has since been defined as the whole-body pathology caused by excessive exposure to LFN. In 1987, the first autopsy of a VAD patient was performed. Among the plethora of findings that laid the foundation of many concurrent avenues of research, was the enormous thickening of the pericardium (a thin sac, <0.5mm thickness, that surrounds the heart). Based on this finding, an echocardiography program was set up among an initial group of 10 technicians. This report exposes the chronological findings of echocardiography in VAD patients. Methods. The results of echocardiograms performed among aircraft technicians, commercial airline pilots and flight attendants, and populations exposed to environmental LFN are gathered and collectively discussed. Results. Echocardiograms of...
Introduction. Vibroacoustic disease (VAD) is the whole-body pathology caused by excessive exposur... more Introduction. Vibroacoustic disease (VAD) is the whole-body pathology caused by excessive exposure to LFN. For the past 25 years, it has been know that low frequency noise (LFN, <500 Hz, including infrasound) targets the respiratory system. In LFN-exposed rodents, the morphological changes of respiratory tract tissue partially explained some respiratory symptoms reported by VAD patients. However, many questions remain unanswered. Recently, some volunteer VAD patients underwent bronchoscopy in order to ascertain possible damage that could be associated with their respiratory complaints. Methods. Fourteen fully-informed and volunteer VAD patients were submitted to bronchoscopy, and biopsies were removed for analysis. Results. All patients exhibited small submucosal vascular-like lesions near the spurs, consisting of increased collagen and elastin fibres. Histology disclosed cilliary abnormalities, basal membrane hyperplasia, and thickening of vessel walls. In five patients, collage...
Previous studies show that exposure to low frequency noise (LFN) (< or =500 Hz, including infr... more Previous studies show that exposure to low frequency noise (LFN) (< or =500 Hz, including infrasound) produces irreversible lesions in Wistar rat respiratory epithelia. Recovery periods for LFN-induced lesions have thus become an object of interest. Changes in the respiratory epithelia of Wistar rats after continuous short-term exposure to LFN are described. Twelve rats were exposed to continuous LFN for 48 hrs, and 10 age-matched rats were kept in silence. Animals were treated in accordance with 86/609/CE. After exposure ceased, two rodents were sacrificed immediately, and another two after 6, 12, 24, 48 hrs, and 7 days of post-exposure silence. Respiratory epithelial fragments were prepared for light and scanning/transmission electron microscopy. Six hours after exposure, intense and irregular cellular tumefaction was visible and rosetta structures, formed by secretory cells (SC) centered on a brush cell (BC), were identifiable. Cilia were shorter and shaggy. BC microvilli tend...
foi definida como uma patologia induzida pelo ruído e caracterizada pelo crescimento anormal de c... more foi definida como uma patologia induzida pelo ruído e caracterizada pelo crescimento anormal de colagénio na ausência de processos inflamatórios. Descreve-se aqui uma revisão cronológica dos achados durante a investigação e as fases clínicas desta doença (para exposições ocuapacionais). Os exames médicos utilizados para diagnosticar a DVA são também descritos. Em 2008, a DVA foi pela primeira vez reconhecida pelo Ministério do Trabalho como a causa para a incapacidade para o trabalho de uma assistente de bordo da aviação comercial. É objectivo deste trabalho fornecer informação sobre a DVA a um público mais alargado. Palavras-chave: infrasons, ruído de baixa frequência, espectro acústico, ocupacional, ambiental
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