Definition: Noise is undesirable and unwanted sound. 

Sources of noise pollution

There are several sources of noise pollution that contribute to both indoor and outdoor noise pollution. Noise emanating from factories, vehicles, playing of loudspeakers during various festivals can contribute to outdoor noise pollution while loudly played radio or music systems, and other electronic gadgets can contribute to indoor noise pollution.

Effects of noise pollution on physical health

The most direct harmful effect of excessive noise is physical damage to the ear and the temporary or permanent hearing loss often called a temporary threshold shift (TTS). People suffering from this condition are unable to detect weak sounds. However hearing ability is usually recovered within a month of exposure. Permanent loss, usually called noise induced permanent threshold shift (NIPTS) represents a loss of hearing ability from which there is no recovery.

Effects of noise pollution on mental health:

Noise can also cause emotional or psychological effects such as irritability, anxiety and stress. Lack of concentration and mental fatigue are significant health effects of noise. 

As noise interferes with normal auditory communication, it may mask auditory warning signals and hence increases the rate of accidents especially in industries. It can also lead to lowered worker efficiency and productivity and higher accident rates on the job.

Thus noise is just more than a mere nuisance or annoyance. It definitely affects the quality of life. It is thus important to ensure mitigation or control of noise pollution With environmental crisis looming over us, relevance of Reduce, Reuse and Recycle is very high. Adopting these measures have been very effective in curbing pollution at an individual level.

Not all sound is considered noise pollution. The World Health Organization (WHO) defines noise above 65 decibels (dB) as noise pollution.

there are lots of sources of noise pollution. some of them are as follows-

1.Traffic noise Traffic noise accounts for most polluting noise in cities. For example, a car horn produces 90 dB and a bus produces 100 dB.

2.Air traffic noise There are fewer aircraft flying over cities than there are cars on the roads, but the impact is greater: a single aircraft produces 130 dB.

3.Construction sites Building and car park construction and road and pavement resurfacing works are very noisy. For example, a pneumatic drill produces 110 dB.

4.Catering and night life Bars, restaurants and terraces that spill outside when the weather is good can produce more than 100 dB. This includes noise from pubs and clubs.

5.Animals Noise made by animals can go unnoticed, but a howling or barking dog, for example, can produce around 60-80 dB.

Effects of Noise: Noise is generally harmful and a serious health hazard. It has far-reaching consequences and has many physical, physiological as well as psychological ef­fects on human beings.

(i) Physical Effects:

The physical manifestation of noise pollution is the effect on hearing ability. Repeated exposure to noise may result in temporary or permanent shifting of the hearing threshold of a person depending upon the level and duration of exposure. The immediate and acute effect of noise pollution is impairment of hearing (i.e. total deafness.) Human ears have sensory cells for hearing. If these cells are subjected to re­peated sounds of high intensity before they have an opportunity to recover fully, they can become permanently damaged leading to impairment of hearing. Be­sides the sensory cells, the delicate tympanic membrane or the ear drum can also be permanently damaged by a sudden loud noise such as an explosion.

(ii) Physiological Effects:

The physiological manifestations of noise pollution are several as mentioned be­low:

(a) Headache by dilating blood vessels of the brain.

(b) Increase in the rate of heart-beat

(c) Narrowing of arteries.

(d) Fluctuations in the arterial blood pressure by increasing the level of choles­terol in the blood.

(e) Decrease in heart output.

(f) Pain in the heart.

(g) Digestive spasms through anxiety and dilation of the pupil of the eye, thereby causing eye-strain.

(h) Impairment of night vision.

(i) Decrease in the rate of colour perception.

(j) Lowering of concentration and affect on memory,

(k) Muscular strain and nervous breakdown.

(l) Depression and fatigue which considerably reduces the efficiency of a person.

(m) Insomnia as a result of lack of undisturbed and refreshing sleep

(n) Straining of senses and annoyance as a result of slow but persistent noise from motorcycles, alarm clocks, call bells, telephone rings etc.

(o) Affecting of psychomotor performance of a person by a sudden loud sound

(p) Emotional disturbance

*Noise Pollution Level and its Harmful Effects:

Level (in db)

Effects

up to 23 ………………………..

No disturbance

30—60 ………………………..

Stress, tension, psychological (illness, heart attact) effects especially at upper range.

60—90 ………………………..

Damage to health, psychological and vegetative (disturbance in stomach-gall function, pains in muscles, high blood pressure, disturbance in sleep­ing)

90—120 ………………………

Damages to health and ontological (ear diseases) ef­fects

Above 120 …………………….

Painful effects in long run.