original ppt credits to dr yoganand. uploading again as a part of syllabus. i dont claim any authorship

1. Noise pollution
Dr.S.Yoganand
1st year pg
Dept of Community Medicine

2. NOISE
• Who definition
• Noise is unwanted sound, emitted from all sources
except at industrial work place
• WHO stated that “Noise must be recognized as a
major threat to human well-being”
• It is an underrated environmental problem
because of the fact that we can’t see, smell, or
taste it.

3. NOISE
• “Wrong sound, in the wrong place, in wrong time.”
• 20th century is described as Century of noise.
• Noise pollution describes variety of noise
produced in this modern era lead to very
important stress factor.

4. sources
• Transportation systems are the main source of noise
pollution in urban areas.
• Factories
• Industries
• Air crafts
• Railway junction
• Bus terminals
• Radio
• Television
• Water motor pump
• War fields
• Festivals- Crakers
• Blow Horns

5. Properties of noise
• Loudness
• Frequency

6. Loudness
• Amplitude of the vibration which initiated the
sound
• Loudness is measured in decibels
• The SI unit of sound pressure is the pascal (Pa)
• 20 micropascals = 0 dB
• 0.0002 microbar or dynes/cm2
• A dyne is 1/1000000th of atmospheric pressure

7. A B
• Consider, we have two loudspeakers, the first playing a
sound with power P1, and another playing a louder
version of the same sound with power P2
• The difference in decibels between the two is defined to
be 10 log (P2/P1) dB where the log is to base 10.
• If the second produces twice as much power than the
first, the difference in dB is10 log (P2/P1) = 10 log 2 = 3 dB.
• if the second had 10 times the power of the first, 10 dB.
• If the second had a million times the power of the first,
the difference in dB would be 10 log 1,000,000 = 60 dB.

8. • The ratio of the sound intensity that causes
permanent damage during short exposure to that
of the quietest sound that the ear can hear is
greater than or equal to 1 trillion
• ratio =(1:1012).
• Loudness :human ear does not respond equally to
all frequencies: we are much more sensitive to
sounds in the frequency range about 1 kHz to 4 kHz
than to very low or high frequency sounds.

10. Accepted maximum level

11. FREQUENCY
• HERTZ
• ONE hertz is equal to one wave
per second
• Audible frequency 20Hz to
20,000Hz
• The phon is a psycho-acoustic
index of loudness, considering
both frequency and intensity

12. Frequency
(Hz)
Octave Description
16 to 32 1st
The lower human threshold of hearing,
and the lowest pedal notes of a pipe
organ.
32 to 512
2nd to
5th
Rhythm frequencies, where the lower
and upper bass notes lie.
512 to 2048
6th to
7th
Defines human speech intelligibility,
gives a horn-like or tinny quality to
sound.
2048 to
8192
8th to
9th
Gives presence to speech,
where labial and fricative sounds lie.
8192 to
16384
10th
Brilliance, the sounds of bells and the
ringing of cymbals and sibilance in
speech.
16384 to
32768
11th
Beyond Brilliance, nebulous sounds
approaching and just passing the upper
human threshold of hearing

13. Community Noise Equivalent
Level (CNEL)
• is a weighted average of noise level over time. It is
used to compare the noisiness of neighbourhoods.
• CNEL is frequently used in regulations
of airport noise impact on the surrounding
community.
• A CNEL exceeding 60db is generally considered
unacceptable for a residential neighbourhood.

14. Acceptable Noise level (Standard)
AREA SPOT SOUND
LEVEL
Residential
Bed room 25
Living room 40
Commercial
Office 35-45
Conference 40-45
Restaurant 40-60
Industrial
Workshop 40-60
Laboratory 40-50
Educational
Class room 35-40
Library 30-40
Hospitals Wards 20-35

15. INSTRUMENTS
1. Sound Level Meter:
measures intensity
in dB
2. Octave Band
Frequency Analyser:
measures the noise
in octave bands
3. Audiometer :
measures the
hearing ability

16. Three kinds of sound measuring
instruments
The IEC 61672-1 specifies,
1. "Conventional" Sound Level Meter,
2. The Integrating-averaging Sound Level Meter, And
3. The Integrating sound level meter.

17. EFFECTS OF NOISE EXPOSURE
1) Auditory effects
2) Non auditory effects

18. Auditory effects
1) Auditory fatigue:
• Temporary shift of the auditory threshold known as a ”temporary
threshold shift ”
• It appears in the 90 db region and greatest at 4000hz. S/E- whistling
and buzzing in ears
• Full recovery from TTS can be achieved in approximately 2 to 10 min.
2) Deafness:
• The most serious pathological effect
• Temporary hearing loss is due to specific exposure to noise, become
normal after a period of 24 hrs
• 4000hz to 6000hz

19. • Permenant hearing loss is due
to repeated or continues
exposure to 100dB noise
• Minor changes or complete
destruction of organ of corti
neuronal damage occurs
• If this permanent HL happens in
industries it is called
occupational hearing loss.
• Exposure to 160dB will rupture
the tympanic membrane.

20. Non auditory effects
3) Interference with speech
• radio, music, television and
others
• Noise interfere with speech
communication, 300- 500Hz.
• For good speech intelligibility
speech sound dB need to be
increased by 12 dB.

21. 4) Annoyance:
• Psychological response, Feeling of
displeasure, neurotic people are
more sensitive to noise
• Workmen exposed to higher
intensity of noise will have
irritation, short tempered and
impatient
• noise impulses more annoying
than a steady noise.
• It can also cause memory loss,
severe depression, and panic
attacks.

22. 5) Efficacy:
• Reduction in noise is always found
to increase outcome.
6) Physiological changes:
• Startle and defence reaction
leading to potential increase of
blood pressure
• Heart rate, Intracranial pressure
• Breathing, sweating
• Giddiness, Nausea, Fatigue
• Sleep disturbance, Visual
disturbance
• Besides affecting health, it is
significant factor in economic losses.

23. 7) Effects on other animals and other living things
• can be felt on animals, birds, mice, fishes and domestic animals for
they are susceptible to various effects of due to exposer noise
levels change their places.
• Birds avoid migrating to places where noise level is above 100 dB.
• The noise emissions caused by supersonic aircraft, railway noise
emissions etc., may cause miscarriage in mammals and fishes.
8) Effect on non-living things.
• High intensity explosions can break glass panes and
vibrations in the buildings.
• The noise booms cause cracks in national and archeological
monuments as well as very high levels of noise are the cause of
cracks in hills.

24. WHO - Pyramid Of Noise

25. Control of noise
1) Care full planning of cities
• Division of cities in to
separate zones.
• Planting bushes and trees in
and around sound generating
sources is an effective
solution for noise pollution.
• Widening of main streets to
reduce noise penetration.

26. 2) Control of vehicles
• Heavy vehicle should not be allowed in
residential area
• Pressure horn should prohibited
• Traffic should be reduced
• Regular servicing and tuning of automobiles
can effectively reduce the noise pollution.
3) improve acoustic insulation of buildings
• Construction of detached buildings
• Sound proof rooms
4) Industries and railways
• Control of noise at source
• Protective green belt must be laid
• Marshalling yards

27. 5) Protection of exposed person
• Ear protection for all ->85dB in 150Hz
• Periodical audiogram check-up
• Use of ear plugs, ear muffs
6) Legislation:
• Many states have adopted legislation
• Chhattisgarh Government Bans Use
Of Firecrackers With High Decibel
Levels

28. 6) Legislation:
• The Central Pollution Control Board constituted a
Committee on Noise Pollution Control.
• The Committee recommended noise standards for
ambient air and for automobiles, domestic
appliances and construction equipment's, which
were later notified in Environment(Protection)
Rules,1986.

29. Code AREA Day time Night time
A Industrial area 75 70
B Commercial area 65 55
C Residential area 55 45
D Silence Zone 50 40
• Day time is 6 a.m. to 9 p.m. Night is 9 p.m. to 6 a.m.
• Silence zone is referred as areas up to 100 meters
around such premises as hospitals, educational
institutions and courts.
• Use of vehicular horns, loudspeakers and bursting of
crackers shall be banned in these zones.

30. Public Address System
1. License must be obtained by all parties intending to
use loudspeakers for any occasion.
2. loudspeakers should not be used at night between
9 p.m. to 6 a.m. except in closed premises.
3. Loudspeakers should be directed at the audiences
and not away from audience (i.e.not towards the
neighbourhood).
4. Loudspeakers should not be allowed for
advertisement and commercial activities.
5. The permitted strength of power amplifier should
be just adequate to cover the audience, and noise
level beyond the boundary limit of the noise source
premises should not be increased by more than 5
dB(A) above the ambient noise level.

31. Aircraft Operations
• Aerodrome should be located away from the
city.
• Aeroplanes should take off in direction
radially away from the city.
• During boarding and unboarding operations
the plane should be sufficiently away from
the airport buildings.
• Night-time operations should be minimised.
• During maintenance and repairs of the
aeroplane, workers should use ear muffs.
• Portable silencers should be used in the
plane intake as well as exhaust during idling
period at the airport.

32. Burning of Crackers
• Manufacture and sale of crackers having an
impulsive noise of more than 90 dB at 5 meters
distance from the site of bursting should be banned.
• Manufacture and bursting of joined crackers should
be banned.
• Bursting of crackers during night between 9 p.m.
and 6 a.m. should be banned.
• Bursting of crackers may be permitted only during
public festivals.

33. Criminal Procedure Code and Noise Control.
• under Sec. 268 of the Indian Penal Code, 1860, noise
is actionable as “public nuisance”.
• Sec. 290 of the IPC, which prescribes a punishment,
which may extend to two hundred rupees
• Provisions under the Sec. 133 of the Criminal Procedure
Code, 1973, The Magistrate has the power to make
conditional order requiring the person causing nuisance
including that of noise to remove such nuisance.
• Under the Indian Aircraft Act, 1934 causing wilful
damage or injury is actionable.
7) Education:
• Awareness programmes.

34. References
• Who (1966). NOISE, an occupational hazard and public
nuisance. Public health paper 30.
• Park text book of community medicine (2017)ed.
• Who, guidelines on community noise, TRB session 391
“setting an agenda for transportation noise
management policies in the united states”,10 January
2001, Washington DC, USA.
• Noise standards and guidelines by Government Of
India, ministry of environment & forests, paryawaran
bhawan, cgo complex, lodi road, new Delhi - 110 003
India.

35. Thank you…