After a dip in 2012, noise levels have spiked on Diwali. This year was no different, but the spike was steeper. In 2012, noise levels had dipped by 6-8 decibels (dB) in all CPCB monitoring stations except ITO. Thereafter, levels rose by 2-3 dB every year. This year, the jump was to the tune of 6 to 8 dB.
These levels recorded by CPCB indicate the 24-hour averages on Diwali. Experts say they do not account for real-time peaks in noise pollution during the hours firecrackers are burst.
CPCB scientists said noise pollution this Diwali was largely linked to firecrackers, and not vehicles unlike previous years. In 2014, the CPCB had noted that the overall increased impact of noise level was mostly due to pre-Diwali plying of a large number of vehicles.
Dr Dipankar Saha, head of CPCB’s air lab, said, “In general, there was increase in ambient noise level due to bursting of firecrackers. Fewer vehicles came out this year on Diwali so levels of vehicular pollutants remained within safe limits. Scientifically, to get a real picture of the noise pollution, the positioning of the monitoring unit should not be very close to the source to get a true picture of ambient noise levels.”
In 2014, noise levels had increased in five monitoring stations on Diwali. Mayur Vihar and Kamla Nagar at 83 and 81 dB saw the highest noise levels. These two locations have seen the highest noise levels since 2013. This year, the two stations again reported the highest levels, jumping to 86 dB at night.
According to CPCB, the noise levels increased on Diwali night at all locations except Delhi Technological University at Bawana. The standard “safe” noise level ranges should be around 55 to 60 dB.
The monitoring by CPCB shows noise levels ranged from 65 to 72 dB at night at 10 monitoring stations and between 65 and 73 dB in the morning. Incidentally, the ITO, Pragati Maidan monitoring station, located at a traffic intersection, saw noise levels drop by 5 dB. It had seen a four dB spike in 2014.
Delhi government’s environment department authorities, based on data collected from the Delhi Pollution Control Committee (DPCC), said there was scope for “further improvement”.