Smog screen in Delhi thickens, to stay

NEW DELHI: The thick smog that settled over Delhi last Sunday is showing no signs of dissipating and has, in fact, intensified. Sunday was touted as the worst day of the week in terms of air quality as the general visibility did not go over 800m through the day and averaged about 400m. The Met department confirmed that agricultural fires in Punjab were contributing to about 20-30% of the pollution load in the city though local pollution was sufficient to have caused the smog in any case.

"The haze re-intensified on Sunday due to fresh inflow of dust and pollutants from agricultural burning from Punjab and Haryana under the influence of favourable northerly winds at lower levels. Also, local pollution added to such formation as local atmosphere was extremely stable on Sunday. The winds were calm up to a height of 4,000m on Sunday against 3,000m on Saturday," said R K Jenamani, director in-charge, IGI Met.

Since around 1 am on Sunday, visibility at the IGI Airport remained below 800 m, going to a low of 300 m for a few hours after 8am. Pollution levels were also high across all parts of the city. At Punjabi Bagh, levels of particulate matter (10) till 9.30pm ranged between 653 and 904 mg/cu m against the standard of 100 mg/cu m. At Mandir Marg, PM10 was in the range of 617-953mg/cu m while at R K Puram it was between 533 and 936 mg/cu m. Levels at most places peaked between 5 and 8pm.

The Met department has predicted that similar smoggy conditions are likely to remain on Monday and will gradually weaken by November 7. The haze had lifted slightly on Saturday with visibility improving to 2,000m. Officials explained that a light wind had picked up which cleared the suspended pollutants and permitted some sunlight to stream through.

Jenamani added: "This is not unusual for this time of the year when winter has still not set in and the atmosphere is stable with no vertically mixing and calm winds. But this time, in the aftermath of cyclone Nilam having crossed the south-eastern coast of India, such conditions intensified and prevailed for a long time."