New Delhi: The air quality in the national capital on Wednesday entered the "severe" category after remaining in the "very poor" level for the past seven days.
The air quality index (AQI) in the city bordered "severe" levels at 399 at 8.41 am. By 10.40 am, it had entered the severe category and was recorded at 402.
The AQI in neighbouring areas -- Faridabad (392) and Gurgaon (366) -- was recorded in the very poor category.
The AQI in Ghaziabad (436), Greater Noida (441) and Noida (425) was in the severe category.
An AQI between 0-50 is considered "good", 51-100 "satisfactory", 101-200 "moderate", 201-300 "poor", 301-400 "very poor" and 401-500 "severe". An AQI above 500 falls in the "severe plus" category.
The air quality remained in the "very poor" category in the national capital for the seventh consecutive day on Tuesday as the cold weather and calm winds allowed accumulation of pollutants.
The AQI in the city was recorded at 356 at 8.45 am on Tuesday.
(This story has not been edited by News18 staff and is published from a syndicated news agency feed - PTI)