Lack of transparency on Delhi pollution sources may impact clean air fight

Delhi is facing a severe lack of data to monitor and combat its air pollution problem, as three key data streams have become inaccessible to the public. The systems that estimate and project the sources of pollution and air quality in the city have not been updated since last week or have been put behind login pages. Experts have warned that this lack of information is hindering efforts to address the issue, particularly as the worst period of air pollution caused by stubble burning approaches.

The three data streams that could estimate and project what is polluting Delhi’s air on a particular day have been offline or put out of reach for the public, leaving the city virtually blindfolded in its battle against bad air with the worst just around the corner, according to several experts.

A smoggy Thursday on the Delhi-Meerut expressway. (Sanjeev Verma/HT Photo)

The Capital has typically relied on the Decision Support System (DSS), the System of Air Quality and Weather Forecasting and Research (Safar), and the Real-Time Advanced Air Source Management Network (R-Aasman) for a sense of which the main sources were or whether they could worsen the air quality.

The DSS last shared an update on Sunday, and has been put behind a login page since Tuesday; Safar’s website last gave an estimate of how much farm fires were a factor in air pollution on October 13; and R-Aasman has not been updated since last week -- blocking what experts said was crucial information.

DSS and Safar are products of collaborations between the Union ministry of earth sciences (MoES) and Indian Institute of Tropical Meteorology, and R-Aasman involves the Delhi Pollution Control Committee (DPCC) and two Indian Institute of Technology (IIT) colleges.

None of the organisations involved responded to requests for comments on the lack of updates, although the R-Aasman is now at the centre of a political fight, with the Aam Aadmi Party government accusing the bureaucracy that reports to the Union government of not releasing the funds required to keep it running.

Mrutyunjay Mohapatra, director general of IMD and named as an advisory member on the DSS website, said he was not aware of why data was no longer being shared. “This only IITM would be able to share,” he said.

Madhavan Rajeevan, former secretary, MoES, said he was not aware of why access was restricted, and reiterated that it was important for Delhi to know its sources of pollution. “Broadly, we know the sources of pollution that impact Delhi at different times of the year, but these emissions vary on a day-to-day basis and from season to season, and for that, real-time data is important. For example, stubble burning only impacts Delhi for a brief window, during the harvesting season,” he said.

The period of stubble-burning -- when farmers mostly in Punjab and Haryana set paddy remnants on fire as a cheap and quick way to clear their fields -- triggers the worst pre-winter air quality crisis. As the winter season passes by, there are usually several more episodes when air quality plunges. At fault mostly is high baseline pollution that is trapped by cold and still conditions typical of the winter season.

Data pertaining to farm fires suggested the worst is yet to come in the current spell of bad air, which has seen a peak AQI of 313 (very poor) on October 22 so far.

Data from the Indian Agricultural Research Institute (IARI), which collates farm fire data from states, showed Punjab recorded its highest single-day count of the season on Thursday, with 589 cases recorded through satellite imagery, the most yet for the season. In Haryana, this number was 67.

On Thursday, Delhi’s AQI was 256, a reading in the “poor” zone.

Before it was put behind a lock, the DSS showed smoke from farm fires made up for 16.4% of the ultrafine PM2.5 pollutant. It projected the share to rise to 30.6% on Monday and 32.8%, on Tuesday but the site was not updated after that.

On Wednesday, Delhi environment minister Gopal Rai disclosed they were not getting real-time source apportionment data from eight sectors since October 18 because the study was halted by DPCC. He said DPCC’s chairman, Ashwani Kumar, had refused to release funds up to the tune of ₹2 crore to IIT Kanpur, which developed the forecasting system, citing he was not convinced with the data.

A senior Union environment ministry official, when contacted, said: “It is not our mandate to share the contribution of sources, including stubble burning.”

Sunil Dahiya, analyst at the Centre for Research on Energy and Clean Air (CREA), said both the Centre and the Delhi government invested significant funds to set up such machinery and develop models, which are now being wasted. “We have to utilise the models that have been developed just to provide transparency on what is polluting Delhi. So far, October is turning out to be more polluted than previous years, but lack of data means there is less transparency on this. This then ultimately impacts policy-level decisions,” he said.

Anumita Roychowdhury, executive director, research and advocacy at the Centre for Science and Environment (CSE) said a critical aspect of air quality management was to utilise scientific tools for decision making and forecasting. “This includes using real-time data to track the changes in source contribution. Such tools have been developed only for this region and Delhi has benefitted considerably for it so far. It is important to continue to use such data, which also helps in creating public awareness,” she said.