A walk in the woods where only the chirping of birds and the rustling of leaves in the wind can be heard - a soothing experience. Because it gives us the opportunity to forget the noisy everyday life around us. But due to the constantly growing cities, the increase in traffic and the densification of living space, we are in reality almost permanently surrounded by negatively perceived sound, in short noise. Sounds that can assume enormous volume for a short time usually cause acute injuries to the inner ear, such as bursting of the eardrum. Long-term noise, e.g. from traffic, can cause various long-term physical and psychological health problems (13). And although noise has been clearly identified as a health risk by the EU and also by the WHO (10, 12), the legal basis is still in its infancy in many EU countries and existing laws are often enforced with low priority (10).
The human brain can partially block out disturbing influences like noise. As a result, we hardly notice this permanent influence consciously. Nevertheless, we perceive the disturbance subconsciously via the autonomous nervous system (6). As a reaction to this, the body releases stress hormones such as adrenalin and cortisol and puts our body on alert. With our ancestors, these hormones ensured that alertness was increased in dangerous situations and that both muscle and brain functions could be fully exploited (6). Our ancestors were thus able to react more quickly to danger. This state occurred for a limited period of time when acute danger was imminent and was naturally beneficial from an evolutionary point of view. Subconsciously, we are still lurking under the influence of noise, ready to go into battle or flee at any moment.
These days, this almost permanent stress load can lead to nervousness and tension. It affects our concentration and performance, and makes us easily irritable and restless. In severe cases, the noise disturbance leads to aggressiveness and can cause anxiety (13). Above all, the noise disturbance perceived during the day has an increased effect on the state of mind and can cause far-reaching psychological damage (5). If the release of stress hormones decreases in moments of calm, the body suffers from fatigue and dejection (13). Studies with schoolchildren found that noise pollution had a negative effect on their motivation and that both their reading comprehension and long-term memory were affected (1). In the Netherlands, it has been shown that noise from road and rail traffic can lead to increased depression in socially disadvantaged groups (1). A study in Southampton, England, also found that socially weaker members of the population usually had less access to quiet areas and therefore suffered more from the effects of noise pollution. However, a link between socio-economic status and the health effects of noise could not be confirmed in other studies. One reason is probably that city centres and areas with good accessibility are generally seen as favoured living spaces even by socially strong social classes (1).
Since the autonomic nervous system is not consciously controlled, our body also reacts to noise pollution at night (6). In the long term, this stress perceived during the body's resting phase can cause, for example, seriousphysical problems and have a negative effect on the cardiovascular system and blood pressure (6). Researchers in a study in Berlin found that older people in particular were almost twice as likely to be treated for high blood pressure if they were exposed to noise levels above 55 dB at night, compared to those who were less than 50 dB loud (6). The Federal Environment Agency found that men who lived for a long time in a place where they were exposed to enormous noise at night were particularly affected by cardiovascular diseases (3). A Danish study also found that noise was clearly associated with a higher risk of heart attack (9). Research by the Federal Environment Agency in Bremen found that noise pollution was associated with an increased incidence of certain types of cancer, such as leukaemia and breast cancer in women (7). Another study in Berlin found an association between noise pollution and metabolic problems and the susceptibility of the immune system (5). A Swiss study on night-time exposure showed that it was associated with cardiovascular risks as low as 40 dB. A study at Cologne/Bonn airport on the effects of night-time aircraft noise drew similar conclusions (1).
The World Health Organisation (WHO) has therefore classified night-time air traffic at over 40 dB as harmful to health (6). For road noise, the recommendation is a maximum of 53 dB during the day and a maximum of 45 dB at night (12). However, these limits are usually exceeded: In Europe, about 100 million people are regularly exposed to road traffic noise of over 55 dB. This affects 70 million EU citizens within conurbations, the remaining 30 million in rural areas, mostly along main roads (10). In addition, noise sources such as rail and air traffic and industry affect another 20 million people (10). This means that around one in five Europeans live in areas where noise levels are harmful to health (1). But even in the office, on buses and trains, and at home and at night, many people are exposed to high noise levels (11). In 2012, more than half, around 54% of respondents in a representative survey, felt annoyed by road traffic in their place of residence. Rail and air traffic (33% and 20% of respondents) were also perceived as annoying (2). This results in serious health consequences: For the year 1999, about 4,000 heart attacks in Germany were already attributed to noise exposure (4). In more recent calculations, the WHO states that every year in Western Europe alone over 1 million years of life are lost through traffic-related noise pollution. This also includes less extreme conditions such as sleep disturbance and aggressiveness, but 61,000 years of life are allotted to coronary heart disease, i.e. the calcification of the coronary vessels, which can lead to a lack of oxygen in parts of the heart and thus trigger a heart attack (12). This makes noise pollution the second largest environmental burden in Western Europe after air pollution (1, 12).
The Environmental Noise Directive 2002/49/EC of the European Union creates a legal framework to combat this exposure, but the Directive does not set EU-wide noise limits. Only a few EU countries have set national limit values (10). Nevertheless, the Directive requires the drawing up of so-called noise maps which identify the problem at local and regional level and on which action plans can now be built. However, since noise protection is not a clear priority in many EU Member States, the preparation of concepts to combat noise pollution is delayed (10). Nevertheless, more and more local measures are being taken to tackle the problem. In Austria, for example, the first noise protection zones have recently been set up in which drivers with excessively loud vehicles are flashed by specific devices. In Germany and Switzerland, this concept is also gaining support. Ecological retreats are also increasingly being set up in European cities (10). These clean the air, reduce heat in the city and provide protection against flooding. But studies also show that urban greening can counteract the negative psychological effect of noise pollution (8). Nevertheless, the trend towards urbanisation and the consequent expansion of conurbations and increase of vehicles on the roads will not make it easier to reduce noise pollution. What is certain is that, given the clear harmful effects on health and the number of people exposed to this pollution, it is becoming increasingly important to pay more attention to this environmental problem.
- European Environment Agency (2020). Healthy environment, healthy lives: how the environment influences health and well-being in Europe.
- Weinandy, R. (2013). Schwerpunkte 2013 – Jahrespublikation des Umweltbundesamtes; Kapitel Lärm.
- Babisch, W. Umweltbundesamt. (2004). Die NaRoMI-Studie - Noise and Risk of Myocardial Infarction.
- Babisch, W. Umweltbundesamt. (2006). Transportation Noise and Cardiovascular Risk.
- Maschke, C. et al. (2003). Epidemiologische Untersuchung zum Einfluss von Lärmstress auf das Immunsystem und die Entstehung von Arteriosklerose.
- Umweltbundesamt (2015). Stressreaktionen und Herz-Kreislauf-Erkrankungen. https://www.umweltbundesamt.de/themen/verkehr-laerm/laermwirkung/stressreaktionen-herz-kreislauf-erkrankungen#auswirkungen-des-larms-auf-die-gesundheit
- Greiser, E. Greiser, C. Umweltbundesamt. (2015). Umgebungslärm und Gesundheit am Beispiel Bremen.
- Dzhambov, A.M, Dimitrova, D. (2014): Urban green spaces' effectiveness as a psychological buffer for the negative health impact of noise pollution: A systematic review
- Roswall, N et al. (2017). Long-term residential road traffic noise and NO2 exposure in relation to risk of incident myocardial infarction – A Danish cohort study
- Europäische Kommission (2017). Bericht der Kommission an das Europäische Parlament und den Rat über die Durchführung der Richtlinie über Umgebungslärm gemäß Artikel 11 der Richtlinie 2002/49/EG.
- Yoa, C.M.K.L. et al (2017). Noise exposure while commuting in Toronto - a study of personal and public transportation in Toronto