Noise pollution: an underestimated threat

When we hear the word “pollution” we usually think of trash on lawns, traffic emissions, and chemicals in the water environment. However, noise pollution is not less harmful to health. This type of pollution emerged together with industrialization: cities grow, traffic increases, we use more and more equipment - and the noise level rises. Dr Rojas, an environmental health researcher from Spain, says that noise pollution even “beats air pollution as a risk factor in Barcelona”

What can be the risks?

In 2015, in the article published in the European Heart Journal, Vol. 36, Issue 39, a team of researchers listed several ways exposure to noise impacts on human health:

• it affects the autonomic nervous system increasing heart rate and blood pressure;
• it causes the increase of concentrations of noradrenaline, a stress hormone thus leading to cardiovascular diseases, central nervous system diseases, and gastrointestinal diseases.

These health outcomes are the results of long-term exposure to road traffic noise, i.e. are especially pertinent to large cities dwellers (e.g., London which served as a subject in the research). So, large city noise creates the conditions for the development of cardiovascular diseases, hypertension, and emotional disorders.

The scientists also noted the indirect effects of long-term exposure to urban noise, such as sleep problems. The lack of sleep, in its turn, leads to fatigue, impaired concentration and memory, mental disorders, etc.

The conclusions of the British researchers correspond with Dr Rojas’s assessment of the threat of noise pollution. In their article it is called the second largest “environmental burden of disease” after airborne particulate matter.

Particular research

Jaana I. Halonen and a group of scientists carried out a large-scale research in London and established the association between cardiovascular hospital admissions and day (7.00 - 22.59) and nighttime (23.00 - 06.59) road traffic noise.

It was found that “daytime road traffic noise increased the risk of hospital admission for stroke with relative risk 1.05 in adults, and 1,09 in the elderly <...> Nighttime noise was associated with stroke admissions only among the elderly”.

Besides, the researchers found out that “daytime noise was significantly associated with all-cause mortality in adults” and the elderly.

The connection between strokes and other diseases and noise levels was established. The number of strikes was larger in regions with noise levels higher than 60 dB, and smaller in the regions with noise level lower than 55 dB.

Thus, the scientists proved that long-term exposure to urban noise “was associated with small increased risks of cardiovascular disease and all-cause mortality in the general population”. While a large body of evidence links traffic noise exposure with hypertension.

A neglected threat

Then why is the noise threat not taken seriously? According to Dr. Rojas, we can “tune the problem out”. “When we have a background noise, the brain has the capacity to adapt to this noise”.

But even if we’re not conscious of this noise, it doesn’t mean it has no impact on us. The problem has a cumulative effect.

Dr Rojas sees the solution in the purposeful policies aimed at noise reduction, for example the development of cycling infrastructure and popularisation of walking. The reduction of the number of cars could solve two problems of modern cities: air and noise pollution.

An alternative way to protect yourself from urban noise - is the noise insulation of living spaces. It’ll help reduce the negative impact of the urban environment and normalize sleep which is a crucial factor of proper rest and productivity.