Noise pollution - Environment and health

Noise pollution ppt.

2. Definition
•Wrong sound, in the wrong place, at the
wrong time.

4. Two important properties
Properties of noise pollution
•Loudness or intensity - Measured in Decibels (db)
•Frequency. - Denoted as Hertz. (Hz)

6. Instruments to measure noise
•Sound level meter
•Octave band frequency analyser
•Audiometer

7. Two types
Effects of noise exposure
•Auditory effects
•Non auditory effects

8. 1. Auditory fatigue
Auditory effects
•May be a/w side effects such as whistling and buzzing in the ears
•Appears in the 90 db region and greatest at 4000 Hz

9. 2. Deafness
•Temporary hearing loss/ Temporary threshold shift- disability disappears after a period
of time up to 24 hr following the noise exposure (4000-6000 Hz)
•Permanent hearing loss- Repeated or continuous exposure to noise around 100db may
result in permanent hearing loss.

10. Non auditory effects
•Interference with speech
•Annoyance
•Efficiency
•Physiological changes

11. Interference with speech
•Noise interferes with speech communication.
•In everyday life the frequencies causing most disturbance to speech communication lies in
the 300-500 Hz range
•Such frequencies are commonly present in noise produced by road and air traffic

12. Annoyance
•Primarily a psychological response.
•Neurotic people are more sensitive to noise than balanced people
•Workmen exposed to higher intensity of noise in occupational capacities were often
irritated, short tempered and impatient

13. Efficiency
•Reduction in noise has been found to increase work output and better concentration.

14. Physiological changes
•Rise in blood pressure - may lead to heart attacks
•Rise in intracranial pressure
•An increase in heart rate and breathing
•An increase in sweating

15. Other effects of noise
•Causes visual disturbances
•Interferes with sleep
•Digestive problems
•Abortion
•Aggressive behaviour
•Effects on vegetation
•Effects on property
•General symptoms such as nausea , fatigue and giddiness may also occur.

16. Variety of approaches may be needed to control noise
Control of noise
•Careful planning of cities
•Control of vehicles
•Protection of exposed person
•Legislation
•Education