Delhi Suffocates in Smog, ‘Severe’ AQI; Is it Stubble Burning or Vehicular Emissions?

The share of stubble burning in Delhi's PM2.5 pollution jumped to 38% on Thursday, which, experts said was the reason behind the thick layer of pungent smog over the national capital.

Delhi's air quality slipped back into the "severe" zone Thursday morning, according to Central Pollution Control Board data, amid raging farm fires and stagnant conditions at night. The overall air quality index stood at 419 at 9 am. 

The increase in stubble burning has kicked off a political slugfest, with Union Environment Minister Bhupender Yadav, and AAP leader and Delhi Chief Minister Arvind Kejriwal blaming each other for the rising incidents of stubble burning in Punjab.

Gufran Beig, founder project director, SAFAR, a forecasting agency under the Ministry of Earth Sciences, noted that the rise in the share of stubble burning in Delhi's pollution is “quite significant."  The air pollution situation is the worst in Noida which falls into the path of emissions being transported from stubble burning, he said. 

However, there seem to be indications that there is a disproportionate emphasis on the role of stubble burning in Delhi’s continued air pollution crisis.

Around 53% of the Delhi-NCR residents identify stubble burning in neighbouring states as the "primary cause" of rising levels of air pollution, according to a survey. The survey conducted by LocalCircles is based on responses from 20,000 citizens.  

The data breakup shows that a much smaller percentage or 13% believe the primary cause is "motor vehicle emissions", while 7% of the respondents blamed it on "garbage burning in the city".  Around 7% of respondents held "industrial emissions" responsible, and 7% blamed "construction activity", the survey said.   

When asked about the Odd-Even vehicle program, around 10,547 of the respondents, which is 56%, said they "don't support" the scheme, the survey said.

However, data analysis by the Centre for Science and Environment (CSE), a Delhi-based organisation that focuses on environment-related research and advocacy, indicates that much of the air pollution in the city over the week of October 21 to 26 was caused by vehicular emissions within, the Indian Express reported. This was the week that Delhi recorded its first ‘very poor’ air quality day of the season.

The CSE’s analysis found that Delhi’s local sources caused around 32.9% of the pollution in the city. The remaining share came from NCR districts (32.8%), other districts (25.8%) and biomass burning in the neighbouring states (9.5%). Among these, vehicular emissions may have contributed to around 51% of the PM2.5 levels in Delhi. Local sources refer to the sources within the city. Among the local sources, the next largest contribution was from residential sources at 13%, and from industries at 11%.

The analysis further underlined that as a measure of mitigating the vehicular emissions issue, emphasis needs to be put on public transport. It said, “Delhi needs congestion and pollution pricing and other restraint measures to control the traffic volume.” It added that the targets set for the electrification of the new vehicle fleet should be accelerated and met, according to the Indian Express report.

An AQI of above 400 is considered “severe” and can affect healthy people and seriously impact those with existing illnesses.

Anand Vihar and Jahangirpuri were the most polluted places in the capital with AQI at 460 on Thursday.

(With PTI inputs)