Dhaka, Feb. 19 -- Dhaka has again topped the list of cities worldwide with the worst air quality with an AQI score of 309 on Monday morning for the second consecutive day.

Dhaka's air was classified as 'hazardous', posing serious health risks to residents, according to the air quality index, as per UNB reports.

Pakistan's Lahore, India's Delhi and Mumbai occupied the second, third and fourth spots on the list, with AQI scores of 214, 183 and 179 respectively.

When the AQI value for particle pollution is between 101 and 150, air quality is considered 'unhealthy for sensitive groups', between 150 and 200 is 'unhealthy', between 201 and 300 is said to be 'very unhealthy', while a reading of 301+ is considered 'hazardous'.

The AQI, an ind...