Air quality 'very poor' despite light rain

New Delhi: Despite Delhi witnessing light rain on Thursday morning, the air quality in the city entered "very poor" category, with grey clouds sorrounding the skies. The overall Air Quality Index (AQI) hovered at an average of 309. Data from the Delhi Pollution Control Committee (DPCC) and the Central Pollution Control Board (CPCB), published here, show that levels of PM 2.5 — particulate matter less than 2.5 microns in diameter that lodge deep in the lungs — have climbed to very unhealthy levels in most parts of the Delhi and the NCR.

As opposed to better air quality, Delhi witnessed a fall in air quality, with many areas like Anand Vihar (333), Bawana (339), DTU (308), Dwarka Sector – 8 (318), ITO (337), Lodhi Road (312) remained in "very poor" category. However, Central government based agency, System of Air Quality and Weather Forecasting And Research (SAFAR) has predicted that there might be a slight improvement in AQI by Thursday evening unless the rainfall is too low.

"Little rain or only drizzling in colder weather turn counter productive by secondary particulate formation. The surface and boundary layer winds are from the south, its interaction with upper air westerly through is likely to produce fairly widespread rainfall throughout northwest India. Slight improvement in AQI from poor is expected by today's (Thursday) evening unless the rainfall is too low," it forecasted.

A change in wind direction back to north-westerly and plume intrusion is expected by November 9. "Thereafter, a marginal deterioration to the higher end of poor to very poor category is expected and further deterioration to the higher end of very poor category by November 9," said a report by SAFAR.