When travelling on public
transport, you may want to
cover your ears
By InnoHEALTH Editorial Team
T
he noise levels commuters
are exposed to while using
public transport or while
biking, could induce hearing
loss if experienced repeatedly and
over long periods of time, according
to a study published in the open
access Journal of Otolaryngology
- Head & Neck Surgery. Efforts
to control noise should focus on
materials and equipment that
provide a quieter environment,
researchers at the University of
Toronto suggest. Hearing protection
while using public transport should
also be promoted.
Dr. Vincent Lin, the corresponding
author said: “This study is the first to
look at and quantify the amount of
noise people are exposed to, during
their daily commute, specifically
on the Toronto Transit System. We
are now starting to understand that
chronic excessive noise exposure leads
to significant systemic pathology, such
as depression, anxiety, increased risk
of chronic diseases and increased
accident risk. Short, intense noise
exposure has been demonstrated to
be as injurious as longer, less intense
noise exposure.”
Dr. Lin said: “We were surprised at
the overall average noise exposure
commuters experience on a daily basis,
especially the peak noise intensity
not only on trains but also on buses.
Planners need to be more considerate
of noise exposure in future planning
of public spaces and public transit
routes. Toronto in particular, as the
transit network expands, needs
to consider ways to reduce noise
exposure as a preventive measure for
future health risks.”
According to thresholds recommended
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Volume 3 | Issue 3 | July-September 2018
To measure noise exposure, the
researchers used noise dosimeters,
which they carried on their shirt
collars about two inches away from
their ears. The researchers collected
210 measurements in total, comparing
the noise on subways, buses and
streetcars, while driving a car, cycling,
and walking. They measured in-
vehicle noise and outside or boarding
platform noise for all modes of private
and public transportation.
by the US Environmental Protection
Agency (EPA), exposure to 114
A-weighted decibels (dBA) for longer
than four seconds, exposure to 117
dBA for longer than two seconds
and exposure to 120 dBA for longer
than 20 seconds may put people
at risk of noise-induced hearing
loss. A-weighted decibels express
the relative loudness of sounds
experienced by the human ear; taking
into account that sensitivity to noise
differs depending on noise frequency.
Peak noise levels in dBA across
both public and personal transport
exceeded the EPA recommended
thresholds. The average noise levels
by bike were greater than any level
caused by modes of public transit.
Measuring noise exposure on
public (subways, trams and
buses) and private (cars, bikes,
walking) transport in Toronto,
the researchers found that while
noise on average was within
the recommended levels of safe
exposure, bursts of loud noise on
both public and private modes of
transportation could still place
individuals at risk of noise-
induced hearing loss.
The authors found that 19.9% of the
loudest noises (peak noise) measured
on the subway were greater than
114 dBA, while 20% of the loudest
noises inside streetcars were greater
than 120 dBA. 85% of peak noise
measurements from bus platforms
were greater than 114 dBA, while 54%
were greater than 120 dBA. All peak
noise exposures while riding a bike
exceeded 117 dBA, with 85% being
greater than 120 dBA.
When the authors extrapolated the
EPA recommended noise thresholds
for an average Toronto commuter
who uses public transport, the
recommended level of noise exposure
was exceeded in 9% of subway, 12% of
bus and 14% of biking measurements
but not when using streetcars, bikes
or when walking.
The authors caution that the
number of measurements taken
for individual modes of transport
is relatively low and that the cross-
sectional nature of the study
does not allow for conclusions
about cause and effect. Further
studies are needed to investigate
other factors that may contribute
to noise exposure such as use
of music players and lengthy transit
times.