During the first week of November, Delhi went under a thick blanket of smog. The breeze nearly stopped, and the skies turned grey and dank. Cool and calm weather led to fumes settling close to the ground. People held masks, scarves or handkerchiefs to their faces. The resultant outcry in the smog-hit city had officials stubbornly insisting that this was nothing new and that it happened every winter.
The new twist came from the NASA snapshots of smoke billowing in from agricultural fires in neighbouring Punjab. This triggered a blame game: who is behind the smog -- Delhi's vehicles or errant farmers' smoke?
Smog, after all, is not uncommon in winters. The cool air closer to the ground is denser, does not rise, and so stays trapped with pollutants. What is uncommon this time is the pollution level in the city and the way it has climbed up. What's going on?
This year's smog has been particularly severe because overall pollution levels in the city have gone up manifold - the tiny particle less than 10 micron size (PM10) that goes deep inside the lungs has increased by 47 per cent between 2000 and 2011. Its levels have exceeded the standards by six to eight times. Nitrogen dioxide, the respiratory assaulter, has gone up by 57 per cent. High exposure to such killer particles increases hospitalisation for asthma, lung diseases, chronic bronchitis and heart damage. Long-term exposure can cause lung cancer.
Delhi is facing a multi-pollutant crisis. The toxic cocktail of particulate matter, nitrogen dioxide, carbon monoxide, ozone and benzene is playing havoc, as per official monitoring. Some of these come predominantly from vehicles. In fact, daily pollution peaks strongly correlate with peak traffic hours and truck movement in the city.
The air shed is already so saturated that it has no room left for more pollution. This even dimmed the festivities of Diwali that came close on heels of the smog episode. Fumes from crackers added to the woes.
The city cannot dismiss winter smog as routine. Delhi has lost its air quality gains from the first phase of action that included natural gas vehicle programme, age cap on old commercial vehicles, some improvement in emissions standards and fuel quality among others. The smog now occurs more frequently and with greater intensity as the pollution is rising. This is further spiked by the trans-boundary movement of pollution.
The smog episode has spurred Delhi Chief Minister Sheila Dikshit to look at remedial measures. A second generation action plan, already under preparation for over seven months now, will be finalised and implemented soon. Alongside, emergency measures have also been identified for immediate effect. These include stringent action and penalty on polluting vehicles, stopping trucks that have no business in the city, penal action on garbage and leaf burning, no generator sets in public and social events and health alerts during smog episodes.
The Chief Justice of the Supreme Court has also reacted to the situation. The Supreme Court-appointed Environment Pollution (Prevention and Control) Authority has held dialogues with the neighbouring states of Punjab and Haryana to address regional pollution concerns.
Controls on vehicle numbers and diesel are urgently needed, but Delhi is taking a long time to scale up its public transport system.
In other parts of the world, governments issue warnings and take stronger pollution emergency measures during such severe pollution episodes. Paris authorities advise drivers to postpone trips to the city or bypass it, use public transport or resort to car-pooling; other measures include minimizing combustion of high-sulphur fuels in industry and curtailing industrial operations.
In Mexico, phase 1 pollution alert requires cutting down of 30-40 per cent of industrial pollution; stopping 50 per cent of government-owned vehicles and polluting vehicles from plying; exempting alternative fuel vehicles from restrictions. In phase 2 alert, schools are closed, and one-day-a-week ban on vehicles is extended to two days. In phase 3 alert, industries are closed down.
In Berlin, older polluting vehicles are not allowed in the city centre.
During the 1940s and 50s, the Western world had experienced severe pollution episodes in winter. But the infamous London Smog (that had killed 4,000 people in a week in December 1952) and other similar events are now a matter of the past -- simply because of aggressive policy action to control pollution. Delhi can also do this.
(Anumita Roychowdhury is executive director-research and advocacy, Centre for Science and Environment, New Delhi)