Tag Archive: noise pollution

How a tsunami revealed human noise pollution

 

Photo credit: Calbear22, photo released into the public domain

Phys.org reports how a tsunami that struck Hawaii in 2011–caused by the same earthquake that hit Japan and created the tsunami that triggered the Fukushima nuclear disaster–caused a temporary halt to boat traffic that allowed scientists “a rare glimpse into what the bays might sound like without human activities.” By luck, the tsunami hit while “a Duke University-lead team was recording underwater sound in four bays” on Hawaii’s Kona coat.

It turns out that oceans are pretty loud. On the day of the tsunami, the loudest part of the day reached 98.8 decibels. Why are oceans so loud? “Because sound waves travel and are amplified differently in water than in air.” But 98.8 decibels was quiet compared to a reading on a typical day, as noise from boat traffic can reach up to 125 decibels, and the sound from nearby sonar exercises tops 143 decibels.

So what did the Duke study conclude? It showed that humans created the loudest disruptions and boat traffic and sonar were “significant causes of noise in all four bays.” Human-made noise has long been a concern of conservationists who fear that “interactions caused by dolphin-encounter boat tours and other human activities” are disrupting dolphins’ sleeping behaviors and potentially interfering with their hunt for food, since dolphins rest in the bays during the day to ready themselves for the hunt at night.

Oysters can hear noise

 

Photo credit: Daniel Schwen licensed under CC BY-SA 4.0

and it’s stressing them out! Jean-Charles Massabuau, a marine biologist at the French National Centre for Scientific Research, was working on a different project when a diver noted he had never dived in such a noisy spot. Massabuabu wondered if the oysters in that location could hear the noise. After setting up an experiment to see if they would react (they did!) and how (shutting their shells), Massabuabu and team wrote up their findings. Although the oysters had a way to shut out the noise, it comes at a price–they can neither eat nor breathe when their shells are closed.

There is a well-established body of research about ocean sound, but Massabuabu thinks his study results suggest “we should expand our concerns about the impact of noise pollution beyond today’s focus on only dolphins and whales.”

We agree.

Though we must add that while noise pollution may stress out oysters, it’s probably pales in comparison to waiting to be shucked and served with a side of cocktail sauce.

Will electric vehicles contribute significantly to a quieter world?

Photo credit: cytech licensed under CC BY 2.0

Jeanine Botta, of Silence the Horns, expresses some doubts in her post, “Marketing quiet while adding to noise pollution.” Botta writes about a recent post on Huffington Post that discusses the health effects of traffic noise.  She notes that the piece, which “tells us that ‘EVs are bringing the quiet’ and concludes that ‘…you could say we’re about to enter a golden age of silence,'” was promoted by Nissan, with “Brought to you by ELECTRIFY THE WORLD – A NISSAN INTELLIGENT MOBILITY INITIATIVE” appearing next to the Huffington Post banner.  “Welcome to the world of advertorial marketing,” she says. 

What follows is Botta’s thoughtful analysis of why electric cars may not be “bringing the quiet” any time soon.  More importantly, if concern about vehicle noise is more than a marketing ploy, manufacturers should look at Botta’s suggestions on how they can “substantially reduce vehicle noise pollution” right now in both electric vehicles and in internal combustion engine cars by simply phasing out audible alarms and signals.

Click the first link above to read Botta’s entire piece.  It is well worth your time.

Human noise pollution wreaks havoc on U.S. wildlife

Photo credit: USFWS Mountain-Prairie licensed under CC BY 2.0

Rachel Buxton, a postdoctoral research fellow at Colorado State University, writes about the impact expanding transportation networks are having on remote places. Buxton notes that “noise from sources such as vehicle engines is spreading into remote places,” and cautions that “[h]uman-caused noise has consequences for wildlife, entire ecosystems and people.” Buxton and her team conducted a study using “millions of hours of acoustic recordings and sophisticated models to measure human-caused noise in protected areas,” focusing on “human sources of noise in natural environments, such as sounds from aircraft, highways or industrial sources.” The study found that “noise pollution doubled sound energy in many U.S. protected areas, and that noise was encroaching into the furthest reaches of remote areas.”

What are the consequences of these findings? Buxton writes that “[h]uman-caused noise in protected areas interferes with visitors’ experience and alters ecological communities,” adding that “noise may scare away carnivores, resulting in inflated numbers of prey species such as deer.” In addition, although plants can’t hear, they too are affected by noise because “noise changes the distribution of birds, which are important pollinators and seed dispersers.”

The news isn’t all bad, however, as Buxton was “encouraged to find that wilderness areas – places that are preserved in their natural state, without roads or other development – were the quietest protected areas, with near-natural sound levels.”  Unfortunately, the team also found that 12% of “wilderness areas experienced noise that doubled sound energy.”

But all is not lost, as thoughtful management of our protected areas can help to reduce the impact of human-caused noise. Buxton concludes her piece by identifying the strategies that can be implemented to do this, including “establishing quiet zones where visitors are encouraged to quietly enjoy protected area surroundings, and confining noise corridors by aligning airplane flight patterns over roads.”

Is man-made noise making desert insects disappear?

Photo credit: Ferran Pestaña licensed under CC BY-SA 2.0

Veronique Greenwood, The Atlantic, writes about the gas compressors in the San Juan Basin of New Mexico and the effect they are having on desert insects. The San Juan Basin is “the nation’s second-largest natural gas field, [where] for miles in every direction, gas compressors are running more or less constantly, filling the desert with their eerie, broadband roar.” When compressors are near people, Greenwood reports, efforts are made to dampen the sound, but not so when the only thing that can hear them are the creatures that live in the desert.

What do the compressors sound like? Greenwood says that they “create a curiously oppressive noise, with both high and low frequencies at very high volume, running 24 hours a day, seven days a week, nearly 52 weeks a year.” Sounds hellish. And apparently desert insects agree, as ecologists have discovered that many insect groups are disturbed by the compressors “and by high decibel levels of noise in general.” How disturbed? Although some insects groups showed no change, “[t]here were 24-percent fewer grasshoppers in compressor plots, 52-percent fewer froghoppers, and a whopping 95-percent fewer cave, camel, and spider crickets.”

The long-term effects aren’t exactly known–one researcher noted that the study was “is just the very tip of the iceberg”–but as insects avoid the sound of man-made noise, their altered behavior will likely affect the bats and birds that eat them.

Click the link above to read the entire piece.

 

 

Study: Noise and air pollution adversely affect heart health

Photo credit: G.M. Briggs

CTV News reports that a new European study has found that exposure to excessive traffic noise is linked to a higher risk of heart disease. What makes this study particularly interesting, is that “[a]lthough air pollution has already been linked to an increased risk of heart disease, stroke, asthma, and risk of death, and noise pollution linked to raised blood pressure, disturbed sleep, and an increase in stress hormones, until now little research has been carried out on the effects of noise pollution and air pollution — which are often found together — on health.”

For purposes of the study, “noise pollution” was defined as “noise louder than conversation level — around 60 decibels (dB).”  To determine the effect of noise pollution on health, “the researchers tested the participants’ blood for a range of biological markers that could indicate heart disease…and blood sugar levels, which are linked to heart disease, diabetes and stroke at higher levels.” After taking into account lifestyle factors (age, sex, smoking habits, etc.), the researchers found “an increase of just 5dB in noise levels was linked to 0.3% higher blood sugar levels than those living in quieter neighborhoods.”

But the bad news about noise pollution doesn’t end there. The researchers “also believe noise could be increasing the risk of heart disease by causing long-term psychological stress due to lack of sleep and an increase in the production of stress hormones.”

The results should not be entirely surprising. Anna Hansell, one of the authors of the new study, was the lead author on a study linking noise to adverse health effects in BMJ in 2013, and a senior author on another study  linking road traffic noise and cardiovascular morbidity, in 2015.

Additional studies will follow, as the researchers intend to continue their efforts “to add to the limited body of research in this area.”

 

How can big cities deal with noise pollution?

Based on a recent increase in news items about noise in cities, the issues of urban soundscapes and noise pollution seem to be getting more attention. Included in this recent spate is an article by Robert Bright, The Huffington Post, who writes about smart, sound solutions to urban noise. Bright begins his article by noting that most people tend to think of noise pollution as “a cause of irritation and sometimes anger,” but fail to regard it as “doing us any physical harm.” But Bright shows that noise is more than a mere nuisance, as he discusses a recent study by Mimi Hearing Technologies which shows that people who live in noisy cities are more likely to suffer hearing loss, a not insignificant health problem. In fact, the World Health Organization estimates that the cost of hearing loss is $750 billion globally, which  includes medical bills, lost earnings, and related problems people suffer when they lose their hearing (but does not consider other effects of noise, like stress, fatigue, and poor sleep quality).

So, armed with the knowledge that urban noise pollution is a serious health threat, what can we do? Bright thinks that electric vehicles (EVs) will help to quiet the din, as they make very little noise. He also suggests that the ubiquity of smartphones coupled with free, downloadable sound meter apps will allow cities to compile noise maps that will allow users to avoid noisy areas and help city governments target noisier areas for sound mitigation. Other possibilities exist too, like the development of “radical new materials” that “could provide hitherto unimaginable forms of sound proofing in the future,” to ridiculous street furniture designs like the “Comfort-Shell,” “a giant helmet-shaped object positioned above the head which drastically reduces noise.”

The good news is that whatever method or products are used to address noise in the future, it is clear that noise can no longer be ignored. As Bright concludes, there is a marked “shift in approach to noise pollution” that “combined with citizen activism, increased EV usage and a more mindful attitude to how we are affected by the sounds around us…is putting city life on the cusp of a ‘quiet revolution.’”

 

National Parks: Why quiet matters

By David Sykes, Vice Chair, The Quiet Coalition

On May 4, Science and Phys.org™ published news reports about a recent, significant, multi-year study about the pervasiveness of noise pollution in 492 national parks and natural areas across the U.S.

In “Noise Pollution is invading even the most protected natural areas,” Science writer Ula Chrobak notes that:

The great outdoors is becoming a lot less peaceful. Noise pollution from humans has doubled sound levels in more than half of all protected areas in the United States—from local nature reserves to national parks—and it has made some places 10 times louder, according to a new study. And the cacophony isn’t just bad for animals using natural sounds to hunt and forage—it could also be detrimental to human health.

Under the study, researchers from the National Park Service and Colorado State University “recorded noise at 492 sites across the country with varying levels of protection, [and] used the recordings to predict noise throughout protected areas in the rest of the country.” They also estimated naturally occurring ambient noise and compared the noise levels with and without humanmade noise. The results were damning: noise pollution doubled sound levels in 63% of protected areas and caused a 10-fold increase in 21% of protected areas.

And the impacts of that noise pollution affect all living things withing these areas.  Phys.org reports interviews Rachel Buxton, the study’s lead author and post-doctoral researcher, who states that “[t]he noise levels we found can be harmful to visitor experiences in these areas, and can be harmful to human health, and to wildlife.” The noise pollution findings means that “noise reduced the area that natural sounds can be heard by 50 to 90 percent,” which “also means that what could be heard at 100 feet away could only be heard from 10 to 50 feet.”

So what is the impact on humans and wildlife?  Phys.org explains:

This reduced capacity to hear natural sound reduces the restorative properties of spending time in nature, such as mood enhancement and stress reduction, interfering with the enjoyment typically experienced by park visitors. Noise pollution also negatively impacts wildlife by distracting or scaring animals, and can result in changes in species composition.

High levels of noise pollution were also found in critical habitat for endangered species, namely in endangered plant and insect habitats. “Although plants can’t hear, many animals that disperse seeds or pollinate flowers can hear, and are known to be affected by noise, resulting in indirect impacts on plants,” said Buxton.

The study results have been widely reported, showing that there is real interest in protecting our national parks and natural areas.  Researchers know that “many people don’t really think of noise pollution as pollution,” but they hope that this study will encourage more people to “consider sound as a component of the natural environment.”

The National Park Service’s huge portfolio of parks and natural areas provides a huge canvas for researchers concerned about the impacts of “noise pollution.” You may be surprised to learn that the National Park Service has a research division called “Natural Sounds and Night Skies Division” that has been looking for several years at the effects of noise not only on visitor experiences, but also on plants and animals. Their work is fascinating and resulted in a 2014 report from the National Academy of Engineering called “Preserving National Park Soundscapes.

David Sykes chairs/co-chairs four national professional groups in acoustical science: The Acoustics Research Council, ANSI S12 WG44, The Rothschild Foundation Task Force on Acoustics, and the FGI Acoustics Working Group. He is also a board member of the American Tinnitus Association, co-founder of the Laboratory for Advanced Research in Acoustics (LARA) at Rensselaer Polytechnic Institute, lead author of “Sound & Vibration 2.0 (2012, Springer-Verlag), and a contributor to “Technology for a Quieter America” (2011, National Academy of Engineering). A graduate of the University of California/Berkeley with graduate degrees from Cornell University, he is a frequent organizer of and speaker at professional conferences in the U.S., Europe, Asia, and the Middle East.

Is it too late to save the orcas?

Wanyee Li, Toronto Metro, reports that researchers are concerned about the state of the health of the 78 remaining orcas of the Salish Sea orca population.  “The killer whales are declining for a variety of reasons ranging from infection, starvation, and conflict with large ships, both head-on and from the noise pollution they emit.”  Researchers say they know what to do to save these animals, but the problem is finding the political will to do it.

Kim Dun, an oceans specialist with  World Wildlife Fund Canada, said that “noise pollution is among the biggest threats to the whales,” because a “noisy environment that makes it harder for the whales to do what they need to do to survive.”  The combination of threats is enough “to choke the iconic animals until there are not enough whales to keep the population alive.”

In related news, recordings show that baby humpback whales and their mothers “whisper” just in case killer whales are nearby.  Ecologists studying the humpbacks say that this determination highlights the need to regulate ocean noise, because the discovery “suggests that human-produced machinery sounds could be particularly harmful to calves and their mothers.”