Medical and scientific news

Safe noise exposure for the general public

Daniel Fink, M.D., Interim Chair of the Quiet Communities Health Advisory Council, has written a post for the Quiet Communities’s blog that tackles a question which is rarely addressed: What noise level IS safe for preventing hearing loss?

In his post, Dr. Fink discusses the seeming contradiction between a 1974 Environmental Protection Agency (EPA) determination that “a 24-hour average noise exposure level of 70 decibels (dB) or less prevent[s] measurable hearing loss over a lifetime” with statements from various governmental and nonprofit organizations that suggested that “a much louder noise level − anything up to 85 dB − was safe for our ears.”  In the course of researching the issue, he received a communication from the National Institute of Occupational Safety and Health (NIOSH) that explained where the 85 dB figure came from; the information in that communication formed the basis of a post on NIOSH’s Science Blog in February 2016 (which is discussed here).

Long and short, the NIOSH communication explained that the 85 dB was an occupational noise exposure standard developed to protect workers over a lifetime of work, whereas the EPA determination of 70 dB averaged noise exposure over 24 hours was believed to protect the general public from hearing loss over a lifetime.  As Dr. Fink notes that the clarification of the difference in noise exposure limits is important in setting public policy and protecting public health, and he concludes that, based on his research, “[t]he much lower 70 dB average noise exposure level is the only published safe noise level to protect the public’s hearing.”

 

NIOSH Science Blog clarifies difference between occupational and general noise exposure limits

Many people are confused about what is a safe noise limit for the general public because the only noise limit the public may have heard about is the 85 decibel recommended exposure limit (REL) that National Institute for Occupational Safety and Health (NIOSH) established for occupational noise exposures.  Fortunately, the NIOSH Science Blog has just posted an informative piece* that discusses acceptable RELS for both, titled: Understanding Noise Exposure Limits: Occupational vs. General Environmental Noise.

The authors state that in 1998, NIOSH established the REL for occupational noise exposure to be 85 decibels based on an 8-hour shift for a 5-day work week, adding that the REL “assumes that the individual spends the other 16 hours in the day, as well as weekends, in quieter conditions,” and cautioning that “the NIOSH REL is not a recommendation for noise exposures outside of the workplace in the general environment.”  The difference between the occupational and general environmental noise exposures is that:

The NIOSH REL is not meant to be used to protect against general environmental or recreational noise; it does not account for noisy activities or hobbies outside the workplace (such as hunting, power tool use, listening to music with ear buds, playing music, or attending sporting events, movies and concerts) which may increase the overall risk for hearing loss.

The authors point out that a 1974 Environmental Protection Agency (EPA) report recommended 70 decibels over a 24-hour average exposure limit for general environmental noise (while noting the EPA’s caution that its recommendation was not a standard, specification, or regulation).  This recommendation was determined in a similar manner as the NIOSH REL, but it’s focus was on general environmental noise and not the workplace.  As the EPA report states, their recommendation “was chosen to protect 96% of the general population from developing hearing loss as well as to protect ‘public health and welfare.’”

The authors note that both limits “are based on the same scientific evidence and the equal-energy rule,” but “are designed to protect against different problems.”  As a result, the limit values differ because “the EPA limit was averaged over 24 hours with no rest period while the NIOSH limit is averaged for just 8 hours and includes a rest period between exposures,” and the EPA limit includes an allowance “to protect against exposures for 365 days a year versus the NIOSH REL’s calculation that aims to protect against work place exposures for 250 working days a year.”   The authors add that “the EPA limit did not consider cost or feasibility of implementation as the Occupational Safety and Health Administration (OSHA), in accepting a NIOSH REL as the basis for a mandatory standard, [was] required to do under the Occupational Safety and Health Act of 1970.”

Long and short, the authors conclude that the 85 decibel REL is a work standard that neither mandates nor recommends decibel limits for the general public.  Rather, it is the EPA’s recommendation of 70 decibels that provides the appropriate exposure limits for the public with regard to general environmental noise.

*The post was prepared by NIOSH engineer, Chuck Kardous, MS, PE; NIOSH audiologist, Christa L. Themann, MA; NIOSH research audiologist Thais C. Morata, Ph.D., who is also the Coordinator of the NORA Manufacturing Sector Council; and W. Gregory Lotz, Ph.D, Captain, US Public Health Service, Division Director of the Division of Applied Research and Technology (DART), and the manager of the NORA Manufacturing Sector Council.

Turn It Down: How to protect yourself against noise pollution

In “Turn It Down,” Dangerstoppers (Beverly Hills Television) highlights the dangers of noise exposure and its adverse effect on hearing.  The video is very good at informing viewers about dangerous levels of sound and provides tips on how one can limit his or her exposure to noise pollution.  Included in this important piece is Dr. Daniel Fink’s segment on ear plug options for hearing protection.

Thanks to Daniel Fink, M.D., a noise pollution activist in the Los Angeles area, for the video link.  Dr. Fink serves on the board of the American Tinnitus Association.

The costs of hearing loss:

The New York TIme’s Jane Brody writes about the high cost of hearing loss in Hearing Loss Costs Far More Than Ability to Hear.

Brody’s post focuses on a psychologist, Mark Hammel, who addressed his hearing loss by (finally) getting hearing aids.  Dr. Hammel provides insights into how hearing loss inflicts real and profound costs on sufferers, many of whom become socially isolated as a result of their condition.  But the post highlights the other costs as well, noting that “30 to 48 million Americans have hearing loss that significantly diminishes the quality of their lives — academically, professionally and medically as well as socially.”  Brody adds that hearing loss can affect physical health (e.g., increased risk of dementia, stress, fatigue), as well as create safety and financial risks.  And those around the hearing impaired suffer as well, as “[m]any who are hard of hearing don’t realize how distressing it is to family members, who typically report feeling frustrated, annoyed and sad as a consequence of communication difficulties and misunderstandings.”

Loud noise causes hearing loss, a preventable medical problem that will continue until and unless people understand the consequences of ignoring it.  The first step to implementing protections against excessive noise is getting poeple to recognize the real and significant costs to the sufferer, his or her family and friends, and society as a whole.  Kudos to Brody for her thoughtful post.

Thanks to Daniel Fink, M.D., a noise pollution activist in the Los Angeles area, for the link.  Dr. Fink serves on the board of the American Tinnitus Association.

10/07/2015 Update: Brody follows through with a companion piece that discusses the literal cost of hearing loss in The Hurdles to Getting Hearing Aids.  Among other things, Brody notes that while a failure to recognize hearing loss is one reason why people do not get hearing aids when needed, “the more important reason people fail to get hearing aids when they are needed is the cost, which is rarely covered by insurance and not at all by Medicare, unless the device is for a child.”  Given that the cost for one hearing aid (and most people need two) range from about $1,200 to $2,800,  it’s clear that the high cost of hearing aids keeps them out of the hands of the people who made need them the most.

Insidious indoor noise

Do you ever wonder why restaurants are so loud?  Don’t assume it’s due to poor design, because it may be deliberate.  Peggy Hernandez, writing for the Boston Globe, found that for some restaurant owners, striking the right noise level is key.  But while she found some restaurant owners who were addressing unnecessary noise by installing professional soundproofing, others, “aiming for a lively atmosphere,” actively encouraged the party atmosphere. “We wanted bustling energy, conviviality, and a party feel,” says Tony Maws, chef and owner of The Kirkland Tap & Trotter, in Somerville.”  Based on my experience, Maws is not alone,  But it seems odd that a restaurant owner would deliberately maintain a loud space when you consider that, “[t]he 2014 Zagat Boston Restaurants Survey found restaurant noise level to be the number-one irritatant about dining out.”  The Zagats survey added that “[o]ver 70 percent of those surveyed avoid restaurants that are too loud…[with] similar results in New York City.”  So why would restauranteurs turn up the volume, or ignore it, when noise level is a common complaint?

Cara Buckley, writing for the New York Times on Indoor noise in New York restaurants and retail stores, reported that “[s]ome customers like the loudness. Younger people can withstand loud music longer, while older ones may run from it, helping proprietors maintain a youthful clientele and a fresh image.”  Further, “[s]ome research has shown that people drink more when music is loud; one study found that people chewed faster when tempos were sped up.”  So to maintain a “fresh image” or make a few more dollars, some restaurant owners deliberately expose their customers and employees to damaging loud noise.  The damage is not limited to hyperacusis, tinnitus, or hearing loss, as the article notes, “repeated exposure to loud noise often damages hearing and has been linked to higher levels of stress, hypertension and heart disease.”

The article includes three paragraphs that highlight the problem facing those of us who want restaurants and other spaces to lower the volume.  Namely, there are customers who enjoy the din:

Recent changes in restaurant design have also increased sound levels. The trend of making restaurants look like brasseries and bars to resemble speakeasies has bred an abundance of hard surfaces that can reflect and amplify sound: ceramic tiles, concrete floors and tin ceilings. This despite the fact that one of the biggest customer complaints about restaurants, according to Zagat, is noise. Yet those who like noisy places said they were energizing and gave them a sense that they were where it’s at.

Maria Vasquez, 22, a design student who spends time at Lavo — home to the 96 decibel levels and migraine-afflicted waitress — said she found the cacophony there fun. Tiffany Trifilio, 26, a fashion analyst who frequents the Standard Hotel’s Biergarten, said the din made her feel part of the crowd. And Katherine Gold, 35, who often stays at home with her baby, reveled in Lavo’s noise one recent night. “I spend my days in my apartment and at Central Park,” she said. “I have enough quiet.”

Patrons of spin classes also said the din was part of the draw. The pounding music helped them forget they were exercising, they said, and made them feel they were reliving the club days of younger years.

Loud music is fun and invigorating for some.  Sadly, by the time the young women in the NY Times story begin to experience hearing loss, or go home one night with ringing in their ears that never goes away, it may be too late to do anything about it.

One way to stop this madness is to offer incentives to responsible business owners who monitor sound levels.  And there is no bigger incentive than knowing that attention to this one detail can drive more foot traffic through their doors.  To that end, keep an eye on this space.  In the next few months we will be posting reviews of restaurants, bars, coffee shops, parks, and other places around Manhattan where the focus will be on sound quality.  Food quality, service, and other factors are obviously important considerations when picking a restaurant, for example, but we will not be posting typical reviews.  Rather, at most each review will include a brief description about the quality of the food, drink, or goods offered, decor, and service of each reveiwed place, but the emphasis will be on a simple standard: can you have a conversation in the space without raising your voice.  Over time, we hope to have a map that offers many options for those seeking  reasonably quiet spaces in every neighborhood in Manhattan. 

Thanks to Daniel Fink, M.D., a noise pollution activist in the Los Angeles area, for the article links.  Dr. Fink serves on the board of the American Tinnitus Association.

Noise can cause hyperacusis and tinnitus, but can it also be bad for your heart?

New York Times Health blogger, Nicholas Bakalar, posted a piece on a report by British researchers that suggested that “[c]ontinual exposure to traffic noise may increase the risk for cardiovascular disease.”   The study, published in The European Heart Journal, noted that, as compared with average noise levels below 55 decibels, “levels above 60 decibels were associated with higher rates of hospital admissions for stroke — 5 percent higher among people 25 to 74 and about 9 percent higher among those over 75.  All-cause mortality was 4 percent higher for people in noisy neighborhoods.”

As Bakalar notes, 60 decibels is not especially loud as it “is much quieter than most urban environments and many indoor public places like popular restaurants, gyms, movie theaters and sports arenas.”  The  researchers suggest that the cumulative effect of constant noise over years could be significant.

If you have a sound meter on your smart phone, load it up when you are at a restaurant, theater, or gym and look at the decibel level.  My guess is that if most people did this just to get a sense of the normal sound levels they are continually exposed to, they would be stunned.

Research into the affect of noise on health is at the nascent stage, so more attention and funding has to be directed to this emerging and important field of study.  One hopes that once there is some consensus regarding the ill effects of noise on health, that businesses and political bodies will have no choice but to address it.  After all, cities and suburbs are not getting any quieter.

Thanks to Daniel Fink, M.D., a noise pollution activist in the Los Angeles area, for the link.  Dr. Fink serves on the board of the American Tinnitus Association.