Note: Transcripts may contain errors. If you wish to re-use all, or part of, a transcript, please contact CBC for permission. Please check the corresponding audio before quoting in print. Copyright © CBC 2023

The Dose Transcript for June 22, 2023

Host: Dr. Brian Goldman

BRIAN GOLDMAN: Hi, I'm Dr. Brian Goldman. Welcome to The Dose.

SOUNDCLIP

[a siren wails, vehicle and street noise]

BRIAN GOLDMAN: Well, unwanted noise like that is all around us, especially if you live in a big city. But while we may learn to tune it out around our ears, it turns out it's doing a number on our well-being. So this week we're asking: How is the noise around me harming my health? Hi, Tor. Welcome to The Dose.

TOR OIAMO: Hi. Thanks for having me.

BRIAN GOLDMAN: Until I started working nights in the E.R., I would never have believed that a floor polisher could make the most annoying sound on the planet. At least to me. So what noise bothers you the most?

TOR OIAMO: Oh, wow. Tough question right off the top. Yes, I have to say traffic noise because that's what I talk about most of the time.

BRIAN GOLDMAN: And you don't tune it out.

TOR OIAMO: I think I've probably taught myself how to tune into it more than I would like to, just by virtue of my line of work.

BRIAN GOLDMAN: Sounds like you're the person we should be talking to. But before we begin, can you give us a Hi, my name is? Tell us what you do and where you do it. Just ad lib.

TOR OIAMO: Sure. My name is Tor Oiamo. I'm an Associate Professor in the Department of Geography and Environmental Studies at Toronto Metropolitan University. And this year only, I'm also a visiting researcher at the Norwegian Institute of Public Health, where I'm helping them with a national noise project.

BRIAN GOLDMAN: Sounds interesting. Well, let's begin with our questions, and let's begin with a little bit of noise.

SOUNDCLIP

[an airplane flyover at low altitude, train and construction noises]

BRIAN GOLDMAN: So these are some of the sounds that, at least some of us, hear every day. Tor, how aware do you think we are of them?

TOR OIAMO: We do get used to it in some sense, but our bodies don't necessarily agree with that. So our nervous system and our sensory system is really trained and evolved to be on guard all the time. And that includes our hearing. So 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 to some extent. And there's going to be some small response that can cascade in various forms and at various levels throughout our body.

BRIAN GOLDMAN: So let's try to break that down a little bit. What is happening inside our bodies when we experience the kind of noise that we just heard, the variety of noises that we just heard?

TOR OIAMO: Any sound, when it's first registered, is going to go through some parts of our brain, where it's assessed in some manner to decide whether or not it poses a threat to us; if it's something that we need to respond to. If we do not immediately or familiarly know that it's not a harmful threat, it does cascade and a bit of a stress response goes through the system -- our stress axis, as we call it. Which then release a number of different stress hormones in our body. And over time, just small stimulations of that system releasing even small amounts of those stress hormones, can lead to pretty serious outcomes over several years or decades. And that's where we see those-- the worst health outcomes that are associated with excessive noise exposure, like cardiovascular disease.

BRIAN GOLDMAN: We'll get into those in just a moment. But I just want to just nail down that point about awareness. How aware of noise do you have to be to have your health affected by it?

TOR OIAMO: There's obviously individual differences. Some of us will sleep through literally anything and are better able to tune sounds out, I suppose. And others are very noise-sensitive. But it doesn't really have a strong correlation with the health outcomes on the other end of it. So it turns out it doesn't seem to matter that much, at least at the population level, how sensitive we are as individuals. There's definitely a lot of evidence suggesting that the extent to which you are annoyed doesn't necessarily determine the extent to which persistent noise exposure can be harmful.

BRIAN GOLDMAN: So we do want to focus on the impact on our health. So what has the research shown about how noises like an airplane flying overhead every few minutes or the traffic outside our window, how do they impact our health?

TOR OIAMO: Yeah, so there's been a lot of research over many decades now. Like, this really goes back to well over 100 years. As soon as industrialization started, people started being suspicious that these new mechanical sounds that were becoming persistent in daily life were going to have some effect on us. But going back to sort of the modern era of it in the '50s, '60s, and even '70s, you know, they found that around 50 to 55 decibels of sound averaged, over a 24-hour period, which can be the result of a lot of different types of sound exposures of course, significant health effects start occurring.

BRIAN GOLDMAN: And Tor, are those health effects primarily cardiovascular effects?

TOR OIAMO: Noise is a stressor, and high blood pressure is the pretty obvious outcome of stress, like any other type of stressor might be. So immediately, I suppose, when we had the opportunity to do these big epidemiology studies, cardiovascular disease is where we went first. And with respect to blood pressure specifically, there's been some mixed findings actually. But ischemic or coronary heart disease, where vessels in your heart start clotting up a bit and not passing blood through properly due to inflammation of the muscles and arteries in the heart, that's definitely the most common and most well-evidenced or documented health outcome. And in particular, that outcome linked to traffic noise, traffic as a specific source, is the one that's been studied the most. But there are some really good and robust studies now that also find effects on stroke, on diabetes, and other more downstream health outcomes.

BRIAN GOLDMAN: Noise has been identified by the World Health Organization as a major risk to health, so that would suggest that at least that body believes that there's enough evidence here to declare that noise is a health risk. Would you agree?

TOR OIAMO: Oh, 100%. So those WHO recommendations or statements that you referred to, are based on a really comprehensive meta-analysis for a review of, you know, more or less all the studies that had been conducted up until 2018 or so. Yes, the link between traffic noise and ischemic heart disease, like I said before too, is what we know has the strongest evidence. That's the one-- There's high confidence around that. And then when you get into exposures and outcomes-- For example, air traffic noise and high blood pressure. There's just not the number of studies out there to have high confidence in the results, but that doesn't-- You know, that bar is really, really high, right? We're talking about very, very, very demanding qualifications on the evidence when it's put together to that level. Which of course, there should be.

BRIAN GOLDMAN: So that's physical health. What do we know about the connection between noise and mental health?

TOR OIAMO: That's definitely an area that's had less focus on large scales at least, and large longitudinal studies. But based on what we do know, it's not unreasonable to say that if, again, you're exposed to levels that are causing annoyance on a daily basis, that's probably disturbing daily activities that's going to have some effect on your mental well-being too, whether that's your ability to concentrate. A lot of us have been working more at home the last few years, and I'm sure many of us have been forced into paying attention to sounds in a different way than we were before, too. And whether that qualifies as a mental health outcome, you know, again, over time, these things can add up as well.

BRIAN GOLDMAN: I did want to ask you, how do constant noise and intermittent noise affect us differently? Are they different?

TOR OIAMO: Yes. So there's some-- a consensus, I guess you can say, within the noise research community, that noise sources that have intermittent peaks that tend to stand out from the background noise, is going to be more harmful or more annoying than sort of the constant hums. Those peaks or diversions from background noise levels definitely seem to be more important than the hum. But that, of course, depends as well. If you live right next to a 6- or 12- or 18-lane highway, probably going to have noise levels up towards, you know, 90 or 100 decibels. That's so loud, regardless, that you're going to have the same effects as someone who lives perhaps in proximity to a busy thoroughfare, that might sort of hum along at around 60 or 65 decibels, but whenever there's a particularly loud vehicle or a truck passes by, it peaks up to, you know, 75 or 80 decibels, and you hear that-- the odd sort of unpredictable event stand out.

BRIAN GOLDMAN: What do researchers consider a healthy level of noise?

TOR OIAMO: The W.H.O. guidelines are really where we want to limit it. Specifically 53 decibels above that. So for every 10-decibel increase above 53 for 24-hour traffic noise levels, you get an 8% increased risk of ischemic heart disease. So go to your 61 decibels, which is fairly busy, but not that busy of a road. Most of us living anywhere near anything other than a very quiet side street will have that type of noise level in a city. And then go another 10 decibels up to 73 decibels, and you're looking at proximity to, you know, fairly major roads and thoroughfares. I talk a lot about traffic noise because that's the most ubiquitous, it's the most common exposure. It's the one where we can get the most bang for the buck in terms of reduction, and consequently reduced health effects too. But yeah, anything above 55 decibels we know can have health effects. But there-- a lot of other factors come into play too. You know, whether or not you keep your windows open; the type of windows that are in place. The orientation of bedrooms; the types of facades you have; if there's any type of mitigation from the source, or, you know, during transmission. There's a lot of different factors at play. But, you know, if you have noise levels inside your living quarters - whether that be your bedroom or living room - at an average above 45 decibels, you're living in a pretty loud place. That means it's likely, you know, 75 decibels or higher, constantly, outside of your dwelling.

BRIAN GOLDMAN: You talk a lot about doing studies that assess traffic noise, which of course is something that you're going to be exposed to to a greater extent if you live in a big city. But suppose you live in a small town, are you less likely to surpass those dangerous levels?

TOR OIAMO: Definitely less likely to. But-- And we can go back to that discussion about background versus intermittent versus, you know, constant hums. You know, if you're, say, living in a small town where it's generally quieter, you know, your average sound levels are likely or most definitely going to be lower than in a big city. But there are those intermittent sources. You know, they can definitely be annoying. I'm sure people can tell that. If you're in that type of exposure where things are annoying, then there's a possibility that there's-- there can be harms to health, too.

BRIAN GOLDMAN: You briefly touched on noise regulations, and I think you mentioned that they pertain mostly to the work environment. Can you amplify that? Can you elaborate on the kinds of noise regulations that exist in Canada?

TOR OIAMO: That's my least favourite question, to be honest. Because it's, it's difficult to answer. A lot of us in the research world, you know, we also have dabbled in air pollution, you can say. There's a lot of similarities, obviously, between air quality and noise in terms of the sources and the methodologies we use to study them. When we compare them: for air quality or air pollutants, the ones that we know most certainly have harmful health effects, there are federal limits. There are no limits on noise levels, federally or provincially. There are guidelines provincially for dealing with transportation sources like roadway and railway exposure. Whether that's when you're doing an environmental assessment to expand a road, or when you're putting in a new neighbourhood. But it's really left up to whoever is receiving that assessment to decide whether they want to follow those guidelines or not. I would say, in general, the legislative framework for environmental noise of this-- of the sorts that I have been talking about and that we do research on, is weak.

BRIAN GOLDMAN: A lot of it is going to be left to personal responsibility. So what's your advice to people who are trying to shut out noise in their environments?

TOR OIAMO: I don't think people should have to deal with noise that they are not the cause of, I suppose. And a lot of the solutions are-- can be really expensive, right? Like, if you are not able to, you know, reorient your house or change your living situation so that you're, well, either moving away from the exposure altogether, but moving things around so that you minimize it, fixes to facades and windows can be really costly. Telling people to just put earplugs in and deal with it is not the solution that I think is reasonable. Paying attention; I think there's people that they might not be aware that they're losing sleep over it. Just trying to tune in and figure out what's happening, where it's coming from. It's a physical property, it's a sound wave. It's quite predictable where it comes from and where it goes, so.

BRIAN GOLDMAN: How can people measure noise in their environment? Is there somebody you can hire who can come in and tell you how noisy it is?

TOR OIAMO: Yeah. So there's quite a few consulting firms that do this on a regular basis, but that's probably not within the scope of reasonable expense for individuals. There are more and more apps available. We all, pretty much all of us, carry a smartphone with us and we can download apps that measure sound pressure levels. How precise they are is, of course, questionable. But iPhone apps, particularly one called NIOSH, which was made by the American Occupational Health Institute -- that's a pretty reliable one because they've been calibrated, and all iPhones are the same. When you get into Android phones it's a bit all over the place, but you'll still get a pretty good idea of the general levels that you're around.

BRIAN GOLDMAN: We know, of course, that noise can affect health, and patients in poor health tend to be hospitalized. How important is it to reduce noise in hospitals?

TOR OIAMO: Yes, there's been quite a bit of research looking at noise in hospitals, as I'm sure you're aware of, and research suggesting that, you know, people with less noisy environments around the hospitals actually recover more quickly. I think it's a very high priority. So when I think about what needs to be done first in a city like Toronto, but anywhere for that matter, is looking at health care facilities and schools and making sure those are places where we mitigate the noise to the best extent possible, first. You know, the vulnerable-- vulnerable people; people who are sick and trying to recover. Any additional stressor there is going to be an issue, of course. And for students, you know, we know that there's cognitive impairments from too much noise exposure that can be differences between reading and learning and writing comprehension in environments that are really loud. So I think it's very important.

BRIAN GOLDMAN: And finally, Tor, on a larger scale, on a more conceptual or philosophical scale, how could we think about sound differently?

TOR OIAMO: I like to put the rhetorical question out there. You know, we care a lot about what things look like in our cities and in our built environments. Why don't we care as much about what they sound like? It's a very important sensory system that can bring great pleasure, as we all know, when we listen to music and hear pleasant sounds in general. But on the flip side, it can be very harmful, too. So I think it's just a matter of realizing that it doesn't have to be this way. There are alternatives and there are better ways to move forward, which is happening in different ways all around the world. And, you know, there's no reason why a city can't also be a pleasant soundscape. Of course, you're not going to, you're not going to eliminate cars, you're not going to eliminate transportation sound. But, you know, we can do a better job of keeping those away from people. At least in the environments that people have to be in.

BRIAN GOLDMAN: Well, Tor Oiamo, thank you so much. That's good advice. And I'm certainly going to be paying more attention to noise as a result. Thank you for coming on The Dose.

TOR OIAMO: Thanks for having me.

BRIAN GOLDMAN: Tor Oiamo is an Associate Professor in the Department of Geography and Environmental Studies at Toronto Metropolitan University. Here's your dose of smart advice. Noise is all around us. The connection between noise and hearing loss seems obvious. Hearing loss is one of the most common chronic health conditions, right up there with diabetes and cancer. Noise exposure away from your job can damage your hearing just as much as working in a noisy place. There's a growing body of evidence that chronic exposure to noise can be hazardous to our health in other ways, yet it's a risk that goes largely unrecognized by many of us. Exposure to 50 or 55 decibels on average, over 24 hours, affects health adversely. Noise exposure activates a part of the brain called the amygdala, which enables the body to sense danger and react to it by secreting excess cortisol and other stress hormones. In turn, these hormones increase the risk of high blood pressure, heart attacks and strokes. Noise also activates the sympathetic nervous system, which raises heart rate and blood pressure, and triggers the production of inflammatory cells which damage the body. Noise also has an adverse effect on mental health, though the research thus far is less robust. Studies have shown that people who live in areas with high levels of transportation noise, are more likely to have highly activated amygdalas, inflammation in their arteries, and major cardiac events like heart attacks and strokes. According to the World Health Organization, average road traffic noise above 53 decibels, or average aircraft noise exposure above 45 decibels, are associated with adverse health effects. There's little evidence that people get used to noise in any way that minimizes the impact on health. If anything, prior exposure to noise primes the body to react, which increases the impact of cardiovascular risk. And while rural and remote areas might have less constant noise than big cities, those who live in the countryside are at risk from sudden intermittent noise, such as from trains and passenger jets flying overhead. To prevent health problems related to noise, the W.H.O. recommends nighttime noise exposures of less than 30 decibels inside the bedroom, and less than 40 decibels outside the bedroom. Things you can do to reduce exposure include wearing earplugs and investing in windows that block out noise. But many of these fixes are well beyond the price range of individuals. Canada has laws on the books that restrict noise pollution, but these laws tend to be weak on enforcement. If you have topics you'd like discussed or questions answered, our email address is thedose@cbc.ca. If you like this episode, please give us a rating and review wherever you listen. This edition of The Dose was produced by Isabelle Gallant. Our senior producer is Colleen Ross. We're taking our usual summer break, but we'll be back in September with new episodes. In the meantime, you can listen to previous episodes wherever you listen to podcasts. And this summer, we'll be airing extended versions of some of our favourite episodes on CBC Radio One, Thursdays at 7:30 p.m., 8 p.m. in Newfoundland, and on the CBC Listen app. The Dose wants you to be better informed about your health. If you're looking for medical advice, see your health care provider. I'm Dr. Brian Goldman. Until your next dose.

Back To Top »

Provide Transcript Feedback

CBC would like to acknowledge the support of the Broadcasting Accessibility Fund.

How is the noise around me harming my health? - Transcript

More Stories Like This