The city woke up to both colours and thick black smoke emanating from the Holika Dahan or bonfires lit on Sunday evening.
Air pollution saw a significant increase between Friday to Monday as the pollutant measuring indicator — air quality index (AQI) — moved from 75, falling under the ‘good’ category, which also happened to be the cleanest air day in 2017 so far, to 315 on Monday, falling under the ‘very poor’ category. AQI levels fell to 313, still under the ‘very poor’ levels by Monday evening. AQI levels between 0-100, falls under the ‘good’ category, 101-200 is ‘moderate’, 201-300 is ‘poor’ and 301-above is ‘very poor’.
When wood and other organic material is burnt, more than one gas is released. Other than carbon dioxide (CO2) and carbon monoxide (CO), chemicals are produced, including one of the most potent greenhouse gases, nitrogen dioxide (NO2).
Eight of 10 locations in Mumbai recorded ‘very poor’ AQI levels with Mazgaon, Bhandup, Chembur and Malad recording the city’s worst air quality. The two locations that recorded marginally cleaner air, but still fell under ‘poor’ levels were – Navi Mumbai and Borivli. The System of Air Quality Weather Forecasting and Research (SAFAR) research records AQI levels across 10 locations in Mumbai.
Mumbai also recorded a sharp drop in night temperatures between Sunday night and Monday morning. The weather station at Santacruz recorded the night temperature at 15.2 degrees Celsius, almost 6 degrees Celsius below normal while Colaba recorded 21 degrees Celsius, 1.5 degree Celsius below normal.
Officials from SAFAR attributed the rise in pollution to open burning cases as an additional factor to already existing meteorological conditions. “Along with weather factors such as low wind speed and low temperatures, the additional factor of open burning led to the sudden rise in air pollution. This is a temporary condition and pollution levels will fall to the ‘moderate’ category by Wednesday,” said Gufran Beig, director, SAFAR.
‘750 Holika fires this year in Mumbai’
Holika Dahan are lit on the eve of Holi, symbolising ‘truth prevailing over evil’. Environmentalists said there were fewer Holika fires this year. “We observed around 750 Holika Dahan bonfires across the eastern and western suburbs, but hardly any were seen in south Mumbai this time,” said Godfrey Pimenta, trustee, Watchdog Foundation.
Environmentalists suggested that bonfires should not be lit in every building and there should be community celebrations. “In the city it makes no sense to have large fires as it will further deplete the already poor air quality. The smaller the fires the better through the idea of one symbolic community bonfire to reduce pollution,” said Stalin D, director, NGO Vanashakti.
South Mumbai residents said that the spike could have also been due to trash burning with the Holika. “We saw one large community bonfire in Malabar Hill but the SAFAR data indicates that additional refuse might have been burnt that further deteriorated the city’s air quality,” said Indrani Malkani, managing trustee, V Citizens Action Network.
Meanwhile, different departments from Brihanmumbai Municipal Corporation (BMC) and Mumbai police were unware about the number of bonfires as permissions are not given by either authority during the festival. “We will conduct a check in terms of tree hacking across the city, which we do after Holi every year. We will take strict action against anybody found cutting trees,” said a senior official from BMC.