Noise pollution

Environmental Factor - Noise Pollution, Its Effects and Remedies

1. Environmental Engineering : N oise Pollution prepared by : Parth Desani

2. Contents What is noise and sound ? Difference between noise and sound Characteristics of sound Sources of noise pollution Effects of noise pollution Control of noise pollution

3. What is noise and sound ? Sound : What we hear is known as sound. Noise : The unwanted and unpleasant sound is known as noise.

4. Difference between sound and noise Sound Sound is what we hear. It has a constant pitch or frequency. It has a periodic motion. It produces meaningful communication. It’s unit is Hertz (Hz). Noise Noise is unwanted and unpleasant sound. It has a variable pitch or frequency. It has a non periodic function. It does not produce meaningful communication. It’s unit is decibel (dB).

5. Characteristics of sound Sound contains following characteristics in it : Frequency (f) Time Period (T) Intensity (I) Wavelength ( λ ) Sound Pressure Sound Power Sound Pressure Level Amplitude of Wave (A)

6. Sources of noise pollution The presence of unwanted and unpleasant sound in the atmosphere, which may cause discomfort is called noise pollution. The sources of noise pollutions are as follows : Traffic sources Industrial sources Constructional sources Other sources

7. Traffic Sources : Noise created by various means of transport like trucks, tractors, buses, autorickshaws , trains, aeroplanes , etc. are the traffic related sources of noise pollutions. It may be in the form of, - horn of vehicles - raise of accelerator - vehicle with damaged silencer - noise produced by a diesel car will be more than produced by a petrol car - a jet aircraft will produce more noise than a propeller type of aircraft

8. Industrial sources : industrial noises are usually produced by : - reciprocating or rotating machinery - cutting of materials, grinding - blow hammers - generators - high pressure and high velocity gases, etc.

9. Constructional sources : Noise produced by various constructional activities are : - rock crushers for production of aggregates - pile driving equipments - boring and drilling equipments - road rollers - material handling by belt conveyors, chute, hoist - rock blasting

10. Other sources : In residential area – loud voice of T.V., music systems, radio, etc. Public address systems – public functions, navratri festival etc. Sirens – Police van, industries

11. Effects of noise pollution The major effects of noise pollution are : Physical effects Physiological effects Psychological effects Physical Effects : Loss of hearing – long time exposure of loud sound (80 – 90 dB) for more than 8 hours a day, may cause loss in hearing. Total deafness (acoustic trauma). Sudden loudness particularly from crackers and explosions may affect the ear drum and sensitive ear membrances .

12. Physiological Effects : Headache, nausea Dizziness, gastric ulcers High rate of heart beat Fluctuations in blood pressure and sugar Psychological Effects : Annoyance , sleep interference Depression fatigue Mental stress Speech interference Effects on performance Decrease in efficiency

13. Control of noise pollution Noise is a serious environmental pollution and health hazard. Noise pollution can be effectively controlled by taking the following measures : Control at receiver’s end Acoustic zoning Supression of noise at source Planting trees Sound insulation at construction stages Legislative measures

14. Control at Receiver’s End : People working in a noisy installations, ear – protection aid like ear – plug, ear – muffs, noise helmets, headphones, etc. must be provided to reduce occupational exposures. Acoustic Zoning : Silence zones near the educational, hospitals and residential area should required. Increasing distance between source and receiver of noisy industrial areas, bus terminals and railway stations, aerodromes, etc. away from the residential areas would go a long way in minimizing noise pollution.

15. Supressions of Noise at source : If working methods are improved by : - installing noisy machines in sound proof chambers - proper maintenance and lubrications of machine - use of sound absorbing materials for covering noise-producing machines - use of silencers to control noise from automobiles, ducts, exhausts, etc - designing, fabricating and using quieter machines to replace the noisy ones - reducing noise from vibrating machines by vibration damping. i.e. damping materials e.g. rubber, neoprene, cork and plastic beneath the machine

16. Planting Trees : Planting green trees along the roadside, near hospital, schools, educational institutions etc. help in noise reduction. Sound insulation at construction stages : Gap between the door and wall should be packed with sound absorbing materials. In noise proof recording rooms, acoustical tiles, perforated plywood etc. can be fixed on walls and ceiling etc.

17. Legislative measures : Strict legislative measure need to be enforced to reduce noise pollution. - framing a separate Noise Pollution Act - minimum use of loud speakers and amplifiers especially near silence zones.

18. Thank You…!!