New Delhi: Delhi woke up to thick smog on Tuesday morning, a day after the national capital celebrated Diwali. The air quality index of Delhi deteriorated and slipped in the ‘very poor’ category, recorded at 346 at 5.30 am.

Those in the most polluted city in the world once again found themselves breathing dangerously toxic air. Some areas in Delhi recorded an AQI of over 400, slipping into the ‘severe’ category.

Part of Delhi showed an air quality index (AQI) of more than 500, which is 10 times higher than the level deemed healthy by the World Health Organization.

In some areas, levels of PM2.5 and PM10 – the toxic particles causing pollution – recorded peaks of 1,800, which is 15 to 20 times higher than those deemed healthy. As per the CPCB, Bawana recorded AQI of 423 as of 8 am, Jahangirpuri had an AQI of 407 and Wazirpur with an AQI 408 remains the worst hit areas with air quality falling under ‘Severe’ category.

The AQI in Anand Vihar stood at 358, Ashok Vihar 389, Burari Crossing 399, Chandani Chowk 350, IGI Airport (Terminal 3) 302, ITO 342, Lodhi Road 322, Mundka 366, Najafgarh 336, Narela 358, Patparganj 342 and Punjabi Bagh 376.