Noise wise, India is one of the most polluted countries in the world

Last week a person who gives out on hire his Dolby music truck for marriages and other functions used a vacant plot near our house to test his equipment. The heavy dose of bass that he blasted from his truck towards our house made me sick to the core. Such loud music is a common occurrence in cities and small towns of India, more so during the various religious festivals like Ganpati, Dussehra and the like. This noise pollution is further exacerbated by firecrackers during Diwali and marriage festivals.

Similarly, some years ago I had gone to attend a friend's son's marriage in Mumbai. The drums were beaten so loudly that it caused palpitations in my heart and despite completely covering the ears with my palms, the noise penetrated deep inside the body and I suffered a momentary loss of hearing.

Noise-wise, India is one of the most polluted countries in the world. The data on noise pollution is scarce, but whatever little exists for India shows that in most cities the noise reaches dangerous levels.

Sound intensity levels or noise levels are described in decibels (dB) with a logarithmic increasing scale and they double up with every 10 dB increase. Thus, the noise level at 40 dB is twice as loud as that at 30 dB.

The sound level of normal human conversation is between 40-50 dB and that of rock or loud music concert is on an average 140 dB. Thus, rock music is approximately 500 times louder than the human conversation.

Recent data shows that some of the Indian cities have noise levels greater than 75 dB and in peak traffic jams the deafening sound of horns blowing can reach 100-120 dB. Poor traffic sense, lax patrolling by police and bad roads exacerbate the noise pollution further. Medical data also shows that around 6-7 per cent of India's population is deaf though the actual numbers maybe much higher since most people never get tested for deafness.

Effect on health

Scientists have shown that all sound levels greater than 85 dB are dangerous to human health. In the long run, they damage hearing and increase the level of stress. Large scale studies all over the world have shown that increased sound levels cause elevated blood pressure, loss of sleep, increased heart rate, cardiovascular constriction and changes in brain chemistry.

I feel the increase of anger and aggression in the city population is probably due to the noise pollution.

We hear sound through our ears where the pressure waves (sound) are converted into electrical signals and these signals are processed in the auditory centres of the brain. However, when the sound is loud enough it also has the ability to pass through the human skull - the thinnest among all animals - and reach the brain directly.

Various scientific studies worldwide have shown the effect of mechanical forces on the working of the brain. Under various mechanical stresses, the brain chemistry gets altered, thus affecting neuron communications and general functioning of the brain. Loud noise vibrations passing through the skull can therefore easily affect the brain -- the softest tissue in the human body. In some ways, the effect of a very loud sound may be similar to head trauma injury.

Nature has evolved so as to take into account all the forces impinging on a body and I am sure that this pressure wave passing through the skull affects the brain directly.

Music affects humans profoundly. Great music lifts the mood, is a balm to the soul and can have profound effect on the wellbeing in the long run. We still are not sure how music affects the whole brain since the auditory centres occupy only a small portion of the brain. However, sound vibrations creating mechanical stresses in the brain may provide an answer.

Similarly, "ugly and loud" sound may affect the whole brain and in the long run may have profound detrimental effects on human health. Even music, which may be soothing at low volumes, becomes cacophonous when played loudly.

Loud music has the same detrimental effect on nerves as multiple sclerosis. It destroys the insulation of nerve cells which go from the ear to the brain. It is not necessary that only loud music heard in the open affects our health; even headphones with loud music have the same effect.

I feel the stress, foul mood and general aggressiveness comes from continuously being exposed to loud music. The young population, which is constantly chatting or hearing music via headphones is very susceptible to this phenomenon.

Another way by which sound pollution affects our health is by creating sleep deprivation. Because of sound pollution at night, we do not get deep sleep. Studies the world over have shown that without deep sleep the detoxification of brain does not take place; thereby creating long-term stress which affects all aspects of mental and physical health.

Studies have also shown that not only humans but also animal health has been adversely affected by sound pollution. The beaching of whales and dolphins has been linked to sonar experiments during various military exercises in oceans around the world. Similarly, biologists have found urban noise pollution affects adversely the communication signals of songbirds.

We just celebrated our 70th Independence Day. However, I feel the true independence will be when we get freedom from noise pollution. Then only will we get on the path of emotionally happy and sustainable living in India.

By Anil K. Rajvanshi

(The author is the Director of the Nimbkar Agricultural Research Institute at Phaltan in Maharashtra. The views expressed are personal. He can be reached at [email protected])