1. Noise Pollution
[Environmental Noise[

2. Definition:
• It is any unwanted, disturbing or harmful sound that
impairs or interferes with hearing, causes stress,
hinders concentration and work efficiency, or causes
accidents.
• It can also be defined as displeasing human or
machine created sound that disrupts the activity or
happiness of human or animal life.

3. • The sensation of loudness is related to the intensity of
the energy carried by the sound waves and is
measured in units of decibels (dB).
• Sound pressure becomes damaging at about 85 dB
and painful at around 120 dB. At 180 dB it can kill.
• Human ears can take sound up to about
60dB without damage or hearing loss.

4. Sources of noise pollution:
The source of most noise worldwide is
1. Transportation systems, motor vehicle noise, but also including aircraft
noise and rail noise.
2. Poor urban planning may give rise to noise pollution, since side-by-side
industrial and residential buildings can result in noise pollution in the
residential area.
3. Office equipment, factory machinery, construction work, appliances,
power tools, lighting hum and audio entertainment systems.
• The sound of an automobile is about 70 dB; the sound of a jet aircraft
taking off, about 120dB; sound level in the interior of a home is about
45 dB. So, prolonged exposure to sound levels above 85dB can cause
permanent hearing damage.
• Noise in the range of 50-60 dB is sufficient to interfere with sleep,
producing a feeling of fatigue upon awakening.

5. Human health effects:
1. Noise disturbs sleep
2. Can damage physiological and psychological health
3. Can cause annoyance and aggression, hypertension, high stress levels,
tinnitus, hearing loss, and other harmful effects
4. Tinnitus (ringing or buzzing in the ear) can lead to forgetfulness, severe
depression and at times panic attacks.
5. Chronic exposure to noise may cause noise-induced hearing loss.
6. High noise levels can contribute to cardiovascular effects.
7. Rise in blood pressure
8. Noise poses a danger to children's development [low birth weights and
fetal defects, such as cleft palate]
9. Blood is thickened by excessive noise. Eosinophilia, hyperglycaemia,
hypokalaemia and hypoglycaemia are caused by alteration in the blood
due to noise.

6. Environmental effects:
1. Can have a detrimental effect on animals by causing stress,
increasing risk of mortality by changing the delicate
balance in predator/prey detection and avoidance.
2. Interfering with animal's use of sounds in communication
especially in relation to reproduction and in navigation.
3. Can lead to temporary or permanent loss of hearing to
animals.
4. Very loud noise may affect plant growth indirectly because
it produces vibrations that shake the plants.

7. Environmental effects of noise depends on:
1. Total energy
2. Sound's pitch
3. Frequency
4. Time pattern and,
5. Length of exposure to the sound.

8. How can we reduce noise pollution:
1. Ear Protection
2. Modifying noisy activities and devices
3. Shielding noisy devices or processes
4. Shielding workers or other persons from the noise
5. Moving noisy operations or machinery away from
people
6. Using anti-noise (a technology that cancels out one
noise with another).
7. Use of noise barriers
8. Limitation of vehicle speeds,
9. Limitation of heavy duty vehicles

9. 10. Use of traffic controls that smooth vehicle flow to reduce
braking and acceleration
11. Aircraft noise can be reduced to some extent by design of
quieter jet engines,
12. Redesign of industrial equipment, shock mounting
assemblies and physical barriers in the workplace.
13. Research now shows that plants can also help to reduce
background noise levels inside buildings by up to 5 decibels
14. Interior plants can absorb, diffract or reflect background
noise in buildings, thereby making the environment more
comfortable for the occupants [especially plants with lots of
small leaves]
15. Law enforcements.

10. Learning to protect yourself from Noise
Pollution:
1. Always wear hearing protection when working
around loud noises
2. Take breaks when working in noisy areas
3. Limit exposure to loud music
4. Have regular hearing tests for any loss of hearing
5. keep indoor plants

11. Noise levels of common sounds
Pain 130 dB
120 dB
Aircraft taking off 110 dB
Loud Rock Music 100 dB
Semi Truck (short term hazard) 90 dB
Jack Hammer 80 dB
Traffic (ocupational limit) 70 dB
Conversation 60 dB
Background office noise 50 dB
Windmill 40 dB
30 dB
Quiet bedroom 20 dB
10 dB
Threshold of hearing 0 dB