On Diwali night, firecrackers continued to burst well after 10pm, the Supreme Court-mandated deadline, confirm data generated by most of the 10 noise level measuring stations set up by the Central Pollution Control Board in Calcutta.
Even around midnight, most of the stations recorded decibel levels much higher than the national limit. Several recorded noise levels similar to or more than what was recorded by them around 10pm.
The measuring station in Bagbazar, a residential area in north Calcutta, recorded 88.9 decibel around 12.30am. The reading at 10pm was 76.
Patuli, a residential pocket off EM Bypass, on the south-eastern fringes of the city, recorded 68.1 decibel after midnight. At 10pm, the reading was 29.4.
The limit for residential areas from 10pm is 45 decibel.
Even hospitals — designated as “silent zones”, which means microphones cannot be played and firecrackers cannot be burst within 100m — were affected.
The RG Kar Medical College and Hospital, in north Calcutta, recorded 61.2 decibel at 8.30pm, 62.6 decibel at 10pm and 63.3 decibel around midnight.
The average ambient noise level at SSKM Hospital remained almost static from 10pm to 12.30am — 51.4 to 51.5 decibel.
The permissible level at hospitals at night is 40 decibel.
The measuring station at New Market, a commercial hub, was 84.8 decibel at 12.30am. The night-time limit for commercial areas is 55 decibel.
Tollygunge and Kasba, designated as commercial areas, recorded 84.5 and 82 decibel, respectively, at 12.30am.
Taratala, also a commercial area, was relatively quiet, recording around 48 decibel throughout the evening.
Bagbazar recorded the highest noise level in the city on Sunday: 81.1 decibel around 2am. It came down to 56.3 around 3am.
It also recorded Calcutta’s highest night-time noise level: 98.3 decibel.
Kasba and Patuli recorded 80 and 64 decibel, respectively, between 1 and 2am.
“At most stations in Calcutta, the average hourly noise levels increased between 1am and 2am, compared with the period from 10pm till 11pm,” said a Union environment department official.
“We received about 40 complaints and the majority of them came after 10pm. It’s a fact that the violations increased post-10pm,” said Kalyan Rudra, chairman of the state pollution control board.
Sabuj Mancha, a green platform, received more than 20 complaints after 10pm.
“Not only fireworks, we saw loudspeakers blaring well after the 10pm deadline set by the government. That contributed to the heightened noise level as well,” said Naba Dutta, secretary of the platform.