< How noise pollution from planes, trains and automobiles can harm human health

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EMILY KWONG: You're listening to Short Wave from NPR. Joanne Silberner was living in Seattle when it started to get loud.

JOANNE SILBERNER: I couldn't talk to you like this in the backyard and be heard.

KWONG: When she moved to the area in 2010, the nearby highway had just been resurfaced.

SILBERNER: But over time, the highway surface wears away, and the sound of the tires on the roadway get louder and louder and louder.

KWONG: Joanne was experiencing noise pollution, which is unwanted sound that, over time, can cause harm. She moved to Bainbridge Island for some quiet, but as a longtime health reporter, she couldn't shake this growing concern about the impact of loud and persistent noises on human health.

SILBERNER: The noise pollution that I'm most concerned about is the everyday noise pollution of gas-powered leaf blowers, of schools that are right next to elevated train tracks in New York City, of loud factories that are right next to where people are living, the highways that go through the middle of cities. A lot of it is invisible or you're habituated to it, and you don't even know it's there.

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SILBERNER: You might not notice your blood pressure going up when loud things are happening. Or you might not notice that your stress hormones are higher. But they are.

KWONG: And as with many health inequities, noise pollution affects people of color and poor communities disproportionately.

SILBERNER: When the interstate highways started being built, they started running them through poorer neighborhoods who, you know, weren't as politically powerful enough to object.

KWONG: This is where many of us are today, caught amid the hustle and bustle of a busy life, a soundtrack that, depending on where we live, may be hurting our health. Case in point, the 4th of July is often celebrated to the tune of booming fireworks. In 1972, there was a window of time when our sonic future could have been different, quieter. Congress passed the Noise Control Act the same year as the Clean Water Act. The Environmental Protection Agency, the EPA, set up the Office of Noise Abatement and Control to study the impact of noise on nearby populations. But it was closed less than a decade later, and noise pollution became the responsibility of state and local governments. And then last year, an anti-noise advocacy group decided to do something about this.

SILBERNER: There's a group called Quiet Communities, and they got together, filed a lawsuit against the Environmental Protection Agency, saying, hey, you really need to sit up and do what Congress told you to do. It's written in the Act, in the 1972 Act, that EPA should be doing research, setting regulations, you know, understanding, monitoring, and controlling noise pollution.

KWONG: Even with this lawsuit, Joanne says the issue of noise pollution largely flies under the radar, seldom taken up by environmental groups.

SILBERNER: The only thing I can presume is that there were so many other battles, you know, with clean air and clean water that this was just a battle that wasn't fought.

KWONG: Today on the show, what the research says about the costs of noise pollution. how loud is too loud, and when does noise start affecting our health? I'm Emily Kwong. You're listening to Short Wave the science podcast from NPR.

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KWONG: OK, Joanne, we're going to talk about noise itself. You write that there are two factors that pose a health risk to people. It's exposure time, so how long and persistently you're hearing noise, that train that goes by when you're asleep at night, and also decibel levels. But that's kind of measured in terms of something called a weighted decibel. What's a weighted decibel? And what are different weighted decibels?

SILBERNER: Weighted decibel looks at the effect on the ear. Not just the loudness, but what is more--

KWONG: OK.

SILBERNER: --audible to the human ear. And it gives extra weight to that. So the less audible ends of that spectrum don't factor into that number. So you've got a 20 dBA is a whisper in a quiet room. 85 dBA, louder than an alarm clock--

[ALARM CLOCK SOUND]

SILBERNER: --softer than a lawn mower.

[LAWN MOWER SOUND]

SILBERNER: 110 dBA is a rock concert or a jackhammer.

[JACKHAMMER SOUND]

SILBERNER: And when you look at it in terms of time, the very loud noises, very short amount of time to do physical damage to the ear.

KWONG: Yeah.

SILBERNER: The softer noises-- say, when you're talking about being near a louder washing machine-- that kind of noise, that's not physically damaging to the ear, but it is going to have the effect of raising blood pressure, raising stress hormones, things like that.

KWONG: What's worse, a really loud noise that you hear every so often or a pretty loud noise that's, like, constant in your life?

SILBERNER: It depends on what you're worried about. The pretty-- the loud noise, the rock concert, the jackhammer, that's deafness. The softer noises are blood pressure, corti-- stress hormone levels, things like that.

KWONG: In terms of health concerns.

SILBERNER: Right.

KWONG: OK. So what happens if a person is exposed to loud noise for a long period of time?

SILBERNER: Well, studies have shown increases in stress hormones, ultimately increases in heart disease and diabetes, definite problems in sleep. You know, the slightly louder side of the spectrum wakes you up. You might not know it. And sleep disturbances are related to an awful lot of illnesses that I think are-- it's underappreciated. Diabetes, for one.

KWONG: And you wrote about all of this in a piece for Undark magazine and NPR's Shots blog. You noted there was a recently published review by European researchers looking at studies on transportation noise and cardiovascular health. What was their summary?

SILBERNER: Their summary says that studies definitely show an effect, definite increases in heart disease, in heart failure, in stroke. And the numbers weren't huge. In terms of the increased risks, I think it was like 3% or 5% in that level. Which, you know, in a lot of studies, you see numbers that small, and you think, oh, no big deal. But those diseases are so common. You know, if you're talking about a 3% increase in something that almost never happens, you're only talking about a few people. If you're talking about a 3% increase in something like heart disease, or heart failure, or stroke, that's very common, you're talking big numbers. And in fact, there is a conclusion that the World Health Organization came to some years ago when they looked at traffic-related noise just in Western Europe and they added up, what does this do, they found that it took away-- 1.6 million healthy life years were gone--

KWONG: Oh.

SILBERNER: --were taken away by transportation-caused increases in cardiovascular disease and other-- and similar problems. So 1.6 million years of life lost in Western Europe alone in one year from traffic noise.

KWONG: That is just a shocking finding. And earlier, you know, we talked about the Noise Control Act that was passed in 1972. You note that the EPA hasn't suggested new noise limits in decades. What did they propose back then?

SILBERNER: They proposed a daytime average of 45 decibals indoors and 55 decibals outdoors. Now, for reference, a refrigerator hum would be about 40.

[REFRIDGERATOR HUMMING]

SILBERNER: Normal conversation or a room air conditioner would be about 60 decibels.

[AIR CONDITIONER RUNNING]

SILBERNER: Somewhere a little bit higher than listening to a refrigerator hum for 24 hours, that would be their limit, and a little bit quieter than an air conditioner in a house, averaged over 24 hours. And when you think about your life, you know, you do have quiet times, a lot of quiet times. But you've got noisy times, too. So you've got to think about the average.

KWONG: This level of noise sounds incredibly serene and just wonderful, really. Did the EPA say how they would even go about enforcing that? I mean, ensuring that transportation noise was no louder than an air conditioner for someone living nearby.

SILBERNER: They did not at that time that I know of. But you know, if you go to European cities, a lot of them are a lot quieter. And if you go to, you know, in some cities here, you know, the retaining walls that not only block the view of the highway, they block the sound of the highway. That's doable. So you can resurface highways, that quiets things down. You can build sound barriers. You can have quieter cars. There are ways-- there are lots and lots and lots of ways to make things quieter.

KWONG: Yeah. OK, so flash forward to now. It's 2024. We live in the world with the noise we do. What can people do, as they're hearing you and I talk about this, if they're concerned about noise in their neighborhood?

SILBERNER: You can get ordinances passed. And people have done this in individual communities through community activism. Quiet Communities is actually an interesting place to go to because I think they help people organize or answer questions about what can you do in your own community in terms of getting rules passed saying replace gas-powered lawn mowers and blowers with electric ones. You know, you can do things like that. On a bigger level, if you've got highways, I think it's going to take a different level of activism to get them taken care of. So getting involved in letting your politicians know you want something done. You know, I guess what I'm saying here is there really are things you can do.

KWONG: Like, why now would-- would the kind of the wishes of the people who made this law all those years ago come true?

SILBERNER: No reason at all except, you know, there is a little bit more information on the health effects than-- there's certainly more information on the health effects, so you have more ammunition if you're trying to make a change.

KWONG: And I mean, right here in DC, since 2022, there's been a ban on gas-powered leaf blowers. And this is a noise ban pass on the local level. Do you think local measures like this are enough, though?

SILBERNER: No. Personally, no, I don't. It takes a lot of effort, and sophistication, and knowledge, to understand what needs to be done and what should be done. And you know, there are a lot of other problems going on in the world. And people look, and they say, well, wait a minute, we've got a lot of crime. We need more money here. We have lead in our water. You know, we may have problems there. So I personally think it is going to take a federal effort to really make a difference. If you're lucky enough to live in a community where you've got people who are involved enough and who can effect a change, then you're in good shape. But I don't think most of us are.

KWONG: There's so much more we could talk about.

[LAUGHTER]

KWONG: Because I'm like, I'm now thinking about the trade-offs between other-- I'll just call them amenities, but like transportation infrastructure people demand. They want their car. They want like-- all of this has come about from stuff we want, too.

SILBERNER: My answer to that would be it is doable.

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SILBERNER: Other cities have done this in other countries. Rural areas, you know, there are things that can be done to keep noise within factories or other places to contain that noise. It is doable. We haven't done it. Doesn't mean it can't be done.

KWONG: Joanne Silberner, thank you for writing this piece and raising the profile of this public health issue.

SILBERNER: Thank you for talking to me.

KWONG: Joanne Silberner wrote about noise pollution for Undark magazine and NPR. We'll link to her story in our episode notes. This episode was produced by Berly McCoy and Rachel Carlson. It was edited by our showrunner Rebecca Ramirez and fact checked by Berly and Rebecca. The audio engineer was Kwesi Lee. Beth Donovan is our senior director, and Colin Campbell is our senior vice president of podcasting strategy. I'm Emily Kwong. Thank you for listening to Short Wave, the science podcast from NPR.

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