MINISTER OF ENVIRONMENT AND FORESTS (SHRI T.R.BAALU)
(a), (b), (c)&(d) A statement is laid on the Table of the House.
STATEMENT REFERRED TO IN PARTS (a),(b),(c)&(d) OF LOK SABHA
STARRED QUESTION NO.398 FOR REPLY ON 21.8.2000 REGARDING
NOISE POLLUTION
(a) &(b) According to the World Health Organisation, no
such study has been made.
(c)&(d) The Government have taken several measures to
regulate and control noise pollution, including the
following:-
(i) Noise pollution is regulated under the Air (Prevention
& Control of Pollution) Act and the Environment
(Protection) Act. Ambient noise standards have been
prescribed under the Environment (Protection) Act.
(ii) Noise limits have been prescribed for automobiles,
domestic appliances and construction equipment at the
manufacturing stage. There are standards and guidelines
for control of noise pollution from stationary diesel
generator sets.
(iii) Recently, the following steps have been taken for
controlling noise pollution under the Environment
(Protection) Act:
(a) Standards for fire crackers have been notified in
October, 1999.
(b) The Noise Pollution (Regulation & Control)
Rules, 2000 have been notified in February,
2000.
NOTE FOR POSSIBLE SUPPLEMENTARIES TO THE LOK SABHA STARRED
QUESTION NO.398 FOR REPLY ON 21.8.2000 REGARDING NOISE
POLLUTION
1. DEFINITION
Noise is considered to be any unwanted sound that may
adversely affect the health and well being of individuals or
populations. Physically, sound is a mechanical disturbance
propagated as a longitudinal wave motion in air and other
elastic or mechanical media, such as water or steel. Its
main features are sound intensity, measured as sound
pressure, and frequency spectrum indicating the distribution
of the total sound over high and low frequencies. The
spectrum is important with respect to the effects of noise
on people and with respect to the engineering costs to
reduce the noise.
2. SOURCES OF NOISE POLLUTION
The main sources of noise pollution are automobiles,
domestic appliances, construction equipments, reckless use
of loud speakers, air craft operations and bursting of
crackers during festivals. The Central Pollution Control
Board has conducted surveys on the ambient noise levels at
residential, commercial, industrial and other selected areas
of major cities of the country from time to time.
3. INCIDENCE OF NOISE IN METRO CITIES OF INDIA
Noise pollution has reached a high level in most of the
metropolitan cities. Studies carried out on noise pollution
have revealed that average ambient noise levels in the
residential, commercial areas and silence zones of all the
major cities were found to be higher than the prescribed
standards. The ambient noise levels recorded in four mega
cities have been given in the Table-I.
TABLE-I
Average Noise Levels {in decibels} in various Metropolitan Cities
City Day (0600-2100 hrs/ Industrial Commercia Residential Silence Night (2100-0600 hrs) Area Area Area Zone
Calcutta Day 78 82 79 79 Night 67 75 65 65
Mumbai Day 76 75 70 66 Night 65 66 62 52
Chennai Day 71 78 66 63 Night 66 71 48 49
Bangalore Day 78 76 67 67 Night 53 57 50 NA
Ambient noise standards (CPCB) are :
Industrial area - 75 (day)/70 (night); Commercial area - 65 (day)/55 (night); Residential area - 55 (day)/45 (night); Silence Zone - 50 (day)/40 (night).
Source : State of the Environment, 1995, MoEF.
Data on noise pollution from selected locations of
Delhi for 1999 indicates that noise levels in many
commercial and residential areas as well as in silence zone
are quite high compared to the prescribed ambient noise
levels (Table-II). Noise levels are particularly high
during the night-time which indicates that high levels of
noise persists even during the sleeping hour.
TABLE-II
Average Noise Levels (in decibels) in various locations in Delhi for 1999
Location Day Night Average Average Maximum Minimum
ITO 74.73 71.1 84.7 62.7
Connaught Place 74.2 68.4 86.9 56.5
LNJP Hospital 64.23 59.1 70.8 49.5
AIIMS 74.67 71.3 82.2 55.8
Moolchand 63.1 60.8 73.0 54.6
New Friends Colony 58.8 53.1 69.9 48.8
Wazirpur 77.17 78.0 89.0 67.3
Ashok Vihar 70.57 66.6 81.8 50.8
Karol Bagh 74.4 64.2 85.0 57.1
Anand Pravat 73.27 62.3 90.1 56.4
4. STEPS TAKEN TO CONTROL NOISE POLLUTION
The Government have taken various measures to regulate
and control noise pollution, which include the following:-
(i) Noise pollution has been included in the Air
(Prevention & Control of Pollution) Act. Ambient standards
in respect of noise for different categories of areas
(residential, commercial, industrial and silence zones) have
been notified under the Environment (Protection) Act, 1986.
(ii) Noise limits have also been prescribed for automobiles,
domestic appliances and construction equipment at the
manufacturing stage.
(iii) Standards and guidelines for control of noise
pollution from stationary diesel generator sets have been
evolved and notified in January, 1999.
(iv) A notification has also been issued specifying the
standards for fire crackers in October, 1999.
(v) The Noise Pollution (Regulation & Control) Rules, 2000
has been notified on 14th February, 2000.
(vi) A code of practice has been evolved by the Central
Pollution Control Board for control of noise.
5. NOISE STANDARDS
Ambient Air Quality Standards in respect of Noise
Noise pollution has been included in the amended
Air (Prevention and Control of Pollution) Act, 1987.
Ambient air quality standards in respect of noise for
different categories of areas (industrial, commercial,
residential and silence zones) have been notified under
Environment (Protection) Act, 1986 as given in Table-I.
Table-1 :
Ambient Air Quality Standards in respect of Noise
Area Category of Area Limits in dB(A), Leq Code
Day Time Night Time
(A) Industrial Area 75 70
(B Commercial Area 65 55
(C) Residential Area 55 45
(D) Silence Zone 50 40
Table-2 :
Noise Limits for Automobiles (Free Field at 7.5 metre in dB (A) at the manufacturing stage)
Category of Vehicle Noise Limit in dB(A)
(a) Motorcycle, scooters & Three Wheelers 80
(b) Passenger Cars 82
(c) Passenger or Commercial Vechicles upto 4 MT 85
(d) Passenger or Commercial Vechicles above 4 MT and upto 12 MT 89
(e) Passenger or Commercial Vehicles exceeding 12 MT 91
Table-3 :
The noise limits for Domestic Appliances and Construction equipments at the Manufacturing Stage
Category of Domestic Appliances/Equipments Noise Limits Construction in dB(A)
(a). Window Air Conditioners of 1 tonne to 1.5 tonne 68
(b). Air Coolers 60
(c). Refrigerators 46
(d). Diesel generator for domestic purposes 85-90
(e). Compactors (rollers), Front loaders, Concrete 75
Mixers, Cranes (movable), Vibrators and Saws
The Urban noise level acceptable under international standards, as prescribed by
the World Health Organisation (WHO)
Recommended Noise-Exposure Limits by WHO 1980
Environment Recommended maximum level
Industrial/Occupational 75 decibels
Community/Urban
Day-time 55 decibels
Night-time 45 decibels
Indoor/Domestic
Day-time 45 decibels
Night-time 35 decibels
A. Noise Standards for Fire-crackers
(i) The manufacture, sale or use of fire crackers
generating noise level exceeding 125 dB(AI) or 145
dB(C)pk at 4 meters distance from the point of
bursting shall be prohibited.
(ii) For individual fire-cracker constituting the series
(joined fire-crackers), the above mentioned limit be
reduced by 5 log10(N) dB, where N= number of
crackers joined together.
B. The broad requirements for measurement of noise from
fire-crackers shall be -
(i) The measurements shall be made on a hard concrete
surface of minimum 5 meter diameter or equivalent.
(ii) The measurements shall be made in free field conditions
i.e., there shall not be any reflecting surface upto 15
meter distance from the point of bursting.
(iii) The measurement shall be made with an approved
sound level meter.
C. The Department of Explosives shall ensure
implementation of these standards.
Note:- dB(AI) : A- weighted impulse Sound Pressure Level in decibel dB(C) pk : C-weighted Peak Sound Pressure Level in decibel.
Standards/Guidelines for Control of Noise Pollution from Stationary Diesel Generator(DG) Sets.
(A) Noise Standards for DG Sets (15-500 KVA)
The total sound power level, Lw, of a DG set should be
less than, 94+10 log10(KVA), dB(A), at the manufacturing
stage, where, KVA is the nominal power rating of a DG set.
This level should fall by 5 dB(A) every five years, till 2007, i.e. in 2002 and then
in 2007.
(B) Mandatory acoustic enclosure/acoustic treatment of room
for stationary DG sets (5 KVA and above)
Noise from the DG set should be controlled by
providing an acoustic enclosure or by treating the room
acoustically.
The acoustic enclosure/acoustic treatment of the room
should be designed for minimum 25 dB(A). Insertion Loss or
for meeting the ambient noise standards, whichever is on
the higher side (if the actual ambient noise is on the
higher side, it may not be possible to check the
performance of the acoustic enclosure/acoustic treatment.
Under such circumstances the performance may be checked for
noise reduction upto actual ambient noise level,
preferably, in the night time). The measurement for
Insertion Loss may be done at different points at 0.5 m
from the acoustic enclosure/room, and then averaged.
The DG set should also be provided with proper exhaust
muffler with Insertion Loss of minimum 25 dB(A).
(C) Guidelines for the manufacturers/users of DG sets(5 KVA
and above)
1. The manufacturer should offer to the user a standard
acoustic enclosure of 25 dB(A) Insertion Loss and also a
suitable exhaust muffler with Insertion Loss of 25 dB(A).
2. The user should make efforts to bring down the noise
levels due to the DG set, outside his premises, within the
ambient noise requirements by proper siting and control
measures.
3. The manufacturer should furnish noise power levels of
the unsilenced DG sets as per standards prescribed under
(A).
4. The total sound power level of a DG set, at the user`s
end, shall be within 2 dB(A) of the total sound power level
of the DG set, at the manufacturing stage, as prescribed
under (A).
5. Installation of a DG set must be strictly in compliance
with the recommendations of the DG set manufacturer.
6. A proper routine and preventive maintenance procedure
for the DG set should be set and followed in consultation
with the DG set manufacturer which would help prevent noise
levels of the DG set from deteriorating with use.
Code of Practice for Controlling Noise from Sources other
than industries and automobiles evolved by Central Pollution
Control Board
Public Address System
- Licence must be obtained by all parties intending to
use Loudspeakers or public address system for any
occasion.
- Public address system and loudspeakers should not be
used at night between 9 p.m. to 6 a.m. except in closed
premises.
- Loudspeakers should be directed at the audiences and
not away from audience (i.e. not towards the
neighbourhood).
- Loudspeakers should not be allowed for advertisement
and commercial activities.
- The permitted strength of the 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.
Aircraft Operations
- Aerodrome should be located away from the city and
growth of the city should not be allowed to extend upto
the Aerodrome.
- 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 of the aircraft 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.
Railway Operations
- Erection of acoustic barrier, reducing speed and
avoiding whistling within and along the municipal limits
and habitation zones are recommended for adoption to the
extent possible.
Construction Activities
- Acoustic barriers should be placed near
construction sites.
- The maximum noise levels near the construction site
should be limited to 75 dB(A) Leq. (5 Min) in industrial
areas and to 65 dB(A) Leq. (5 Min) in other areas.
- There should be fencing around the construction site
to prevent people coming near the site.
- Materials need to be stockpiled and unused equipment to
be placed between noisy operating equipments and other
areas.
- Constructing temporary earth bund around the site using
soil etc. which normally is, hauled away from the
construction site.
6. EFFECTS OF NOISE POLLUTION
There are two types of effects of Noise Pollution:
Auditory effects as well as Non-auditory effects.
(a) Auditory Effects:
i) Auditory Fatigue:-
A person entering a very noisy area may experience a
measurable loss in hearing sensitivity but will recover some
time after returning to a quiet environment. This
phenomenon can be measured as a shift in audio-metric
thresholds and is called a noise-induced temporary threshold
shift. Recovery depends on the extent of the hearing shift,
individual susceptibility, and the type of exposure. If
recovery is not complete before the next noise exposure, it
is possible that some of the loss will become permanent.
ii) Hearing Impairment:-
In the normal auditory process, sound vibrations in the
air travel through the ear canal and cause the eardrum to
vibrate. The vibrations are then transmitted by the bones
of the middle ear to the sensory organ of the inner ear, the
cochlea. Here they are transduced by hair cells into nerve
impulses and transmitted to the brain.
Blasts and other intense or explosive sounds can
rupture the ear drum or cause immediate damage to the
structures of the middle and inner ear. Hearing loss due to
prolonged noise exposure is generally associated with
destruction of the hair cells in the inner ear and, as such
a loss is of a neural type, irreversible injury is caused to
the inner ear.
b. Non-Auditory Effects
i) Speech Interference:-
The interference of noise with speech
communication occurs when one of two simultaneous sounds
renders the other inaudible. In occupational as well as
leisure situations the failure of individuals to hear
warning shouts or signals may lead to injury. For 100%
speech intelligibility, the speech level should exceed the
noise level by at least 10 dB. Measurements indicate that,
during relaxed conversation indoors, the speech level at 1
metre`s distance from the speaker is approximately 55 dB(A).
However, owing to the reverberations off the walls, floor,
ceiling and objects in a room, there is no simple formula
that will predict speech interference indoors. On the basis
of the average noise levels that have been found acceptable,
a background noise level of less than 45 dB(A) is required
for 100% speech intelligibility.
ii) Sleep Disturbance:-
Noise intrusion can cause difficulties in falling
asleep and can wake people who are asleep. Studies have
indicated that disturbance of sleep becomes increasingly
apparent as ambient noise levels exceed about 35 dB(A).
Individuals who sleep well at 35 dB(A) average sound
pressure level (Leq) complain about sleep disturbance and
have difficulty in falling asleep at 50 dB(A) Leq. Weak
stimuli can interfere with sleep if they are unexpected. It
has been found that the probability of sleeping persons
being awakened by a peak sound level of 40 dB(A) is 5%,
increasing to 30% at 70 dB(A). Within a population,
differences in sensibility to noise are related to such
factors as age and sex. Adaptation has been observed only
when noise stimuli are of low intensity. On the basis of
the limited data available, a level of less than 35 dB(A) is
recommended to preserve the essential and restorative
process of sleep.
iii) Stress Reaction :-
Exposure to noise has been reported to evoke several
kinds of reflex response which are part of a response
pattern commonly named the stress reaction. The heart,
blood vessels, intestines and endocrine glands are all
organs in which noise associated changes have been observed.
However, more studies are required to evaluate the long term
health risks due to the action of noise on the autonomic
nervous system. Social and cultural factors may need to be
taken into account in assessing noise-induced strains that
lead directly or indirectly to the development of fatigue
and non-specific health disorders. Annoyance reactions
reflect the individual reactions to the same noise. On the
basis of surveys of aircraft and road traffic noise in
residential areas, it appears that few people will be
seriously annoyed by day time community noise exposure below
55 dB(A).
iv) Efficiency at Work :-
The disruptive or distracting effects of noise on
manual or mental productivity or performance of tasks are
not well understood. Noise can change the individual`s
state of alertness and may increase or decrease efficiency.
Performance of tasks involving motor or monotonous
activities is not always degraded by noise but mental
activities involving vigilance, information gathering, and
analytical processes appear to be particularly sensitive to
noise. However, no generalized criteria relating task
efficiency with the level or duration of noise can be
stated.
