With the Supreme Court imposing a temporary ban on the sale of firecrackers in Delhi and the National Capital Region, air in the city was cleaner this Diwali and the day after compared to 2016 although the level of major pollutants remained far above permissible limits, according to data released by the Central Pollution Control Board (CPCB) and the Delhi Pollution Control Committee (DPCC).
According to a post-Diwali analysis by DPCC, which collected data from 16 stations across Delhi, the concentration of Particulate Matter (PM) was lesser as compared to last year (see box).
According to air quality data, the concentration of major pollutants went up at night. “Major changes were observed after 8 pm when the fireworks started. Ambient Air Quality in Delhi was already in the ‘poor’ category due to accumulated pollutants,” the Delhi government’s environment department said in a statement.
“The cumulative effect of existing pollution load and pollutants released due to use of fireworks as well as meteorological conditions… (had an) impact on ambient air quality during Diwali. However the ranges of concentration of PM 10 and PM 2.5 at 1 pm Friday has shown improvement,” it said.
Union Minister of Environment Dr Harsh Vardhan said air quality in Delhi was better than last year. He said, “The number of ‘good’, ‘satisfactory’ and ‘moderate’ days has increased and ‘poor’ and ‘very poor’ category has reduced significantly compared to 2016.”
Vardhan said that he had held meetings with officers from Haryana and UP on stubble-burning and that added efforts were being made to “provide farmers with an alternative to burning, so that they can create wealth from waste.”
On October 9, the Supreme Court had banned the sale of fireworks in Delhi-NCR to help regulate air pollution levels and assess the impact on air quality. However, the ban was flouted by several traders, with many selling fireworks online and through middlemen. The sale is banned till November 1 and the comparative reports will be analysed by the court.
According to CPCB data, the air quality on the day after Diwali was also better this year as compared to the last. The air quality index on Friday was 403 as compared to Diwali day (October 31) last year when it was 445. Both, however, fall under the “severe” category and the air remained heavily polluted throughout the day.
At India Gate, the PM 2.5 value at 10 am was 985 micrograms per cubic metre, according to the DPCC’s real-time readings, putting the air in the “severely polluted” category. The level of pollutants was more than 16 times the permissible limits before dipping to 169 micrograms per cubic metre by 5.30 pm.
According to System of Air Quality and Weather Forecasting and Research, air quality will be in the “severe” category even on Saturday when the PM 2.5 levels are expected to be 318 micrograms per cubic metre. PM 10 concentration is expected to be 476 micrograms per cubic metre.
Anumita Roychowdhury, Centre for Science and Environment, said that only a long-term plan can ensure cleaner air. “It is clear that the Delhi-NCR region requires a longer-term and systemic action than a one-off ban,” she said.
“The Supreme Court has already ordered a phase-down strategy with the help of regulation of chemicals, standards, reduced quantum of crackers, controlled bursting of crackers through community events, locational controls, etc. This must be implemented without delay for a longer term solution to the problem,” said Roychowdhury.
“A comprehensive action plan must combine short and long term strategies for vehicles, industry, waste burning and construction activities for more sustained and longer term gains,” she said.
Of the 16 stations monitored by DPCC, data from RK Puram, Mandir Marg, Punjabi Bagh, Civil Lines and Anand Vihar was analysed last year as well. Eleven other stations, including Jawaharlal Nehru Stadium, Major Dhyanchand National Stadium, PGDAV College (Sriniwaspuri), DITE Okhla and Mother Dairy (Patparganj), were added this year.
According to CPCB data, while Diwali day this year was less polluted as compared to last year, the month of October has seen more pollution: the average air quality index, which was 230 in October 2016, rose to 235 this time (till October 19). The CPCB said in a statement that weather conditions this year were worse than last year, which aided the accumulation of pollutants.