Which one of the following is the permissible level of noise in a silent zone at daytime ?

In India, the Noise Pollution (Regulation and Control) Rules, 2000, framed under the Environment (Protection) Act, 1986, establish ambient air quality standards for noise across different zones [t1][t9]. A 'Silence Zone' is defined as an area comprising not less than 100 meters around hospitals, educational institutions, and courts [c1][t3]. According to the Central Pollution Control Board (CPCB) and the Ministry of Environment, Forest and Climate Change, the permissible noise level for a silence zone is 50 dB during the daytime (6:00 AM to 10:00 PM) and 40 dB during the nighttime (10:00 PM to 6:00 AM) [t2][t5][t7]. For comparison, the daytime limits for industrial, commercial, and residential areas are 75 dB, 65 dB, and 55 dB, respectively [t7][t8]. Therefore, the permissible level in a silent zone at daytime is 50 dB.

Sources

1. [1] https://gomatipolice.tripura.gov.in/sites/default/files/uploaded-file/The%20Noise%20Polluation%20Rules.pdf
2. [2] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 6: Environmental Degradation and Management > Control of Noise Pollution > p. 43
3. [3] https://cpcb.nic.in/noise-pollution-rules/
4. [4] https://www.dpcc.delhigovt.nic.in/noise_standards
5. [5] https://cpcb.nic.in/air/Deepawali-2020.pdf