Scientists from the University of Southampton have discovered that exposure to ultrasound in public places could be making people ill.

For a number of years, researchers have been aware that workers who are frequently exposed to ultrasound from industrial cleaning or drilling machinery can suffer various detrimental health effects.

Research now suggests that exposure to high frequency sounds beyond the range of human hearing from public address systems, loudspeakers and door sensors in train stations, libraries, schools and other civic spaces could be linked to health complaints such as nausea, vertigo, migraines, fatigue and tinnitus.

“Existing guidelines are insufficient for such large public exposures as the vast majority refer to occupational exposure, where workers are aware of the exposure, [it] can be monitored and [they] can wear protection,” says Tim Leighton, Professor at the University of Southampton and lead author of the study. “Furthermore, the guidelines are based on the average response of a small group, often adult males,” he adds.

Leighton recommends that further research should be carried out to protect the public from the inaudible hazard, and suggests that public or residential exposure should not be measured via the same occupational guidelines.

The Professor and his team gathered data from various high frequency ultrasonic fields (VHF/US) in busy public spaces.

Findings revealed that members of the public are regularly exposed to ultrasound frequencies above the threshold for occupational guidelines, which currently stands at 20 kHz.

“Individuals who are unlikely to be aware of such exposures are complaining, for themselves and their children, of a number of medical conditions,” said Leighton, whose findings are due to be published in the journal Proceedings of the Royal Society A.

“The lack of research means that it is not possible to prove or disprove the public health risk or discomfort. However, it is important that sufferers are able to identify the true cause of their symptoms, whether they result from VHF/US exposure or not,” he concludes.

Additional reporting by The Guardian.

Image via Shutterstock.

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