Delhi's air quality deteriorates to 'very poor' category with drop in wind speed

Delhi's air quality deteriorated to 'very poor' category on Wednesday due to decline in wind speed that has slowed the dispersion of pollutants, according to authorities.

According to the Central Pollution Control Board (CPCB) data, the overall air quality index (AQI) in the city was 333, which falls in the 'very poor' category.

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

Thirty-one areas in Delhi recorded 'very poor' air quality while four areas recorded poor air quality, according to data by the Central Pollution Control Board.

In the National Capital Region, Ghaziabad, Noida and Greater Noida recorded 'very poor' air quality while Gurgaon recorded poor air quality, it said.

The overall PM2.5 level -- fine particulate matters in the air with a diameter of less than 2.5 micrometers -- in Delhi was 165, while the PM10 level was 275, it said.

The Centre-run System of Air Quality and Weather Forecasting (SAFAR) said overall air quality in Delhi was recorded in 'very poor' category.

"This deterioration is a typical pre-shower winter impact. Now winds have also declined a bit. However, there is likelihood of rain tomorrow due to westerly disturbances related moisture saturation which may bring AQI in moderate category," the SAFAR said.

Delhi's air has been oscillating between 'moderate' and 'poor' category for the past ten days.