Gopal Rai says 69% air pollution due to sources outside city

Rai also referred to a 2018 TERI source apportionment study which found that local sources were responsible for 36% of the total air pollution in Delhi.

Delhi environment minister Gopal Rai on Thursday urged his Union government counterpart to hold a meeting and formulate a joint action plan to tackle sources of pollution in the National Capital Region (NCR) that were impacting Delhi.

Rai also referred to a 2018 TERI source apportionment study which found that local sources were responsible for 36% of the total air pollution in Delhi. (PTI File Photo)

Citing data from a Centre for Science and Environment (CSE) analysis carried out for the period between October 24 and November 8, Rai said local sources contributed only 31% of the pollution load in Delhi and the remaining 69% originated the NCR towns.

Rai also referred to a 2018 TERI source apportionment study which found that local sources were responsible for 36% of the total air pollution in Delhi.

According to the Central Pollution Control Board (CPCB) data, Delhi has witnessed the second worst post-Diwali pollution episode since 2015 when the AQI record keeping began. The city recorded its worst pollution spell in 2016 when a dense smog had enveloped the city. The state government announced emergency measures on Saturday, but only after a nudge by the Supreme Court and the pollution levels hitting severe levels.

So far, only meteorological factors -- mostly improved wind speed -- has helped flush out pol-lutants in the city.

CSE carried out its analysis using Indian Institute of Tropical Meteorology’s (IITM) Decision Support System (DSS). It found that for the two weeks , Delhi’s own sources of pollution contributed to 31% of its total PM 2.5 load, 54.5% came from 19 nearby NCR districts and the remaining 14.5% was from stubble burning.

The minister added that the state government has been trying to meet the Union environment minister and discuss the importance of preparing a joint action plan for NCR.

“The Delhi government has constantly been working to reduce the pollution from Delhi. But no matter how hard the people of Delhi try, controlling the 70% external pollution is out of their hands. Therefore, I have repeatedly requested the union environment minister to have a meeting to frame a joint action plan. Until we formulate this plan and set in place teams to monitor its implementation, Delhi and its people will not be free from pollution.” he added.

Commenting on the study, an expert said the contribution of local sources doe not remain constant, and it keeps changing depending on the meteorological conditions.

Anumita Roy Chowdhury, executive director, research and advocacy at CSE, who was also part of the analysis, explained,”During this two-week period, the contribution of Delhi’s own sources was 30%. But this can change, and it may go up to 70%. The point we are trying to make is that there is a need to work on the region as a whole, as Delhi’s pollution impacts NCR and vice-versa,” she said.

Sachin Ghude from IITM, who is handling the DSS, said the contribution of external sources may vary at different times of the year.

“There is a possibility that dust winds are coming from north-western India and outside Delhi. There is also a lot of trans-boundary movement of pollutants within NCR states as the area is one large airshed,” he said.