There is no denying the fact that pollution has posed a great challenge to human health. Of all types of pollution created by man, noise pollution is undoubtedly the most hazardous. Today, there appears to be no getting away from the rising decibels of noise in our lives, particularly in the big cities. Noise has become an inseparable part of the everyday existence. And it is slowly eating into our health, both physical and mental.

One of the most dangerous effects of unwanted noise is on man's hearing. Scientific studies have established that a noise level of 50 db (decibels) is fit for man and any increase from it starts disturbing him. According to a WHO report, sound at 75 db is moderately loud,' at 95 db it is 'very loud,’ at 120 db, it is 'uncomfortably loud.' At 140 db, sound becomes 'painfully loud'.

After only a few minutes' exposure to sound at 140 db, severe pain end temporary loss of hearing are inflicted. The heavy traffic in big cities produces a sound of 90 db. Sound, in a discotheque is at 120 db and a .let airliner's take-off produces more than 140 db of sound.

Dr. Rashmt Mayur, eminent environmental scientist and Head of Urban System Centre, Mumbai, "Each year noise pollution is increasing in quantity and variety and most people adapt to it by accepting impaired hearing and damages to health, unconsciously as if noise has become an essential part of modern living."

According to Dr. Samuel Rosen, an American ear surgeon, sudden and loud noise, after striking the ear, produces numerous physiological changes. "Heart beats rapidly, the blood vessels contract, the pupils dilate and the stomach and intestines are seized by spasms."

Constant exposure to unwanted noise — and a short term exposure to noise at 150 db — results in a gradual decrease of-the heart rate. Other ill effects on the body include increased blood pressure, respiratory diseases, exhaustion and nervousness. High pitched noise also reduces the body's resistance to disease and may aggravate allergies like asthma. In an experiment, a group of patients was in a noisy room, while another was kept in a calm and quiet room. It was observed that the patients of the noisy room took almost twice as much time to heal as the ones kept in peaceful surroundings.

The loud noise is very injurious to the pregnant women. The growing embryo has to suffer on account noise of the outer world. Excessive noise can result in congenital defects in the child, such as abnormal behavioral patterns. In many cases it leads to premature births. Studies carried out in Japan reveal that infants born in noisy surroundings fail to gain weight.

The high decibels cause havoc on the psycho-physiological level also. Environmental scientists believe that a prolonged exposure to noise causes frustration, sleeplessness, lack of cooperation and social conflicts. It also results in disturbed continuity of thought, distracted attention, .affected mental mood and brings about exhaustion in about half the normal time.

The deafening sound from discotheques and night clubs has the most damaging and destructive effect on man’s health. The sound pressure level in a rehearsal room is 120 to 130 db -- much higher than the sound in a very noisy factory which is usually at 100 db, A middle-aged woman in England reportedly took her life as she couldn't endure the noise coming from 'a neighbouring discotheque.

Dr. Samuel Rosen conducted a study of the Mabaans of Sudan, a primitive African tribe, living in quiet surroundings. .He found that there was no obesity, no hypendicitus. duodenal ulcers and bronchial asthma among them. The ten-year-old Mabaans and 90-year-old Mabaans had almost the same blood pressure. The 75-year-old Mabasn heard as perfectly as a, normal American citizen of twenty-five.

Robert Koch, Nobel Laureate and great bacteriologist predicted more than 90 years ago. "A day will come when man will have to fight noise as the worst enemy of mankind."
The day has come.