After almost two months of clean air and blue skies, Delhi has entered the fourth phase of the nationwide lockdown with air quality index (AQI) above the 200 mark.

The level of Particulate Matter (PM) with diameters of 2.5 and 10 microns, which are too small to be filtered out of the body, stood at 83 and 183 micrograms per cubic metre, respectively.

Delhi’s air quality index (AQI) was above the 200 mark in many areas, which is classified into the ‘poor’ category. Furthermore, certain localities in the national capital have even recorded pollution levels that are closer to being categorised as ‘very poor’.

According to CPCB data on 19th May 2020 (12pm), the Punjabi Bagh locality in Delhi has registered an AQI of 299, followed by Anand Vihar with an AQI of 216. Rohini (256), ITO (212), and Mundka (281) all recorded AQI’s above 200.

AQIs between 201 and 300, are categorized as ‘poor’ while those from 301 to 400 lie within the ‘very poor’ bracket.

Delhi’s air quality largely remained in the ‘satisfactory’ to ‘moderate’ category during the earlier phases of nationwide lockdown since vehicles were off roads and industries were not operating.

According to the System of Air Quality and Weather Forecasting And Research, the spike in pollution levels may be down to the “dust transport from Rajasthan”, especially considering the unfavorable southwesterly winds blowing into the landlocked capital.

The weather forecasting agency further said that the dust is likely to be a dominant factor in contributing to particulate pollution for the coming days.

According to a study conducted by the Indian Institute of Technology (IIT) Delhi, in the earlier stage of the lockdown, the country had witnessed 43 and 31 percent decreases in PM 2.5 and PM 10 as compared to previous years.

But, in the past few days it appears to be increasing again.

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, the study had stated.