A layer of fog enveloped parts of the national capital on Thursday morning lowering the visibility as pollution figures entered severe category and particulate content crossed the emergency level.
Met department officials said the morning haze was a result of fog mixed with pollutants due to low air speed leading to smog-like conditions. “The condition would improve in a day or two as we expect the wind speed to increase and disperse the pollutants,” said Kuldeep Srivastava, a senior Met department scientist.
The Air Quality Index (AQI) — a measure of pollutants in the air on the scale of 0 to 500 — spiked to 436 qualifying as ‘severe’ on Thursday morning. According to the Central Pollution Control Board (CPCB) the AQI is expected to become worse as the day progresses. PM2.5 — particulate matter which is one of the main pollutants in Delhi’s air — was recorded at 303 ug/m3 at 9am entering emergency levels (above 300). The last time this level was recorded was on November 14 when pollution had peaked. PM10 is also expected to cross emergency levels.
Thursday morning’s AQI was 77 notches higher than Wednesday’s 24-hour average of 359 falling under ‘very poor’ category. On Tuesday, the AQI was 300 and 234 on Monday. In the neighbouring Noida and Gurgaon, the AQI levels on Thursday were 489 (severe) and 342 (very poor), respectively.
The visibility at the IGI airport was between 600 metre to 900 metre and flights equipped with low visibility operations were able to operate. As many as 30 trains were delayed, 11 rescheduled and 15 cancelled due to low visibility and other operational reasons