BbcWe are surrounded by an invisible killer. Such a common that we barely notice that it shortens our lives.
This causes heart attacks, type 2 diabetes and studies now even binds it to dementia.
What do you think it could be?
The answer is noise – and its impact on the human body goes far beyond the harmful hearing.
“This is a public health crisis, we have a large number of people exposed in their daily lives,” said Professor Charlotte Clark, of St George’s, University of London.
It’s just a crisis that we are not talking about.
So I investigated when the noise becomes dangerous, chatting with people whose health suffers and saw if there is a way to overcome our noisy world.
I started by meeting Professor Clark in a laboratory of his strangely silent. We will see how my body reacts to noise and I was equipped with a device that looks like a smartwatch
This will measure my heart rate and how much my skin sweats.
You can also join us if you have any headphones. Think of these five sounds make you feel.
The one I find really creaky is the noise of the traffic of Dacca, Bangladesh, which has the most noisy city in the world. I immediately have the impression of being in a ginormous and stressful traffic jam.
And the sensors pick up my agitation – my heart rate rises and my skin sweat more.
“There is very good proof that traffic noise affects your heart health,” said Professor Clark because the next sound is prepared.
Only the joyful sounds of the playground have a calming effect on my body. The dogs that bark and the neighbor of the neighbor at the beginning of early childhood lead to a negative response.
But why does sound change my body?
“You have an emotional response to the sound,” said Professor Clark.
The sound is detected by the ear and transmitted to the brain and a region – the amygdal – performs emotional evaluation.
This is part of the body’s combat or flight response that has evolved to help us quickly react to sounds as a predator that crashes through the bushes.
“So your heart rate increases, your nervous system is starting to get started and you free up stress hormones,” said Professor Clark.
All this is good in an emergency, but over time, it is starting to cause damage.
“If you are exposed for several years, your body reacts like that all the time, it increases your risk of developing things like heart attacks, high blood pressure, STVE and type 2 diabetes,” said Professor Clark.
Insidiously, it happens even while we sleep quickly. You might think that you adapt to noise. I thought I was doing when I lived in a rental near an airport. But biology tells a different story.
“You never cut your ears; when you sleep, you always listen. So these answers, like your heart rate increases, this happens while you sleep,” adds Professor Clark.
Noise is unwanted sound. Transport – traffic, trains and planes – are a major source, but we also have a good time. One person’s big party is an unbearable noise from another.
I meet Coco in his fourth floor apartment in the historic region of Vila de Grà cia in Barcelona, ​​Spain.
There is a bag of freshly picked lemons attached to its door offered by a neighbor, its refrigerator contains a tortilla baked by another and it offers me fanciful cakes made by a third neighbor who trains in pastry.
From the balcony, you can see the famous city cathedral, the Sagrada Familia. It is easy to see why Coco fell in love with life here, but it has a huge price and she thinks she will be forced to leave.
“It’s extremely noisy … It’s a 24-hour noise,” she told me. There is a dog park for the owners to walk their dogs which “shelter at 2, 3, 4, 5 am” and the courtyard is a public space which is used for everything, from birthday celebrations to concerts all day ended with fireworks.
She takes out her phone and plays the music recordings which is exploded so hard that the glass in her vibrates windows.
His house should be a refuge for work stress, but noise “brings frustration, I want to cry”.
She was “hospitalized twice with chest pain” and “absolutely” thinks that noise causes stress, which damages her health. “There is a physical change that I feel, it does something for your body, with certainty,” she said.
In Barcelona, ​​there are around 300 heart attacks and 30 deaths per year just because of traffic noise, according to researcher Dr. Maria Foraster, who examined the proofs of the world of the World Health Organization.
Across Europe The noise is linked to 12,000 early deaths per year as well as millions of seriously disturbed sleep cases as well as a serious annoyance of noise which can have an impact on mental health.
I meet Dr. Foraster in a cafe separated from one of the busiest roads in Barcelona by a small park. My sound counter says that the sound of distant traffic is just over 60 decibels here.
We can easily discuss the noise without raising our voices, but it is already an unhealthy volume.
The crucial number for heart health is 53 decibels, she said, the more you become, the higher health risks.
“This 53 means that we must be in a rather calm environment,” explains Dr. Foraster.
And it’s just during the day, we need even lower levels for sleep. “At night, we need calm,” she said.
Although it is not only a question of volume, the disruption of the sound and the amount of control that you have on it affects our emotional response to noise.
Dr. Forester maintains that the impact on noise health is “in terms of air pollution” but is much more difficult to understand.
“We are used to understanding that chemicals can affect health and that they are toxic, but it is not so easy to understand that a physical factor, like noise, affects our health beyond our hearing,” she said.
A strong party can be the pleasure that makes life worth lived and the intolerable noise of someone else.
The sound of traffic has the greatest impact on health because so many people are exposed to it. But traffic is also the sound of going to work, shopping and taking children to school. Tacking the noise means asking people to live their lives differently – which creates their own problems.
Dr. Natalie Mueller, of Barcelona Institute for Global Health, takes me to walk in the city center. We start on a very busy road – my sound counter is inserted at more than 80 decibels – and we head towards a quiet avenue bordered by trees where the noise is in the 1950s.
But there is something different on this street – it was a very busy road, but the space was consulted at pedestrians, cafes and gardens. I can see the ghost of an old road crossed by the shape of flower beds. Vehicles can always come here, just slowly.
Remember earlier in the laboratory, we found that some sounds can appease the body.
“It is not completely silent, but it is a different perception of sound and noise,” explains Dr. Mueller. My heart rate dropped and I stopped sweating.
Getty imagesThe initial plan was to create more than 500 zones like this, called “superblocs” – areas adapted to pedestrians created by grouping several city blocks.
Dr Mueller Research Projecting a reduction of 5 to 10% of noise in the city, which would prevent “150 premature deaths” of noise alone each year. And it would be “just the tip of the iceberg” of health benefits.
But in reality, only six superblocs were built. The municipal council refused to comment.
Urbanization
The dangers of noise continue to grow. Urbanization puts more people in noisy cities.
Dhaka, Bangladesh, is one of the megapities that knows the fastest growth in the world. This brought more trafficking and gave the city a cacophonic soundtrack from Klaxual horns.
The artist Moma Raman Royal won the label of the “lonely hero” because his silent protests have focused attention on the problem of the noise of the city.
For about 10 minutes a day, it is held at the intersection of a few very busy roads with a large yellow sign accusing drivers who hide aloud to cause massive nuisance.
He took the mission after the birth of his daughter. “I want to prevent all the horns not only from Dhaka, but from Bangladesh,” he said.
“If you see birds or trees or rivers, no one makes noise without humans, therefore humans are responsible.”
But here there are also the beginnings of political action. Syeda Rizwana Hasan, who is the environment advisor and Minister of the Government of Bangladesh, told me that she was “very worried” of the impacts on noise health.
There is a repression against horn horns to reduce noise levels – with an awareness campaign and a more strict application of existing laws.
She said: “It is impossible to do it in a year or two years, but I think it is possible to make sure that the city becomes less noisy, and when people feel that, they feel better when it is less noisy, I am sure that their habit will also change.”
Noise solutions can be difficult, complicated and difficult to solve.
What I have left is a new appreciation to find a little space in our lives to escape noise because, in the words of Dr. Masrur Abdul Quader, from the University of Professionals in Bangladesh, it is “a silent killer and a slow poison”.
Loud was produced by Gerry Holt. Additional Bangladesh reports by Salman Saeed