In a new survey of noise levels of the New York City transit system, researchers at Columbia University's Mailman School of Public Health found that exposure to noise levels in subways have the potential to exceed recommended guidelines of the World Health Organization (WHO) and the U.S. Environmental Protection Agency (EPA).
According to the research, as little as 30 minutes of exposure to decibel levels measured in the New York City transit system per day has the potential to result in hearing loss. The findings have just been published in the September issue of the Journal of Urban Health, a publication of the New York Academy of Medicine.
"Noise exposure and noise-induced hearing loss is a global health problem of significant magnitude, especially in urban settings, yet published data are extremely limited," said Robyn Gershon, DrPH, professor of Sociomedical Sciences at the Mailman School of Public Health and lead author of the study. Dr. Gershon and co-authors report that the findings suggest that, "Daily exposure to noise on subway platforms and subway cars has the potential to cause hearing loss. At the highest level obtained on the platform (106 decibels), the allowable limit under WHO and EPA is only 30 seconds. More than 1 in 10 of the platform measurements exceeded 100 decibels -- which translates into an allowable limit of only 1.5 minutes."
Further, Dr. Gershon notes that "maximum levels inside of subway cars were even greater, and could lead to serious exposures, although more research is needed to determine exactly how much exposure that frequent, long distance, long-term riders experience." This research by safety experts at the Mailman School is the first scientific subway noise assessment in over 30 years, and believed to be one of only two papers published on NYC subway noise; the last one was in the 1930s.
Average and maximum noise measurements were made using a precision sound level meter on subway platforms located in the four New York boroughs with underground subways (Manhattan, Brooklyn, the Bronx, and Queens). The average maximum noise level on subway platforms measured was 94 decibels (dBA). The average maximum inside of subway cars was 95 dBA, and at bus stops, the average maximum was 84 dBA. For comparison, approximate levels of familiar sounds are: 45-60 dBA for normal conversation, 100 dBA for a chainsaw and 140 dBA for a gunblast. The logarithmic nature of decibels means that every 10 dBA equals a 10 fold increase in intensity. Thus a 90 dBA sound is 10 times as intense as an 80 dBA sound.
"Several factors have the potential to contribute to hearing loss, including years of ridership, frequency of ridership, and length of rides," observes Dr. Gershon. If a rider is exposed to other high noise-level activities such as a personal listening device, the potential for hearing loss is even greater." Dr. Gershon further notes that even short exposures to very high noise levels can cause the same amount of damage as much longer exposures at lower levels.
To determine if noise levels varied by location on the subway platforms, measurements were made at three different locations on each platform: the front end, the middle section, and the rear section of the platform. For all measurements, other conditions that could affect noise levels, such as passing trains, air brake release, police sirens, subway musicians etc., were also noted.
Earlier research by Columbia University's Mailman School of Public Health offered a comprehensive look at subway-related health and safety hazards that might affect both riders and subway workers. While this assessment found that subways in general, and the New York City subway system in particular, are relatively safe, especially in comparison to automobile use, they may be associated with a wide range of potential health hazards.
The New York City subway system is the largest and the second oldest system in the U.S., with over 450 subway stations, 500 subway trains, and over 2,000 miles of track. Operating 24 hours a day throughout NYC, it has almost 4 million riders per weekday, which is the fifth largest ridership in the world.
Because excessive noise exposure can ultimately result in noise induced hearing loss, Dr. Gershon notes that risk reduction is the best strategy. Many steps have been taken and continue to be taken by large transit systems, including the Metropolitan Transit Authority, to help reduce subway noise. Steps that individuals can take include the use of personal hearing protection devices (e.g., earplugs and earmuffs). The use of cotton or fingers only reduces the noise levels slightly. The use of personal listening devices, which many may think is protective, can actually contribute to noise exposure if they are played at high volumes. Public education and awareness on hearing protection in general, is highly recommended.
Stephanie Berger | EurekAlert!
Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology
Pan-European study on “Smart Engineering”
30.03.2017 | IPH - Institut für Integrierte Produktion Hannover gGmbH
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
30.03.2017 | Health and Medicine
30.03.2017 | Health and Medicine
30.03.2017 | Medical Engineering