Noise is all around us. And it's harming our health
It may seem like just an annoyance, but noise has an impact on our bodies
The rumble of trucks passing on the highway. The hammering of a construction site. The roar of an airplane taking off overhead.
If you live in a big city in Canada, chances are you regularly hear noises that are harmful to your health.
And though small towns and rural areas tend to be generally quieter, loud sounds like trains passing can still be disruptive.
"We think of noise as simply an annoyance," said Hugh Davies, a professor in the school of population and public health at UBC.
"We're bathed in an acoustic sea. And I think it's hard for people to realize that some of that is hazardous," he said.
Noise regulations in North America are generally piecemeal, experts say, and tend to focus on things like parties or concert venues, instead of the sources of noise that actually cause us the most harm: noises from transportation.
But there is plenty of research to show that being regularly exposed to loud traffic noises, as many Canadians are on a daily basis, can have harmful long-term health effects beyond just our hearing.
How do we experience noise?
Our nervous systems have evolved to be constantly on guard, and that includes hearing, Tor Oiamo told Dr. Brian Goldman, host of CBC's The Dose.
"While we might not wake up, we might not be annoyed or disturbed by a sound, we're still going to register those sounds and our nervous system is still going to process that," said Oimao, an associate professor in geography and environmental studies at Toronto Metropolitan University.
This is why our alarms wake us up in the morning, said Davies.
"You're always listening. Even in the middle of the night, your brain is processing sound," he said.
Fight or flight
Hearing a noise sets up our fight-or-flight response, said Erica Walker, an assistant professor of epidemiology in the school of public health at Brown University in Providence, R.I.
"Your heart rate increases. You begin to sweat. You begin to release these hormones that get you prepared for battle — or prepare you to run away from it," said Walker.
That ongoing stress response over time can lead to adverse health outcomes.
How noise harms our health
For decades, research has shown that rates of cardiovascular disease are elevated among people who are exposed to higher levels of noise.
Davies has been studying this issue for years, and has used population-level health data in Vancouver to show that heart disease rates are higher for people living in noisy neighbourhoods.
To do that research, he and his team used a map of the noise levels in B.C.'s lower mainland, which was the first of its kind in Canada at the time the study came out in 2012.
Using the same data, Davies found higher diabetes rates as well as reduced birth weight among babies whose mothers lived in noisy areas.
There has also been research showing that at schools with chronic airplane noise, elementary students had lower reading scores.
What is safe sound?
The World Health Organization recommends that average noise exposure to road traffic should be no louder than 53 decibels during the day, and no more than 45 decibels at night.
For reference, 53 decibels is about the noise level of a quiet residential street.
As the traffic noise outside your window gets louder, your risk of ischemic heart disease goes up, said Oiamo, because your body's response to noise can cause elevated levels of stress hormones and an increased heart rate.
A fairly busy road has an average decibel level of 61, he said.
"Most of us living anywhere near anything other than a very quiet side street will have that type of noise level," Oiamo said.
Noise is affected by urban planning
For Walker, noise isn't just a public health concern — it's also an environmental justice issue.
At Brown University, she runs a lab where she works with people trying to deal with noise in their neighbourhoods.
Walker said the noise issues she sees are the result of poor urban planning practices, such as building neighbourhoods near airports, industrial activities or major highways.
The communities she works with are usually home to lower-income people who are often racialized.
"We decide that we will dump our acoustical trash in those communities where they just don't have the power to organize and fight back," Walker said.
"Do we need to put condominiums or apartment houses next to a highway? Do we need to put schools next to a highway?"
WATCH / The inequalities of noise pollution:
The acoustical soundscape — and not just the landscape — needs to be considered in planning decisions, said Walker.
Tor Oiamo in Toronto has a similar perspective.
"You're not going to eliminate cars. You're not going to eliminate transportation sound. But we can do a better job of keeping those away from people," he said.
How can we reduce the noise around us?
For many of us, reducing noise in our environments can be cost-prohibitive, such as moving to a quieter neighbourhood or soundproofing our homes.
If you have the option, consider which side of the home your bedroom is on, said Davies.
"Noise varies dramatically from one side of the house to another, so you could move to a quieter part of the house to sleep," he said.
Experts also recommend informing yourself about the noise around you by measuring the decibel levels on your phone.
For iPhone users, Oimao recommends an app developed by NIOSH, the National Institute for Occupational Safety and Health at the U.S. Centers for Disease Control and Prevention.
The app isn't available for Android, but there are other noise apps users can download.
Other than that, and stocking up on earplugs, experts say fighting back against noise requires larger policy solutions.
"I've been working with communities that have been fighting over issues for many years with no moving of the needle," said Walker.
Her advice?
"Collect data, show up when your voice is needed, but give input."