Diwali 2017: Air pollution better than in 2016, but spiked after 8 pm when firecrackers started

The concentration of major pollutants went up at night. “Major changes were observed after 8 pm when the fireworks started.

Mallica Joshi

With the Supreme Court imposing a temporary ban on the sale of firecrackers in Delhi and the National Capital Region, air in the city this time was cleaner on 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 done 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… attribute to 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.

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 through home delivery and 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 that on 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 at a very high 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 the 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.