An advocacy body on environment has found a dramatic reduction in the exposure levels to particulate pollution on the stretch from Red Fort to India Gate during the Car- Free Day rally held on Thursday. 

The Centre for Science and Environment (CSE) said that pollution levels were 60 per cent lower than the levels observed in the same place at the same time on Wednesday. 

This observed reduction is further supported by the city-wide official ambient monitoring done by the Delhi Pollution Control Committee (DPCC) as it has shown an overall drop of 45 per cent in PM 2.5 level in the city due to low traffic on the national holiday of Dusshera. 

By implementing Car-Free Day, the Delhi government has proven that reducing car numbers can significantly bring down pollution in a city. 

CSE executive director Anumita Roychowdhury said, "This initiative of the Delhi government has only helped to prove how the growing car numbers in Delhi aggravate toxic pollution; if these numbers are controlled, pollution can be lowered significantly. Though this event has been planned for one road stretch a day every month to help build public awareness, this will need simultaneous action to restrain car usage on a daily basis for the real change. Otherwise, this will get reduced to only a symbolic gesture. Restraint on cars can help to save lives and protect the lungs of our children." 

The CSE carried out real time exposure monitoring on the stretch from Red Fort to India Gate that was earmarked for the half-day car-free event. This monitoring is different from the ambient monitoring that the government does. 

Exposure monitoring captures the pollution on road and roadside that is influenced by the direct emissions from vehicles within our breathing zone.This is normally higher than the ambient level. The exposure monitoring on the road was carried out by CSE first on 21 October — a regular day — and during the car-free event on 22 October. 

As per the research, on 21 October when the road stretch from Red Fort and India Gate had high traffic volumes, the PM10 level was as high as 750 microgramme per cubic metre (cu m) and the PM2.5 level was 689 microgramme per cu m.This was three times higher than the average ambient PM2.5 level in the city. On the other hand, there was dramatic drop in pollution exposure level – as much as 60 per cent on 22 October. The PM10 level was 310 microgramme per cu m and PM2.5 level was 265 microgramme per cu m. 

Besides, the official monitoring also showed higher pollution in the morning hours than in the noon. In the morning, the hourly average of PM2.5 level was 384 microgramme per cu m. But by noon it dropped to 148 microgramme per cu m – as much as 61 per cent drop. 

The CSE, said in its report that, "The number of cars should be restrained to make Delhi pollution and congestion free. Delhi has much more cars per 1000 people than some of the wealthiest cities in the world that have adopted car restraint policies. Delhi has 157 cars per 1000 people where as Singapore has 38 cars per 1000 people and Hong Kong only 25.What will happen when as per the slogan of the ruling government of Delhi each household will own and use one car?" 

"While a public event like Car-Free Day once a month can help build public awareness about the perils of car dependency and the need for car restraints, the real change is possible only if this is leveraged immediately to implement the urgent measures of providing alternative to cars and actively discouraging car usage on a daily basis. Globally cities are adopting parking policy for restraint, congestion and road pricing, capping of cars, restricting cars in congested and low emission zones to fight pollution congestion and energy guzzling," the report reads. 

The CSE stressed upon the immediate measures to be taken and urged to scale up integrated public transport system, safe walking and cycling, limit legal parking and make parking more expensive. It asked to ‘impose high taxes on cars besides restricting car movement in congested parts’. It also urges to prepare pollution emergency plan for the coming winter.