Effects of Noise Pollution
The WHO suggests that noise can affect human health in a number of ways. These include physical, physiological and psychological effects.
(a) PhysicalEffects
These are high blood pressure, other cardiovascular changes, problems in digestive system and general fatigue.
Prolonged exposure to noise levels 80 dB and above can cause deafness.(b) Physiological Effects
These arise due to interference in the biological functioning of the body due to noise pollution. They include anxiety, insomnia, hypertension, nausea and giddiness. Noise levels in the range 120-150 dB can affect respiratory system and cause dizziness, loss of physical control etc.
A loud noise can also cause increased secretion of hormones of the pituitary gland viz. adrenocorticotropic hormone (ACTH), which stimulates adrenal gland for further secretion of several other hormones. This chain of secretions enhances sensitivity of the body to adrenalin, increase in level of blood sugar, suppression of immune system and a decrease in the ability of liver to detoxify blood.
Chronic noise may also lead to abortions and congenital defects. Frequent exposure to noise levels 85 dB or above can lead to increased pulse rate, higher cholesterol levels and violent behaviour. The noise levels of 70 dB can cause Constrictionofbloodvesselsinsldn.
(c) Psychological Effects
These include loss of working efficiency resulting in reduced output, absentism and higher rates of accidents and injuries. Noise can also interfere with sleep which in turn affects overall mental and physical health of a person.
Noise levels of 45-50 dB can cause changes in sleep patterns and affect deep sleep. Noise levels df 50 to 60 dB can also interfere with communication. At times, it may not be possible to hear warning signals.
Even very low levels of noise can cause annoyance to some people. It can lead to ill temper, quarrel or enmity.
In addition to humans, noise can be equally adverse to wildlife also. Animals in the zoo are quite sensitive to the noise in their surroundings and their behaviour can be affected by noise.
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