Delhi’s air quality slips to very poor category

New Delhi: Delhi's air quality slipped to 'very poor' category due to slow wind speed and high humidity on Sunday, authorities said. The Centre-run System of Air Quality and Weather Forecasting (SAFAR) said the overall air quality index (AQI) was recorded at 326, which comes under 'very poor' category. 

The air quality is very poor and expected to remain in the same category with gradual increase for the next three days as wind speed is slow and humidity is high, it said. The Central Pollution Control Board (CPCB) data showed that 20 areas in Delhi recorded 'very poor' air quality, while 13 recorded 'poor' air quality.  

On Sunday, the PM2.5 — particles in the air with a diameter of less than 2.5 micrometres — level was recorded at 163, while the PM10 level was recorded at 306, according to CPCB data. Ghaziabad, Faridabad, Noida and Greater Noida recorded 'poor' air quality while Gurgaon recorded moderate air quality, the data said. 

An 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'. 

"Fire counts from stubble burning declined significantly and hence have negligible impact," it said. 

Delhi's air quality showed significant improvement on Wednesday and Thursday after rain washed away the pollutants, but the rainfall also led to increased air capacity to hold pollutants, the SAFAR said.