Nepal's capital was blanketed in acrid smog Thursday as wildfires across the country pushed air pollution levels to among the worst in the world.
Experts say that widespread wildfires, fueled by an exceptionally dry winter and stagnant atmospheric conditions, have caused the thick and throat-burning smog to cover the Kathmandu valley, AFP reported.
Levels of PM2.5 pollutants -- cancer-causing microparticles that enter the bloodstream through the lungs -- registered above 178 micrograms per cubic meter on Thursday, according to Swiss monitoring firm IQAir.
A reading above 15 in a 24-hour period is considered unhealthy by the World Health Organization (WHO), and IQAir ranked Kathmandu the world's most polluted city.
The Himalayan nation sees a spate of wildfires annually, usually beginning in March, but their number and intensity have worsened in recent years, with climate change leading to drier winters.
"The prevailing dry conditions have significantly increased the frequency of forest fires across the country, further worsening air pollution," Khushboo Sharma, an air pollution analyst at the Kathmandu-based International Centre for Integrated Mountain Development(ICIMOD) told AFP.
"This year, precipitation was exceptionally low, with hardly any rainfall, leaving forests dry and more susceptible to fire," she added.
Sharma said that stagnant meteorological conditions are also causing pollution to accumulate over the valley.
On social media, people complained of stinging eyes and itchiness because of the pollution.
Low visibility caused by the smog also disrupted flights at Kathmandu airport, sparking long delays.
"The mountain flights... as well as some other flights have been disturbed because of the pollution," said Rinji Sherpa, the airport's spokesman.
The health ministry issued a notice Wednesday requesting Nepalis to "avoid unnecessary travel" and to wear a mask when outside.
The government has also urged people to avoid construction and burning rubbish.
The Air Quality Life Index, issued by the University of Chicago, estimated that in 2024 air pollution stripped 3.4 years off the life of an average Nepal resident.