New Delhi, June 9 -- The national capital Delhi witnessed a marginal deterioration in its air quality on Tuesday morning. The city's Air Quality Index (AQI) rose to 159 from 151 yesterday, according to the data of the Central Pollution Control Board (CPCB). The reading continues to remain in the 'moderate' category.

According to CPCB data, several areas remained in the 'poor' category, which included Alipur (205), Dwarka Sector 8 (206), Jahangirpuri (229), and Wazirpur (230). However, air quality in Anand Vihar deteriorated to the 'severe' category with an AQI of 404.

Compared to the national capital, several other major cities in India recorded significantly better air quality. Chennai recorded an AQI of 97, while Ahmedabad stood at 86...