© Getty Images

What is noise pollution? -

Any unwanted sounds in the environment can be considered noise pollution if it's deemed loud enough. The World Health Organization (WHO) defines noise above 65 decibels (dB) as noise pollution.

© Shuttestock

What causes noise pollution? -

Noise pollution can be caused by a number of different things, including traffic, aircraft, construction, railway, animals, and people.

© Shuttestock

But aren’t we surrounded by sound? -

Indeed, humans have always been surrounded by sounds. From a bird singing, to water running, and the wind blowing on trees. But these are all part of the environment and not loud enough to reach unhealthy levels.

© Shuttestock

How is noise pollution measured? -

Noise is sound, so it is measured in decibels (dB). The higher the dB, the further the sound travels. That’s why you still hear a very loud airplane even though it’s so far away.

© Shuttestock

Decibels -

A quiet night in the countryside or in a suburban area is typically around 20-30 dB.

© Shuttestock

Decibels -

For sake of comparison, a regular conversation is usually about 60 dB.

© Shuttestock

Decibels -

Cars and trucks can range around 70 to 90 dB, depending on the type of road and the distance. For instance, a highway will be noisier than a town road and the closer you get to it, the noisier it gets.

© Getty Images

Decibels -

And then you have the big boys of noise pollution, such as sirens and airplanes, that can reach 120 dB or more. Construction works can also reach high dB levels, and so can trains.

© Getty Images

More than just a nuisance -

Noise pollution can be annoying, but some people just get used to it; especially those who live in the city. However, this doesn’t necessarily mean that noise pollution is not harming these people’s mental and physical health.

© Getty Images

How it works - Our brain is always on alert for sounds that can signal danger. This happens even when we’re asleep.

© Shutterstock

How it works -

As the noise reaches the brain, it activates both the auditory cortex and the amygdala. The latter responds by sending a distress signal and triggering a stress response.

© Shutterstock

How it works -

This stress response triggers the sympathetic nervous system, which puts your body in a “fight-or-flight” state.

© Shutterstock

How it works -

As a result, your body will be flooded with the stress hormone cortisol, adrenaline will be released, and blood pressure rises, among other physiological responses.

© Shutterstock

How it works -

This would be handy if you were sleeping in the savanna and a lion was approaching your camp, but not so much when you’re in the comfort of your own bed, safe from danger.

© Shutterstock

Effects -

It’s easy to see how this will disrupt one’s sleep, even if the person doesn’t wake up. It disrupts sleep quality, which can have disastrous health consequences.

© Shutterstock

Effects -

Numerous conditions have been associated with exposure to noise pollution, both physical and psychological.

© Shutterstock

Effects -

These include anxiety, depression, high blood pressure, stroke, and heart disease.

© Shutterstock

Effects -

Not to mention people who are regularly exposed to high levels of noise (e.g construction workers, touring musicians, and ground crew members, among others) who can experience health issues such as hearing loss and tinnitus.

© Getty Images

Effects -

Exposure to unhealthy levels of noise can also impact on learning. A study found that 12,500 schoolchildren in Europe are estimated to suffer from learning impairment in school due to exposure to aircraft noise.

© Shutterstock

How many people are affected? -

It is estimated that about a third of people in Europe and the US are regularly exposed to noise above 70 dB.

© Shutterstock

How many people are affected? -

The European Environment Agency estimates that noise pollution is linked to approximately 12,000 premature deaths. It’s also associated with 48,000 new cases of ischemic heart disease per year in Europe.

© Shutterstock

How many people are affected? -

According to a report by the WHO, each year western Europeans are losing more than 1.6 million years of healthy life due to traffic noise.

© Shutterstock

How many people are affected? -

A study found that people living near the Frankfurt Airport in Germany have a 7% higher risk of stroke.

© Shutterstock

How many people are affected? -

A 2011 study found that a 10-dB increase in aircraft noise was associated with a 28% increase in anxiety medication use by people living near seven major European airports.

© Shutterstock

How many people are affected? -

A study found that people who lived in areas with more road traffic noise were 25% more likely to have symptoms of depression, when compared to those living in quieter areas.

© Shutterstock

How will it look in the future? -

The United Nations estimates that by 2050 about 70% of people will be living in cities, so the number of people affected by noise pollution is likely to increase.

© Shutterstock

What you can do about it -

If you live in a city or in an area where you are exposed to high levels of noise pollution, there are a few steps you can take to make things quieter.

© Shutterstock

What you can do about it -

Good quality windows can make all the difference, and so can acoustic insulation panels, soundproof curtains, and more.

© Shutterstock

What you can do about it -

Sometimes it’s not possible to change the place you live in structurally, but you can still do something about it.

Earplugs are your friend. Find a good comfortable pair and use them when you go to bed. It’s a cheap, easy, and effective way to cut off dBs while you sleep.

Sources: (BBC) (European Environment Agency 1 and 2) (Brainfacts) (Medical News Today) (WHO)

See also: The most polluted rivers in the world (5 are in the US)

© Shutterstock