Featured Research

from universities, journals, and other organizations

Got Ear Plugs? You May Want To Sport Them On The Subway And Other Mass Transit, Researchers Say

Date:
June 20, 2009
Source:
Columbia University's Mailman School of Public Health
Summary:
Recent public health studies on the US mass transit system have identified several sources of environmental hazards associated with mass transit, including excessive noise. Scientists have found that MTA subways had the highest average noise levels of all mass transit in New York City, with levels high enough to potentially increase the risk of noise induced hearing loss.

A subway train in New York City. The Metropolitan Transit Authority (MTA) subways had the highest average noise levels of all mass transit in New York City, with levels high enough to potentially increase the risk of noise induced hearing loss.
Credit: iStockphoto

The U.S. mass transit system, the largest in the world, provides affordable and efficient transportation to more than 33 million riders each weekday. The system is generally considered one of the safest modes of travel. But recent public health studies have identified several sources of environmental hazards associated with mass transit, including excessive noise, a large and growing problem in urban settings.

Now, a team of researchers from the University of Washington and Columbia University have found that Metropolitan Transit Authority (MTA) subways had the highest average noise levels of all mass transit in New York City, with levels high enough to potentially increase the risk of noise induced hearing loss. Researchers studied the risk of excessive exposure to noise related to mass transit ridership, and conducted an extensive set of noise measurements of New York City mass transit systems.

Noise induced hearing loss, a permanent, irreversible health problem, is estimated to affect more than 30 million people worldwide, and as many as 10 million in the U.S. alone.

Using sensitive noise dosimeters, the team of researchers, led by exposure scientist Richard Neitzel from the School of Public Health at the University of Washington and Robyn Gershon, DrPH, an environmental and occupational health scientist and faculty member at the Columbia University Mailman School of Public Health, conducted hundreds of measurements of noise levels at platforms and stations, as well as inside of vehicles on New York City subways (MTA and PATH), buses (MTA), ferries (Staten Island), commuter railways (LIRR, SIRR and Metro North), and the Roosevelt Island tramway.

The scientists found that on average, the MTA subways had the highest noise levels, at 80.4 decibels (dBA), followed by the Path trains, at 79.4 dBA, and the tram, at 77.0 dBA. The lowest average levels measured, 74.9 dBA and 75.1 dBA, were obtained from the LIRR and Metro-North trains, respectively. The very highest levels measured in the study were found on an MTA subway platform (102.1dBA) and at a bus stop (101.6 dBA).

In contrast, the noise level of a whisper is 30 dBA, normal conversation is 60 to 70 dBA, a chainsaw is 100 dBA, and gunfire is 140 dBA.

In general, noise levels were significantly higher at platforms compared to inside vehicles for all forms of mass transit, except for ferries and the tram. The borough with the highest mass transit noise levels was Manhattan, followed by Queens and the Bronx. Major hubs were noisier than local stops and underground trains and stations were significantly louder than those aboveground. According to Dr. Gershon, of all mass transit, subways had the highest noise levels, with roughly half of the maximum levels exceeding 90 dBA. "At some of the highest noise levels we obtained (ex. 102.1 dBA on the subway platforms), as little as two minutes of exposure per day would be expected to cause hearing loss in some people with frequent ridership, based upon the International Organization for Standardization models for predicting hearing impairment from noise."

"Even though compared to subways, lower levels were obtained for commuter rail, buses, ferries and the tramway, chronic exposure to noise from these other forms of transit could also present a risk of noise induced hearing loss given sufficient exposure duration," notes Mr. Neitzel. "The risk rises quickly with even small increases in noise levels. For example, 95 dBA is 10 times more intense than 85 dBA and 100 times more intense than 75 dBA."

The U.S. Environmental Protection Agency and the World Health Organization recommend daily exposures of no more than 70 dBA for a 24 hour average. Noises that register below 70 dBA generally have no impact on hearing health and don't cause people to exceed the daily recommendations.

But as Dr. Gershon points out, "For many people, unless the noise is also considered to be a nuisance, such as noisy neighbors late at night, exposure to most loud noise levels is often not perceived as potentially hazardous, and precautions are rarely taken." Further, she states , "People do not necessarily pay attention, for example, to excessive noise from attending concerts, riding motorcycles or even listening to MP3 players at high volume for extended periods," Additionally, as Mr. Neitzel notes, "Transit-related noise levels are high enough to potentially present a risk of noise-induced hearing loss to some frequent transit riders, and this risk could increase substantially when we account for riders' other noise exposures from work and recreational activities." Another important and often overlooked fact, according to Dr. Gershon, is that in addition to impacting your hearing health, excessive noise exposure is linked to hypertension, heart disease, disruptions in stress hormones, sleep disorders and it has been shown to adversely affect learning in children.

For these reasons, the scientists said that noise control efforts, including increased transit infrastructure maintenance and the use of quieter equipment should be a priority. What's more, the use of personal protection will also be helpful. Music headphones and earbuds generally do little to reduce noise exposures, and in fact often increase exposures, as users turn the volume of MP3 players up even higher than normal to drown out surrounding noise.

But a variety of earplugs and earmuffs are commercially available, most of which would be sufficient to reduce transit noise exposures to below the recommended limits. "A loss of just 10 decibels in your hearing acuity can damage your ability to hear other people talking," Neitzel said. "Therefore protection – and, even better, avoidance of high noise exposure when possible - is the best way to preserve your hearing."

The research team is currently following up this study with a large, community –based study of noise exposures from multiple sources to develop accurate predictions of noise-induced hearing loss in urban populations.

The study was funded by the National Institute of Environmental Health Sciences. Co-authors include Marina Zeltser, Allison Canton, and Dr. Muhammad Akram.


Story Source:

The above story is based on materials provided by Columbia University's Mailman School of Public Health. Note: Materials may be edited for content and length.


Journal Reference:

  1. Noise Levels Associated with New York City's Mass Transit Systems. American Journal of Public Health, online June 18; in print August 2009

Cite This Page:

Columbia University's Mailman School of Public Health. "Got Ear Plugs? You May Want To Sport Them On The Subway And Other Mass Transit, Researchers Say." ScienceDaily. ScienceDaily, 20 June 2009. <www.sciencedaily.com/releases/2009/06/090619112339.htm>.
Columbia University's Mailman School of Public Health. (2009, June 20). Got Ear Plugs? You May Want To Sport Them On The Subway And Other Mass Transit, Researchers Say. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2009/06/090619112339.htm
Columbia University's Mailman School of Public Health. "Got Ear Plugs? You May Want To Sport Them On The Subway And Other Mass Transit, Researchers Say." ScienceDaily. www.sciencedaily.com/releases/2009/06/090619112339.htm (accessed July 24, 2014).

Share This




More Health & Medicine News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com
Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Newsy (July 24, 2014) Sheik Umar Khan has treated many of the people infected in the Ebola outbreak, and now he's become one of them. Video provided by Newsy
Powered by NewsLook.com
Condemned Man's US Execution Takes Nearly Two Hours

Condemned Man's US Execution Takes Nearly Two Hours

AFP (July 24, 2014) America's death penalty debate raged Thursday after it took nearly two hours for Arizona to execute a prisoner who lost a Supreme Court battle challenging the experimental lethal drug cocktail. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com
China's Ageing Millions Look Forward to Bleak Future

China's Ageing Millions Look Forward to Bleak Future

AFP (July 24, 2014) China's elderly population is expanding so quickly that children struggle to look after them, pushing them to do something unexpected in Chinese society- move their parents into a nursing home. Duration: 02:07 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins