Noise pollution can come from various sources like transportation, construction, and industrial activities. It is measured in decibels and exposure to loud noise over 85dB can cause hearing damage over time. Noise affects humans physically and psychologically, reducing sleep quality and increasing stress. It also harms animal communication and habitats. Methods to reduce noise include better urban planning, equipment modifications, noise barriers, and controlling vehicle speed. Regulations establish limits and standards provide guidelines but enforcement can be improved.

1. Noise Pollution
Week 10

2. Learning Outcome
At the end of this week, student
should be able to :
1. Identify pollution sources
2. Characterize of noise
3. Understand the noise control
equipment design

3. Noise Pollution
 Noise, basically is unwanted or
nuisance sound that disrupts
activity or balance of human or
animal life.
 The word noise comes from the
Latin word noxia meaning
"injury" or "hurt".
 Noise or sound is measured in
decibels, dB.

4. Concept of Sound
 Sound is the transfer of energy without transfer of mass
 The medium usually is air
𝑾𝒂𝒗𝒆𝒍𝒆𝒏𝒈𝒕𝒉 (𝒎) =
𝒄
𝒗
C = velocity of sound in a given medium (m/s)
V = frequency (cycle/sec)

8. 𝑰 = 𝑷 𝟐
I = sound intensity (watts)
P = amplitude pressure (N/m2)
𝑰𝑳 = 𝐥𝐨𝐠 𝟏𝟎
𝑰
𝑰 𝟎
I = sound intensity (watts)
I0 = Intensity of the least audible sound,
usually = 10-12 watts

9. 𝑺𝑷𝑳 (𝒅𝑩) = 𝟐𝟎 log 𝟏𝟎
𝑷
𝑷 𝒓𝒆𝒇
SPL = Sound pressure level
P = amplitude pressure (N/m2)
Pref = 0.00002 N/m2

10. Noise Pollution
 30 dB: A quiet library or soft whisper.
 70 dB: Busy traffic, noisy restaurant. At this level, noise
may begin to affect your hearing if exposure is
constant.
 80 dB: Heavy city traffic, alarm clock at two feet, and
factory noise. These noises are dangerous if you are
exposed to them for more than eight hours.
 100 dB: A chain saw, stereo headphones, pneumatic
drill. Even two hours of exposure can be dangerous at
100 dB, and with each 5 dB increase, the “safe time” is
cut in half.

11. Noise Pollution
 120 dB: Sound at a rock concert in front of speakers,
sandblasting, thunderclap. The danger is immediate.
At 120 dB, exposure can injure your ear.
 140 dB: A gunshot blast and a jet plane. Any length of
exposure time is dangerous and may cause actual
pain in the ear.
 180 dB: The sound at a rocket launching pad. Noise at
this level causes irreversible damage if ear protection
is not used, and hearing loss is inevitable.

12. Sources
 Transportation systems-including motor
vehicle noise, aircraft noise and rail noise
 Poor urban planning - since side-by-side
industrial and residential buildings can
result in noise pollution in the residential
area
 Office equipment, factory machinery,
construction work, audio entertainment
systems, noisy people etc

13. Sources
transportation
systems
Poor urban planning
car alarms
emergency
service sirens office
equipment
construction work
grounds keeping
equipment
barking dogs
audio
entertainment
systems
loudspeakers

14. Sources

15. Case Study
Vicinity of Time LEQ
 Ruang Legar Stesen Keretapi Kuala Lumpur 0850 73.6
 Ruang Legar Stesen Bas Pudu Raya 0905 81.1
 Ruang Legar Stesen Teksi Pudu Raya 0920 78.8
 Rumah Pangsa Jalan Loke Yew 0920 66.0
 Lorong Enggang 9, Taman Keramat 1015 54.3
 Kampung Periuk 0945 57.1
 Pusat Membeli-belah The Mall 1115 66.6
 Pasar Chow Kit 1050 70.7
 Taman Tasik Titiwangsa 1050 48.6
Noise Level At Selected Community Areas, 1993

16. Case Study
Vicinity of Time MAXP MAXL LEQ
 Jalan Chan Sow Lin 0900 114.7 83.4 67.5
2000 91.5 74.5 57.8
 Jalan Chan Sow Lin 1000 92.7 79.4 67.4
2100 93.5 77.9 65.2
 Jalan Kuchai Lama 1100 97.1 81.2 69.7
2200 96.7 80.4 70.9
 Kepong 0900 114.4 82.4 67.1
2000 86.6 71.2 59.5
 Kepong 1000 94.2 80.9 71.6
2100 85.1 73.7 70.1
Noise Level at Selected Industry Areas, 1994

17. Effects
 Subjected to 45 decibels of noise,
the average person cannot sleep.
 At 120 decibels the ear registers
pain, but hearing damage begins
at a much lower level, about 85
decibels.
 However the duration of the
exposure is also important

18. Effects
1. Human health effects
a) Psychological
 Noise pollution can cause
annoyance and aggression,
hypertension, high stress levels,
sleep disturbances, and other
harmful effects.
 Furthermore, stress and
hypertension are the leading
causes to health problems,
whereas tinnitus can lead to
forgetfulness, severe depression
and at times panic attacks.

19. Effects
b) Physiological
 Chronic exposure to noise may cause
noise-induced hearing loss.
 High noise levels can also contribute
to cardiovascular effects and
exposure to moderately high levels
during a single eight hour period
causes a statistical rise in blood
pressure as well as to increased
incidence of coronary artery disease.

20. Effects
c) Affecting Productivity
 According to a study by Cornell University, it
examined children who were exposed to
long term exposure to airport noise as
compared to children in a quiet
environment.
 The result concludes that children exposed
to loud noise do not perform as well in oral
aspects.

21. Effects
2. Animals by ;
 Causing stress, habitat reduction and
loss of hearing;
 Increasing risk of mortality by
changing the delicate balance in
predator;
 Prey detection and avoidance;
 Interfering with their use of sounds in
communications - reproduction and
in navigation.

22. Noise Pollution – effects?

23. Measuring Transient Noise
 Transient noise data are gathered by reading by
reading sound level at regular interval
 Noise pollution Level (NPL)
𝑵𝑷𝑳 𝒅𝑩 = 𝑳 𝟓𝟎 + 𝑳 𝟏𝟎 − 𝑳 𝟗𝟎 +
𝑳 𝟏𝟎−𝑳 𝟗𝟎
𝟐
𝟔𝟎

24. NPL
Time (sec) dB Rank dB
% of Time Equal to
or Exceeded (eq)
10 71 1 69 92%
20 75 2 70 83%
30 70 3 71 75%
40 69 4 72 67%
50 88 5 73 58%
60 83 6 75 50%
70 81 7 75 42%
80 90 8 81 33%
90 110 9 83 25%
100 75 10 88 17%
110 72 11 90 8%
120 73 12 110 0%

26. Example
Time (sec) dB Rank dB
% of Time Equal to
or Exceeded (eq)
10 71 1
20 75 2
30 70 3
40 69 4
50 88 5
60 83 6
70 81 7
80 90 8
90 110 9
100 75 10
110 72 11
120 73 12
130 82 13
140 63 14

27. SCHEDULE OF PERMISSIBLE SOUND LEVELS
MAXIMUM PERMISSIBLE SOUND LEVEL (Leq)
BY RECEIVING LAND USE FOR PLANNING
AND NEW DEVELOPMENT

28. MAXIMUM PERMISSIBLE SOUND LEVEL (Leq) OF NEW
DEVELOPMENT(ROADS, RAILS, INDUSTRIAL) IN AREAS OF
EXISTING HIGH ENVIRONMENTAL NOISE CLIMATE
L90 is the measured ninety percentile sound level for the respective time period of the existing areas of interest in
the absence of the proposed new development.

29. Mitigation
 Aircraft noise can be reduced to some extent by
design of quieter jet engines, reconsideration of
operations - altering flight paths and time
 Exposure of workers to industrial noise include
redesign of industrial equipment, shock mounting
assemblies and physical barriers in the
workplace.
 Mitigation of roadway noise can be reduced
through urban planning, roadway design, noise
barrier design, speed control, surface pavement
selection and limitation of heavy vehicles.

30. Mitigation
1. Urban Planning and Roadway
Design
 There are many design decisions
regarding alignment and roadway
geometrics that can affect the sound
level created
 Use of technology to predict future
sound levels - exposure of sensitive
receptors to elevated sound levels
can be minimized

31. Mitigation
2) Surface Pavement Selection
 Selection of surface pavement affects
sound level create when vehicles
travel on it due to different surface
friction.
 Quieter pavements are porous with a
negative surface texture
 Louder pavements have a
transversely tined/grooved surface,
and/or a positive surface texture

32. Mitigation
3) Speed Control
 Effective.
 The lowest sound emissions arise
from vehicles moving smoothly at
30 km/h to 60 km/h.
 Above that range, sound emissions
double with each 3 km/h of
speed.

33. Mitigation
4) Noise Barriers
 Can be used for existing road-
building projects
 Can reduce adjacent land use
by 10 dB
 Double glazed windows can
block out 90% of the noise from
outside

34. Measurement
sound level meter
dosimeter

35. Regulations
 The only environmental noise related
legislation with noise limits is the
Environmental Quality (Motor Vehicle
Noise) Regulations 1987.
 This regulation stipulates permissible noise
emission from motor vehicle, and has been
enforced, from time to time by the authorities
(Department of Environment, Road Transport
Department and the Police).

36. Standards
 WHO recommended noise limits for
community environment is 55 dBA (Leq)
daytime and 45 dBA (Leq) nighttime.
 The Malaysian DOE guidelines are 55
dBA daytime and 50dBA nighttime.
 The WHO recommended noise limits for
indoor/domestic areas are 45 dBA
daytime and 35 dBA nighttime.
 There is currently no Malaysian
recommended indoor noise limits.

37. THANK YOU