Dhaka, April 27 -- A spell of rain on Sunday evening and early Monday brought much-needed relief to Dhaka residents, significantly improving the city's air quality.

The showers washed away accumulated dust and pollutants, leaving the air noticeably cleaner and more refreshing.

Dhaka, one of the world's most densely populated capitals, ranked 66th on Monday morning, recording an Air Quality Index (AQI) of 47 at 8:40 am. According to the AQI scale, this level is classified as "good."

India's Delhi, Pakistan's Lahore and Nepal's Kathmandu topped the list of most polluted cities, with AQI scores of 260, 192 and 148, respectively.

An AQI reading between 101 and 150 is considered "unhealthy for sensitive groups," while 151-200 is deemed "un...