Mumbai’s Diwali status: Loud and unclear
City records worst Diwali air quality in three years, while noise levels were much higher compared to last yearUpdated: Oct 22, 2017 01:01 IST
The city woke up to a smog-laden sky on Friday as it recorded its worst post-Diwali air in three years. However, the air quality improved significantly on Saturday as a result of the dispersion of pollutants accumulated by firecrackers.
The level of tiny particulate matter — small particles predominantly a part of dust 10 microns in size that can penetrate deeper into the lungs and enter the bloodstream — were five times the safe limit at 487 microgrammes a cubic metre (µg/m3) throughout Friday as against the permissible levels of 100µg/m3, according to the National Air Quality Index recorded by the Central Pollution Control Board (CPCB) for Mumbai.
The pollutant measuring indicator – air quality index (AQI) — recorded by the System of Air Quality Weather Forecasting and Research (SAFAR) was 316 (very poor) on Friday morning that increased to 319 (very poor) by the evening. While the city recorded relatively cleaner air on Diwali day compared to the past two years with an AQI of 204, 319 on Friday was the worst since 2015 for the day after Diwali.
Mumbai recorded high pollution levels last Diwali (October 30, 2016), with an AQI of 278 (poor) on Diwali day and 315 (very poor) the day after.
In 2015, the city recorded an AQI of 279 (poor) on Diwali day (November 11) and 313 (very poor) the day after.
On Saturday, the city recorded an AQI of 190 (moderate) and SAFAR predicted 176 (moderate) for Sunday.
The CPCB also released 24-hour average AQI levels for the Mumbai Metropolitan Region between Thursday and Friday with Mumbai recording 249 (poor – prominent pollutant PM10), Navi Mumbai recording 100 (satisfactory – PM10 prominent pollutant), and Thane recording 332 (very poor – prominent pollutant ozone).
AQI level from 0-50 is considered good, 51-100 is satisfactory, 101-200 is moderate, 201-300 is poor, 301-400 is very poor, and 401 and above is severe. The post-Diwali AQI levels in Diwali were ‘severe’ at 500+, Pune with ‘very poor’ AQI at 314 and 340 ‘very poor’ at Ahmedabad.
Researchers said air pollution built up rapidly in the city’s air between Thursday and Friday owing to three factors. “The wind direction over the city changed from sea breeze to warm air from the land leading to pollutants getting stagnated in the city’s air. The wind speed also became slow thereby allowing pollutants to be suspended longer. There was rapid increase in local emissions owing to firecrackers suddenly since October 18, leading to hazy conditions,” said Gufran Beig, project director, SAFAR. “On Saturday morning, the emission load from crackers reduced significantly and air quality is likely to remain in moderate category till Monday.”
He added that the share of toxic PM2.5 (smaller particles of the size 2.5 microns that can enter our respiratory system fast and easy) in PM10 was high confirming that emissions were indeed s result of maximum fire cracker use. “Winds are expected to remain south-easterly (warm and calm) until Sunday leading to poor air quality and cleanup thereafter,” he said.
On Diwali day (October 19) PM2.5 concentration was found to be 99.4µg/m³, falling under the ‘poor’ category and post Diwali day (October 20) PM2.5 concentration was 143.1µg/m³, which was ‘very poor’ .The safe limit for PM2.5 is 60µg/m³. The highest levels of PM2.5 were observed between 10pm Thursday and 3am Friday.
Officials from CPCB said while Mumbai fared far better than other megacities with similar population, the weather factors did not favour a cleansing of Mumbai’s air a day after the festival. “The indication that PM10 levels are significantly high is an indicator of high vehicular pollution combined with external combustion from firecrackers. If we take a conscious decision to not burst crackers in coming years, it will strongly help improve Mumbai’s air quality,” said D Saha, additional director, CPCB.
Doctors said if people with existing respiratory issues with discomfort post Diwali should visit their nearest doctor immediately. “The smog settled in the city’s air is dangerous as the tiny particles can aggravate already existing lung problems. Even if there allergic symptoms such as redness of eyes and nose, an immediate visit to your physician is necessary,” said Dr Sanjeev Mehta, pulmonologist, Lilavati Hospital in Bandra.
Crackers burst well beyond 10pm time limit
Noise levels were much higher this Diwali than last year with the highest decibel (dB) level at 117.8dB, almost as loud as a thunderclap, at Marine Drive at 11.30pm, according to NGO Awaaz Foundation.
Last year, noise levels were at 113.5dB. However, in 2013 and 2015, levels were as high as 124dB and 123.1dB.
Anti-noise campaigners said that while there were not too many people bursting crackers on Thursday night, festivities went on till 1am at some locations and throughout the night till early Friday morning at other locations in the city, even with police presence.
According to noise rules, the extension for noise limits on Diwali is only for loudspeakers till 12am, and not firecrackers, which are allowed only till 10pm.
“The trend of reducing noise pollution over the past several years continued in Mumbai this year, although peak decibel levels beyond 10pm increased from last year,” said Sumaira Abdulali, convener, Awaaz Foundation.
She added that up to 10pm, there was very little cracker use. “Post 10pm there was an increased use of noisy crackers at Marine Drive, and noise levels were near constantly more than 100dB. The noisy crackers used were mostly anars with added crackling sound, and exploding aerial crackers. There were very few atom or serial bombs used this year,” she said. “Peak noise levels continued until the police substantially shut down firecracker use by about 12.30 am, although stray violations continued.”
Citizens took to social media portals to file complaints with the Mumbai police about firecracker noise till 5am Friday.
The Mumbai police twitter handle had several complaints from Worli, Parel, Bandra, Andheri, Kandivli, Dahisar, Powai and a few areas along the eastern suburbs that noisy crackers were being burst through the night.
“There is no issue that people burst crackers till 10pm. The problem we face is that at various areas within the city surrounded by buildings and flyovers, the noise echoes, making it louder than it already is. My family could not sleep till 3am until three police complaints ensured that the crackers were stopped,” said Raju Patankar, Lower Parel resident.
Officials from Mumbai police said they did receive complaints but there were no major violations on Thursday night. “All complaints were dealt with in less than half an hour. We had our staff patrolling all promenades and within city limits, stopping people from bursting crackers post 10pm. Celebrations were much quieter than previous years,” said Deepak Deoraj, deputy commissioner of police (operations) and Mumbai police spokesperson.
Abdulali added that rather than banning crackers, the state government needs to ensure that the Controller of Explosives in Nagpur identifies that decibel levels on each cracker post noise monitoring by the state pollution control board. “This will set a precedent for not only Mumbai but the entire country to celebrate the festival responsibly and avoid crackers that are either too loud or have dangerous chemicals in them,” she said.