City chirpier as sound of birds replaces honking

NEW DELHI: For nearly a month, there’s been no honking, no whirr of vehicular engines, no echo of loudspeakers and no clanking of machinery in factories. For nearly a month since the lockdown was clamped, Delhiites have been waking up to the chirping of birds.Like the now clear water of the Yamuna and the clean air of the city, Delhi’s noise pollution has drastically fallen, thanks to closed factories, mostly empty roads and an absence of commercial events.Prashant Gargava, member secretary of Central Pollution Control Board (CPCB), the apex body for measuring noise pollution across the country, says it is carrying an analysis on pollution levels during the lockdown, results for which are likely to be shared soon.While the diurnal decibel level limit in residential areas in normal times is set at 55 dB(A) and 45 at night, chances are the current figures range between just 30 and 40. “The chirping of birds measures around 40-50 decibels,” Pravesh Biyani of IIIT-D, which is conducting a study, says, “When the surround sound is lower than that of the chirping, people get to hear the birds.”A senior Delhi Pollution Control Committee (DPCC) official says the drop in noise pollution has been significant. DPCC, too, will study the current data.CPCB and DPCC have five noise monitoring stations each. These cover industrial, residential and commercial locations like Anand Vihar, Civil Lines, Punjabi Bagh Mandir Marg , RK Puram, ITO, East Arjun Nagar, Dilshad Garden, Bawana and Dwarka.In a recent submission to the National Green Tribunal , DPCC analysed noise pollution levels between April and October 2019 from its five stations, with Anand Vihar recording the highest average day-time and night-time noise levels. The highest was recorded at 65.7 dB(A) in October.The lowest average day-time reading was recorded at Punjabi Bagh in June 2019 at 55 dB(A), while the lowest night-time average was recorded at Mandir Marg in June 2019 at 49.1 dB(A).For industrial areas, the standard is 75 dB(A) during the day and 70dB (A) at night time. Anumita Roy Chowdhury, executive director, Research and Policy at the Centre for Science and Environment (CSE) says the impact is being seen most across industrial areas and traffic hotspots. “Busy roads which would constantly get noise pollution from horns and vehicles driving by are completely quiet now. Industries too which have shut down during the lockdown, meaning noise pollution there is extremely low as well,” said Chowdhury.A study by Indraprastha Institute of Information Technology (IIIT) Delhi carried out recently had found that honking of vehicles is a bigger noise polluter than firecrackers with decibel levels going up to 100 db(A) and higher. The study was conducted by Biyani, assistant professor with Electronic and Communication (ECE), department of IIIT-D. Noise pollution was measured on eight prominent roads and 12 intersections of the city, including Anand Vihar, IP Extension, Govindpuri metro station, Maharani Bagh, Dwarka Sector 10 and Connaught Place.Biyani said the Govindpuri Metro station area, which had sound decibels of around 100 daily, “has now reduced to around 50-60 decibels due to the less number of vehicles on the road.”Dr Faiyaz Khudsar, scientist in-charge at Yamuna Biodiversity Park (YBP) says noise levels above 20 dB(A) are known to disturb birds. However, with reduced human activity and noise, their chirping is being heard clearly now.