Delhi’s rising air pollution may have an invisible Covid link
The pandemic has resulted in reduction in use of public transport, leading to more use of personal vehicles in the national capital. More vehicles on road mean more emissions and with poor dispersal, it leads to higher ambient air pollution levelsUpdated: Oct 16, 2020, 09:17 IST
Environment minister Prakash Javadekar on Thursday said that 95% of Delhi’s present air pollution was because of local sources, triggering a debate on whether the deterioration in air quality could be an indirect consequence of Covid-19 pandemic.
The pandemic has resulted in reduction in use of public transport, leading to more use of personal vehicles in the national capital, like elsewhere in the country. More vehicles on road mean more emissions and with poor dispersal, it leads to higher ambient air pollution levels.
This was evident on Thursday with air pollution in Delhi and its neighbouring towns -- Ghaziabad, Faridabad and Gurugram -- being in the very poor category.
According to the data provided by Delhi Metro Rail Corporation, the Metro ridership in the past fortnight has been 78% of the number of people who took the public transport during the same period last year. Even though the ridership is rising, Metro spokesperson said it would take some months before the passenger level reaches pre-Covid level.
Similarly, the Delhi Transport Corporation, another major public transport mode, has recorded a dip in daily ridership of passengers. Transport minister Kailash Gehlot had said last week that there was about 54% dip in ridership due to Covid-19 restrictions which allows filling only half of the seats.
Even as people are working from homes, traffic on Delhi roads is rising. Data from Google’s community mobility trends shows traffic on Delhi roads was just 30% less than that of the pre-Covid period baseline of January 3 to February 6, this year. In August, this dip was 67% and in April, 80%.
As only limited public transport was available, Delhi witnessed a spike in purchase of vehicles after Covid unlock was implemented from June 8. According to Society for Automobile Manufacturing (SIAM), Delhi has seen an increase of about 10.7% in sale of new passenger vehicle -- cars and two-wheelers -- from the same period last year. The overall vehicle sale increase in August in India was 14.6%. SIAM is yet to release auto sale data for September.
“The pandemic outbreak has changed people’s preferences and we believe they will opt for personal mobility solutions rather than shared mobility,” co-founder and CEO of CarDekho Amit Jain said.
A scientist at Indian Institute of Technology, Kanpur, who was not willing to be quoted, said more vehicles on road is one main reasons for bad air quality in and around Delhi. Most of the pollution load is coming from within and around 70 kms of Delhi, he said.
“Yes, the higher number of vehicles on roads contribute to air pollution but very low wind speed, which causes localised heat islanding, is the main cause for air being foul,” the scientist, who has earlier done pollution source appropriation study for Delhi, said. He said industrial emissions, dust and biomass burning are the other contributors.
Javadekar on Thursday had said that 95% air pollution in Delhi happens because of dust, construction and biomass burning. He said stubble burning this year has contributed only 4-5% to Delhi’s pollution load.
Environment ministry said the share of stubble burning in capital’s pollution load varies on daily basis. In 2019, stubble burning contribution to Delhi’s pollution load was more than 15% only for six days between October 8 and December 9. And, only on one day it was more than 40% in this period, the ministry said, after Raghav Chadha of Aam Aadmi Party claimed that Central had last year claimed that the contribution of stubble burning to Delhi’s pollution was 44%.
Anil Sood, a scientist at Punjab Agriculture University, Ludhiana, who monitors stubble burning through satellite mapping in the state, said that the farm fire incidents recorded between September 21 and October, 2020, were three times more than those in 2019. About 2,900 farm fire incidents were reported this year as compared to 755 in 2019.
He attributed the increase in farm fires to early harvest of paddy this year because of the dry weather in September unlike 2019 when monsoon rains were prevalent till October 12 in northern India, leading to delay in harvest. Sood expected stubble burning to finish by October-end.
However, the IIT scientist predicted said there would be some respite in the next three to four days because of improvement in wind speed. The pollution levels will rise again in the latter part of October and would remain high till Diwali , that falls on November 11, he said.
Anumita Roy Choudhary of Centre for Science and Environment said the impact of Covid-19 on air pollution management has thrown up new challenges for air pollution management. “We cannot intensify public transport as Covid-19 restrictions would remain. We may need to reinforce work from home option to prevent unnecessary travel to cope with winter pollution,” she said.
(With inputs from Vijdan Mohammad Kawoosa in New Delhi)