The consequences of noise pollution

Noise pollution is a silent (but not so silent) threat to the environment. The idea of creating too much noise is often seen as a human problem; usually your neighbour complaining about how loud a party is. Aside from these inconveniences too much noise can harm animals and our health too. 

How does noise pollution harm human health? 

WHO published a report called ‘Burden of disease from environmental noise’ (2011) which outlines the main concerns of noise pollution and provides evidence from studies they have conducted. There are links to several health conditions such as cardiovascular disease. This is because the noise stimulates increased nervous and endocrine (endocrine system produced and releases hormones) system activity causing blood pressure to increase, increase risk of hypertension and other heart related problems. The ears never rest because they are constantly picking up sounds and your nerves will react to them in different ways by releasing hormones. Furthermore, noise while sleeping can cause a stress response which will raise blood pressure and heart rate, both of which can lead to cardiovascular disease. Many people who live in busy cities experience constant noise when sleeping, worsening their health in the long term.

There have also been links to cognition. Children who have grown up living near airports or motorways experienced greater levels of memory impairment, slow reading and lower attention levels. This may be due to interrupted sleep too where your ears are far more active at night than they should be.

This shows the statistics in the EU. As you can see, there is a greater number of annoyance reports which is why we hear about this effect of noise pollution the most. Credit: European Environment Agency

However, high levels of annoyance can increase levels of stress which will increase the risk of heart disease. They are often linked factors that will lead to many premature deaths.

To give you an indication of how damaging the noise we experience every day is, I will explain how loud something is! Sound is measured in decibels. Ears can be harmed at around 85+ decibels but these things are even louder:

  • Lawn mowers = 90 decibels
  • Motorcycle = 90 decibels
  • Subway trains = 90-115 decibels
  • The wail of a siren = 120-140 decibels
  • Aeroplane = 140 decibels

These levels of noise we experience on a daily basis may have long term health consequences.

Noise pollution is becoming a serious problem and has been named the second most harmful environmental problem to human health (the first being air pollution). Sound is an important way to communicate and is a valuable sense that we have. However, loud and constant noise is damaging our own health. Hence it is becoming a greater priority to reduce noise particularly at night.

How does noise pollution harm ecosystems? 

Aside from human health, there are also significant impacts on animals in the environment. Animals rely on sounds for many of their daily habits. If other non-natural sounds interfere, they are unable to communicate with one another.

Noise pollution affects many forms of life, making it a widespread problem – on land, in the air and in the ocean.

On land

The main sources of noise pollution on land are the traffic from cars and construction sites (machines are major sources of noise). These can affect wildlife. Prairie dogs have impressive cognitive abilities and they usually recognise predators by specific alarm calls. They live in colonies as highly social animals and in order to protect their families they will use distinct sounds. Increased background noise makes it easier for predators to prey on prairie dogs undetected. As a result they are more likely to have short lifespans.

Each and every animal is important to an ecosystem. If one animal population depletes it usually means other species within a system will also die out. Hence it is becoming a great threat to ecosystems around the world with the emergence of busy cities. Some of the loudest cities are as loud as working in a factory for an entire day and they will often exceed the recommended noise levels. These cities include Mumbai (India), New York City (USA), Shanghai (China) and Tokyo (Japan).

Prairie Dogs. Credit: BBC

In the air

Birds are affected by the sounds of aeroplanes and other vehicles apart of the aviation industry. Birds communicate using the syrinx, a vocal organ, that produces songs and sounds. Bird songs are usually how they attract mates, find food and defend their territory. Noise can interfere with these things making it less likely they will survive to reproduce. Therefore, bird numbers will decline. Furthermore, noise can impact migration patterns. Birds will migrate away from noise which will change their habitats. They may find it more difficult to find suitable habitats are may leave ecosystems they help to maintain.

In the ocean

There is a common misconception that the ocean is void of noise. But it is full of noises from both marine animals and from man-made machines.

Below is a video on why whales sing to stress the importance of vocal communication for marine life.

In the vast ocean it is often easy for a calf to loose its mother, so whales will use songs to find their way back. Some other animals such as dolphins and beluga whales use echolocation to communicate and navigate. The water makes it difficult for animals to smell and see well so hearing is a significant sense that they rely on. Increased noise pollution will disrupt these communication systems that have developed among these animals. Major sources of noise are:

  • Military activity
  • Seismic surveys – used to find gas reserves under the Earths surface using sound waves. It claims to be ‘non invasive’ but still harms marine life through noise pollution.
  • Shipping and fishing boats – fishing boats are damaging to whales and marine life not just for over-fishing.
  • Sonar
Here you can see how sonar works. It uses sound propagation to detect objects under water.

Considering all these effects of noise pollution, would wind turbines be a beneficial source of energy to combat climate change and replace fossil fuels? They may not be as helpful to wildlife or our own health.

In actual fact, wind turbines don’t produce too much noise because of how far they are away from the houses of residents. They would have the effects of around 40-60 decibels (which is around the same as a refrigerator) which won’t effect human health. Credit: General Electric

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