Natural and Artificial Sources of Noise Pollution!
The sources of noise can be divided into two categories, viz., natural and artificial. Natural sources are associated with natural phenomena like lightning, thunder, volcanic eruption, earthquake, sound of the ocean waves, etc.
These reasons are local or regional and generally their impact is very limited and not very harmful. On the contrary, noise produced by man is much greater and harmful.
Artificial sources are mainly responsible for noise pollution. The sources of noise pollution in an industrial society are manifold. In cities these are associated with transportation, automobiles, motorcycles, rail engines, buses, fire brigade, police cars, ambulances, aeroplanes, industries, high pitched musical instruments, etc. During religious or domestic functions and in political
meetings during elections noise pollution often increases due to the use of electronic medium of sound.
The main source of noise, however, comes from transport. The number of vehicles, particularly diesel engine vehicles, has increased the level of noise enormously. This problem is more in metropolitan cities where a large number of vehicles ply simultaneously and their noise is unbearable. The horns and sirens used by these vehicles, specially the pressure horns, are very noisy.
The value of horns and sirens, except in emergencies, is questionable. The whistle of rail engines is very harmful to the ears. Busy traffic streets, highways, bus stands and railway stations all have problems of noise pollution.
Larger and faster jet aircrafts have become one of the most troublesome sources of noise pollution. For example, O’Hare International Airport, in Chicago (USA), the busiest airport in the world, has more than a thousand operational jet flights on an average day. This means a flight in or out every 40 seconds.
The residents within 20 km radius from the airport are facing great problems not only in their conversations, television viewing, sleep and relaxation but it has also started affecting their health adversely. The air traffic has increased to such an extent that nobody likes a new airfield in his neighborhood.
Noise associated with manufacturing, building construction, mining, road building, etc., are second in intensity to transportation noises. But, their impact is felt more by factory and other workers. It is reported that noise inside factories can become a health hazard causing deafness. Industrial noise, particularly from mechanical saws and pneumatic drills, is unbearable and a nuisance to the ears.
The impact of noise in a factory varies with age groups. For workers below 30 years of age, the 95 decibel noise is not harmful, but for 40 to 50 years age group this limit is 84 decibels and for 50 to 60 years ago the bearable limit is 80 decibels. In mining, noise produced by blasting and digging is also a source of uncomfortable noise.
Nowadays, music has also become noisy. In a closed space, high volume music is harmful and is responsible for noise pollution. Similarly, during social and religious functions, marriages and other gatherings, including election meetings, the use of high volume loudspeakers has become a common feature and an irritating cause of noise pollution. The popular ‘pop music’ may be entertaining but its ultimate impact is not healthy on man.