Papers by mariana Alves-Pereira
Journal of laryngology and voice, 2014
Background: Vibroacoustic disease (VAD) is a systematic pathology characterized by the abnormal g... more Background: Vibroacoustic disease (VAD) is a systematic pathology characterized by the abnormal growth of extra-cellular matrices in the absence of infl ammatory processes, namely collagen and elastin, both of which are abundant in the basement membrane zone of the vocal folds. VAD can develop due to long-term exposure to infrasound and low-frequency noise (ILFN, <500 Hz). Mendes et al. (2006, 2008 and 2012) revealed that ILFN-exposed males and females presented an increased fundamental frequency (F 0), decreased jitter %, and reduced maximum phonation frequency range, when compared with normative data. Temporal measures of maximum phonation time and S/Z ratio were generally reduced. Study Aims: Herein, the same voice acoustic parameters of 48 males, 36 airline pilots and 12 cabin crewmembers (age range 25-60 years) were studied, and the effects and interaction of age and years of ILFN exposure were investigated within those parameters. ILFN-exposure time (i.e. years of professional activity) ranged from 3.5 to 36 years. Materials and Methods: Spoken and sung phonatory tasks were recorded with a DA-P1 Tascam DAT and a C420III PP AKG head-worn microphone, positioned at 3 cm from the mouth. Acoustic analyses were performed using KayPENTAX Computer Speech Lab and Multi-Dimensional Voice Program. Results: Results revealed that even though pilots and cabin crewmembers were exposed to occupational environments with distinct (ILFN-rich) acoustical frequency distributions and sound pressure levels, differences in the vocal acoustic parameters were not evident. Analyzing data from both professional groups (N = 48) revealed that F 0 increased signifi cantly with the number of years of professional activity. Conclusion: These results strongly suggest that the number of years of professional activity (i.e. total ILFN exposure time) had a signifi cant effect on F 0. Furthermore, they may refl ect the histological changes specifi cally observed on the vocal folds of ILFN-exposed professionals.
Background: Over the past two decades, the increasing and unregulated production of infrasound an... more Background: Over the past two decades, the increasing and unregulated production of infrasound and low frequency noise (ILFN, ≤200 Hz) has led to a considerable rise in associated noise complaints and health-related issues. The most recent of such ILFN sources are industrial wind turbines (IWT). Acoustical field-data was collected within a home located in the vicinity of IWT, to which the AUC Rule 012 and its requirements were applied. In Ontario, IWT noise complaints were gathered under the Freedom of Information legislation. Goal: To explore the usefulness of current noise control rules when protecting human populations against ILFN generated by IWT.
Environmental Sciences
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...
European journal of public health, Apr 1, 2019
European journal of anatomy, 2005
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.
Central European Journal of Public Health, Mar 1, 2006
Introduction: Exposure to low frequency noise (LFN) can lead to vibroacoustic disease (VAD), reco... more Introduction: Exposure to low frequency noise (LFN) can lead to vibroacoustic disease (VAD), recognized as a systemic disease with lesions in a broad spectrum of organs. Although gastrointestinal complaints are common among individuals exposed to noise, only few studies tried to evaluate the digestive lesions. The authors performed this study in order to investigate gastric lesions in an animal model of VAD. Material and methods: Adult Wistar rats were exposed to continuous LFN. After five weeks they were sacrificed. The stomachs were studied by light microscopy and scanning electron microscopy, and compared with stomachs of animals kept in silence. Results: Superficial erosions were present in the noise-exposed animals. Massive cell death of the gastric epithelium was observed, both by light and electron microscopy. Discussion: The erosions, reflecting cellular degeneration and death, occurred without inflammation, similar to what has been observed in other LFN-exposed organs.
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.
Characterising acoustical environments where humans may be sleeping requires hi-fidelity recordin... more Characterising acoustical environments where humans may be sleeping requires hi-fidelity recordings of the entire soundscape, which allows relevant post-processing of the data. The ongoing Citizen Science Initiative for the Acoustical Characterisation of Human Environments (CSI-ACHE) is dedicated to capturing quality recordings of such human acoustical environments. This paper introduces the recording system created to capture such soundscapes. It provides the specifications for the device, as well as the implementation and the tests used to characterise the performance and calibrate against a Class 1 instrument. This system has been marketed as SAM Scribe and fundamentally consists of a two-channel device that can measure at sampling rates up to 44.1 kHz, and that delivers the data streams via USB to a Windows notebook computer to store as uncompressed wav files to hard disk. GPS information is stored as metadata in the files, which also include a digital signature. Storage of several months of continuous recordings can be achieved using an external USB 3.0 hard drive. The system can accurately record from 0.5 Hz to 10 kHz and is simple to operate.
Proceedings of the International …, 1999
Background. The importance of information technologies in public awareness of environmental issue... more Background. The importance of information technologies in public awareness of environmental issues is especially clear when a new occupational disease is identified. This is certainly the case with Vibroacoustic Disease (VAD), a whole-body noise-induced pathology, that is not particularly related to the ear. The Problem. The social and economic costs of VAD are staggering, and continuously aggravated by the fact that environmental noise assessments pay little attention to the noise that causes VAD-Low Frequency (LF) noise (* 500 Hz), focusing primarily on that which causes hearing impairment. An erroneous assumption justifies these incomplete noise assessment requirements: noise only affects the ear. Thus, all noise protection measures and evaluation procedures focus exclusively on the frequencies affecting the auditory system (* 500 Hz). The Solution. Physical protection against LF noise is not feasible, given the large wavelength of LF (in meters). Preventing the evolution of VAD to clinically severe stages is feasible. The requirements are twofold: a) entry-level and yearly echocardiogram of jobcandidates and exposed individuals; b) education of workers, occupational physicians, and management. There is an urgent need to include LF in all noise assessments, and use prevention medicine against this ubiquitous environmental hazard. However, this can only be achieved with active participation of a wellinformed public. THE STATUS QUO Noise pollution is often considered a contained problem because hearing protection devices are generally efficient, and legislation regarding noise-induced hearing loss is relatively effective. Additionally, common noise assessments are a fairly simple process, normally requiring a hand-held instrument that measures the sound pressure level (SPL) of the acoustic field, in decibels (dB). Permissible exposure levels are primarily based on the dB-level measurements, and are regulated on an hourly basis. Noise pollution is largely regarded as an agent that causes hearing loss and/or minor annoyance and discomfort. The notion that no other harmful organic effects can be attributed to noise exposure is widespread, and exceptions to this are few and far between (Alves-Pereira, 1999). The human ear captures sound within a specific window of the acoustic spectrum, generally within the 20-20000 Hz range. However, it is most responsive to sounds within the mid-frequencies: 1000-10000 Hz. Noise exposure protection focuses primarily on these frequencies, because its goal is to prevent hearing loss. Acoustic phenomena within the low frequency (LF) range (* 500 Hz) are also audible, but require a higher intensity to be perceived. Infrasound (* 20 Hz) is non-audible to humans; it is therefore considered to have no impact upon hearing loss, and consequently, environmental noise assessments within the infrasonic range are a rarity (Alves-Pereira, 1999). For the remainder of this report, LF noise will refer to acoustic phenomena within the 0-500 Hz range, hence infrasound is also included.
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...
Progress in Biophysics and Molecular Biology, 2007
At present, infrasound (0-20 Hz) and low-frequency noise (20-500 Hz) (ILFN, 0-500 Hz) are agents ... more At present, infrasound (0-20 Hz) and low-frequency noise (20-500 Hz) (ILFN, 0-500 Hz) are agents of disease that go unchecked. Vibroacoustic disease (VAD) is a whole-body pathology that develops in individuals excessively exposed to ILFN. VAD has been diagnosed within several professional groups employed within the aeronautical industry, and in other heavy industries. However, given the ubiquitous nature of ILFN and the absence of legislation concerning ILFN, V AD is increasingly being diagnosed among members of the general population, including children. V AD is associated with the abnormal growth of extra-cellular matrices (collagen and elastin), in the absence of an inflammatory process. In V AD, the end-product of collagen and elastin growth is reinforcement of structural integrity. This is seen in blood vessels, cardiac structures, trachea, lung, and kidney of both VAD patients and ILFN-exposed animals. VAD is, essentially, a mechanotransduction disease. Inter-and intra-cellular communication is achieved through both biochemical and mechanotranduction signalling. When the structural components of tissue are altered, as is seen in ILFN-exposed specimens, the mechanically mediated signalling is, at best, impaired. Common medical diagnostic tests, such as EKG, EEG, as well as many blood chemistry analyses, are based on the malfunction of biochemical signalling processes. V AD patients typically present normal values for these tests. However, when echocardiography, brain MRI or histological studies are performed, where structural changes can be identified, all consistently show significant changes in VAD patients and ILFN-exposed animals. Frequency-specific effects are not yet known, valid dose-responses have been difficult to identify, and large-scale epidemiological studies are still Jacking.
Revista Portuguesa de Pneumologia, 2003
Apesar do importante acervo de evidência científica já existente, a patologia respiratória provoc... more Apesar do importante acervo de evidência científica já existente, a patologia respiratória provocada pela exposição crónica a ruído de baixa frequência (RBF) continua por reconhecer. O objectivo deste trabalho de revisão consiste em: ABSTRACT Noise-induced pulmonary pathology is still an issue that is regarded with much suspicion despite the significant body of evidence demonstrating that acoustic phenomena target the respiratory tract. The goal of this review paper is threefold: O ruído e o aparelho respiratório Noise and the respiratory system
Revista Portuguesa de Pneumologia, 2006
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...
Revista Portuguesa de Pneumologia
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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Papers by mariana Alves-Pereira