Environmental Noise and Health: The Latest Evidence

1
Environmental Noise and Health The Latest
Evidence

• Professor Deepak Prasher
• Institute of Laryngology and Otology
• University College London

2
Day and Night Noise Levels

• Typical Noise Level LeqdBA
• Day Night Acoustical Quality
• 35 35 natural sounds only
• 50 40 quiet rural environment
• 55 45 suburban neighbourhood
• 65 50 urban noise situation
• 75 75 very noisy, unfit for
• permanent habitation

3
Noise Level and Effect

• lt55dBA Desirable level outdoor Suburban
  neighbourhood
• 55-65dBA Urban Grey Areas Annoyance
• gt65dBA Black spots
• Stress effects, sleep disturbance,
  communication performance deficits
• gt75dBA Unfit for Human habitation,
• hearing loss, cardiovascular effects

4
European City Noise

• Desirable Indoor Comfort Leq lt65dBA
• New Residential Areas outdoor levels lt55dBA
• Urban Grey Areas Levels 55-65dBA
• Black Spots Levels gt65dBA
• Large European CitiesNumber of People
• exposed to high levels 3 times national average
• Percentage living in grey areas increasing
• (OECD 1991)

5
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

6
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

7
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

8
Noise Environment in Europe

• 450million (65) exposed to gt55dBA
• 113 million (17) exposed to gt65dBA
• 9.7million (1.4) exposed to gt75dBA
• No systematic differences across Europe
• Eastern European Cities noisier than Western
• Data poor from Central and Eastern Europe

9
Costs of Noise to Society

• Estimate 0.2 to 2 GDP
• 0.2 equates to 12Billion Euros annually

10
Noise Sources in Europe

• Road Traffic
• Air Traffic
• Rail Traffic
• Industry
• Recreational Activities
• Construction Sites
• Traffic on Waterways

11
Auditory Effects

• Acoustic Trauma Sudden hearing damage
• Tinnitus Ringing in the Ears
• TTSTemporary threshold shift
• PTS Permanent threshold shift
• Interference with Communication

12
Non-Auditory Effects

• Annoyance
• Sleep Disturbance
• Attention
• Motivation
• Stress reactions
• Cardiovascular problems
• Endocrine problems

13
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

14
Annoyance from Street Noise

• West Germany (UBA 1988)
• Inhabitants Percentage Annoyed
• lt 5000 14-16
• 5-20,000 17-19
• 20-100,000 19-25
• gt100,000 22-33
• Annoyance increases with increase in Population

15
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,
  listeners activity interference, predictability
  of noise, individual personality

16
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

17
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

18
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

19
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

20
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 gt85dBA but
  did with use of headphones
• Noise exposure during gestation leads to enhance
  HPA responses to stressors in later life

21
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 gt65-70dba
• Association shown between noise and serum lipids
  in women and young men

22
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

23
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

24
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

25
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

26
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?

27
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

28
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

29
Special Groups

• Children
• Elderly
• Sick People
• Hearing Impaired People
• These groups may constitute 30 of Population

30
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