NEW DELHI: Delhi’s air quality deteriorated to ‘poor’ on Saturday as the advantage from rainfall washing out pollutants “levelled off”. The pollution levels are likely to rise further in the next three days. 
The overall Air Quality Index (AQI) increased from Friday’s 151 and was recorded in the ‘poor’ category at 233, as per data from the Central Pollution Control Board (CPCB).

An AQI between 100 and 200 comes under the ‘moderate’ category, 201 to 300 is considered ‘poor’, 301 to 400 ‘very poor’, while that between 401 and 500 is ‘severe’.

“Overall AQI is gradually increasing as the deficit rainfall washout is levelled off. Persistence cool conditions still not allowing boundary layer to lift up. The AQI may slowly deteriorate and is predicted to touch the lower end of the ‘very poor’ range during the next three days,” said System of Air Quality and Weather Forecasting and Research (SAFAR), under the Ministry of Earth Sciences. 

The concentration of pollutants PM2.5 (Particulate Matter) and PM10 in the air was recorded at 96 microgrammes per cubic metre (ug/m3), and 159 ug/m3 respectively, according to SAFAR. The safe levels for the pollutants are 60 and 100 ug/m3, respectively.