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Noise Health. 2004
Apr-Jun;6(23):3-20. |
Vibroacoustic disease.
Branco NA, Alves-Pereira M.
Center for Human Performance, Alverca, Portugal. mariana.pereira@oninet.pt
Vibroacoustic disease (VAD) is a whole-body, systemic pathology, characterized
by the abnormal proliferation of extra-cellular matrices, and caused by
excessive exposure to low frequency noise (LFN). VAD has been observed in LFN-exposed
professionals, such as, aircraft technicians, commercial and military pilots
and cabin crewmembers, ship machinists, restaurant workers, and disk-jockeys.
VAD has also been observed in several populations exposed to environmental LFN.
This report summarizes what is known to date on VAD, LFN-induced pathology, and
related issues. In 1987, the first autopsy of a deceased VAD patient was
performed. The extent of LFN induced damage was overwhelming, and the
information obtained is, still today, guiding many of the associated and
ongoing research projects. In 1992, LFN-exposed animal models began to be
studied in order to gain a deeper knowledge of how tissues respond to this
acoustic stressor. In both human and animal models, LFN exposure causes thickening
of cardiovascular structures. Indeed, pericardial thickening with no
inflammatory process, and in the absence of diastolic dysfunction, is the
hallmark of VAD. Depressions, increased irritability and aggressiveness, a
tendency for isolation, and decreased cognitive skills are all part of the
clinical picture of VAD. LFN is a demonstrated genotoxic agent, inducing an
increased frequency of sister chromatid exchanges in both human and animal
models. The occurrence of malignancies among LFN-exposed humans, and of
metaplastic and displastic appearances in LFN-exposed animals, clearly
corroborates the mutagenic outcome of LFN exposure. The inadequacy of currently
established legislation regarding noise assessments is a powerful hindrance to
scientific advancement. VAD can never be fully recognized as an occupational
and environmental pathology unless the agent of disease--LFN--is acknowledged
and properly evaluated. The worldwide suffering of LFN-exposed individuals is
staggering and it is unethical to maintain this status quo.
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Noise Health. 2004
Jan-Mar;6(22):5-13. |
Health effects caused by
noise: evidence in the literature from the past 25 years.
Ising H, Kruppa B.
Rheinstr. 69, D-14612 Falkensee, Germany. hmising1@aol.com
Traffic noise is the most important source of environmental annoyance.
According to the Environmental Expert Council of Germany, severe annoyance
persistent over prolonged periods of time is to be regarded as causing
distress. Previously, extraaural noise effects were mostly assessed using a
paradigm in which the sound level played the major role. On the basis of this
paradigm the relatively low sound level of environmental noise was not
considered to be a potential danger to health. In contrast to this numerous
empirical results have shown long-term noise-induced health risks. Therefore a
radical change of attitude - a change of paradigm - is necessary. For an
immediate triggering of protective reactions (fight/flight or defeat reactions)
the information conveyed by noise is very often more relevant than the sound
level. It was shown recently that the first and fastest signal detection is
mediated by a subcortical area - the amygdala. For this reason even during
sleep the noise from aeroplanes or heavy goods vehicles may be categorised as
danger signals and induce the release of stress hormones. In accordance with
the noise stress hypothesis chronic stress hormone dysregulations as well as
increases of established endogenous risk factors of ischaemic heart diseases
have been observed under long-term environmental noise exposure. Therefore, an
increased risk of myocardial infarction is to be expected. The results of
individual studies on this subject in most cases do not reach statistical
significance. However, according to the Environmental Expert Council, these
studies show a consistent trend towards an increased cardiovascular risk if the
daytime immission level exceeds 65 dB(A). Most of the previous studies on the
extraaural effects of occupational noise have been invalidated by exposure
misclassifications. In future studies on health effects of noise a correct
exposure assessment is one of the most important preconditions.
Publication Types:
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Review
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Review, Tutorial