Environmental Noise and Health:

The Latest Evidence

Professor Deepak PrasherInstitute of Laryngology and

Otology

University College London

Day and Night Noise Levels

Typical Noise Level LeqdBADay Night Acoustical Quality35 35 natural sounds only50 40 quiet rural environment55 45 suburban neighbourhood

65 50 urban noise situation75 75 very noisy, unfit for

permanent habitation

Noise Level and Effect <55dBA Desirable level outdoor

Suburban neighbourhood 55-65dBA Urban “Grey Areas”:

Annoyance >65dBA Black spots:

Stress effects, sleep disturbance, communication performance deficits

>75dBA Unfit for Human habitation, hearing loss, cardiovascular effects

European City Noise Desirable Indoor Comfort Leq <65dBA New Residential Areas outdoor levels

<55dBA Urban “Grey Areas” Levels 55-65dBA Black Spots Levels >65dBA Large European Cities:Number of Peopleexposed to high levels 3 times national

average Percentage living in “grey areas” increasing

(OECD 1991)

Noise Levels in Environment

Normal Conversation 45-55dBA Car 50km/h 60-80dBA HGV 50km/h 80-95dBA Motorcycle 50km/h 75-100dBA Train 200km/h 95-100dBA pk Discotheque(Leq) 85-100dBA Jet (Take off,100m) 110-115dBA Military low level flights 105-120dBA

Speech Communication in Noise Socially people talk at 2-4m distance:

Noise should not exceed 55-60dBA Outdoor recreation people talk at 5-

10m: Noise levels should not exceed 45-55dBA

At work people can converse at 1m with difficulty with noise at 78dBA.

For prolonged conversations noise level must be lower than 78dBA at work

Hazardous Noise Levels Level Hazardous if communication

not possible when in the sound Tinnitus (ringing in ears) after

sound exposure Sounds muffled after leaving sound

exposure area

Noise Environment in Europe

450million (65%) exposed to >55dBA 113 million (17%) exposed to >65dBA 9.7million (1.4%) exposed to >75dBA No systematic differences across

Europe Eastern European Cities noisier than

Western Data poor from Central and Eastern

Europe

Costs of Noise to Society Estimate: 0.2 to 2% GDP0.2% equates to 12Billion Euros

annually

Noise Sources in Europe Road Traffic Air Traffic Rail Traffic Industry Recreational Activities Construction Sites Traffic on Waterways

Auditory Effects Acoustic Trauma: Sudden hearing

damage Tinnitus: Ringing in the Ears TTS:Temporary threshold shift PTS: Permanent threshold shift Interference with Communication

Non-Auditory Effects Annoyance Sleep Disturbance Attention Motivation Stress reactions Cardiovascular problems Endocrine problems

Annoyance Noise is annoying Generally the louder the noise the

greater the annoyance But there are non-acoustic factors

affecting annoyance Degree of annoyance not directly

related to adverse health effects

Annoyance from Street Noise

West Germany (UBA 1988)Inhabitants Percentage

Annoyed< 5000 14-165-20,000 17-1920-100,000 19-25>100,000 22-33Annoyance increases with increase in Population

Factors affecting Annoyance Primary Acoustic: Sound level,

frequency and duration Secondary Acoustic: Spectral

complexity, fluctuations in frequency, level, localisation of noise source

Non-acoustic: Adaptation and past experience, listener’s activity interference, predictability of noise, individual personality

Noise and Sleep Increases time taken to fall asleep Causes awakenings and changes in sleep

stages; reduces REM and slow wave sleep Sleep disturbance in turn may lead to poor

performance and change in modd next day Noise sensitive individuals and elderly

more vulnerable Chronic exposure leads increase of cortisol Adaptation possible but not complete

habituation

Noise and Sleep In Europe 10-26% (55-143 m) : Severe

difficulties falling asleep or staying asleep

Chronic Sleep disorders lead to loss of efficiency, psychological well being, learning in childhood, social interaction and driving ability

Drivers falling asleep cause 20% of accidents on German Roads

Noise and Performance Distracting effects of Noise impair

performance especially in children, noise sensitive and anxious people

Type and degree of control important in degradation of performance

Learning in Schools impaired due to outdoor and/or indoor noise levels

Memory: Recall impaired in children

Noise and Hormones Prolonged exposure to stress leads to

immune dysfunction and increased vulnerability to disease

Environmental stress leads to production of stress-related hormones

Hypothalamus-pituitary-adrenal (HPA) axis plays a crucial role in this

Cortisol is closely associated with stress related health problems

Noise and Hormones Noise can affect the HPA function Salivary cortisol enhanced during

mental work under 90dBA noise and NOT under quiet conditions

Circadian decline in cortisol NOT seen in chronically exposed workers to noise >85dBA but did with use of headphones

Noise exposure during gestation leads to enhance HPA responses to stressors in later life

Noise and Cardiovascular Effects

Acute noise effects: increase in heart rate, blood pressure and peripheral vasoconstriction

Heart rate changes to noise during sleep do not habituate

No epidemiological evidence of relationship between noise exposure and blood pressure in adults BUT consistently seen in children

Increased risk of ischaemic heart disease with outdoor levels >65-70dba

Association shown between noise and serum lipids in women and young men

Noise and Mental Health Community based Studies show

high levels of environmental noise associated with depression and anxiety

Aircraft noise in children impairs quality of life but no depression or anxiety

Noise and Fatigue Increased fatigue and irritability after

work in noisy environments Fatigue and headache more common

among noise exposed workers in a survey of 50,000 workers

Reaction times prolonged after one week in high noise levels increasing gradually compared to controls which improved

Noise and Children Aircraft noise : Difficulties in attention,

communication, learning and memory Concentration, motivation and

language acquisition affected by increased outdoor and/or indoor noise levels

Raised blood pressure seen with prolonged noise exposure to traffic noise

Leisure Noise Risk to hearing and tinnitus from: Loud music : Concerts,

discotheques, Personal cassette players

Noisy toys, arcade and computer games

Sports activities and venues DIY activities

Social Noise induced hearing impairment Audiometric thresholds may be

within normal limits but impairment may be present

Inability to decipher speech in noisy conditions

Tinnitus: An early warning signal? Early onset of presbycusis?

Loud Music and Hearing

Percentage of young people reporting dulled hearing and/or tinnitus

Rock Concerts (100-120dBA) 63-73%

Night Clubs ( 95-110dBA) 47-66%

Personal Stereos( 80-110dBA) 17%

Strategies EC 5th Environmental Action Programme

No Person should be exposed to noise levels which endanger health and quality of life

Exposure to 65dBA night Leq should be phased out

At no time should a level of 85dBA be exceeded

No increase in level for those affected by 55-65dBA

Special Groups Children Elderly Sick People Hearing Impaired PeopleThese groups may constitute 30% of

Population

Noise measures and Health Noise measures based only on

energy summation NOT sufficient to :

characterize noise environments health effects or predict health outcome Noise fluctuations, number of noise

events and inclusion of low frequency components is important