Noise Pollution

Module 3 - POLLUTION

63. Causes/sources of noise pollution

Noise is the undesirable or unwanted sound. It is not harmful as the contamination of air and water. But it is a pollution problem that affect the human being.

Sources of Noise pollution

-    Factories
-    Vehicles
-    Loud speakers
-    Music systems
-    Fire crackers

64. Effects of noise pollution

- Physical damages to the ear and temporary or permanent loss of hearing.
-  In addition to the hearing loss, excessive sound for a long period of time cause harmful effects on circulatory system by rising blood pressure and altering pulse rate.
-  Noise also cause emotional or psychological effects such as irritation, anxiety, stress, lack of  concentration and mental fatigue.
 
-  Underwater species like whales are seriously affected by noise rom the marine transport.

65. Control devices for noise pollution

There are 4 fundamental ways by which noise can be controlled.

1. Reduce noise at the source
2. Block path of the noise
3. Increase the path length
4. Protect the recipient

1. Reduce the noise at the source
Noise can be reduced by effectively muffing the vehicles and machines with sound absorbing materials.
In industries noise reduction can be done by
    i)   Using rigid sealed enclosures around the machine lined with sound absorbing materials
    ii)  Isolate the machines and their enclosures from the floor using special shock absorbing mounts and pads.
    iii) Use flexible couplings in joints.
    vi)  Regular and thorough maintenance of machineries and vehicles.

2. Block the path of the noise

Isolate the source of noise from the recipients by blocking the path by sound proof material.

3. Increase the path length

    i)   Locate noisy compressors, generators and other equipment away from work sites.

    ii)  Establish schools and hospitals away from traffic areas, airports and industries.

4. Protect the recipient

The use of earmuffs can protect the individuals from excessive noise level