New Delhi: Witnessing azure skies and breathable air for the last three months, Delhi on Monday recorded deterioration in its air quality, with particulate matter with diameter of 2.5 and 10 microns — too small to be filtered out of the human body — standing at 52 and 297 micrograms per cubic respectively.Also Read - Massive Dust Storm Heads Towards Gujarat, Rajasthan: IMD Issues Alert For 12 Hours

Gufran Beig, Project Director of System of Air Quality Weather Forecasting and Research (SAFAR), said that the sudden spike in air pollution is due to a mild dust storm blowing from Rajasthan. Also Read - Several Flights To and From Delhi Airport Delayed as Dense Fog, Low Visibility Affects Aerial Movement

“Since the wind direction is changing and moist air is coming in, the air quality in Delhi will become better by tomorrow,” Beig told IANS. Also Read - Rain Likely in Delhi Today, Air Quality Deteriorates to Severe Category

Central Pollution Control Board (CPCB) data showed that the overall air quality near Delhi Technical University (DTU) area stood at 326 micrograms per cubic, followed by 308 at Narela and 307 at Mundka.

Out of 36 stations, the AQI in as many as 30 stations was above 200 micrograms per cubic till 1 pm on Monday.

The System of Air Quality Weather Forecasting and Research categorises air quality in the 0-50 range as good, 51-100 as satisfactory, 101-200 as moderate, 201-300 as poor, 301-400 as very poor, and above 400 as severe.

According to SAFAR’s website, “PM 10 (coarser dust particle) is the lead pollutant. AQI is likely to improve to moderate category by tomorrow, and further improvement is expected by July 1.”

Researchers indicated that PM 10 and PM 2.5 will be 170 and 47 micrograms per cubic on Tuesday.

With no vehicles plying on the roads or industries shut due to the lockdown since March 25, Delhi’s air quality had improved drastically.

According to a study conducted by the Indian Institute of Technology (IIT), Delhi, if the low levels of air pollution reached during the lockdown period are maintained, India’s annual death toll could reduce by 6.5 lakh.