Step out on to the road and the first thing you are greeted with is the traffic snarls. What hits you next is the smoke and pollution, leaving you groping for a piece of cloth to cover your nose, shut out those fumes.

Urban air pollution has become a serious concern to both citizens and planners given its direct impact on health and indirect contribution to green house gas effect. Unfortunately, economic development has a direct proportion to pollution, each moving in the same direction. 

Indian mega cities are listed among highly polluted cities in the world.  Available air quality data shows that particulate matter is of concern in many Indian cities. According to WHO estimates, as many as 1.4 billion urban residents in the world breathe air that fails to meet WHO air quality guidelines.

Steps to be taken

Pollution levels increase further when older models of cars continue to ply, besides the two-stroke engine two and three wheelers. While the age and technology incorporated in the automobile has a bearing on the level of pollution, the manner of driving too has a significant impact on the quantum generated. For instance, frequent slowing down and stopping, pot-holed roads can increase the level of pollution. In fact, the presence of bad roads significantly increases the level of pollutants in the ambient air. 

While it may not be possible to completely remove pollutants from the air, steps that are feasible and can be easily implemented need to be taken to bring the level down to permissible limits. Few such measures which can reduce vehicular pollution are improvement in the fuel quality, better technology, traffic management etc. 
Over the last decade, various policies of the government have been effective in addressing fuel, like the introduction of unleaded petrol has resulted in reduction of lead content in the ambient air. Four stroke engines in two and three wheelers will check pollution as a four stroke engine has lower emission levels. A two stroke engine motorcycle consumes 30 percent more fuel as compared to  a four stroke engine. Its emission level amounts to 1.0 gram per passenger kilometre as against 0.2 gram for a four stroke engine. When viewed against the number of two and three wheelers plying our roads, the potential reduction in pollution is sizeable. 

The introduction of alternate fuels like CNG and LPG for public transport is a positive step. This is especially so as the emission from diesel exhaust has high levels of particulate matter. Currently, lack of sufficient availability of this alternate fuel is acting as a deterrent for wider adoption.

Traffic management

While good roads, strict emission standards, better technology and alternate fuels would help reduce pollution levels from automobiles, there is also an urgent need for better traffic management to prevent congestion. This can be achieved through incentives and disincentives besides increasing awareness among public. 

Steps like mandatory school buses, staggering of timings for offices and schools, car pooling, encouraging the use of public transport, would go a long way in achieving this objective. However, for any of these measures to be successful, an efficient public transport is imperative. In fact the most effective way to control pollution would be to opt for integrated, efficient pubic transport system. Singapore, Hong Kong and Tokyo are forerunners in this sphere. 

Besides measures to decongest traffic, steps like fuel switching can be adopted and this can be done in two ways—with fixed clean technology and with accelerated clean technology. 

In the absence of adequate measures to control pollution, it is estimated that  NO2 and SO2 emission levels will be three times 1990 emission levels by 2030 in the Asia Pacific region. In the light of accelerated clean technologies being introduced, this is expected to be lower, registering a 6 percent and 60 percent increase respectively over 1990 levels. However, if efficient public transport is combined with this, a sharp fall is estimated, with respective emission levels of SO2 and NO2 registering only 1.5 percent and 45 percent increase over 1990 levels. 

Dr Uma Rajarathnam

(The author is Head- Environment Practice, Enzen Global Solutions, an energy and environment consulting firm.)