Not surprisingly, given the spurt in pollution in Delhi around Diwali, the Supreme Court (SC) has banned the sale of crackers in the Delhi-NCR area. But, apart from the fact that the ban will be difficult to enforce—there is no ban on bursting crackers purchased from outside Delhi-NCR or stocked from an earlier period—it is not clear what the plan to clean up the capital’s air is since it is not just around Diwali that it gets unbreathable. In just the last week, for instance, PM2.5 levels have shot up from 159 micrograms per cubic meter to 277, and this is despite no crackers being burst so far—with the safe level at 60 micrograms, it shows just how bad the situation is in even ‘normal’ times. According to the IIT Kanpur report on Delhi that analyses data over 2013-15, while PM2.5 levels can shoot up to 600-700 micrograms around Diwali, they averaged around 375 micrograms in winter, and a lower, but still very dangerous, level of 300 micrograms in summer.
On Diwali day in 2013, the IIT report points out, PM2.5 levels crossed 600 micrograms at the Rohini monitoring station but they fell to around 350 the very next day—after many days of ups and downs, they crossed 700 micrograms on November 23. The Okhla monitoring station recorded PM2.5 levels of 900 on Diwali on November 3, 2013, but a dramatic fall to 300 the day after and a rise to 700 on November 22. If this makes it clear a Diwali crackdown is of little help, PM2.5 levels rose to 600 on April 23, 2014 at the Rohini station and to 650 on April 8 at Okhla. The obvious question that arises is that if banning crackers in Diwali can solve the problem for a few days in that month, what is the solution in April or in other months when pollution levels are intolerable and many times more than the permissible levels?
Any solution to Delhi’s pollution problem has to centre around what causes the pollution and to understand that what happened one year need not necessarily happen the next. With Diwali coming earlier this year and the temperatures not dipping significantly, for instance, things could be better this year. But, more important, as the IIT-Kanpur report points out, a fourth of Delhi’s PM2.5 levels in winter are due to burning of crop stubble in neighbouring states like Haryana and Punjab while vehicular pollution and road dust add to another 24%; secondary particles contribute to another 30%. Little or no meaningful action has been taken to ensure there is no burning of stubble since this has to be done by Haryana and Punjab, the Delhi government has made little progress in mechanical cleaning of roads and DTC continues to be starved of buses—this is critical if vehicular pollution has to be tackled. Unless a solution takes care of all facets, it is unlikely to achieve much. Indeed, when the Delhi government started its odd-even plan to stop cars from plying on roads, it didn’t take into account the fact that trucks caused half of the pollution caused by vehicles or that, with poor quality fuel and engines, and their vastly higher numbers—Delhi had 1.8 lakh cars versus 3.8 lakh scooters when odd/even was introduced—two-wheelers contributed more to emissions; the SC ban on diesel vehicles with an engine capacity of over 2,000cc was of a similar piece, since the number of such vehicles was quite limited. The cracker ban will provide some respite on Diwali, but nothing more than that.