Dhaka, May 25 -- Dhaka, the capital of Bangladesh, ranked ninth among the world's most polluted cities on Monday morning, with an Air Quality Index (AQI) score of 92.

According to the AQI scale, the city's air quality was classified as 'Moderate' at 9:30am.

India's Delhi, Santiago in Chile and Riyadh in Saudi Arabia were the three most polluted cities, with AQI scores of 185, 182 and 166 respectively.

An AQI between 101 and 150 is considered 'unhealthy for sensitive groups', while a score between 151 and 200 is classified as 'unhealthy'. AQI readings between 201 and 300 are termed 'very unhealthy', and anything above 301 is considered 'hazardous', posing serious health risks.

The AQI is a daily indicator of air quality, showing how cl...