With the quality of Delhi’s air has again reached critical levels with severe pollution, alarm bells have gone off, and the Delhi government announced it would bring back the “odd-even” scheme, that seems to be turning into an annual ritual. (The plan has been temporarily kept on hold after the National Green Tribunal directed that most of the exemptions be withdrawn, after which the Delhi government suspended its order.) The fact that the second edition of the “odd-even” scheme didn’t bring any reduction in air pollution is something to be noted. In fact, the second time air pollution actually worsened in the first week of the scheme. The “odd-even” scheme may not have been responsible for it, but it highlights how factors other than vehicular emission are more important in determining air quality in Delhi. It’s also important to note that the reduction in vehicle population in the second year was much less because people had developed coping mechanisms like owning a second car that could be second-hand, and therefore even more polluting.

A comprehensive study at IIT Kanpur has found that the major source of Delhi’s pollution is not vehicles but road dust. Meteorological conditions also leave a huge impact. But on average, the four-wheelers covered in the scheme contribute only 10 per cent to total SPM in Delhi’s air. Thus even if there is a 30 per cent reduction in the car population on the roads, the total reduction in pollution will be only three per cent. A TERI study had found that the reduction in vehicle population during the scheme was only 21 per cent. If the odd-even scheme is repeated, the reduction will be even less this time. While initiatives like the “odd-even” scheme created a huge media buzz and hence raised awareness levels in Delhi, we are still missing the big picture. There is a perception that Delhi’s air quality has become bad only in recent years. The fact, however, is quite the opposite. In the 1990s, the annual average SPM-10 level between 1990 and 1998 was 368 micrograms per cubic metre. In comparison, the annual average SPM-10 level in 2007-2015 was at 225.56 micrograms per cubic metre. The comparison has to be made on the SPM-10 level as we don’t have data on SPM-2.5 for earlier years. Hence, there is reasonable ground to believe that the average pollution level has actually decreased over time. But since we don’t have adequate information about SPM-2.5 and how the nature of that may have changed, it is hard to say how the harmfulness of pollutants have changed.

The relocation of industries away from Delhi and the introduction of CNG buses may have been partially responsible for this, but what’s more important to note is that Delhi’s poor air quality isn’t not just a recent problem but a historical one. Another important aspect of air pollution in Delhi is that it’s not a local problem. Air pollution, particularly in the winter months, has been a problem throughout the nation’s northern and eastern cities. Hence, it’s quite clear that it will be extremely difficult to reduce air pollution only by taking action in one or two cities. We need coordinated steps across the whole of northern and eastern India. Adopting an “odd-even” scheme is the easiest that the government can do as it doesn’t require much effort by it. But curbing pollution will require sustained efforts on several fronts over a long period. We haven’t seen too many efforts in that direction. The “odd-even” type of initiative also gives us a false sense of accomplishment, but there will be little change in the situation on the ground. The question is — what steps can be taken to make a real difference. Every morning a huge army of municipal workers get on to the roads with huge brooms in their hands, which is the first onslaught of the day on the air quality. People in rural areas know this and hence, in many villages, they sprinkle water before sweeping with brooms. Before Independence, the municipal authorities used to wash roads with water on a regular basis in cities like Delhi and Kolkata. Last year, the Delhi government declared it would vacuum clean roads. However, there has been little progress in that direction.

In Western cities, the soil has been covered either with paved tracks or with greenery. Delhi has a good number of trees, yet vast stretches are simply bare soil. In many places, footpaths haven’t been built, elsewhere they are not maintained well. Stretches of land that are meant to be kept aside for small plants are now bare soil, which generate dust. Bikes and sometimes even cars running through muddy stretches are a common sight in Delhi. In many parks, there is hardly any grass and children play on the bare soil. Maintaining green cover (not just trees, but also grass and small plants) is a big challenge in Delhi due to the shortage of water. It might not be feasible to wash roads as was done in the British era due to shortage of water, but efforts must be made to maintain the green cover. It is important to explore if there are varieties of grass and plants that survive with little water. Delhi has not been able to treat its sewage properly. It would be worthwhile to explore if the city can put in place decentralised sewage treatment plants at ward levels and the recycled water can be used to maintain green cover. Municipal workers responsible for sweeping can be trained to maintain the green cover. The revival of the Yamuna river is also of utmost importance.

On roads which have no footpaths the government must build them. We also need design innovation so that the soil is not exposed, yet groundwater can be recharged. This will not only help pedestrians, but will also prevent vehicles from running over unpaved portions of roads and generating dust. One can see in several parts of Delhi that new footpaths made or renovated just prior to the Commonwealth Games are being dismantled even if they are in excellent condition, to make them once again. Resources thus don’t seem to be a problem. As far as construction is concerned, which is also a major source of pollution, the government must adopt an appropriate policy to use prefabricated materials not only in infrastructure projects like the Metro and flyovers, but also for buildings. There can be better ways to manage dust at construction sites. Even certain types of construction activities that generate more dust can be suspended during the winter months.

Similar action must be taken in all cities and of course an appropriate policy devised to reduce crop residue burning. However, it must also be noted that air pollution was high in northern India even when crop residue burning was not so widespread. It seems we don’t have a complete understanding of air pollution in northern and eastern India yet, and so more research is needed. As an emergency measure, it is difficult to imagine any action other than water sprinkling, which is also not easy at times. But it appears we haven’t yet initiated long-term measures to tackle the problem as we got overwhelmed by the “odd-even” scheme.