New Delhi: The air quality in the national capital on Monday further deteriorated to the ‘very poor’ category. However, pollution is expected to decrease from Tuesday due to change in winds and also a significant drop in stubble burning in neighbouring states, according to the forecast by System of Air Quality and Weather Forecasting and Research (SAFAR).

It is to be noted here that Delhi is currently suffering largely due to pollution generated by local sources.  The Weather Department expects the situation to improve from Tuesday as Delhi is expected to receive dry north-westerly winds, which will bring down pollution levels as well as the temperature.

An Air Quality Index (AQI) between 0 and 50 is considered ‘good’, 51 and 100 ‘satisfactory’, 101 and 200 ‘moderate’, 201 and 300 ‘poor’, 301 and 400 ‘very poor’, and 401 and 500 ‘severe’.

The major pollutant PM2.5, or particles with a diameter less than 2.5 micrometres, also intensified over the day as easterly winds brought along moisture.

“Delhi currently is polluted with its own pollutants. But the situation is expected to improve from Tuesday evening,” said Mahesh Palawat, Director at private weather forecasting agency Skymet.

The average presence of the major pollutant PM2.5 was 174 microgrammes per cubic meter in Delhi on Monday against 163 units on Sunday. Across over 40 regions in the National Capital Region (NCR) it was 171 units at 4 p.m.

Across NCR, Gurugram with an AQI of 289 or “poor” had the cleanest air. The AQI was 364 in Ghaziabad, 346 in Greater Noida, 336 in Noida and 348 in Faridabad. SAFAR has issued an advisory cautioning people in Delhi against outdoor physical exercises.

Recently, NASA had released images showing rampant stubble burning activity in the two states. On its official website, it had stated that burning of crop residue in Punjab and Haryana has increased significantly over the past 10 days in and near Amritsar, Ambala, Karnal, Sirsa, and Hisar.

The Supreme Court had refused to impose a blanket ban on the bursting of firecrackers and allowed the use of only green firecrackers with reduced emission and decibel levels during all religious festivals.

Last year, the national capital had witnessed a blanket of thick smog after Diwali, bringing air quality standards to an all-time low in the national capital.