Transport noise and health

Noise homepage

Contents:

1. Introduction
2. Hearing loss
3. Annoyance and stress
4. Sleep deprivation
5. Cardiovascular disease
6. Psychological wellbeing
7. Noise effects on children
8. Noise and health links
9. References

Introduction

Noise is increasingly recognized as a serious health hazard as well as a nuisance.  The WHO recognizes community noise, including traffic noise, as a serious public health problem. The sections below outline the various health effects of noise and provide links to further information. The effects must be considered in the European context where half of citizens live in noisy surroundings, and a third experiences levels of nighttime noise that disturb sleep [1].

Recent studies have attributed fatality figures to traffic noise. Studies as part of the Danish Road Noise Strategy estimated that 800-2200 hospitalisations due to cardiovascular disease and between 200-500 premature deaths in Denmark each year are attributable to traffic noise [2]. As well as physical health problems including hearing loss, raised blood pressure and heart disease, the psychological effects of annoyance and sleep deprivation also have extremely serious consequences. Evidence shows that traffic noise also hinders communication and learning processes, especially in children [3].

The most vulnerable members of society are often the most adversely affected; the young, the elderly and those who already suffer physical or mental health problems. Social inequalities may also be exacerbated, as the most deprived areas are often located in close proximity to major transport axes, such as railway stations or depots, main roads, busy junctions, airports and flightpaths. These areas are often at the highest risk from noise exposure as well as from air pollution.

There is a general consensus about the noise levels which cause health impacts [4]:

• Environmental noise above 40-50dBA Leq is likely to lead to significant annoyance.
• Noise levels between 65-70 dBA Leq may be risk factors for school performance and ischemic heart disease.
• Outdoor noise levels of 40-60 dBA Leq may disturb sleep.
• Traffic noise of 70dB(A) may cause hearing impairment.

Hearing loss

Approximately 10% of the population in industrialized societies suffers from significant hearing loss. The principal cause is exposure to elevated sound levels, which can be either from brief exposure to extremely loud noise, or also from prolonged exposure to lower levels. For example, volumes of around 70dB(A), which are common along major roads, can result in cumulative hearing damage over time. It is now accepted that ageing alone is not the principal cause of hearing loss, but that it is rather due to cumulative long-term exposure to environmental and occupational noise [5]. Hearing loss is usually irreversible.

Annoyance and stress

Annoyance caused by noise varies depending on the source, time of day, frequency of occurrence and from person to person. How noise is perceived depends heavily on a person’s attitude to the source of the noise and its usefulness. Annoyance has knock-on effects on health. Annoyance causes physiological effects demonstrated by stress indicators (hormone release, increased blood pressure). The long-term effects of elevated stress levels can be very serious for cardio-vascular health. [6]

Annoyance and stress result in difficulty concentrating, irritability and increases in aggressive behaviour [7]. Motor vehicle and aircraft noise are the most important sources of sound levels which give rise to these effects.

The graph demonstrates that aircraft noise is perceived as annoying by a greater number of people than road or rail noise. At the WHO guidance limit for noise exposure of 55dB(A), approximately 30% of people are still annoyed by aircraft noise, approximately 20% are annoyed by road noise and around 10% are annoyed by railway noise.  50% of people are annoyed by aircraft noise at around 65dB(A), and by road noise at around 70dB(A).

Sleep deprivation

Noise in the evening, early morning or nighttime has substantially more serious annoyance effects, as it is more likely to disturb recreation, relaxation or sleep. Sleep disturbance occurs from 30dB(A), and the WHO recommends maximum nighttime outdoor noise levels of 45dB(A).

Sleep disturbance is clearly detrimental to wellbeing, and longer term disturbances are damaging to physical and mental health. Tiredness also reduces concentration spans, which decreases productivity and performance at work or school and increases the risk of accidents.

Cardiovascular disease

The link between noise and heart disease has been investigated since the 1960s. Over recent years, results from many epidemiological studies have been collated to show that there is a causal link between noise – even at relatively low volumes – and serious health problems including high blood pressure and heart disease. The relationship has been demonstrated in studies by increased need for medication and prevalence of disease.

A study by the German Federal Environment Agency has recently carried out research firmly establishing the causal link between road traffic noise and heart disease. Noise triggers the release of adrenalin, noradrenalin and cortisol as a stress reaction in the brain. Prolonged chronic exposure to noise, particularly from road or air traffic, can result in permanent functional and metabolic changes due to the imposed stress and elevated hormone levels. This is in turn linked to a higher risk of cardiovascular diseases, including high blood pressure and heart attacks.

The study found an observable increase in incidence of heart attacks in people exposed to road traffic noise over 60dB(A) during the day. The German Federal Environment Agency used the results of the study to estimate that 27,000 cases of ischaemic heart disease in Germany, including 4000 heart attack cases per year are attributable to road traffic noise alone. [8] A study for the Danish Environmental Protection Agency has also estimated that between 200 and 500 premature deaths in Denmark each year are attributable to noise. [9]

Some recent studies have investigated the link between health effects of noise and those caused by air pollution. [10] Particularly in the case of traffic, where noise and air pollution stem from the same source, the cumulative health effects of cardiovascular and respiratory disorders still merit further investigation.

Psychological wellbeing

As well as annoyance and stress reactions, some evidence has been found of a relationship between road traffic noise exposure and mental health disorders. [11] The World Health Organisation’s Community Noise Guidelines also note a link between neighbourhood noise and mental health problems, which is indicated by an increased demand for medication, incidence of psychiatric symptoms and admissions for psychiatric treatment linked to noisy areas. [12]

Noise effects on children

Noise has particularly harmful effects on children [13], as noise in the classroom or at home interferes with communication and therefore learning processes. Research has demonstrated that children in a noisy environment have problems filtering out background noise and interpreting speech. A study for the European Commission (known as RANCH) investigated road traffic and aircraft noise exposure and children's cognition and health. It was found that children exposed to noise levels over 55dB(A) achieved lower scores in reading tests.[14] Affected children will be disadvantaged in their development of speech and reading abilities as well as more general communication skills.  Noise may also have effects on foetal development due to (stress) effects on expectant mothers. [15] Environmental noise also has cognitive effects in older children and adults, due to hindering communication, as shown by studies of aggression, mental health and anxiety.  

Noise and health links

World Health Organisation:  

• Noise homepage
• Noise and health indicators
• WHO Guidelines for Community Noise (2000): Berglund, B., Lindvall, T., Schwela, D.H. Guidelines for Community Noise, World Health Organisation, Geneva, 2000
• WHO Night time Noise Guidelines (forthcoming)
• Noise and sleep

European Commission:

• Directorate-General Environment noise homepage
• EU Environmental Noise Directive 2002/49/EC, "Directive of the European Parliament and of the Council of 25 June 2002 relating to the assessment and management of environmental noise", Official Journal of the European Communities L 189, 12-25 (2002)
• Directorate-General Health and Consumer Protection

European Environment Agency:

• Noise homepage
• TERM Reports (Transport and Environment Reporting Mechanism), annual indicator reports, including exposure to and annoyance by traffic noise
• http://reports.eea.europa.eu/eea_report_2007_1/en/eea_report_1_2007.pdf

EU research projects:

• CALM network
• CALM database

Health impact assessment of noise:

• HEARTS (2002-2005) Health effects and risks of transport systems
• HYENA (2002-2006) Hypertension and exposure to noise near airports study
• PINCHE (2002-2005) Policy interpretation network on children's health and environment
• RANCH: Road traffic and aircraft noise exposure and children's cognition and health
• NOPHER
• Transport Hot Spots : developing a methodology to assess population exposed to high levels of noise and air pollution close to major transport infrastructures

Noise exposure:

• HARMONOISE (2001-2005) Harmonised noise exposure computation methods for roads and railways:
• IMAGINE (2003-2006) Integrated environmental noise database
• Urban Audit, measures quality of life in towns and cities
• TRENDS (Transport and Environment Databases System)
• Gipsynoise

References

[1] WHO Guidelines for Community Noise (2000): Berglund, B., Lindvall, T., Schwela, D.H. Guidelines for Community Noise, World Health Organisation, Geneva, 2000, p.XII.
[2] Danish Environmental Protection Agency, quoted at http://www.vejdirektoratet.dk/publikationer/VInot037/html/chapter07.htm
[3] RANCH project
[4] Babisch, W. Internoise presentation, 2006
[5] Rosenhall, Ulf; Pedersen, Kai; Svenborg (August 1990): Alvar Presbycusis and Noise-induced hearing loss, Ear & Hearing 11(4):257-263, Lippincott, Williams & Wilkins.
[6] Bluhm, G., Nordling, E., Berglind, N. (2004). ‘Road traffic noise and annoyance – An increasing environmental health problem’ Noise and Health, Volume 6, Number 24, Jul - Sept 2004, pp. 43-49(7), nRn Publications.
[7] WHO Guidelines for Community Noise (2000): Berglund, B., Lindvall, T., Schwela, D.H. Guidelines for Community Noise, World Health Organisation, Geneva, 2000, p.XIII.
[8] Babisch, W. (2006) “Transportation noise and cardiovascular risk, Review and synthesis of epidemiological studies, Dose-effect curve and risk estimation” WaBuLu-Hefte01/06, Umweltbundesamt, Berlin. 
[9] Danish Environmental Protection Agency, quoted at
http://www.vejdirektoratet.dk/publikationer/VInot037/html/chapter07.htm
[10] Schwela, D., Kephalopoulos, S., Prasher, D. (2005) ‘Confounding or Aggravating Factors in Noise-Induced Health Effects: Air Pollutants and Other Stressors.’ Noise and Health, Volume 7, Number 28, Jul - Sept 2005, pp. 41-50(10), nRn Publications.
[11] Halpern, D. (1995) More then bricks and mortar? Mental health and the built environment. Taylor and Francis: London
[12] WHO Guidelines for Community Noise (2000): Berglund, B., Lindvall, T., Schwela, D.H. Guidelines for Community Noise, World Health Organisation, Geneva, 2000, p.XII.
[13] Evans, G.W., Lercher, P., Meis, M., Ising, H., and Kofler, W. W. (2001) "Community noise exposure and stress in children", Journal of the Acoustical Society of America, No. 109, pp.1023-1027, Acoustical Society of America.
[14] Stansfeld. S.A., Berglund. B., Clark. C., Lopez Barrio. I., Fischer. P., Ohrstrom. E., Haines. M.M., Head. J., Hygge. S., van Kamp. I. & Berry. B. (2005) ’Aircraft and road traffic noise and children's cognition & health: exposure-effect relationships’ The Lancet, 365, 1942-1949
[15] USA Environmental Protection Agency (1978): Noise: A health problem, Office of Noise Abatement and Control, Washington, D.C.