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.

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.