1. NOISE POLLUTION

2. WHAT IS NOISE POLLUTION
Sound that is unwanted or disrupts one’s quality of life is called as noise. When there is lot of noise in the environment, it is termed as noise pollution.
World Health Organization stated that “Noise must be recognized as a major threat to human well-being”

3. MEASURING SOUND INTENSITY
Sound energy travels in waves and is measured in frequency and amplitude
Amplitude measures how forceful the wave is.
It is measured in decibels of sound pressure.
0 dBA is the softest level that a person can hear.
Normal speaking voices are around 65 dBA.
A rock concert can be about 120 dBA.
Sounds that are 85 dBA or above can permanently damage your ears. The more sound pressure a sound has, the less time it takes to cause damage. For example, a sound at 85 dBA may take as long at 8 hours to cause permanent damage, while a sound at 100 dBA can start damaging hair cells after only 30 minutes of listening.

4. Understanding the decibel scale
You have to think about the decibel scale very carefully, it's a logarithmic scale
With a linear scale. On a ruler, a distance of 20cm is twice as long as a distance of 10cm and 30cm is three times as long.
But the logarithmic decibel scale goes up in powers of ten: every increase of 10dB on the scale is equivalent to a 10-fold increase in sound intensity (which broadly corresponds with a doubling in loudness).
That means a sound of 20dB is 10 times more intense than a sound of 10dB and a 30dB sound is 100 times more intense.
A sound of 100dB is actually 1,000,000,000 times more intense than a sound of 10dB and not 10 times as intense, as you might suppose.
That's why sounds high up the decibel scale (from about 85–200dB) are a major cause for concern: the sound waves carry so much energy that they will damage your hearing, sooner or later.

8. Commercial and industrial activities:
Printing presses, manufacturing industries, construction sites, contribute to noise pollutions in large cities. In many industries, it is a requirement that people always wear earplugs to minimize their exposure to heavy noise. People who work with lawn mowers, tractors and noisy equipment are also required to wear noise-proof gadgets.

9. Social events:
Places of worship, discos and gigs, parties and other social events also create a lot of noise for the people living in that area. In many market areas, people sell with loud speakers, others shout out offers and try to get customers to buy their goods. It is important to note that whey these events are not often, they can be called 'Nuisance' rather than noise pollution.

10. Household sources:
Gadgets like food mixer, grinder, vacuum cleaner, washing machine and dryer, cooler, air conditioners, can be very noisy and injurious to health. Others include loud speakers of sound systems and TVs, ipods and ear phones. Another example may be your neighbor’s dog barking all night everyday at every shadow it sees, disturbing everyone else in the apartment.

11. Transportation:
Think of planes flying over houses close to busy airports like Heathrow (London) or grantley adams over ground and underground trains, vehicles on road—these are constantly making a lot of noise and people always struggle to cope with them.

12. Health Risk
Hearing
The immediate and acute effect of noise pollution to a person, over a period of time, is impairment of hearing. Prolonged exposure to impulsive noise to a person will damage their eardrum, which may
result in a permanent hearing impairment. Prolonged exposure to noise can cause irreversible hearing loss and ringing in your ears known as tinnitus.

13. Effects on general health
Health effects of noise include anxiety and stress reaction and in extreme cases fright. The physiological manifestations are headaches, irritability and nervousness, feeling of fatigue and decreases work efficiency. For example, being pounded by the siren of fire fighters, police or ambulance in your city all night everyday leave people (especially elderly people) stresses and tired in the morning.

17. mitigation Social Strategies
Social awareness programs should be taken up to educate the public about the causes and effects of noise pollution.
Using legislation to control noise levels.
Creation of silence zones near schools and hospitals

18. mitigation
Industry
Providing workers with noise cancelling ear protection ( ear muffs,plugs).
Redesigning machine components to be quieter.
Installing sound barriers, sound proofing rooms.
Zoning activities.

19. Transporation
technological improvements to vehicles and aircraft aerodynamics and components, including low noise tyres, train wheels, brake-blocks, and landing gears;
improvements to infrastructure, such as low noise road surfaces and rail tracks;
urban planning that limits encroachment of homes close to busy roads, railways or airports, and rules on the location, layout and acoustic quality of buildings;
traffic management techniques, such as traffic calming, controlling the speed of road vehicles, and low noise operational procedures for aircraft;
restricting access for the noisiest vehicles and aircraft (e.g. at night);
noise barriers and improved soundproofing of dwellings (although only as a last resort because these measures are rarely cost-effective).