Noise Pollution Flashcards
Noise pollution
Unpleasant noise created by people or machines that are annoying, distracting, intrusive and/or physically painful
Causes of noise pollution are road traffic, Jet plans, garbage trucks, construction equipment, manufacturing processes, leaf blowers, boomboxes, etc.
It is measured in decibels (dB). One decibel (0.1dB) equals 10 times the common logarithm of the power ratio.
Increase of about 10 dB is approximately double increase in loudness
A person’s hearing can get damaged if exposed to noise levels 75 dB over a prolonged period of time
The World health organisation recommends sound level to be less than 30 dB indoors.
Monitoring of noise pollution
Ambient noise level monitoring:
Noise pollution (control and regulation) rules of 2000 define ambient noise levels for various areas as follows:
Industrial Area (day) 75 (night) 70
Commercial area (day) 65 (night) 55
Presidential area (day) 55 (night) 45
Silence tone (day) 50 (night) 40
Silence zone is an area comprising not less than 100 m around hospitals, education institutions, courts, religious places, etc.
At present, under the national ambient noise monitoring network, 70 continuous monitoring stations are established. Turn off them are in 7 cities, Mumbai, Delhi, Kolkata, Bangalore, Chennai, Lucknow and Hyderabad.
Impact of noise pollution
It create annoyance to receptors due to sound level fluctuations, a-periodic sound due to irregular occurrences, Displeasure to hearing and causes annoyance
Physiological features like breathing amplitude, blood pressure, heartbeat rate, pulse rate, blood cholesterol levels are affected
Long exposure to high sound levels can cause loss of hearing unnoticed and has adverse impact on hearing function
Working performance of workers and humans get affected which distracts concentration
It affects the nervous system by causing pain, ringing in ears, tiredness and affects the functioning of the human system.
It affects sleeping, inducing people to become restless and lose concentration and presence of mind during activities
It causes damage to buildings and materials by exposure to infrasonic and ultrasonic waves and can even get collapsed
As sound travels faster in denser medium, noise in water bodies affect fishes and other aquatic animals
Control
Control at source: reducing noise levels from domestic sectors, maintenance of automobiles, control over vibration, prohibition on usage of loudspeakers, selection and maintenance of machinery
Control in transmission path: installation of barriers, design of building, green belt development (planting trees), plantation on the roadsides and on road dividers increases the aesthetics and reduces noise.
Using protective equipment: job rotation, reduced exposure time, hearing protection, documentation of noise measurements, continuous monitoring and awareness are needed.
