The Capital has over 8.9 million registered vehicles and another 50,000 commercial vehicles enter the city’s borders each night.

A two-year analysis, submitted by IIT Kanpur to the Delhi government, identified the major contributors to the city’s pollution levels. Vehicular emissions were found to be among the top two contributors.

According to the report, pollution from vehicles grew from 64% to 72% between 1990 and 2000. During the winter season, on an average vehicles contribute up to 25% of PM2.5 and at certain locations this could be above 35%.

In winters, 46% particulate emissions (PM10) were attributed to trucks and 33% to two wheelers. Four wheelers trailed behind at 10%, followed by buses (5%) and light commercial vehicles (4%), the study found. More than a third (38%) of the small particulate matter (PM2.5) not visible to the naked eye was contributed by road dust, while 20% was from vehicular emissions.

“Small particles are the most dangerous as they enter the walls of lungs and clog it. This causes severe respiratory problems and other degenerative diseases,” said Dr Anant Mohan, lungs specialist, AIIMS.

What next

To reduce vehicular pollution the government has taken measures such as introduction of BS-VI standards for fuel by 2020. This will cut down diesel vehicle emissions to petrol levels for all pollutants and slash 55% of the particulate matter and 47% of nitrous oxide emissions. Besides this, initiatives are also being taken to encourage the market of e-vehicles in the city.

However, this not enough to control vehicular emission.

“Just giving subsidies on e-vehicles will not help. The government first needs to provide proper infrastructure. I have two electricity driven cars but I think twice before taking them out for long rides. There are no charging points anywhere in the city and I have to rely on personalised charging kits which I got along with the car,” said Sunil Kumar Dahiya, a pilot with a private airline who has been using e-cars for the past two years now.

AnumitaRoychowdhury, executive director, Centre for Science and Environment (CSE), said vehicular emission has remained a significant source of pollution in the city and the government’s odd-even road rationing scheme and orders to limit the registration of diesel vehicles have proved this.

“The government needs to proactively work on a comprehensive policy package that includes phasing in a policy of obsolescence for vehicles, congestion fees, expansion and integration of public transport. Measures have been taken, but we need to keep up the momentum and encourage public participation,” Roychowdhury said.

In 2013, Dr SarathGuttikunda published a study on environment according to which vehicular emissions contributed 90%, 54% and 33% to Nitrogen Oxide (NOx), suspended particulate matter and sulphur dioxide (SO2) emission, respectively.

In the same year, a study led by Dr Pramila Goyal of IIT-Delhi’s Centre for Atmospheric Studies flagged emissions from two wheelers as a ‘matter of concern’. Two wheelers contribute between 40% and 60% of the total pollution from vehicles, the study said. It identified Heavy Commercial Vehicles (HCVs) to be the major contributors to particulates (92%).

Market trends also show the city’s heavy reliance on private vehicles. Last year, Delhi recorded a 9.5% increase in the sale of cars, excluding the luxury segment.

“Only a good public transport system can reduce people’s dependence on private vehicles. If we do not provide them a comfortable, cheap and well-connected alternative, it will be unfair to expect people to not use their cars,” said PK Sarkar, head of department (transport planning) at the School of Planning and Architecture. “As the dependence on private vehicles increases, the air pollution levels will become more uncontrollable.”