2. The Noise Pollution is a type of energy
pollution in which distracting, irritating, or
damaging sounds are freely audible.
As with other forms of energy pollution
(such as heat and light pollution), noise
pollution contaminants are not physical
particles, but rather waves that interfere
with naturally-occurring waves of a similar
type in the same environment.

3. In simple words the
Noise Pollution can be defined
like the excess of sound that
disrupts the normal conditions of
the environment in a certain
area.

4. While the noise does not accumulate,
moved or maintained at
the time as the others types of pollutions,
can also cause negative effects –
- physiological,
- psychological,
- economic,
- socially
speaking to the quality of life if it is not
controlled properly.

5. Sounds are considered noise pollution if
they adversely affect wildlife, human
activity, or are capable of damaging
physical structures on a regular,
repeating basis.
In the broadest sense of the term, a sound
may be considered noise pollution if it
disturbs any natural process or causes
human harm, even if the sound does not
occur on a regular basis.

7. The decibel (dB) is a measure of sound
intensity; that is, the magnitude of the
fluctuations in air pressure caused by sound
waves.
The decibel scale is logarithmic, not
arithmetic. This means that a doubling of
sound intensity is not represented as a
doubling of the decibel level.
Decibels are usually measured with a
filter that emphasizes sounds in certain
frequencies.

8. The "A" filter (dBA) is the one most
frequently used.
The "C" filter (dBC) puts more weight on
low-frequency sounds such as the bass in
amplified music.
Normal conversation is around 60 dB.
Noise of less than 75 dB, even for long
periods is unlikely to damage your
hearing.

10. The Noise pollution can affect
both your health and well being
in
several different ways.

11. Effects Of Noise On Humans
1. Auditory effects interfering with
hearing; auditory fatigue and deafness.
2. Non-auditory effects interfering
with social behaviour; problems with
communications, sleep, recreation,
mental equilibrium (peace), and the
ability to concentrate at work

12. 3. Physiological effects affecting
biological functions; anxiety,
neurosis, insomnia, dizziness, nausea,
fatigue, visual symptoms,
hypertension, cardiovascular
symptoms, liver changes, nervous
symptoms, changes in skin, fast
irregular heart beats (tachycardia).

13. 4. Endocrine and hormonal changes
relating to stress and noise levels.
i.e. raised adrenaline and
cholesterol.
Noise causes blood vessels to close
cutting down blood supply to the
fingers and toes.
Respiratory changes occur due to
noise.

14. 5. Psychological effects - physical and
mental fatigue, loss of concentration,
lower efficiency, reduced output,
absenteeism, higher rates of accidents,
behavioural changes, errors at work,
loss of sleep, psychosomatic disorders,
diseases related to stress, mental
illness, aggravation of existing stress
problems and mental illness, neurotic
effects, rage anger, crime.

15. However, as more and more research are being
done, more serious health risks have developed due
to the increase in noise pollution.
- Hearing loss (conductive or sensorineural)
- Hypertension
- Aggressive behavior
- Serious sleep loss
- Heart disease (stress related)
- Danger to people - cover warning signals &:
Cause accidents

16. Changes in the immune system and birth
defects have been attributed to noise
exposure, but evidence is limited.
Although some presbycusis may occur
naturally with age, in many developed
nations the cumulative impact of noise is
sufficient to impair the hearing of a large
fraction of the population over the course
of a lifetime.

17. Beyond these effects, elevated noise
levels can create stress, increase
workplace accident rates, and
stimulate aggression and other anti-
social behaviors.
The most significant causes are
vehicle and aircraft noise, prolonged
exposure to loud music, and
industrial noise.

18. Cardiovascular effects
Noise has been associated with important
cardiovascular health problems. In 1999, the
WHO concluded that the available evidence
showed a weak association between long-
term noise exposure above 67-70 dB(A) and
hypertension. Recent studies have suggested
that noise levels of 50 dB(A) at night may
also increase the risk of myocardial
infarction by chronically
elevating cortisol production

21. Industrial noise is usually considered
mainly from the point of view of
environmental health and safety as
sustained exposure can cause
permanent hearing damage.
Traditionally, workplace noise has
been a hazard linked to heavy
industries such as ship-building and
associated only with noise induced
hearing loss (NIHL).

22. Modern thinking in occupational
safety and health identifies noise
as hazardous to worker safety
and health in many places of
employment and by a variety of
means.

24. Noise also acts synergistically with other hazards
to increase the risk of harm to workers. In
particular, noise and dangerous substances (e.g.
some solvents) that have some tendencies
towards ototoxicity may give rise to rapid ear
damage.
A-weighted measurements are commonly used
to determine noise levels that can cause harm to
the human ear, and special exposure meters are
available that integrate noise over a period of
time to give an Leq value (equivalent sound
pressure level), defined by standards.

26. No one on earth can escape the sounds of
noise.
In the past thirty years, noise in all areas,
especially in urban areas, have been
increasing rapidly.
There are numerous effects on the human
environment due to the increase in noise
pollution.

27. Noise can have a negative effect on humans,
domestic and wild animals, ecological
systems, buildings and other structures.
Effect
Physical effects from noise include:
vibration to buildings,
damage to glass windows,
plaster cracking,
damage to building foundations.
Jet aircraft have damaged roads
and buildings.

28. Acoustic Pollution
Several years ago in the protection
regulations of the environment noise was not
considered to be the pollutant. Then in all the
countries of the world there have been
elaborated procedure and bylaws that they
entrust of the protection of the environment
against the excess of noise. The most serious
efforts of the international communities are
translated in policies of prevention and control
of the sonorous pollution.

32. 1. First, we must determine whether the noise
level is such that it causes loss of audition. To
audition
do it, comparing measurements made with
established norms, which indicate noise level
by activity and exposure times, partners both
are taken corrective action to reduce harmful
levels of noise.
2. It is known that a noise level below 85dB (A)
does not cause harm to the employee.
employee
However, it can be very annoying, depending on
the activity taking place.

33. 3. If it is established that the noise is
generated by a machine, we should see
how to modify it, so it produces less
noise.
Sometimes lowering its speed is
sufficient.
You can also make a total closure of
the machine, or you can exchange it
for another quieter.

34. 4. If after applying the earlier
recommendation, the discomfort by the noise
persists, provision for workers protective
equipment such as earmuffs and ear plugs
should be done.
Important is to ensure that workers use the
equipment properly, motivating and
monitoring their use, particularly when the
noise level may injure over time, their
hearing ability.

35. 5. If the walls of the compound are
harsh acoustically, it will produce
echoes and reflections, which will
increase the sound pressure.
In this case, we should seek absorbent
materials for coating the walls,
especially if there are machines located
close to these walls. This will reduce
the sound pressure.

37. Noise-canceling headphones
These reduce unwanted ambient sounds (i.e.,
acoustic noise) by means of active noise
control (ANC). Essentially, this involves
using a microphone, placed near the ear,
and electronic circuitry which generates an
"antinoise" sound wave with the opposite
polarity of the sound wave arriving at the
microphone. This results in destructive
interference, which cancels out the noise
within the enclosed volume of the headphone.

39. Possible
Solutions
•Auditory personalized
protection
•Absorbent materials
•Acoustics barriers
•Isolations

40. Personal Protection
It constitutes one of the most efficient methods
and simultaneously economic.
It is a question of the auditory stoppers
called (or acoustic shells), that they have the
ability to reduce the noise in almost 20 dB,
dB
which allows that the person who uses them
could be located in very noisy environments
without any problem.
Very used by the workmen and other workers
of some noisy industries.

41. VIBRATION

42. DEFINITION
• VIBRATION IS OSCILATORY MOTION
• A CYCLE OF SPECIFIC ACTIVITY BACK-
FORTH, UP AND DOWN RESULTING FROM
REVERSAL OF ENERGY
• FREQUENCIES OF 100 HZ OR HIGHER
ARE ABSORBED BY THE HANDS AND
WRISTS
• FREQUENCIES UNDER 100 HZ ARE
ABSORBED BY THE UPPER LIMB JOINTS

43. RESPONSE DEPENDS ON:
• FREQUENCY OF VIBRATION
• AMPLITUDE OF VIBRATION
• TIME HISTORY OF VIBRATION EXPOSURE
• DIRECTION OF VIBRATION
• POINT OF APPLICATION OF VIBRATION
• HOW MUCH VIBRATION IS TRANSMITTED
• AFFECT OF CLOTHING AND EQUIPMENT
• BODY SIZE (HEIGHT AND WEIGHT)
• BODY POSTURE/ BODY TENSION
POSTURE

44. MAGNITUDE IS INFLUENCED BY:
• TYPE, WEIGHT, AND CONDITION OF TOOL
• ACCELERATION AND FREQUENCY
PRODUCED BY TOOL
– TOOL TYPE, ENVIRONMENTAL, ANTI-VIBRATION
MATERIAL
– OPERATING SPEED, ERGONOMICS OF USE
• GRIPPING FORCES
• ORIENTATION AND POSTURE OF THE
HANDS, ARMS, AND BODY DURING WORK
• PARTS OF HANDS IN DIRECT CONTACT
WITH THE VIBRATING SURFACE

45. TYPES
• WHOLE BODY VIBRATION
• SEGMENTAL (HAND-ARM) VIBRATION

46. WHO’S AT RISK?
• ANYONE WHO ABSORBS MACHINE
VIBRATION THROUGH THEIR HANDS AND
ARMS WHILE WORKING A FAST-MOVING
HAND TOOL --
• OR THROUGH THE BUTTOCKS AND THE
SOLES OF THE FEET WHILE RIDING IN OR
STANDING NEAR VIBRATING, HEAVY
MACHINERY--
• RUNS THE RISK.

47. HOW MANY EXPOSED
• APPROXIMATELY 1.2 MILLION EXPOSED
• 50 - 60 % OF WORKER POPULATION HAVE
SYMPTOMS

48. TOOLS MOST COMMONLY
ASSOCIATED:
• POWERED HAMMERS
• CHISELS, CHAIN SAWS
• SANDERS, GRINDERS, RIVETERS
• BREAKERS, DRILLS, COMPACTORS
• SHARPENERS, SHAPERS

51. WHAT IS VIBRATION SYNDROME
• VASOSPASTIC, NEUROMUSCULAR,
ARTHRITIC DISORDERS OF THE
HANDS AND UPPER LIMBS
• COMPOSITE OF VIBRATION INDUCED
SIGNS AND SYMPTOMS (e.g.
NUMBNESS, TINGLING OF THE
FINGERS, EPISODIC BLANCHING OF
THE FINGERS, PAIN, REDUCED GRIP
STRENGTH AND DEXTERITY

52. SYMPTOMS OF VIBRATION
SYNDROME
• DISCOMFORT FROM COLD
• TINGLING, NUMBING
• BLANCHING FINGERS
• PAIN

53. CONTROL STRATEGIES:
STRATEGIES
• ENGINEERING AND WORK PRACTICES
• ANTI-VIBRATION CLOTHING, EQUIPMENT
AND TRAINING
• GOALS:
– REDUCE THE INTENSITY
– REDUCE THE EXPOSURE DURATION
– IDENTIFY THE EARLY SIGNS AND
SYMPTOMS

54. ENGINEERING CONTROLS:
• REDUCTION AT SOURCE
• REDUCTION OF
TRANSMISSION
• PROCESS MODIFICATION

55. REDUCTION AT SOURCE
• REDUCE SPEED OF TOOL
• REDUCE WEIGHT AND POWER NEEDED
TO DRIVE THE TOOL
• CHANGE TYPE OF TOOL
– E.G. RECIPROCATING ENGINE TO ROTARY OR ELECTRIC MOTOR
• TOOL MAINTENANCE
• MOUNT EQUIPMENT ON SPRINGS OR
COMPRESSION PADS
• USE MATERIALS THAT GENERATE LESS
VIBRATION

56. REDUCTION AT TRANSMISSION
• PROVIDE CUSHION TO ACT AS A
VIBRATION ISOLATER IN A SEATED
TASK
• PROVIDE ANTI-FATIGUE MATS FOR
STANDING OPERATION
• DESIGN TOOLS TO REDUCE VIBRATION
TRANSMITTED TO THE HANDS,
• COUNTER WEIGHT TOOLS TO MINIMIZE
GRIPPING REQUIRED TO OPERATE THEM
– DAMPENING MATERIALS AND GLOVES ARE
USUALLY MORE EFFECTIVE FOR HIGHER

57. PROCESS MODIFICATION
• CHANGES IN ANY ASPECT OF PROCESS
TO ELIMINATE NEED FOR VIBRATING
TOOLS OR EQUIPMENT
• USING MECHANICAL AIDS (CHUCKS,
CLAMPS) TO HOLD MATERIAL
– REDUCES TIME OR INTENSITY OF EXPOSURE
• ROBOTICS
• AUTOMATION
• SUBSTITUTION OF MATERIALS
– PLASTICS FOR HARD METAL

58. WORK MODIFICATION
APPROACHES
• LIMIT NUMBERS OF HOURS
• REDUCE NUMBER OF DAYS PER
WEEK
• ROTATE BETWEEN VIBRATING AND
NON-VIBRATING TOOL TASKS
• SCHEDULE MAINTENANCE BREAKS

59. WORK PRACTICES
• LENGTH OF WORK DAY
• JOB ROTATION
• SELECT LOW VIBRATION TOOLS
• DESIGN WORK TASK AND WORKPLACE
ERGONOMICALLY
• REDUCE GRIP FORCE APPLIED
• REDUCE FORCE APPLIED
• RESTRICT USE OF PIECE WORK AND
INCENTIVE PAY
• ERGONOMIC WORK POSTURES

60. ADMINISTRATIVE CONTROLS
• PPE TO REDUCE TRANSMISSION OF
VIBRATING ENERGY TO THE HAND
• PROTECT AGAINST EXPOSURE TO COLD
AND TRAUMA
• TRAINING
– SOURCE OF VIBRATION
– ADVERSE HEALTH AND SAFETY EFFECTS
– EARLY SIGNS AND SYMPTOMS
– USE AND AVAILABILITY OF VIBRATION PROTECTIVE CLOTHING
– ANTI-VIBRATION DEVICES
– VALUE OF GOOD TOOL MAINTENANCE
– WORK PRACTICE PROCEDURES

62. • Infrasound refers to waves or vibrations with a
frequency below the audibility range of the human
ear (i.e. < 20 Hz). Hence, these waves cannot be
heard by humans.
• They can be felt and, as studies have shown, they
produce a range of effects in some people including
anxiety, extreme sorrow, and chills.
• Infrasonic waves can carry over long distances
[thousands of kilometres] and are less susceptible to
disturbance or interference than waves of higher
frequencies.
• Infrasound may be produced by wind, types of
earthquakes, ocean waves, and certain things such
as avalanches, volcanoes, and meteors etc…

63. • Infrasound is especially dangerous, due to its
strong vibrations, or oscillations.
• They hug the ground, travel for long
distances without losing strength, and are
unstoppable.
• Furthermore, not much amplitude is needed
to produce negative effects in the human
body.
• Therefore, even mild infrasound exposure
requires several hours, or even days, to
reverse the resulting symptoms.

64. • Waves of infrasound are invisible, but
they slam into living tissues and physical
structures with great force.
The sensation vibrates internal organs
and buildings, flattening objects as the
sonic wave strikes.
At certain pitches, it can explode matter.

65. EXAMPLES
• Natural explosions from volcanoes produce
infrasonic waves. When Krakatau exploded, an
entire island was lifted 100 miles into the air, and
windows were shattered 1,000 miles away from
ground zero. The shock waves, affecting both
earth and atmosphere, continued for hours.
• Explosives, such as atomic weapons, produce
weapons
infrasound. Zone one is ground zero and its
destruction. Zone 2 is a powerful, speeding, sonic
wave of reduced air pressure. This concussion
blast travels at great distances away from ground
zero and few survive its destructive path.

66. Uses of infrasound:
1. Medical: (therapeutic devices)
- Several studies conducted in Russia and
Europe reported that infrasound has
therapeutic effects.
- Infrasound peumomassage: At 4 Hz, the
progression of myopia in school children can
be stabilized.
- Infrasound phonophersis in antibacterial
drugs: In treatment of patients with bacterial
keratitis, it is as effective as local instillations
of the same drugs.

67. 2. Monitoring activities of the atmosphere:
- Infrasonic waves will be influenced by the
atmosphere during its propagation, which is
closely related with the distribution of
temperature and wind in the atmosphere.
- By measuring the propagation
properties of infrasonic waves generated
by natural sources, one can detect some
characteristics and rules of the large scale
meteorological motions.

68. 3. Forecasting natural disasters: Many disasters,
such as volcanic eruptions, earthquakes, land-
slides and clear-air turbulences, radiate
infrasound in advance. By monitoring the
infrasound waves, we can forecast these
disasters.
FUN FACTS!
Elephants have the ability to emit infrasound
to communicate at distances of up to 10 miles
(12 - 35 Hz.). Even tigers emit infrasound.
“Odd sensations that people attribute to
ghosts may be caused by infrasonic vibrations” --
Psychologist Richard Wiseman of the University
of Hertfordshire

69. • High-frequency sound waves that is above the
audibility range of the human ear [approximately
22kHz]; Wavelength of about 1.5 mm
• Sound cannot be heard but can be emitted and
detected by special machines
• The speed of ultrasound does not depend on its
frequency; it depends on what material or tissue
it is travelling in.
in
Both the mass and spacing of the molecules
and the attracting force between the particles of
the material have effects on the speed of the
ultrasound as it passes through.

70. How does ultrasound work and how to
produce images of ultrasound?
• Ultrasound waves images are produced by a
transducer.
• A transducer is a device that takes power from
one source, converts the energy into another
form, and delivers the power to another target.
• In this case, the transducer acts as a
loudspeaker or a microphone, it converts
electrical signals to ultrasound waves, and
picks up the reflected waves, converting them
back into electrical signals.
• The electrical signals returned to the transducer
are used to form pictures on a television screen.

71. • Ultrasound travels faster in dense
materials and slower in compressible
materials. In soft tissue sound travels at
materials
1500 m/s, in bones about 3400 m/s, and in
air 330 m/s.
• Travels freely through fluid and soft
tissues but is reflected back as 'echoes'
when it hits a more solid/dense surface
• When the ultrasound 'hits' different
structures in the body of different density, it
sends back echoes of varying strength

72. Uses of ultrasound:
1. Medical:
• sonography: Ultrasound waves can be bounced
off of tissues using special devices. The echoes
are then converted into a picture called a
sonogram.
• Ultrasound is often used to examine a foetus
during pregnancy, or a fatal heart.
• Ultrasound usually ranges from one MHz (one
million cycles per second) to 20 MHz. This is
because tissues absorb higher frequency energy
more readily, hence producing fainter images.

73. • Pulse echo visualization:
• The information of objects is obtained by using
discrete lines of sight, with the transducer position
and orientation which defines the line of sight and
the delay of received echoes, which is used to
determine the range of the echo-producing object.
• It can be used in a wide range of clinical
conditions and is useful in many parts of the body.
• There are 3 modes of the pulse echo visualization
(i.e. A-mode, M-mode, and B-mode)

74. • Doppler effect:
• Ultrasound based diagnostic imaging technique can
be enhanced with Doppler measurements, which
employ the Doppler effect to assess whether
structures (usually blood) are moving towards or
away from the probe, and its relative velocity.
• The principal applications of Doppler effect are in
cardiac and peripheral vesicular diagnostic
specialties. Current qualitative applications involve
2 aspects of blood flow evaluation. Doppler devices
are primarily concerned with the detection and
evaluation of blood flow disturbances resulting from
valves and septal defects.

75. 2. In animals:
• For navigation:
Bats use ultrasound for navigation. They
send out ultrasounds and judges the
distance of objects ahead of them, or what
the objects are, by the received echoes. This
allows them to catch flying insects while
flying full speed in pitch darkness.

76. Communication:
• Whales make use of ultrasounds for
communication purposes. Individual pods
of whales have their own distinctive
dialect of calls, similar to songbirds.
• Singing whales are usually solitary
males who exhibit it in a shallow smooth-
bottomed area where sound propagates
well. They are interpreted as territorial
and mating calls.