Delhi’s air quality out of ‘very poor’ zone for first time in 6 days, but likely to worsen

Delhi’s Air Quality Index (AQI) dropped from 306 on Saturday to 294 on Sunday, bringing the capital under the “poor” category. At these levels, there may be discomfort in breathing on prolonged exposure, while people with heart disease could face discomfort with short exposure.

Pollution levels in the national capital showed marginal improvement on Sunday and came out of the “very poor” zone for the first time in six days. Monday, government agencies warn, could be different with unfavourable weather conditions likely to worsen the situation.

A pedestrian covers his face for protection against air pollution in New Delhi. The Air Quality Index (AQI) dropped from 306 on Saturday to 294 on Sunday, bringing the capital under the “poor” category. (PTI File /)

The Air Quality Index (AQI) dropped from 306 on Saturday to 294 on Sunday, bringing the capital under the “poor” category. At these levels, there may be discomfort in breathing on prolonged exposure, while people with heart disease could face discomfort with short exposure.

Over the past six days, the AQI had been hovering between 301 and 400, the “very poor” category.

“Pollution levels are likely to spike again on Monday because of unfavourable wind. While on one hand the wind speed is expected to slow, moisture is also increasing. Because of the clear sky, high moisture content and calm conditions, there could be formation of fog particularly at night,” said a scientist from Safar, a pollution forecasting wing of the central government.

The slower wind speeds is expected to reduce dispersal of major pollutants in the city. Fine particulate matter — PM 10 and PM20.5 — have already shown a gradual increase in levels from Sunday. A senior scientist of the India Meteorological Department put the slowing wind down to the approaching western disturbance, that causes pressure fluctuations.

“The wind pattern is such that no pollution from outside Delhi are coming in. This is an ideal condition to measure how much the city is polluting. Had there been any contribution from outside, the rise in pollution levels would have been steeper,” said a scientist from Safar.

The level of PM10 was recorded to be 338µg/m3 at 8 pm on Sunday, which was more than three times the safe limit of 100µg/m3. The level of PM2.5 stood at 166µg/m3 at the same time, which was around 2.7 times above the safe limit of 60µg/m3.