Noise Health Impacts
• Prolonged or excessive exposure to noise, whether in the community or at work, can cause permanent medical conditions, such as hypertension and ischaemic heart disease. (ref. [World Health Organization - WHO] Guidelines p.XII)
• Noise can adversely affect performance, for example in reading, attentiveness, problem solving and memory. Deficits in performance can lead to accidents. (ref. [WHO] Guidelines p.XII)
• Noise can cause hearing impairment, interfere with communication, disturb sleep, cause cardiovascular and psycho-physiological effects, reduce performance, and provoke annoyance responses and changes in social behaviour.
… Some 20 years after its last publication on noise, WHO has issued Guidelines for Community Noise. This publication, the outcome of a WHO expert task force meeting in London in March 1999, includes guideline values for community noise (listing also critical health effects ranging from annoyance to hearing impairment), for example: (ref. [WHO] Guidelines p. XVIII)
|Environment||Critical health effect||Sound level dB(A)*||Time hours|
|Outdoor living areas||Annoyance||50 – 55||16|
|Indoor dwellings||Speech intelligibility||35||16|
|School classrooms||Disturbance of communication||35||During class|
|Industrial, commercial and traffic areas||Hearing impairment||70||24|
|Music through earphones||Hearing impairment||85||1|
|Ceremonies and entertainment||Hearing impairment||100||4|
*The ear has different sensitivities to different frequencies, being least sensitive to extremely high and extremely low frequencies. (ref. [WHO] Fundamentals of Acoustics p. 19) Because of this varied sensitivity, the term “A weighting” is used: all the different frequencies, that make up the sound, are assessed to give a sound pressure level. The sound pressure level measured in dB is referred to as “A-weighted” and expressed as dB(A). (ref. [WHO] Guidelines p.IX and X).
The [WHO] guidelines also offer recommendations to governments for implementation, such as extending (and enforcing) existing legislation and including community noise in environmental impact assessments. The role of WHO is to provide leadership and technical support.
(Above ref: World Health Organization Fact Sheet No258 Occupational and Community Noise: http://www.who.int/mediacentre/factsheets/fs258/en/ Accessed 6-11-2009. 13-3-2011: The linked page is now ‘not available in English’.)
The following information has been extracted from the Wikipedia article [accessed 6-11-2009 bold and red typeface added for emphasis]:-
- … studies … have suggested that noise levels of 50 dB(A) at night may also increase the risk of myocardial infarction by chronically elevating cortisol production.
- Fairly typical roadway noise levels are sufficient to constrict arterial blood flow and lead to elevated blood pressure; in this case, it appears that a certain fraction of the population is more susceptible to vasoconstriction. This may result because annoyance from the sound causes elevated adrenaline levels [which] trigger a narrowing of the blood vessels (vasoconstriction), or independently through medical stress reactions.
- Other effects of high noise levels are increased frequency of headaches, fatigue, stomach ulcers and vertigo.
- … the lower threshold for noise producing sleep disturbance is 45 dB(A) or lower.
- … fear of the noise source and sensitivity to noise both strongly affect the ‘annoyance’ of a noise.
- Evidence has shown that when children learn in noisier classrooms, they have a more difficult time understanding speech than those who learn in quieter settings.
- In a study conducted by Cornell University in 1993, children exposed to noise in learning environments experienced trouble with word discrimination as well as various cognitive developmental delays.
- Children from noisy residences often possess a heart rate that is significantly higher (by 2 beats/min on average) than in children from quieter residences.
The following has been compiled from extracts from Noise Pollution: The Sound Behind Heart Effects by M. Nathaniel Mead at Environmental Health Perspectives [accessed 6-11-2009 bold and red typeface added for emphasis]:-
- According to … new figures [from the World Health Organization Noise Environmental Burden on Disease working group – 2007] long-term exposure to traffic noise may account for approximately 3% of coronary heart disease deaths (or about 210,000 deaths) in Europe each year.
To obtain the new estimates, the working group compared households with abnormally high noise exposure with those with quieter homes. They also reviewed epidemiologic data on heart disease and hypertension, and then integrated these data into maps showing European cities with different levels of environmental noise.
- The noise threshold for cardiovascular problems was determined to be a chronic nighttime [sic] exposure of at least 50 A-weighted decibels, the noise level of light traffic.
- Daytime noise exposures also correlated with health problems, but the risk tended to increase during the nighttime [sic] hours. “Many people become habituated to noise over time,” says working group member Deepak Prasher, a professor of audiology at University College in London. “The biological effects are imperceptible, so that even as you become accustomed to the noise, adverse physiological changes are nevertheless taking place, with potentially serious consequences to human health.”
- Other recent support for an association of cardiovascular mortality with noise comes from a study published in the 1 January 2007 issue of Science of the Total Environment. The results showed an 80% increased risk of cardiovascular mortality for women who judged themselves to be sensitive to noise. “Given these findings, noise sensitivity is a serious candidate to be a novel risk factor for cardiovascular mortality in women,” says Marja Heinonen-Guzejev, a research scientist at the University of Helsinki and lead author of the paper.
- The broader implications of chronic noise exposure also need to be considered. “Noise pollution contributes not only to cardiovascular disease, but also to hearing loss, sleep disruption, social handicaps, diminished productivity, impaired teaching and learning, absenteeism, increased drug use, and accidents,” says physician Louis Hagler, who coauthored a review on noise pollution in the March 2007 Southern Medical Journal. “The public health repercussions of increasing noise pollution for future generations could be immense.”
- There is also a potential interaction between noise and air pollution, given that individuals exposed to traffic noise, for example, are often simultaneously exposed to air pollution.
Noise (Ref: New South Wales Government Department of Environment, Climate Change and Water [DECCW] http://www.environment.nsw.gov.au/noise/index.htm – accessed 19th November, 2009) [Emphasis added]
Noise can be annoying, interfere with speech, disturb sleep or interfere with work. Prolonged exposure to loud noise can also result in increased heart rate, anxiety, hearing loss and other health effects. The impacts of noise depend both on the noise level and its characteristics and how it is perceived by the person affected.
Environmental criteria for road traffic noise – the Environment Protection Authority (EPA) [now a subdivision of the DECCW] from: http://www.environment.nsw.gov.au/resources/noise/roadnoise.pdf[Accessed 19th November, 2009; bold, emphasis added.]
From: Technical notes to the tables – i Specified noise values refer to noise from traffic on roads, road bridges and freeways, and do not include ambient noise from other sources. However, they rely on all traffic noise at the receiver location—not only noise due to the project under consideration.
Extracted from Table 2 Road traffic noise criteria for sensitive land uses:-
Schools (internal) [note: 35dB(A) is the sound level deemed by the World Health Organization to cause 'disturbance of communication' in school classrooms]
Technical note x: In cases where existing schools are affected by noise from proposed roads, the daytime criterion is L Aeq(1h) 45dB(A).
Collector and local roads: L Aeq(1h) 55dB(A)
Freeway/arterial roads: L Aeq(15h) 60dB(A)
Hospital Wards (internal)
Day (7 am–10 pm) and Night (10 pm–7 am): L Aeq(1h) 35 dB(A)
Places of Worship (internal)
Day (7 am–10 pm) and Night (10 pm–7 am): L Aeq(1h) 40 dB(A)
Collector and local roads: L Aeq(1h) 55dB(A)
Freeway/arterial roads: L Aeq(15h) 60dB(A)
From page 14 Environmental criteria for road traffic noise:-
Internal noise levels
Sleeping areas are usually the most sensitive to noise impact, so in the absence of any local codes internal levels of 35–40 dBA at night are recommended.