The capital city of Nepal, Kathmandu, has topped the list of polluted cities in the world.

On Sunday, Kathmandu ranked first among the most polluted places in the world, with smoke and haze covering the Valley and the Air Quality Index (AQI) reaching 192. The AQI on Saturday morning was even higher at 244.

The unabated air pollution can cause various health problems including difficulty breathing, especially for those already suffering from respiratory diseases, health experts have requested mandatory use of masks when outdoors.

As many as 42,000 people die every year in Nepal due to diseases caused by air pollution. Seven million people die worldwide because of the same.

Dust from construction works, exhaust from old, poorly maintained vehicles and smoke from coal-burning brick kilns blend in a murky haze that hangs over Kathmandu, raising the risk of cancer, stroke, asthma and high blood pressure, experts say.

Meanwhile, the Meteorological Forecasting Division informed that massive forest fires throughout the country are further contributing to the smoke and haze in the country.