The Central Pollution Control Board in compliance with the National Green Tribunal (NGT) order has released monthly data that highlights the air quality index (AQI) of the Delhi NCR region in the last three months.
The report showed that the air quality levels have been peaking at 350 and above at several points between March and May.
An AQI between 0-50 is considered Good, 51-100 Satisfactory, 101-200 Moderate, 201-300 Poor, 301-400 Very Poor, and 401-500 Severe.
Experts say that the deterioration of air quality is due to dust storm in the west.
The particulates (PM2.5/PM10) are the main issue of concern, necessary steps to control dust emission from roads, construction activity, traffic and industries may be strictly adopted. Increase in NO2 (nitrogen oxide) may also be attributed to vehicle and high ambient temperature, the report said.
The daily city-wise AQI values for Delhi-NCR for the month of March, April and May was found largely lying between moderate to poor category.
The Central Pollution Control Board (CPCB) said the three reports are monthly reports that was submitted to NGT to tell more about the air quality index of the city.