Pollution in Delhi: Why Diwali is just a part of the problem

NEW DELHI: It's around this time every year that air quality in the capital and its adjoining areas starts plunging -due to the onset of winter, coupled with crop burning in Punjab and Haryana and bursting of firecrackers on Diwali. Several experts have welcomed the Supreme Court's move to impose a fresh ban on sale of firecrackers in DelhiNCR. They have a reason to: Pollution worsened considerably in the last fortnight, with PM2.5 levels rising by up to 11 times between September 22 and October 8. This is primarily because of crop burning in Haryana and Punjab, which shot up considerably in the last two weeks. Weather has played its part, too. On most days of October so far, winds have been blowing from north to southeast, bringing haze and toxins into Delhi. Data from last three years showed air quality worsened on Diwali and the day after -it was especially bad last year (see graphic).

Last year, air quality was in the “severe“ category in the festive season, according to the System of Air Quality and Weather Forecasting and Research, with an AQI of 443 on October 30 (Diwali day). It shot up to 472 the next day , before dropping slightly -recording an AQI of 392 on November 1. PM2.5 levels, meanwhile, touched 302 micro grams per cubic metre on Diwali - five times the safe standard and 624 (10 times the safe standard) on October 31.



Dr Ajay Mathur, director general, TERI, told TOI: “This (the ban) will play a crucial role in regulating air pollution and reduce the impact on human health. The ban would ensure that levels of air pollutants don't reach as high a limit as they did last year around Diwali. With meteorological conditions not being favourable for dispersing dust and particulate matter in a short interval, the regulation is a step in the right direction.“ While SC had imposed a similar ban last year, experts felt its implementation remained a problem. The court has also said the impact last year could not be observed properly and directed “a competent authority to assess and compute the impact of a noise and smoke-free Diwali this year“.

Voicing cautious optimism, Greenpeace India said in a statement: “We appreciate the SC decision, as this may give some relief from the episodic air pollution levels in October. However, pollution levels in north India are multiple times higher than the national standard throughout winter. Hence, we need to look at a stricter, comprehensive and time-bound action plan to address all sources of air pollution across India.“

Among the stations where air pollution levels were monitored, Anand Vihar was the worst-hit last Diwali with PM2.5 touching 440 gm3 on October 30 -seven times the safe standard for PM2.5. Punjabi Bagh showed PM2.5 at 402gm3 even as Civil Lines touched 398gm3 -all this against a safe standard of 60gm3.