KATHMANDU, April 8 -- Air pollution in Kathmandu has reached alarming levels, ranking third on the list of the world's most unhealthy cities, according to Switzerland's IQAir, which provides real-time air quality measurements globally. New Delhi in India holds the top spot, followed by Chiang Mai in Thailand.

As of Monday morning, Kathmandu's air quality index (AQI) stands at 173, classified as unhealthy for public health. An AQI between 151 to 200 falls under the red category, indicating 'unhealthy' conditions.

Comparatively, New Delhi records an AQI of 244, with an AQI between 201 to 300 categorized as being extremely unhealthy.

The AQI assesses pollution levels by measuring fine particles known as PM 2.5 and PM 10 in the air. A read...