New Delhi:  The air quality of the national capital remained 'very poor' for the second consecutive day on Thursday and is likely to further deteriorate to 'severe' category in some parts of the city on Friday. According to the Centre-run System of Air Quality and Weather Forecasting (SAFAR), the overall air quality index (AQI) of Delhi was recorded at 334 on Thursday morning.

"The overall Delhi AQI was in the lower end of the 'very poor' category on Wednesday. The SAFAR model forecast suggests a decrease in wind speed and ventilation coefficient for the next three days," SAFAR said.It also said the AQI forecasted to touch the 'severe' category for some regions of Delhi on December 6, overall AQI may still within the 'very poor' category.

The city had witnessed drastic improvement in the air quality last week as the AQI was recorded in double digits at the 'satisfactory' category, after seeing some of the worst air quality days in November.

The air in the national capital was so toxic after Diwali that the Environmental Pollution (Prevention and Control) Authority (EPCA) had declared a public health emergency in the Delhi-NCR and had advised people, especially children and the aged, to limit their exposure to the environment.