Delhi’s air quality slips to ‘severe category’

New Delhi, Dec 23 (ANI): National capital’s air quality continues to degrade as it slips from ‘very poor category’ to ‘severe category.’ According to System of Air Quality and Weather Forecasting and Research (SAFAR), city’s air quality index stood at 404 in the morning of December 23. Dense layers of fog covered several areas of the national capital leading to poor visibility.