Question

In the residential area at night, the standard limit of sound intensity is …………. decibel.
(a)55
(b)70
(c)45
(d)40

Answer 1

A decibel is a unit of sound intensity and a standardized limit is set to prevent noise pollution. Noise is defined as undesired high levels of sound. High sound intensity might be pleasurable and entertaining but it causes some serious psychological and physiological disorders in humans.

Complete step by step answer:
The Central Pollution Control Board (CPCB) is the institute that is responsible for regulating noise pollution. The Air (Prevention and Control of Pollution) Act was introduced in 1981 but amended in 1987 to include noise as a type of air pollution. The sound limits which are permitted for the residential area at night is 45 dB. But during day time, 55 dB of sound intensity is permitted. Several silent zones have been declared 100 meters around schools, colleges, hospitals, and courts where the sound limit is 50 dB during the day and 40 dB during the night.

So, the correct option is ‘45’.

Additional information: Let us look at the various acts introduced in our country to minimize pollution.
Environment (Protection) Act, 1986: The government of India passed this act in 1986 to protect and improve the quality of our environment which included air, water, and soil.
Air (Prevention and Control of Pollution) Act, 1981: This act was introduced to provide for the prevention, control, and abatement of air pollution. It was later amended to include noise as an air pollutant.
Water (Prevention and Control of Pollution) Act, 1974: This act was passed by the government in lieu of the importance of maintaining the cleanliness of the water bodies and it aimed to safeguard the water resources.

Note:
-The sound intensity of 150 dB is equal to the sound produced by the take-off of a jet plane or rocket and can cause permanent impairing hearing ability.
-Noise also causes sleeplessness, increased heartbeat, stress, and altered breathing pattern in humans.
-The sound limit of 65 dB at day and 55 dB at night is allowed in commercial areas.