The Toxic Effects of Noise and What We’re Not Doing About It
Erica Walker had a studio in her Brookline, Mass. apartment where she worked as a bookbinder and furniture maker. That was until a family with two rowdy children moved in above her.
The kids ran amuck, disrupting her sleep and work. Ear plugs weren’t enough to blot out the commotion. Aside from anger and a sense of lost control, the noise increased her heart rate and made her stomach feel like it was dropping, she says.
That’s when Walker realized that noise is a public health problem, not merely an annoyance. She set up her own “mini study” on how the clamor was affecting her. She monitored sound levels in her apartment and sent saliva samples to a lab to measure her stress levels.
Walker ultimately sold her craft equipment and returned to school to study public health. Today she is assistant professor of epidemiology and director of the Community Noise Lab at the Brown University School of Public Health. “We treat noise like a first world problem—like a sacrifice we should have to make for modern conveniences. But it’s a serious environmental stressor,” she asserts.
Our daily soundscape is a cacophony of earsplitting jets, motorcycles, crying babies, construction sites or gunshots if you’re in the military. Noise exposure is the primary cause of preventable hearing loss. Researchers have identified links between excessive noise and a heightened risk of heart disease, metabolic disorders, anxiety, depression, sleep disorders, and impaired cognition. Even wildlife suffers. Blasting oil drills and loud shipping vessels impede the breeding, feeding and migration of whales and dolphins.
At one time, the federal government had our back… and our ears. Congress passed the Noise Control Act in 1972. The Environmental Protection Agency set up the Office of Noise Abatement and Control (ONAC) to launch research, explore solutions and establish noise emission standards. But ONAC was defunded in 1981 amidst a swirl of antiregulatory sentiment.
Impossibly Loud and Unhealthy
Daniel Fink. a physician, WHO consultant, and board chair of The Quiet Coalition, a program of the nonprofit Quiet Communities, likens the effect of noise to the invisible but cumulative harm of second-hand smoke. About 1 in 4 adults in the U.S. who report excellent to good hearing already have some hearing loss. The injury can happen after one loud concert or from years with a blaring TV. Some people are more genetically susceptible to noise-related hearing loss than others.
“People say noise isn’t a big deal but it bothers your body whether you realize it or not,” says Ted Rueter, director of Noise Free America: A Coalition to Promote Quiet. Noise can chip away at your ears or cardiovascular system even while you’re sleeping. Rueter became a “quiet advocate” while a professor at UCLA two decades ago. He was plagued by headaches, fatigue and sleep deprivation caused by the hubbub of Los Angeles, he says.
The louder a sound is, and the longer you are exposed to it, the more likely it will cause nerve damage and harmful fluid buildup in your inner ear. Normal speech is 50-60 decibels (dBs). The EPA recommends that 24-hour exposure to noise should be no higher than 70 weighted decibels over 24 hours (weighted to approximate how the human ear perceives the sound) to prevent hearing loss but a 55 dB limit is recommended to protect against other harms from noise, too.
The decibel scale is logarithmic. That means 80 dB is 10 times louder than 70 dB. Trucks and motorcycles run 90 dBs. A gas-powered leaf blower, jackhammer or snow blower will cost you 100 dBs. A rock concert is in the 110 dB range. Aircraft takeoffs or sirens? 120 dBs.
Walker, the Brown professor, says that sound measurements often use misleading metrics, though, because they don’t include low frequency sound that disturb the body. The high frequency of a screeching bus will register in decibels but the sound that makes your chest reverberate is not accounted for, she explains. ‘How loud?’ is a superficial take when it comes to noise, Walker says.
After realizing the impact of noise on her own health, Erica Walker was inspired to change careers and become director of the Community Noise Lab at the Brown University School of Public Health.
Fink adds that the extent to which noise impairs hearing is underestimated. People assume hearing loss is due to age but it’s not inevitable, he says. He cites studies of older people living in quiet, isolated areas who maintain excellent hearing. Just like you can prevent wrinkles by using sunscreen, you can preserve hearing by using ear plugs when attending fireworks or hockey games.
You can enable push notifications on a Smart Watch to alert you at a bar exceeding healthy sound levels. Free apps like SoundPrint, iHEARu, or NoiseTube can do decibel checks, too, but you don’t need one, says Fink. “If you can’t carry a conversation at normal volume, it’s too loud and your auditory health is at risk,” he says.
About 40 million U.S. adults, ages 20-69, have noise-induced hearing loss. Fink is among them after experiencing tinnitus (ringing or buzzing in the ears) on leaving a raucous New Year’s Eve party in 2007. The condition is permanent and he wears earplugs now for protection.
Fewer are aware of the link between noise pollution and heart disease. Piercing noise is stressful, raising blood pressure and heart rate. If you live near a freeway or constantly barking dog, the chronic sound stress can trigger systemic inflammation and the vascular changes associated with heart attacks and stroke.
Researchers at Rutgers University’s Robert Wood Johnson Medical School, working with data from the state’s Bureau of Transportation, determined that 1 in 20 heart attacks in New Jersey during 2018 were due to noise from highways, trains and air traffic. That’s 800 heart attack hospitalizations in the state that year.
Another study showed that incidence of hypertension and hardening arteries decreased during the Covid-19 air lockdown among Poles in Krakow routinely exposed to aircraft noise. The authors, comparing their pre-pandemic 2015 results to 2020 data, concluded it was no coincidence.
Mental health takes a hit, too. Chronic noise can provoke anxiety, depression and violence. Cognitively, there is ample evidence that noise disturbance lowers student achievement and worker productivity, and hearing loss among older people can speed up cognitive decline.
Noise also contributes to health disparities. People in neighborhoods with low socioeconomic status and a higher percentage of minority residents bear the brunt of noise. Affluent people have the means to live far from airports, factories, and honking traffic.
Out, Out, Damn Noise
Europe is ahead of the U.S. in tackling noise pollution. The World Health Organization developed policy guidelines used by the European Environment Agency to establish noise regulations and standards, and progress reports are issued.
Americans are relying too much on personal protective equipment (PPE) instead of eliminating or controlling noise. The Centers of Disease Control and Prevention rank PPE as the least useful response. Earplugs and muffs are effective, says Walker, but these devices are “a band-aid on a waterfall.”
Editing out noise during product design is the goal. Engineers have an arsenal of techniques and know-how for that. The problem is that these solutions aren’t being applied.
A better way to lower the volume is by maintaining or substituting equipment intended for common use. Piercing building alarms can be replaced with visual signals that flash alerts. Clanking chain and gear drives can be swapped out with belt drives. Acoustical barriers can wall off highway noise. Hospitals can soften beeping monitors and limit loudspeaker blasts. Double paned windows preserve quiet.
Editing out noise during product design is the goal. Engineers have an arsenal of techniques and know-how for that. The problem is that these solutions aren’t being applied, says Jim Thompson, an engineer and editor of the Noise Control Engineering Journal, published by the Institute of Noise Control Engineering of the USA
Engineers have materials to insulate, absorb, reflect, block, seal or diffuse noise. Building walls can be padded. Metal gears and parts can be replaced with plastic. Clattering equipment wheels can be rubberized. In recent years, building certifications such as LEED have put more emphasis on designs that minimize harmful noise.
Walker faults urban planners, too. A city’s narrow streets and taller buildings create a canyon effect which intensifies noise. City planners could use bypasses, rerouting, and other infrastructure strategies to pump down traffic volume. Sound-absorbing asphalt pavement exists, too.
Some municipalities are taking innovative measures on their own. Noise cameras have been installed in Knoxville, Miami and New York City this year and six California cities will join suit next year. If your muffler or audio system registers 86 dB or higher, you may receive a warning, fine or citation, similar to how a red-light camera works. Rueter predicts these cameras will become commonplace.
Based on understanding how metabolic processes affect noise-induced hearing loss in animal models, scientists are exploring whether pharmacological interventions might work to inhibit cellular damage or improve cellular defenses against noise.
Washington, DC, and the University of Southern California have banned gas-powered leaf blowers in lieu of quieter battery-powered models to reduce both noise and air pollution. California will be the first state to ban the sale of gas-powered lawn equipment starting 2024.
New York state legislators enacted the SLEEP (Stop Loud and Excessive Exhaust Pollution) Act in 2021. This measure increases enforcement and fines against motorists and repair shops that illegally modify mufflers and exhaust systems for effect.
“A lot more basic science and application research is needed [to control noise],” says Thompson, noting that funding for this largely dried up after the 1970s. Based on understanding how metabolic processes affect noise-induced hearing loss in animal models, scientists are exploring whether pharmacological interventions might work to inhibit cellular damage or improve cellular defenses against noise.
Studying biochemical or known genetic markers for noise risk could lead to other methods for preventing hearing loss. This would offer an opportunity to identify people with significant risk so those more susceptible to hearing loss could start taking precautions to avoid noise or protect their ears in childhood.
These efforts could become more pressing in the near future, with the anticipated onslaught of drones, rising needs for air conditioners, and urban sprawl boding poorly for the soundscape. This, as deforestation destroys natural carbon absorption reservoirs and removes sound-buffering trees.
“Local and state governments don’t have a plan to deal with [noise] now or in the future,” says Walker. “We need to think about this with intentionality.”
Friday Five: The Therapeutic Value of Bonding with Fellow Sports Fans
The Friday Five covers five stories in research that you may have missed this week. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on new scientific theories and progress to give you a therapeutic dose of inspiration headed into the weekend.
This episode includes an interview with Dr. Helen Keyes, Head of the School of Psychology and Sports Science at Anglia Ruskin University.
Listen on Apple | Listen on Spotify | Listen on Stitcher | Listen on Amazon | Listen on Google
- Attending sports events is linked to greater life satisfaction
- Identifying specific brain tumors in under 90 seconds with AI
- LSD - minus hallucinations - raises hopes for mental health
- New research on the benefits of cold showers
- Inspire awe in your kids and reap the benefits
Matt Fuchs is the editor-in-chief of Leaps.org and Making Sense of Science. He is also a contributing reporter to the Washington Post and has written for the New York Times, Time Magazine, WIRED and the Washington Post Magazine, among other outlets. Follow him @fuchswriter.
Scientists and dark sky advocates team up to flip the switch on light pollution
As a graduate student in observational astronomy at the University of Arizona during the 1970s, Diane Turnshek remembers the starry skies above the Kitt Peak National Observatory on the Tucson outskirts. Back then, she could observe faint objects like nebulae, galaxies, and star clusters on most nights.
When Turnshek moved to Pittsburgh in 1981, she found it almost impossible to see a clear night sky because the city’s countless lights created a bright dome of light called skyglow. Over the next two decades, Turnshek almost forgot what a dark sky looked like. She witnessed pristine dark skies in their full glory again during a visit to the Mars Desert Research Station in Utah in early 2000s.
“I was shocked at how beautiful the dark skies were in the West. That is when I realized that most parts of the world have lost access to starry skies because of light pollution,” says Turnshek, an astronomer and lecturer at Carnegie Mellon University. In 2015, she became a dark sky advocate.
Light pollution is defined as the excessive or wasteful use of artificial light.
Light-emitting diodes (LEDs) -- which became commercially available in 2002 and rapidly gained popularity in offices, schools, and hospitals when their price dropped six years later — inadvertently fueled the surge in light pollution. As traditional light sources like halogen, fluorescent, mercury, and sodium vapor lamps have been phased out or banned, LEDs became the main source of lighting globally in 2019. Switching to LEDs has been lauded as a win-win decision. Not only are they cheap but they also consume a fraction of electricity compared to their traditional counterparts.
But as cheap LED installations became omnipresent, they increased light pollution. “People have been installing LEDs thinking they are making a positive change for the environment. But LEDs are a lot brighter than traditional light sources,” explains Ashley Wilson, director of conservation at the International Dark-Sky Association (IDA). “Despite being energy-efficient, they are increasing our energy consumption. No one expected this kind of backlash from switching to LEDs.”
Light pollution impacts the circadian rhythms of all living beings — the natural internal process that regulates the sleep–wake cycle.
Currently, more than 80 percent of the world lives under light-polluted skies. In the U.S. and Europe, that figure is above 99 percent.
According to the IDA, $3 billion worth of electricity is lost to skyglow every year in the U.S. alone — thanks to unnecessary and poorly designed outdoor lighting installations. Worse, the resulting light pollution has insidious impacts on humans and wildlife — in more ways than one.
Disrupting the brain’s clock
Light pollution impacts the circadian rhythms of all living beings—the natural internal process that regulates the sleep–wake cycle. Humans and other mammals have neurons in their retina called intrinsically photosensitive retinal ganglion cells (ipRGCs). These cells collect information about the visual world and directly influence the brain’s biological clock in the hypothalamus.
The ipRGCs are particularly sensitive to the blue light that LEDs emit at high levels, resulting in suppression of melatonin, a hormone that helps us sleep. A 2020 JAMA Psychiatry study detailed how teenagers who lived in areas with bright outdoor lighting at night went to bed late and slept less, which made them more prone to mood disorders and anxiety.
“Many people are skeptical when they are told something as ubiquitous as lights could have such profound impacts on public health,” says Gena Glickman, director of the Chronobiology, Light and Sleep Lab at Uniformed Services University. “But when the clock in our brains gets exposed to blue light at nighttime, it could result in a lot of negative consequences like impaired cognitive function and neuro-endocrine disturbances.”
In the last 12 years, several studies indicated that light pollution exposure is associated with obesity and diabetes in humans and animals alike. While researchers are still trying to understand the exact underlying mechanisms, they found that even one night of too much light exposure could negatively affect the metabolic system. Studies have linked light pollution to a higher risk of hormone-sensitive cancers like breast and prostate cancer. A 2017 study found that female nurses exposed to light pollution have a 14 percent higher risk of breast cancer. The World Health Organization (WHO) identified long-term night shiftwork as a probable cause of cancer.
“We ignore our biological need for a natural light and dark cycle. Our patterns of light exposure have consequently become different from what nature intended,” explains Glickman.
Circadian lighting systems, designed to match individuals’ circadian rhythms, might help. The Lighting Research Center at Rensselaer Polytechnic Institute developed LED light systems that mimic natural lighting fluxes, required for better sleep. In the morning the lights shine brightly as does the sun. After sunset, the system dims, once again mimicking nature, which boosts melatonin production. It can even be programmed to increase blue light indoors when clouds block sunlight’s path through windows. Studies have shown that such systems might help reduce sleep fragmentation and cognitive decline. People who spend most of their day indoors can benefit from such circadian mimics.
When Diane Turnshek moved to Pittsburgh, she found it almost impossible to see a clear night sky because the city’s countless lights created a bright dome of light called skyglow.
Leading to better LEDs
Light pollution disrupts the travels of millions of migratory birds that begin their long-distance journeys after sunset but end up entrapped within the sky glow of cities, becoming disoriented. A 2017 study in Nature found that nocturnal pollinators like bees, moths, fireflies and bats visit 62 percent fewer plants in areas with artificial lights compared to dark areas.
“On an evolutionary timescale, LEDs have triggered huge changes in the Earth’s environment within a relative blink of an eye,” says Wilson, the director of IDA. “Plants and animals cannot adapt so fast. They have to fight to survive with their existing traits and abilities.”
But not all types of LEDs are inherently bad -- it all comes down to how much blue light they emit. During the day, the sun emits blue light waves. By sunset, it’s replaced by red and orange light waves that stimulate melatonin production. LED’s artificial blue light, when shining at night, disrupts that. For some unknown reason, there are more bluer color LEDs made and sold.
“Communities install blue color temperature LEDs rather than redder color temperature LEDs because more of the blue ones are made; they are the status quo on the market,” says Michelle Wooten, an assistant professor of astronomy at the University of Alabama at Birmingham.
Most artificial outdoor light produced is wasted as human eyes do not use them to navigate their surroundings.
While astronomers and the IDA have been educating LED manufacturers about these nuances, policymakers struggle to keep up with the growing industry. But there are things they can do—such as requiring LEDs to include dimmers. “Most LED installations can be dimmed down. We need to make the dimmable drivers a mandatory requirement while selling LED lighting,” says Nancy Clanton, a lighting engineer, designer, and dark sky advocate.
Some lighting companies have been developing more sophisticated LED lights that help support melatonin production. Lighting engineers at Crossroads LLC and Nichia Corporation have been working on creating LEDs that produce more light in the red range. “We live in a wonderful age of technology that has given us these new LED designs which cut out blue wavelengths entirely for dark-sky friendly lighting purposes,” says Wooten.
Dimming the lights to see better
The IDA and advocates like Turnshek propose that communities turn off unnecessary outdoor lights. According to the Department of Energy, 99 percent of artificial outdoor light produced is wasted as human eyes do not use them to navigate their surroundings.
In recent years, major cities like Chicago, Austin, and Philadelphia adopted the “Lights Out” initiative encouraging communities to turn off unnecessary lights during birds’ peak migration seasons for 10 days at a time. “This poses an important question: if people can live without some lights for 10 days, why can’t they keep them turned off all year round,” says Wilson.
Most communities globally believe that keeping bright outdoor lights on all night increases security and prevents crime. But in her studies of street lights’ brightness levels in different parts of the US — from Alaska to California to Washington — Clanton found that people felt safe and could see clearly even at low or dim lighting levels.
Clanton and colleagues installed LEDs in a Seattle suburb that provided only 25 percent of lighting levels compared to what they used previously. The residents reported far better visibility because the new LEDs did not produce glare. “Visual contrast matters a lot more than lighting levels,” Clanton says. Additionally, motion sensor LEDs for outdoor lighting can go a long way in reducing light pollution.
Flipping a switch to preserve starry nights
Clanton has helped draft laws to reduce light pollution in at least 17 U.S. states. However, poor awareness of light pollution led to inadequate enforcement of these laws. Also, getting thousands of counties and municipalities within any state to comply with these regulations is a Herculean task, Turnshek points out.
Fountain Hills, a small town near Phoenix, Arizona, has rid itself of light pollution since 2018, thanks to the community's efforts to preserve dark skies.
Until LEDs became mainstream, Fountain Hills enjoyed starry skies despite its proximity to Phoenix. A mountain surrounding the town blocks most of the skyglow from the city.
“Light pollution became an issue in Fountain Hills over the years because we were not taking new LED technologies into account. Our town’s lighting code was antiquated and out-of-date,” says Vicky Derksen, a resident who is also a part of the Fountain Hills Dark Sky Association founded in 2017. “To preserve dark skies, we had to work with the entire town to update the local lighting code and convince residents to follow responsible outdoor lighting practices.”
Derksen and her team first tackled light pollution in the town center which has a faux fountain in the middle of a lake. “The iconic centerpiece, from which Fountain Hills got its name, had the wrong types of lighting fixtures, which created a lot of glare,” adds Derksen. They then replaced several other municipal lighting fixtures with dark-sky-friendly LEDs.
The results were awe-inspiring. After a long time, residents could see the Milky Way with crystal clear clarity. Star-gazing activities made a strong comeback across the town. But keeping light pollution low requires constant work.
Derksen and other residents regularly measure artificial light levels in
Fountain Hills. Currently, the only major source of light pollution is from extremely bright, illuminated signs which local businesses had installed in different parts of the town. While Derksen says it is an uphill battle to educate local businesses about light pollution, Fountain Hills residents are determined to protect their dark skies.
“When a river gets polluted, it can take several years before clean-up efforts see any tangible results,” says Derksen. “But the effects are immediate when you work toward reducing light pollution. All it requires is flipping a switch.”