CBCnews
Story Tools: EMAIL | PRINT | Text Size: S M L XL | REPORT TYPO | SEND YOUR FEEDBACK | Bookmark and Share
 

Study recommends ear plugs for frequent mass transit users

Last Updated: Friday, June 19, 2009 | 4:12 PM ET

People who use mass transit frequently would be well advised to wear ear plugs next time they take a ride — or risk irreversible hearing loss, a new study says.

The study, published Thursday in the American Journal of Public Health, measured noise levels on New York City's transit system.

Researchers from Columbia University and the University of Washington found that subways in New York had average noise levels of 80.4 decibels. Roughly half of the maximum levels observed on subway platforms were over the 90 decibel threshold.

Suburban trains, meanwhile, averaged 79.4 decibels, and tramways 77.0 decibels. Underground trains were significantly noisier than those than ran above ground. Major hubs were noisier than local stations.

Decibels are a logarithmic unit of measurement, so a noise level of 80 decibels is 10 times as intense as a 70 decibel reading and 100 times as intense as a 60 decibel level. Normal conversation typically hovers around 60-65 decibels.

There is no known risk to hearing loss at sound levels below 70 decibels, according to Health Canada. The World Health Organization recommends daily exposures of no more than 70 decibels for a 24 hour average.

Sustained exposure to noise levels above 85 decibels can pose a hearing loss risk.

To counter elevated noise levels, like those found in the New York transit system, the researchers recommend people who use transit frequently use ear plugs while riding.

Highest readings comparable to rock concert

The two highest readings were observed on a subway platform (102.1 decibels) and at a bus stop (101.6 decibels). Noise at those levels would be comparable to what someone at a rock concert or who uses a chainsaw might experience. Two minutes of exposure to these levels each day would be enough to cause hearing loss in some frequent riders, the study authors say.

Noises at those levels aren't typical in the transit system, but the researchers say that other factors can contribute to an elevated risk of irreversible hearing loss.

For example, riders who travel on transit systems listening to MP3 players at high volumes to drown out the background noise can compound the problem.

"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," said Dr. Robyn Gershon, one of the study authors.

  •  
Story Tools: EMAIL | PRINT | Text Size: S M L XL | REPORT TYPO | SEND YOUR FEEDBACK | Bookmark and Share
 
 

Consumer Headlines

Tim Hortons defends customer ban
Tim Hortons is defending a New Brunswick store owner's decision to ban a customer who complained repeatedly about its decaffeinated coffee.
500,000 cribs recalled in U.S.
Government safety officials in the U.S. have announced a recall of more than 500,000 drop-side cribs sold at Buy Buy Baby, Kmart, Wal-Mart and other stores after the death of three infants.
Montreal inventor unveils 3-D baggage scanner Video
A Montreal inventor has developed a three-dimensional baggage scanner that he says can make air travel safer and more convenient for passengers.
Hoarder's home boarded up Video
Emergency crews boarded up a Winnipeg home and shut off the power after removing a compulsive collector they said posed a danger to himself.
Competition Bureau challenges real estate group Video
The Competition Bureau says the Canadian Real Estate Association limits consumer choice and forces people to pay for services they may not want in selling a house.

People who read this also read …

Top CBCNews.ca Headlines

Headlines

Trenton colonel's charges spur cold case review Video
The 2001 slaying of a Nova Scotia woman at CFB Trenton in eastern Ontario is among the cases being re-examined after murder charges were laid against Col. Russell Williams.
Alberta budget includes $4.75B deficit Video
Alberta's Progressive Conservative government is projecting a record $4.75-billion budget deficit and planning cuts to many departments while increasing health-care spending.
Ottawa to appeal injection site ruling Video
The federal government is asking the Supreme Court of Canada for leave to appeal a lower court ruling that sanctioned Vancouver's supervised drug injection site.
Haiti man pulled from rubble Video
A 28-year-old man has been pulled from rubble in Port-au-Prince, Haiti, claiming to have been trapped there since the massive earthquake on Jan. 12.
Tories need plan for isotope shortage: Ignatieff
Liberal Leader Michael Ignatieff accused the Conservative government of having no plan of action to deal with a medical isotope shortage expected to worsen later this month.