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Classifying Indoor Air Problems: What Can Go Wrong?
Published in H.E. Burroughs, Shirley J. Hansen, Managing Indoor Air Quality, 2020
H.E. Burroughs, Shirley J. Hansen
Noise has been found to affect human health by volume, sound pressure levels, infrasound and frequency. Noise at 70–80 decibels (dB)is suspected of causing tiredness. The Occupational Safety and Health Administration sets industrial guidelines at 90 dB. In comparing two situations where the sound levels were both approximately 60 dB and room features were similar, frequency analysis revealed sound pressure levels in the 8–125 Hz range were much higher in the area described as “unpleasant” by the workers. In situations where levels are above 120 dB, infrasound (sound waves in 0.1–20 Hz range) may cause dizziness and nausea. The more common situation to cause problems is found where industrial machines or ventilation equipment emit low frequency noise (20–100 Hz).
Radiation Hazards
Published in Dag K. Brune, Christer Edling, Occupational Hazards in the Health Professions, 2020
Measurements of infrasound can be made with conventional sound level meters equipped with a special low pass filter which attenuates signals with frequencies above 20 Hz. The infrasound level (IL) from such a measurement is given in the decibels (IL). In the environment, infrasound originates from thunderstorms, volcanic eruptions, large waterfalls, and air turbulence. In the working environment, infrasound originates from machines, engines, and ventilation installations. By resonance phenomena, the infrasound can be amplified in rooms and ventilation channels. Ventilation fans can produce infrasound through turbulence around the rotating wheels and fan wings. The sound from exhausting steam and gases from valves, turbines, jet engines, etc. has a strong component of infrasound. Also piston engines and compressors can give rise to infrasound which can be amplified in various spaces.
Wind Turbine Acoustics
Published in Thomas Corke, Robert Nelson, Wind Energy Design, 2018
The primary human response to perceived infrasound is annoyance, with resulting secondary effects. Annoyance levels typically depend on other characteristics of the infrasound, including intensity, variations with time, such as impulses, loudest sound, periodicity, etc. Infrasound has three annoyance mechanisms:A feeling of static pressure.Periodic masking effects in medium and higher frequencies.Rattling of doors, windows, etc. from strong low frequency components.
Study on the Coupling Characteristics of Infrasound–Temperature–Gas in the Process of Coal Spontaneous Combustion and a New Early Warning Method
Published in Combustion Science and Technology, 2023
Yuntao Liang, Shuanglin Song, Baolong Guo, Liyang Gao, Jifan Liu, Wei Lu, Wei Wang, Biao Kong
As the research progresses, the limitations of these methods are gradually exposed. The initial temperature change of CSC is not obvious, the detection of index gas is susceptible to interference and the accuracy of judging coal temperature by index gas is not high. Acoustic emission and electromagnetic radiation signals produced by coal heating and cracking are easy to attenuate in coal and rock, and the transmission distance is limited, resulting in insufficient monitoring range. Infrasound wave (IW) is a kind of sound wave whose frequency is less than 20 Hz. It has the advantages of long wavelength and less attenuation. It has been applied in the field of geological hazard monitoring (Arrowsmith et al. 2010; Park, Hayward, and Stump 2018; Pilger et al. 2019). Qiao et al. (2021) analyzed the characteristics of infrasound response during sandstone shear failure through shear failure test, and provided a theory for landslide warning of sandstone slope using infrasound. Jia et al. studied the characteristics of IW during uniaxial loading of coal, and found that the frequency of infrasound signal mainly distributes within 5–10 Hz, which is significantly different from the noise signal (Jia et al. 2017, 2017, 2021; Wei et al. 2017). The use of infrasound waves for monitoring coal and rock damage and destruction has certain advantages, but there is still no research on the application of infrasound waves for monitoring CSC. There is a lack of understanding of the changes in infrasound waves during the CSC process, and a single indicator cannot accurately mark the risk level of CSC inside the goaf. Therefore, it is necessary to study and analyze the characteristics and variation patterns of infrasound waves in the process of CSC, and further reveal the internal relationship between temperature and indicator gases, in order to comprehensively evaluate the CSC process. The research has played a positive role in monitoring and warning of CSC.
Effects of infrasound on health: looking for improvements in housing conditions
Published in International Journal of Occupational Safety and Ergonomics, 2022
David Baeza Moyano, Roberto Alonso González Lezcano
Studies that directly apply to heart cells [90], myocytes [66] and hippocampal neurons [67] have been conducted. In these cases, infrasound has been shown to produce irreversible damage by causing cell movement and distortion.